*Review* **Shaping the Knowledge Base of Bioeconomy Sectors Development in Latin American and Caribbean Countries: A Bibliometric Analysis**

**Maria Lourdes Ordoñez Olivo 1,\* and Zoltán Lakner <sup>2</sup>**


**Abstract:** Academic research on bioeconomy sectors in Latin American and Caribbean countries has developed exponentially over the last few years. Based on the Web of Science (WOS) database and statistical analysis of more than 18.9 thousand documents, the current article offers a bibliometric analysis of these datasets. The main bioeconomy sector identified in the results was biofuel production and all the background terms related to the primary processes of bioenergy. The other segments of the bioeconomy in the Latin America and Caribbean (LAC) region have not yet been studied with the same relevance as biofuels. Since 2008, researchers from Latin American and Caribbean countries have participated significantly in the scientific production of the field studied. However, the most relevant scientific journals belong to European countries or the United States. Journals from Latin American and Caribbean countries have very low representation, although the search topics are directly related to this region. Based on the co-occurrence of keywords, eight clusters with different levels of importance can be distinguished: (1) agriculture; (2) climate change; (3) biodiversity; (4) bioremediation; (5) bioenergy; (6) biofuels; (7) energy efficiency; and (8) bioeconomy. The above results highlight the significant research gap between biofuels and other types of bioeconomy sectors in the region. This is despite the immense biodiversity potential of the LAC countries, which can generate innovative products with bioeconomic added value that can stimulate scientific research in the sustainable bioeconomy.

**Keywords:** bioeconomy; LAC region; bibliometric analysis; biofuels; sustainability; R software

#### **1. Introduction**

According to the Global Bioeconomy Summit in 2018, bioeconomy refers to "the production, utilization, and conservation of biological resources, including related knowledge, science, technology, and innovation, to provide information, products, processes, and services across all economic sectors aiming towards a sustainable economy [1]".

One of the main goals of the bioeconomy is the reduction of non-renewable fossil energy use and its replacement by renewable resources [2–4]. Nevertheless, other objectives include linking all economic and industrial sectors that use biological resources and process them to produce food, feed, bio-based products, and services [5] or, in some cases, the optimization of the life cycle of the products and the creation of secondary markets for bio-based products [6].

According to Linser, S. (2020), many bioeconomy strategies are relevant to several SDGs (14 out of 17), making it a sustainable pathway to achieving the UN Sustainable Development Goals [7,8]. Furthermore, bioeconomy can be seen as a response to at least four emerging and converging global challenges: (a) growing global population; (b) increasing

**Citation:** Ordoñez Olivo, M.L.; Lakner, Z. Shaping the Knowledge Base of Bioeconomy Sectors Development in Latin American and Caribbean Countries: A Bibliometric Analysis. *Sustainability* **2023**, *15*, 5158. https://doi.org/10.3390/su15065158

Academic Editors: Idiano D'Adamo and Massimo Gastaldi

Received: 29 January 2023 Revised: 9 March 2023 Accepted: 10 March 2023 Published: 14 March 2023

**Copyright:** © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

global demand for biomass (at least 60% above current rates), exacerbating the scarcity of natural resources; (c) growing evidence that the era of oil and cheap energy is coming to an end; and (d) concerns about climate change [4,8]. In summary, the relationship of the bioeconomy to SDGs and the global challenges can be grouped into three dimensions: socio-economic, environmental, industrial, and economic drivers [9,10].

These drivers are directly related to the sustainability aspects of the bioeconomy, towards which progress can be made when certain conditions are met [11]: "(i) sustainability of the resource base; (ii) sustainability of processes and products; and (iii) circular processes of material flows" [12]. In addition, the environmental and production components of bioeconomy development approaches need to be closely linked to how bio-resources are supplied, produced, and consumed [13].

The potential of the bioeconomy needs to be steered in the right direction to ensure that it works for people, food and nutrition security, and sustainable economic growth while preventing climate change and not harming the environment [14,15]. Therefore, some countries around the world contributed with significant knowledge, policy, and institutional efforts to develop bioeconomy strategies.

According to the German Bioeconomy Council [1], the bioeconomy has gained strength worldwide and is a certainty in many developed countries such as Germany, France, Finland, the Netherlands, Russia, and Japan [16]. At the beginning of 2018, nearly fifty countries have included a defined bioeconomy policy or strategy in their development plans or in their sub-regional procedures.

Nowadays, the bioeconomy has also been adopted by many low and middle-income countries as a new development concept and as part of their commitments to the Paris Climate Agreement [17]. In the case of Latin America and the Caribbean, a sustainable bioeconomy could open up new opportunities for economic development and industrialization and support economic and social goals [8,18].

Latin American and Caribbean countries have the most significant global endowments of natural capital because of their great diversity and natural resources, which are primarily the basis of their economies [19]. The region possesses the highest biomass production related to the availability of soil, water, and land [20]. Due to its high level of biodiversity, it tends to make a more significant contribution to the quality of life of people on average than other regions of the world [21,22].

In this context, the bioeconomy in Latin America and Caribbean countries has two main sets of objectives. On a global level, the region plays a critical role in contributing to global food, fiber, and energy balances, while improving environmental sustainability. Within the region's boundaries, the bioeconomy is a new source of opportunities for equitable growth through improved agricultural and biomass production [23,24].

Considering the comparative advantages and experiences in the countries of the Latin America and Caribbean region, Trigo et al. identified six distinct pathways that offer a holistic approach to the bioeconomy initiatives in the region. These six pathways include "(a) biodiversity resources exploitation; (b) eco intensification of agriculture, (c) biotechnology applications; (d) bio-refineries and bio-products, (e) value chain efficiency improvement; and (f) ecosystem services" [23].

The aim of this paper is to present a bibliometric analysis of the bioeconomy sectors developed in Latin American and Caribbean countries in recent years, based on the authors' evaluation criteria to determine the final products obtained from biomass processing, which in this study are biofuels, bioenergy, biotextiles, biocosmetics, and biopharmaceuticals. The countries considered in the analysis are those that have relevant bioeconomic approaches according to the revised bibliography (in the case of South America, Brazil, Argentina, Uruguay, Colombia, and Chile and in the case of the Caribbean, Mexico, Cuba, and Costa Rica).

#### **2. Materials and Methods**

In the present research, we applied the traditional bibliometric analysis. Figure 1 presents the workflow of the essential steps used in the dataset.

**Figure 1.** Flowchart of the research.

#### *2.1. Data Sources and Collection*

The bibliometric research has been carried out on the basis of the Web of Science database. A total of 18,971 documents were the subject of the analysis, and the time span of the publications under consideration was between 1977 and 2021.

To determine the most suitable keyword combination, the authors applied the parti pris concept [25]. In the first phase, we downloaded 50 articles using the simplest keyword combinations and then analyzed the distribution of relevant keywords using text mining methods. Subsequently, we set up a preliminary dictionary of potential keywords, which was carried out separately by each of the two co-authors. In the second phase, we determined the standard set of dictionaries and analyses the proportion of such words in the lexicon of each of the authors. At the end of this phase, we applied "Roget's Thesaurus" [26] to determine the potential synonyms of the research terms. After all these stages, we consider that we have achieved the type of keyword combination, which proved to be quite solid and robust, and which includes the main sectors of the bioeconomy developed in Latin American and Caribbean countries, with relevant bioeconomic initiatives related to the final products obtained from biomass.

The present research had the most reliable and interpretable results with the following keyword combination: TS = ((("bioet\*") OR ("bioenergy\*") OR ("biodies\*") OR ("biogas\*") OR ("short rotation crop\*") OR ("biofuel") OR ("energytree\*") OR ("energygaps") OR ("energyplantation") OR ("energy plantation") OR ("energy forest\*") OR ("biomass\*") OR ("biocosmetic\*") OR ("bio-cosmetic\*") OR ("biopharma\*") OR ("biofiber\*") OR ("biofibrer\*")) AND ((("Brazil\*") OR ("Brasil\*")) OR ("Argentin\*") OR ("Chile\*") OR ("Uruguay\*") OR ("Mexic\*") OR ("Cuba\*") OR ("Colombia\*") OR ("Costa Rica\*"))).

Given the large size of the corpus to be analyzed, it was decided to apply structural breaks according to the number of publications that had changed over time for the bioeconomy sectors developed in Latin America and the Caribbean. The structural breaks in the time series were determined using the algorithms of the Strucchange R-package [27], the specialist estimation Z.L, and the econometric time-series analysis carried out by the econometric software Gretl (ver. 2022.c-64) [28]. On this basis, four periods were identified: 2000, 2001, and 2007, 2008 and 2014, and from 2015 to 2021. The interpretation and justification of these four periods are based on the milestone years in various historical datasets that have been researched for this purpose (Table 1), in addition to the results of the mathematical and statistical methods carried out using R and Gretl software. The mentioned sources provide statistical data regarding the established breakpoints and the period variance (Appendix A, Figures A1–A3).

**Table 1.** Historical records of three different variables which support the breakpoints established in the study.


Prior to the year 2000, the bioeconomy sectors in the world were taking their first steps towards development, in particular in regions such as Latin America and the Caribbean. According to the International Renewable Agency [29], public investment in the bioenergy sector did not exceed 13.6 million. This indicator is also related to the consumption of final energy from renewable sources, which was 0.62% lower than the next established breakpoint [30,31]. Since 2001, there has been evidence of significant changes in the level of consumption of biofuels at the global level and in the clean supply of renewable sources in the countries of Latin America and the Caribbean [32,33]. Finally, a significant increase in bioeconomy sectors worldwide occurred between 2008 and 2014; this could also be directly related to the policies and strategies proposed in EEUU, Canada, Germany, Austria, and Finland [34,35].

#### *2.2. Data Analysis*

In order to analyze and visualize the corpus data, a detailed bibliometric analysis was carried out using the Bibliometrix R-package. This program provides a wide variety of statistical functions (linear and non-linear modeling, classical statistical tests, time-series analysis, classification, clustering) and graphical techniques [36,37]. To complement the statistical analysis of the research, we also used the VOSviewer 1.6.18 software [38–40]. Table 2 shows the statistical indicators applied in the present research.

It is important to emphasize that the data obtained are the result of a global search for scientific production in the periods indicated and follow the keywords defined as the most appropriate for this research.


**Table 2.** Software tools applied to the corpus for statistical analysis.

#### *2.3. Limitations*

During the keyword search process, after following the guidelines in Figure 1, we noted that we had achieved the type of keyword combinations that were robust and firm enough to achieve the results to be displayed. The previous statement indicates that subtracting or adding a less relevant keyword could not considerably influence the number of results.

It is important to note that, as described in the methodology, the definition of the search terms was based on the previous review of 50 scientific articles that showed a priority focus on one of the most technologically and economically developed sectors in the region, i.e., biofuels. A few initiatives related to other biomass-derived products could also be considered relevant sectors. Therefore, only those initiatives identified in the keyword search were included.

However, as authors, we are aware that our research only covers some sectors currently considered part of the bioeconomy, which may have been further developed and researched. Similarly, we know this research only covers some relevant articles on the subject, as it is extensive and has grown exponentially in recent years.

#### **3. Results**

#### *3.1. General Characteristics of the Corpus*

The corpus of this research contains 18,971 documents. It represents a global search of scientific production in the four periods indicated, according to the keywords used. The published documents are analyzed according to the authors, the institutions linked to the corresponding countries, and the average number of citations of the articles at the world level [43]. In this set of data, the average number of citations per article per year is relatively high (2.068).

Figure 2 shows the global scientific publications between 1977 and 2021 in relation to the bioeconomy sectors developed in the LAC region. The high level of interest is reflected between the years 2000 and 2021, with 91% of the scientific production concentrated within the evaluation period of 44 years. This interest is also directly related to the investments made in LAC countries in the final products derived from biomass processing, such as biofuels and others. According to the International Renewable Energy Agency [41], there has been an 11 percentage point increase in investment in renewable energy in LAC since 2004, compared to a 6 percentage point increase worldwide. Countries such as Brazil, Argentina, Mexico, and Chile have joined the list of the world's top 10 renewable energy markets.

Table 3 shows an analysis of the cumulative share of publications in the corpus, based on the global search of scientific output in the analyzed period. This cumulative share is a measure constructed from the publication frequency of the corresponding authors (intraand inter-CCP country) during the four periods analyzed. In the early years of bioeconomy development in LAC, it was dominated by the United States and four representative South

American countries: Brazil, Mexico, Argentina, and Chile. The European countries of Germany and the United Kingdom appear in sixth and seventh place among the producing countries in the following period analyzed. From 2008 onwards, there is a rapid increase in the participation of other South American countries, such as Colombia and Cuba, and the appearance of major Asian countries, such as China and India. In recent years, the share of Latin American countries has grown even faster: five countries are among the 20 most productive.

**Figure 2.** Scientific publications between 1977 and 2021 related to bioeconomy sectors developed in Latin America and Caribbean region.

**Table 3.** The cumulative share of the top 15 countries in publications with corresponding authors' contribution to bioeconomy sectors (countries indicated by 3-digit ISO codes).


The above data are consistent with González, C. et al., (2016) findings. They show that developing countries are narrowing their science gap, with R&D investment and scientific impact growing at more than twice the rate of the developed world. However, among the countries assessed, the scientific output and impact are relative to their level of investment and the resources available to them and are not necessarily being carried out in an efficient manner [44].

Figure 3 shows the temporal changes during the four implementation periods of the bioeconomy sectors in Latin America and the Caribbean. It is based on the frequency of publications per country over time and interpreted in the territorial maps. In all the periods analyzed, Brazil and the United States were in the lead in terms of scientific production, followed by Central and South American countries such as Mexico and Argentina. The main difference lies in the frequency fluctuation of publications (expressed as a percentage on the map) among these key countries. Another interesting process observed in the last ten years is the active role of countries such as Brazil, which is the leading producer, accounting for almost 42% of the total number of publications, followed by the United States (17%), Mexico (13%), Argentina (9%), and Chile (7%). All these data highlight the global nature of bioeconomy sectors and the importance of Latin American countries in scientific production on this subject.

;a) 1st Period: 1977-2000 ;b) 2nd Period: 2001-2007

;c) 3rd Period: 2008-2014 ;d) 4th Period:2015-2021

**Figure 3.** Temporal changes in the spatial distribution of bioeconomy-related publications measured by countries' production percentage (Map created in R with base map courtesy of OpenStreetMap).

Based on the number of scientific articles published per journal, Table 4 shows the most relevant academic journals. For the purposes of this analysis, the descendant rank of the journal and the country of origin are taken into account accordingly. It is interesting to note that developed countries account for a higher proportion of top scientific research articles and have a robust research impact in this field. European countries such as the Netherlands, the United Kingdom, and Germany, together with the United States, are in the top 10 of the journal spectrums. Contrary to the previous analysis of country production, in the case of top journals, only a few belong to South American countries, such as Brazil, with the highest participation, followed by Chile and Costa Rica.


**Table 4.** The 14 most relevant academic journals in the 4 periods evaluated in the field of bioeconomy sectors in the Latin America and Caribbean region.

This phenomenon can also be explained in terms of the gross domestic expenditure on R&D that countries invest on an annual basis. In 2018, North America and Western Europe invested around 2.5% of their GDP, while Latin America and the Caribbean invested only 0.7%, according to the Unesco Global R&D Investment Report [45]. If we analyze the countries of Latin America and the Caribbean, Brazil is the country that invests the most, with 1.7% of GDP, and is ranked 9th among the top 10 countries in the world for investing in R&D. Several studies show that there is a strong positive correlation between R&D expenditure and scientific production [46,47]. Melo et al. conclude that countries that spend more on R&D have more universities and ISI-indexed journals and produce a significant volume of research papers.

#### *3.2. Analysis of Keywords and Co-Keywords*

Figure 4 shows the frequency of the different keywords over time. Aspects related to "biomass" and its different variants and concepts such as "biodiversity" reflect permanent growth. Terms related to climate change factors, such as land use change, deforestation, and degradation, are another group of terms identified in the corpus. Keywords associated with renewable fuels reflect their growth in importance over the last 15 years. Finally, terms such as "sustainability" and "life cycle assessment" show less growth. However, these latter terms have a direct cross-cutting relationship with most of the topics analyzed and are fundamental concepts for compliance with Sustainable Development Goals.

**Figure 4.** Frequency of occurrences of keywords on the corpus "−1".

The analysis of the second body is based on the frequency of the relevant words used by the authors during the period described (Figure 5). These words are directly related to the bioeconomy sectors developed in Latin America and the Caribbean. Some keywords appear exponentially as "biofuels" or "biogas", which shows the growing sensitivity of the academic environment towards renewable energy as the most important bioeconomy sector that has been established in this region.

For the purposes of this study, "biomass production" includes other sectors of the bioeconomy (e.g., biocosmetics, biopharmaceuticals) which do not have the same relevance and scientific production compared with biofuels.

Interestingly, terms such as "bioethics" appear with greater frequency from 2006 to 2016 as part of the glossary used by the authors, demonstrating the importance of including moral principles and values in all scientific research. It emphasizes the balance to be struck between ethical principles, technological possibilities, and several conflicting human needs, such as producing food and, in particular, renewable energy based on first-generation biofuels [48].

Finally, the term "REDD" appears with minority participation, although it is a relevant concept for the sustainable management of ecosystems, especially for developing countries such as those in the Latin America and Caribbean region.

#### *3.3. Clustering of Research Topics Based on Co-Occurrence of Keywords*

As mentioned in the previous sections, there have been significant changes in the research area in recent years. For this reason, a co-occurrence-based analysis was carried out in the VOSviewer software between the years 2015 and 2020. Figure 6 shows a summary of the results obtained.

The analysis performed makes it possible to differentiate eight-dimensional coordinate clusters. These clusters are interconnected and have different levels of importance according to the number of items they contain.

The largest cluster in terms of word number includes Agriculture and Soil Research (No. 1, shown by red color). In this cluster, soil management and soil properties are key factors for agriculture productivity. The same applies to biomass production systems, which deal with the use of agricultural land for bioenergy production. In terms of the relationship between sustainability and agriculture, the cluster contains important keywords such as conservative, sustainable, and functional diversity.

**Figure 5.** Frequency of occurrences of specific authors' keywords relevant to the corpus " −2".

**Figure 6.** Key clusters of bioeconomy sectors developed in Latin America and the Caribbean.

The second cluster, indicated by green color (No. 2) consists of 37 items, most of which are related to factors that affect climate change. This cluster highlights the relationship between biomass production strategies, particularly in the context of bioenergy and the impact of climate change.

The third cluster (No. 3, colored blue) deals with diversity and conservation aspects, including important ecosystems located in Latin America and the Caribbean, where high biodiversity indicators are one of the main features. The fourth cluster, shown in yellow, represents the different aspects of bioremediation, highlighting the current techniques used and how they are linked to sustainable agriculture and ecological restoration.

The fifth and sixth clusters are the highest in terms of word frequency and group the most related bioeconomy keywords. Containing a total of 64 words, these items focus on bioenergy and biofuel production as the most important bioeconomy sector developed in Latin American and Caribbean countries. The fifth cluster highlights the environmental impact and the life cycle assessment as evaluation methodologies for this type of model. Bioethics, food security, and COVID-19 appear in cluster six as relevant and topical issues.

The seventh cluster, marked in orange, refers to energy efficiency, the production of oilseeds, and concepts related to the sustainable development of the bioeconomy in Latin America and the Caribbean.

Finally, the eighth cluster brings together in a single word ("bioeconomy") a holistic approach to the previous clusters and summarizes, in a few keywords, the concepts of biomass production (such as biofuels), which is considered the most important sector identified in the region in this study.

In conclusion, it can be said that the bioeconomic sectors developed in Latin America, according to the scientific articles evaluated in this research, are concentrated in the production of bioenergy. The backbone of the field studied is the production of various biofuels, with leading countries such as Brazil and Argentina, which are considered the largest producers in the region. Although other types of biomass production in LAC were included in the keyword search, no words or clusters were found in the results.

#### *3.4. Mapping of Topic-Evolution*

Figure 7 examines the evolution of the topic map of the main research directions in recent years. Among the motor themes, three basic directions can be observed: firstly, the growing importance of bioenergy as a general category, including biofuels and other types of renewable energy; secondly, biomass as a primary source for bioenergy production; and thirdly, climate change as a cross-cutting theme of the previous ones since it is directly related to the production of biofuels as a strategy to mitigate the climate impact of fossil fuels. No basic topics are reported in this period of the research.

According to Plaza-Delgado E. et al., an alternative to reduce the consumption of fossil fuels is the use of biomass as a source of energy, especially in the Latin American and Caribbean region, which has great potential due to its diverse sources of biomass [49]. The study by Bailis R. et al. points out that this region is a world leader in the production of biofuels, accounting for 27% of the world's supply [50]. However, it is important to consider that the production of biofuels could mean an expansion of the production frontier, which poses a serious challenge to the region's environment and biodiversity [51].

Finally, bioethics is still present as an emerging theme in the analysis; according to Gutierrez-Prieto, Hin the last thirty years, Bioethics, as a developing discipline, has obtained gradual and increasing worldwide recognition, not only for its novelty but also for the connection with the future research topics [39]. In the same vein, the Nuffield Council on Bioethics highlighted the ethical issues raised by current and future approaches to biofuel development, as global biofuel production indirectly has serious negative impacts on agricultural and food sustainability [52].

In conclusion, scientific research on the region's bioeconomic sectors in the period 2015 to 2021 has focused on bioenergy as a fundamental strategy in both ways, on the one hand in relation to the production of biofuels as an energy source, and on the other as a transitional energy model for some Latin American and Caribbean countries.

**Figure 7.** Science map of research topics from 2015 to 2021.

#### **4. Discussion**

The results of the bibliometric analysis have highlighted the importance of biofuels as the most important sector of the bioeconomy developed in the Latin America and Caribbean countries evaluated. This finding is in support of the fact that the number of relevant publications in this area has been growing exponentially. Aydogan H. et al. pointed out that biofuels have been rapidly gaining prominence due to their continuous increase in economic value and, at the same time, less harmful effects on the environment [6,30,53].

According to the IICA study, by 2020 Brazil will be the world's second-largest producer of liquid biofuels, with a 23 percent share, behind the United States [54]. On the other hand, Argentina has a significant share in world biodiesel production, with around 7 percent, followed by Thailand, Colombia, and Paraguay [55,56].

Our research has also highlighted the relationship between biofuels and land use, particularly the crops used as feedstock for their production, and their transversal link to the region's ongoing concerns about food security and the sustainable development of such products. The World Bank's 2008 Development Report of Agriculture Development notes that the major challenge for governments in developing countries, such as those in Latin America and the Caribbean, is to "implement regulations and to develop certification systems that reduce the environmental and food security risks of biofuel production" [57].

The sustainability of agricultural land use for biofuel production is one of the priority issues to be discussed in the future, given the importance of biofuels as a major sector in the region. According to UNCTAD, biofuels compete directly with existing arable and grazing land for food production [58]. Moreover, bioenergy crops can lead to agricultural expansion, competition for water, and threats to biodiversity, especially in rural LAC areas with high ecological and social vulnerability [59].

Climate change was another cluster identified within the keyword analysis that is directly related to biofuels. Jeswani H et al. [60] point out that biofuels do not exist in isolation and, like other production systems, have an impact on various ecosystem services such as land, water, and food. In addition, authors such as Prasad, S. et al. [61] point out that producing biofuels from biomass has the potential to promote sustainable development and mitigate climate change while providing socio-economic benefits.

In terms of scientific publications, Latin American and Caribbean countries such as Brazil, Argentina, Mexico, and Chile are among the top twenty countries in terms of scientific production over the last period. This reflects a positive evolution in the concentration of developing countries as producers of scientific publications, compared to previous years when developed countries such as the United States had a significant and majority participation. However, the research shows that in terms of the most relevant scientific journals, the majority of them are from European countries or the United States. The representativeness of journals from Latin American and Caribbean countries is very low, even though the topics covered are directly related to this region.

With regard to the other types of bioeconomy sectors based on the final products obtained from biomass, we did not find any significant scientific publications in the Latin American and Caribbean countries evaluated during the period under review. However, the region has a wide and diverse range of renewable natural resources that could provide the essential basis for the development of a competitive bioeconomy [62] and the production of innovative products with added bioeconomic value [63].

Within the clustering of research topics, we could identify important keywords such as 'bioethics', 'food security', and 'COVID', which are transversally related to the bioeconomy sectors and also represent current topics in the scientific fields. According to Wo´zniak E et al., the "COVID crisis may be the driving force for the global integration related to bioeconomy, especially in implementing the SGD goals, development of national and regional bioeconomy strategies, ensuring food security and protecting biodiversity" [64]. Regarding bioethics as an emerging term, several bibliographical references indicate its importance over time and its close relationship with bioeconomy sectors, especially those environmental and sustainable aspects that seek social agreements to support human well-being while preserving the natural environment [65].

Finally, the structural breakpoints in the research database have been able to indicate the importance of bioeconomy sectors over time. It is noteworthy that since 2013, several European countries, including Germany, Spain, and Finland, proposed major policies to develop their bioeconomy, followed by several public policy documents and research papers covering different aspects of bioeconomy in developing countries at local and national levels [66].

#### **5. Conclusions**

The study highlights the importance of biofuels as the most important bioeconomy sector developed in the Latin American and Caribbean countries evaluated. Brazil and Argentina are the region's main producers and rank first in the world. Even though the region has a wide and diverse range of renewable natural resources, we were not able to find any significant scientific publications on other types of bioeconomy sectors that are based on the final products obtained from biomass.

Based on the co-occurrence keywords, our research has also shown the relationship between the eight identified clusters: (1) agriculture; (2) climate change; (3) diversity; (4) bioremediation; (5) bioenergy; (6) biofuels; (7) energy efficiency; and (8) bioeconomy. The first seven are linked to the region's current concerns for food security and the sustainable development of bioenergy production, while the eighth relates to the holistic approach of the research. In terms of scientific production in recent years, Brazil, Argentina, Mexico, and Chile are at the top positions. However, the research shows that the most relevant scientific journals belong to developed European countries or the United States.

In conclusion, in the LAC countries under review, there has been a significant increase in scientific production in relation to bioeconomy sectors over the last 15 years, with the main focus of research on biofuel production as the main source of bioenergy. The above results highlight the significant research gap on other types of innovative products with bioeconomic added value that could be generated in the region, given its immense biodiversity potential.

**Author Contributions:** Conceptualization, Z.L. and M.L.O.O.; methodology, Z.L.; software, Z.L. and M.L.O.O.; validation, Z.L.; formal analysis, M.L.O.O.; investigation, M.L.O.O.; data curation, Z.L. and M.L.O.O.; writing—original draft preparation, M.L.O.O.; writing—review and editing, Z.L. and M.L.O.O.; supervision, Z.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author. The data are not publicly available due to the intellectual property of the ISI enterprise.

**Acknowledgments:** The authors are particularly grateful to the Hungarian University of Agriculture and Life Sciences for the outstanding informatics support in the access to different databases requested for this research article, as well as the use of statistical software, need it to analyze the data presented.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **Appendix A**

Statistical analysis completed by using "Gretl software" to corroborate the structural breakpoints established by the R-package of the main dataset and the historical records mentioned in Table 1.


**Figure A1.** Article year's production of the main dataset (\*\*\*: *p* ≤ 0.001).


**Figure A2.** Primary energy supply from renewable sources in Latin American and Caribbean countries. (\*\*\*: *p* ≤ 0.001).


**Figure A3.** Renewable share (modern renewables) in final energy consumption, word wide (\*\*\*: *p* ≤ 0.001).

#### **References**


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**Shabarish Shankaran 1, Tamilarasan Karuppiah 1,\* and Rajesh Banu Jeyakumar <sup>2</sup>**


**Abstract:** The core objective of this analysis is to implement a combination of alkaline (NaOH) and sonication pretreatment techniques to produce energy-efficient biohydrogen from the marine macroalgae *Chaetomorpha antennina.* Anaerobic fermentation was implemented in control, sonic solubilization (SS) and sonic alkali solubilization (SAS) pretreatment for 15 days. In control, a biohydrogen production of 40 mL H2/gCOD was obtained. The sonicator intensities varied from 10% to 90% for a period of 1 h during SS pretreatment. About 2650 mg/L SCOD release with a COD solubilization of 21% was obtained at an optimum intensity of 50% in a 30 min duration, in which 119 mL H2/gCOD biohydrogen was produced in the anaerobic fermentation. SAS pretreatment was performed by varying the pH from 8 to 12 with the optimum conditions of SS where a SCOD release of 3400 mg/L, COD solubilization efficiency of 26% and a maximum biohydrogen production of 150 mL H2/gCOD was obtained at a high pH range of 11 in the fermentation. The specific energy required by SS (9000 kJ/kgTS) was comparatively higher than SAS (4500 kJ/kg TS). SAS reduced half of the energy consumption when compared to SS. Overall, SAS pretreatment was found to be energetically favorable in a field application.

**Keywords:** COD solubilization; chemo sonic pretreatment; biohydrogen; specific energy

#### **1. Introduction**

Recently, a lot of environmental issues have been raised owing to the usage of fossil fuels. It motivates researchers and scientists to predict prompt remedial action to create a proper substitute for fossil fuels [1]. Furthermore, most countries extract energy from many natural resources such as wind, hydropower and solar power. Biomass is a significant potential source of energy among these energy resources [2]. As a photosynthetic organism, marine macroalgae has the promising potential to act as a bioresource for biofuel production. Since it is associated with the green color type of marine macroalgae autotrophs, it is a rich source of biopolymers such as protein, carbohydrates and lipids, which are responsible for more biofuel production [3]. Furthermore, the lack of lignin content makes the marine macroalgae even more appropriate for an effective anaerobic fermentation process [4]. Marine macroalgae is a collection of rapidly growing plant organisms that can grow to substantial sizes in marine environments such as rock surfaces. The median photosynthetic activity of this marine macroalgae was 6–8%, much higher than that of earthbound biomass (1.8–2.2%) [5].

The circular economy involves energy recovery from trash and residues, which can fulfil the material and energy cycle. A very promising pathway toward sustainability is the biogas–biohydrogen chain. It can be transmitted into the natural gas grid, used as a vehicle fuel, or transformed into electricity-generating units. It is produced from a variety of different substrates, such as crop leftovers, algae, animal wastes, organic portion of municipal solid wastes and sludge [6,7]. Anaerobic fermentation is the sustainable way of

**Citation:** Shankaran, S.; Karuppiah, T.; Jeyakumar, R.B. Chemo-Sonic Pretreatment Approach on Marine Macroalgae for Energy Efficient Biohydrogen Production. *Sustainability* **2022**, *14*, 12849. https://doi.org/10.3390/ su141912849

Academic Editors: Idiano D'Adamo and Massimo Gastaldi

Received: 1 September 2022 Accepted: 3 October 2022 Published: 9 October 2022

**Publisher's Note:** MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

extracting or generating bioenergy from macroalgae since it is adaptable to this process [8]. Hydrogen (H2) is one of the various fuel sources that evolved from igniting hydrogenholding elements such as natural gas, oil and coal. However, with regards to excessive energy content, hydrogen has an enormous energy density than other surviving sources of fuels such as methane and ethanol [9]. Figure 1 shows the global hydrogen production in the last ten years and its market value based on the report of GHR, 2021 [10].

**Figure 1.** Global hydrogen production in last ten years and its market value.

Additionally, hydrogen is a high potential energy supplier for various utilities such as an ignition engine fuel for vehicles, rocket propellant, fuel cells for power supply and reactor coolant [11]. Furthermore, hydrogen generation makes way for the ecological crisis in the surrounding environment, such as global warming, melting glaciers and icebergs, rising ocean water levels and air pollution. Therefore, the bio-based hydrogen generation method is considered more appropriate than the standard fuel generation source. Moreover, the output of biohydrogen using substrate biomass has quite a few benefits such as uncomplicated performance, outspread accessibility of energy resources such as residues of food, vegetables, fruits, fauna manure such as cow chip, unbiased carbon source and cost worthy in its functions [12]. When specific requirements are met, the bioeconomy can advance toward sustainability: (i) the resource base is sustainable; (ii) processes and products are sustainable and (iii) transport of materials is viable [13]. Furthermore, customer satisfaction with bio-based products is also necessary to assess the influence of green premiums and the significance of sustainability certification [14]. However, these factors affect various industries because they are essential when considering sustainability as a factor that facilitates market success and a competitive advantage source [15]. In this perspective, the use of biological resources to replace non-renewable resources, escalating the use of biomass and reducing biowaste are excellent examples of a circular bioeconomy, which can be crucial in achieving sustainable development goals (SDGs) [16]. Marine macroalgae and biohydrogen satisfy all the mentioned criteria of the bioeconomy. Therefore, both marine macroalgae and biohydrogen are bio-economically feasible. Hydrolysis is the primary step of the anaerobic fermentation at which the cell cleavage occurs, a rate-limiting factor of the fermentation process. It is a difficult stage in anaerobic fermentation since the cell wall of the biomass may be more vital to rupture [17]. To augment the hydrolysis phase, the structural integrity of the biomass can be degraded through various pretreatment techniques and biopolymers such as proteins, carbohydrates, lipids and starch present in the biomass come out for the oxygen-free fermentation process [18]. Therefore, for this purpose, various

pretreatment techniques, such as physical, chemical, mechanical and biological ones, are incorporated [19]. Ultrasonication is a method of generating acoustic waves used to disrupt the cell wall of the biomass [20]. The sonicator gives rise to high-intensity ultrasound waves through a probe over the substrate kept in a beaker with water inside the apparatus. These high-intensity sonic waves are generated with the help of an intensity generator during the sonication process. These high-intensity sonic waves initiate the pressure wave formation and due to these pressure waves, cavitation develops. This cavitation collapses the cell wall of marine macroalgae species and disrupts it [21]. Energy exhaustion is a primary concern because the mechanical (sonication) pretreatment consumes much energy (electric current) to disrupt the biomass cell wall [22]. In order to overcome this problem, additives such as alkali and surfactants can be added, making the operation process of sonication energetically feasible [23]. Microwave–surfactant, microwave–acidic and disperser–ozone were the combinative pretreatment techniques used to solubilize marine macroalgae until now [24]. However, there are no published studies on marine macroalgae (*Chaetomorpha antennina*) solubilization using the sonication and alkali (NaOH) combination. Therefore, the marine macroalgae were solubilized in this study using a novel technique called alkali-assisted sonication. The objectives of this research are (1) to optimize the solubilization conditions for SAS for energy-effective performance; (2) to perform kinetic analysis for SS and to analyze its efficiency; (3) to assess the beneficial impact of this SAS pretreatment; (4) to evaluate the effect of this SAS pretreatment on the production of biohydrogen; (5) to perform an energy analysis of SAS in terms of field applicability.

#### **2. Materials and Methods**

#### *2.1. Marine Macroalgae Sample*

The marine macroalgae biomass species *Chaetomorpha antennina* was collected from ennore, a marine area of chennai (13◦12 23.4864 N, 80◦19 38.0100 E), Tamil Nadu, India. The marine macroalgae were entirely washed with water to detach the residue particles. The cleaned sample was shade-dried and sliced into pieces of less than 2 cm in size for the convenience of pretreatment. This biomass was kept in a refrigerator for the subsequent study [24].

#### *2.2. Biomass Pretreatment*

#### 2.2.1. Sonic Solubilization (SS)

SS pretreatment was implemented to rupture the cell wall of the biomass. The operation mechanism utilized a sonicator (Model VCX130, New Town, CT, USA) instrument with a frequency of 20 kHz and a maximum power input of 130W. A beaker of 1L capacity volume filled with water and substrate sample was taken for this pretreatment. The substrate and water ratio taken for pretreatment was 1:50. The sonication power intensity and the time duration varied from 10 to 90% and from 1 to 60 min, respectively. The sonic probe produces the combined effect of pressure waves and cavitation. This effect results in the marine macroalgae cell wall weakening for enhanced solubilization and biopolymers release. The only drawback of this SS pretreatment was that it consumed more electrical energy to solubilize the marine macroalgae. The samples were taken and examined for a regular period.

#### 2.2.2. Sonic Alkali Solubilization (SAS)

The solubilization of the substrate by SAS was carried out by adding alkali "sodium hydroxide (NaOH)" with an optimum condition obtained from SS pretreatment. The pH of the sample varied from 8 to 12. SAS pretreatment is appropriate for the following reasons: (1) the mechanical (sonication) pretreatment gives high and efficient output within a quick session compared to physical and biological pretreatment methods. (2) Alkali (NaOH), when added to sonication, are divided into cations (Na+) and anions (OH- ). Cations transform into bubbles, clash with the cell wall of marine macroalgae and break it. Anions settle over the marine macroalgae cell wall surface and weaken it. This phenomenon

accelerates the solubilization process of marine macroalgae and more biopolymers are released in a short duration. The samples are taken at a regular time interval and subjected to analysis.

#### *2.3. Anaerobic Fermentation Study*

Anaerobic fermentation was performed for control, SS and SAS, into which anaerobically digested sludge (inoculum) taken from a wastewater treatment plant was added at a ratio of 9:1 in serum bottles of 250 mL volume capacity for three days. To suppress the fermentation within the acetogenic phase and to compute the volatile fatty acids (VFA) produced, a methanogenic phase obstructor 50 mM of 2- Bromo ethane sulphonic acid (BESA) was added to each bottle. The computation of VFA was performed to substantiate the pretreatment and biohydrogen production efficiency [25]. To remove O2, nitrogen gas was introduced into all serum bottles. The bottles were firmly sealed by stoppers and positioned in an orbital shaker under agitation at a speed and temperature of about 150 rpm and 35 ◦C [26]. VFA analysis was performed through the distillation method [27].

#### *2.4. Biohydrogen Potential Assessment (BPA)*

BPA analysis was applied for control, SS and SAS to evaluate the biohydrogen production capability under moderate temperatures. The process of BPA was performed in serum bottles with a functioning volume of 150 mL. In all three serum bottles, the marine macroalgae sample (70%), inoculum (25%) and the nourishment food (5%) were taken [28]. As a point of expelling methanogens in the inoculum and enriching the microbes for hydrogen production, the inoculum was subjected to calefaction for 30 mins at 100 ◦C [29]. To maintain an oxygen-free environment, nitrogen (N2) gas was filled in the remaining bottle area for 10 mins [30]. Rubber stoppers were used to seal the bottles. Finally, the bottles were kept in a shaker and incubated at 37 ◦C at 130 rpm. A gas chromatograph with a thermal conductivity detector and stainless column packed with Porapak Q (3.25 mm diameter, 2 cm length and 80/100 mesh) was used to calculate hydrogen production [31]. The experiments were triplicated. To estimate the cumulative H2 yield, the modified Gompertz Equation (1) was used.

$$\text{AH} = \text{HI} \ast \exp\left(-\exp\left(-\text{pr}(\text{Hc} - \text{Hfb})\right)\right) \tag{1}$$

where:

AH—Increased H2 production (mL); Hl—H2 production (mL H2/g COD); pr—Peak H2 generation rate (mL H2/g COD d); Hc—Commencing phase of hydrogen production (days); Hfb—Lag phase of hydrogen production (days).

#### *2.5. Analytical Methods*

The biopolymers proteins, carbohydrates and lipids released as a result of pretreatment were measured based on the method prescribed by Kavitha et al. (2016) [32]. In addition, total chemical oxygen demand (TCOD), soluble chemical oxygen demand (SCOD), and VFA were analyzed with the help of standard methods as per APHA (2005) [33].

#### *2.6. Statistical Analysis*

One way analysis of variance (ANOVA) (α = 0.05) approach was made to assess the deliverables of the experiment. The differences between experimental deliverables during the pretreatment could be subjected to statistical significance analysis if the p-values were less than 0.05. To be precise, for *p*-values < 0.05, the difference between SCOD release averages was statistically significant. On the contrary, for *p*-values > 0.05, the difference between SCOD release averages was not statistically significant [34].

#### *2.7. Specific Energy for Sonication (SES)*

Specific energy (SE) is considered for the measure of vital energy required by the sonicator to solubilize the cell wall of marine macroalgae. The SE was calculated using the subsequent Equation (2):

$$\text{SES (kJ/kg TS)} = (\text{P}\_{\text{D}} \times \text{S}\_{\text{T}}) / (\text{Vs} \times \text{TS}) \tag{2}$$

where:

SES—Specific energy for sonication;

PD—Power used for disruption of the biomass cell wall (kW);

ST—Sonication treatment time (s);

VS—Volume of the sample (L);

TS—Total solids (kg).

#### *2.8. Energy Analysis*

One prominent contemplation in the massive scale biofuel production is the energy employed in the entire process. From an economic angle, minimum input energy should exhibit the uttermost output energy, which will be profitable [35]. This investigation studied the energy required to treat 1 kilogram of marine macroalgae biomass sample to produce H2 gas. The total net energy that has been dominated was calculated using Equation (3).

$$\mathbf{N}\_{\rm E} = \mathbf{O}\_{\rm E} - \mathbf{I}\_{\rm E} \tag{3}$$

where:

NE—Net energy (kWh);

OE—Output energy (kWh);

IE—Input energy (kWh).

The solubilization energy taken by the sonicator is the input energy as shown in Equation (4).

$$\mathbf{I}\_{\rm E} = \mathbf{P}\_{\rm S} \ast \mathbf{T}\_{\rm S} \ast \mathbf{V}\_{\rm R} \ast \mathbf{B} \tag{4}$$

where:

IE—Input energy (kWh);

PS—Power utilized for the sonication process (kW/kg);

TS—Time consumed for solubilization (h);

VR—Reactor volume (m3);

B—Biomass (kg/m3).

The output energy was calculated based on various parameters such as biomass biodegradability, organic load, the volume of the reactor and hydrogen yield, as mentioned in Equation (5).

$$\mathbf{^\circ O\_E = B\_{SB} \* L\_{COD} \* H\_Y \* V\_R \* B\_{CF}}\tag{5}$$

where:

OE—Output energy (kWh);

BSB—Biodegradability of marine macroalgae biomass (g COD/g COD);

LCOD—COD load (g COD/m3);

HY—Hydrogen yield (m3 /g COD);

VR—Reactor volume (m3);

BCF—Biohydrogen conversion factor.

By determining the optimistic and pessimistic amount of net energy, the profit and loss in the energy are confirmed in the SS and SAS processes.

The energy ratio is given in Equation (6),

$$\mathbf{Err} = \mathbf{O}\_{\mathbf{E}} / \mathbf{I}\_{\mathbf{E}} \tag{6}$$

where: Er—Energy ratio; OE—Output energy (kWh); IE—Input energy (kWh).

#### **3. Results and Discussion**

*3.1. Sequel of SS in the Liberation of Soluble Organics Release*

Solubilization potential was estimated by the release of soluble organics during the SS process. Figure 2 shows the release of the soluble organics for sonication intensity and period. The sonicator was operated by varying its power intensities from 10% to 90% for 1 h. During SS operation, the marine macroalgae that had to be solubilized was kept under the sonicator probe. It was subjected to the impact of high-power ultrasonic waves, which resulted in the emergence of pressure waves and cavity bubbles. This simultaneous evolution of cavity bubbles and pressure waves weakened the marine macroalgae cell wall. At each intensity, the solubilized marine macroalgae sample was taken and analyzed. In Figure 2, it was observed that the release of the soluble organics was classified into two phases, namely, the faster phase (1–30 min) and the slower phase (30–60 min). The figure shows that when the sonication pretreatment time increases, there is an increment found in the soluble organics release. In the faster phase, 1–30 min, the release of soluble organics was high up to 30 mins, but in the slower phase, beyond 30 min, the minor release was found. A steady trend was spotted in the slower phase after 30 min. This trend indicates that most of the soluble organics got unleashed within 30 min in the faster phase. For a sonication process, the pretreatment time was recognized as an ideal parameter [36]. Hence, the sonication pretreatment time of 30 min was acknowledged as an optimum pretreatment time for SS. Furthermore, the sonication intensity for pretreatment also plays an indispensable part in SS. When the release of the soluble organics was reasoned against the intensity of SS, an extraneous behavior was noticed in the release of the soluble organics. In the intensity range (10–40%), there was a minimum release found in soluble organics and the release range was 1750–2320 mg/L. This provided authentic evidence that the marine macroalgae were partially solubilized [37]. When the intensity is further increased to 50%, drastic enhancement in the soluble organics release of 2650 mg/L was obtained due to the combined effort of high-power ultrasonic waves, pressure waves and increased formation of cavity bubbles. This caused the marine macroalgae cell wall to smash and become solubilized. Increasing the intensity beyond 50%, there was no excess improvement obtained. The soluble organics release found between 50–90% was in the SCOD release range of only 2819–3010 mg/L. This marginal release was found because most of the soluble organics got released at up to 50% intensity. Hence, 50% was considered to be optimum for SS. For the soluble organics released during SS, statistical analyses were carried out via ANOVA. Table 1 represents the one-way ANOVA of variance for various intensities of sonicator on the SCOD release basis. When the intensity varied from 10% to 40%, the probability value was found to be 0.46, which was greater than 0.05. This signifies that there is no statistical difference. For intensities between 40% and 50%, the probability value of 0.013 obtained was less than 0.05. This shows that there was a considerable difference found between 40% and 50%. The mean values of SCOD release from 50% to 90% imply a lack of significant difference between them, with a probability value of 0.84, which was greater than 0.05. Therefore, considering all these outcomes, a power intensity of 50% with a duration of 30 min was considered as optimum.

#### *3.2. Response of SE over COD Solubilization*

Significant attention is given to SE regarding the economy of the process for enormous biofuel production. Figure 3 represents the solubilization of SS concerning SE. It was noticed that the solubilization trend increases with an increase in SE input for all sonic intensities. The solubilization tendency can be divided into three phases: X, Y and Z. Slower solubilization was represented by phase X, which corresponds to intensities of 10% to 40%. Phase Y represents a faster solubilization rate, ranging from 40% to 50%. Finally, phase Z extends from 60% to 90%. At a sonicator, SE input of around 1800–7200 kJ/kg TS, solubilization of about 13.46–17.84% was achieved during phase X. The amount of solubilization obtained was insignificant and can be ignored for further analysis. An effective rise in solubilization was observed in phase Y, with a maximum of 21% reached at a sonicator SE input of about 9000 kJ/kg TS for an intensity 50%. Even though the sonicator intensity and SE were increased from 60% to 90% and 9000 kJ/kg TS to 10,800 kJ/kg TS in phase Z, there was no significant increase in solubilization. To increase solubilization from 21% to 22%, for example, a sonicator SE input of 10,800 kJ/kg TS was required. As a result, it can be concluded that simply raising sonicator intensities during the SS process may waste energy. Instead, SS was found to benefit from an optimum sonicator SE input of 9000 kJ/kg TS.

**Figure 2.** Soluble organics release with respect to sonication intensity.



#### *3.3. Impact of SAS in the Discharge of Organic Biopolymers*

Sodium hydroxide (NaOH), as an alkaline solution, has the massive potential to fracture the cell wall's ester bond, resulting in increased cellulose decrystallization [38]. During SAS, alkali, when added to the sample, gets split into cations (Na+) and anions (OH- ). Due to saponification, the cations get transmuted into bubble form, clash with the marine macroalgae cell wall and break it; and due to solvation, it settles in the bottom of the beaker as salts. On the other hand, the anions settle over the cell wall and make it squashy, which makes the sonication process even more rapid and comfortable. This results in the reduction of energy consumption by the sonicator. Thus, the alkali (NaOH) acts as an excellent energy-saving additive and intensifies the sonication pretreatment even more

effectively [39]. In the present study, alkaline (NaOH) was combined with the SS process to enhance the solubilization capability of the previous certainties. Figure 4 signifies the soluble organics and biopolymer release at various pH levels. The alkali was added by differing its pH from 8 to 12. The sonicator was operated at 50% of power intensity and 30 min of duration, which was optimized in SS, and the sample's pH was varied. During the operational time of SAS, for every 5 min, the solubilized biomass sample was taken and examined for each pH from 8 to 12. From the figure, it was understood that the patterns of soluble organics (SCOD) and biopolymers (protein, carbohydrates and lipids) show two divergent phases: an accelerated and a slow phase. The accelerated phase occurs from pH 8 to pH 11, where a soluble organics release (2900–3400 mg/L) was obtained. This proves that the combinative pretreatment was very effective as more SCOD were released in SAS (3400 mg/L) compared to SS (2650 mg/L), as presented in Figure 2. This massive increase in the release of soluble organics during the accelerated phase could be due to the combined action of SAS, which prompts the fracturing of marine macroalgae cell walls and the release of intercellular components. It is similar to the work of Kumar et al. (2017) [40], where the SCOD release of 1603 mg/L was obtained from microalgae via combined pretreatment of sonication and electrolysis. The slow phase lies from pH 11 to pH 12, where a soluble organics release (3400–3450 mg/L) was obtained. A significant hike was found in the release of soluble organics between pH 8 and 11, but in the slow phase beyond pH 11, a minimum rise was noted in the release of soluble organics. This makes it evident that almost all the soluble organics got released within pH 11 and it was adequate to solubilize the marine macroalgae cell wall. Therefore, increasing the pH level beyond 11 will increase chemical cost rather than marine macroalgae solubilization. From Figure 4, it is evident that at optimum solubilization of 21%, SAS consumed less SE (4500 KJ/kg TS) compared to SS (9000 kJ/kg TS), which shows that SAS is more energetically feasible than SS.

**Figure 3.** Solubilization efficiency of SS with respect to specific energy.

**Figure 4.** Soluble organics and biopolymers release in SAS.

The biopolymer's existence in marine macroalgae boosts hydrogen generation. Figure 4 elucidates the biopolymer release from pH 8 to pH 12. Indisputably, the biopolymers trend is similar to the SCOD trend and could be grouped into two phases: active and inactive. The active phase begins at pH 8 and ends at pH 11. A moderate increase in the biopolymers release was observed in this active phase up to a pH of 11, where a protein, carbohydrate and lipid release of 1637, 957 and 390 mg/L was obtained. The inactive phase begins beyond 11 where a protein, carbohydrate and lipid release of 1660, 978 and 402 mg/L, respectively, were obtained and there is no sturdy increase in biopolymers release after that, which signifies that the majority of the biopolymers got released in the pH 11. The collaborative effect of chemo sonic pretreatment makes way for effective solubilization of marine macroalgae cell wall and the liberation of biopolymers into the liquid phase of marine macroalgae. Hence from the facts mentioned earlier, it was concluded that SAS is more effective in solubilization and biopolymers release.

#### *3.4. VFA Production in SS and SAS*

The VFA investigation done for control, SS and SAS pretreated samples during anaerobic fermentation was analyzed and conveyed in Figure 5. In the commencing hydrolysis stage, the complicated hydrolytic components released during pretreatment got converted into sugars, amino acids and fatty acids. In the peripheral stage of acetogenesis, the simple monomers got transmuted into VFA [41]. Due to the biological action of microbes in the inoculum, the biopolymers got transformed into VFA [42]. Anaerobic fermentation was carried out for 72 h. At the end of 72 h, as predicted, SAS showed an enormous decrement in protein, and carbohydrate concentration from 1637, 957 mg/L to 623, 364 mg/L, which denotes the hydrolysis competence. On the other hand, SS showed a slight protein and carbohydrate concentration reduction from 1300, 760 mg/L to 498, 289 mg/L. The depletion in the concentration of biopolymers was found to be a lot less in SS compared to SAS. This made authentic evidence that highly solubilized biopolymers are easily accessible by fermentative microbes, which defines the effectiveness of combinative pretreatment [43]. It is similar to the combinative pretreatment strategy suggested by Tamilarasan et al. (2017) [44]. In contrast, the untreated control sample did not manifest a major decrement; instead, a build-up was spotted in the biopolymer's concentration. In control protein, the carbohydrate concentration was increased from 160,110 mg/L to 180,130 mg/L respectively. The reason behind this is that the biopolymers are not solubilized since there was no pretreatment in control; hence, the microbes try to break the marine macroalgae cell wall and release the biopolymers. This release was found only using disintegration instead of fermentation. The increased VFA production should have a higher hydrogen yield at the end of fermentation process. The VFA production analysis was performed to validate the effectiveness of biohydrogen production in the fermentation process. The utmost liberation of VFA during fermentation intensifies biohydrogen production [45]. Figure 5 clearly states that among control (110 mg/L), SS (860 mg/L) and SAS (1800 mg/L) after 72 h of anaerobic fermentation, SAS showed higher VFA production compared to SS and control due to the alkali sonication impact and effective utilization of pretreated and hydrolyzed biopolymers by acetogenic microbes. From the findings, SAS presents effectiveness in VFA production, hence proving that SAS will yield more hydrogen at the end of the fermentation process.

**Figure 5.** VFA production in control, SS and SAS.

#### *3.5. Biohydrogen Potential Assay (BPA)*

Figure 6 signifies the biohydrogen production in control, SS and SAS. From Figure 6, it was unquestionably understood that the biohydrogen generation got varied with control, SS and SAS. Biohydrogen analysis was done for 15 days. Regardless of augmentation in biohydrogen generation concerning increasing days of fermentation, the generation rate of biohydrogen was less in control (40 mL H2/g COD) in comparison with SS (119 mL H2/g COD) and SAS (150 mL H2/g COD) on the eighth day of fermentation. This is due to the certainty that the microbes in inoculum are more comfortable in the biological degradation of marine macroalgae to generate hydrogen when the biomass is in soluble form than solid form. SAS sample has more effectiveness in biohydrogen production than control and SS because the alkali and sonication gave an impressive hydrolysis effect. Hydrogen-producing microbes' subsequent utilization of acetogenic elements enhances biohydrogen generation [46]. Owing to the combined pretreatment method imposed over the marine macroalgae, the anaerobic culture media had a very suitable approach to liberating biohydrogen. At the same time, depending upon the composition, solubilization

efficiency and pretreatment conditions, the biohydrogen production potential may vary for different substrates. In this condition, the released solubilized compounds, especially proteins and carbohydrates, declined as there was a rise in VFA and biohydrogen production due to the effective hydrolysis and consumption of biopolymers by the microbes. The commencement of biohydrogen fermentation starts with the biopolymer's biodegradation. The proceedings of biopolymers degradation by the fermentative and hydrogen-producing microbes resulted in the emergence of biohydrogen. The biopolymers which were solubilized got exploited by fermentative microbes as a source of energy and electrons [47]. Then, the hydrogen-generating microbes use these compounds and transmute them into biohydrogen. Anaerobic microbes in the inoculum can easily access the biopolymers in the marine macroalgae via this combinative pretreatment. The inoculum (anaerobic sludge) comprises microbes that effectively utilize the solubilized biopolymers and convert them into monosaccharides, thus escalating biohydrogen production [48]. In the preliminary stage, the third day of the operation, the biohydrogen production was low for all samples. This may be due to the instantaneously unadaptable condition of the microbes in the environment. After the third day in the augmented stage, there was a steady increase in the biohydrogen generation where control, SS and SAS showed a biohydrogen production of 5, 75 and 106 mL H2/g COD, respectively. This rising scenario of biohydrogen in the augmented stage guarantees an effective proliferation and fermentative action of microbes. The eighth day of fermentation begins with the sound stage where control, SS and SAS showed a biohydrogen production of 40, 119 and 150 mL H2/g COD respectively, beyond which there was no rise in biohydrogen production since a stable range was observed. The summary of this stable stage shown in Figure 6 shows that the biohydrogen producers have unreservedly exploited the solubilized substrates. A maximum biohydrogen yield of 150 mL H2/g COD was obtained in SAS than SS 119 mL H2/g COD and control 40 mL H2/g COD. This is due to the chemo sonic pretreatment that makes the biopolymers in the marine macroalgae easily approachable to the anaerobic microbes in the inoculum sludge, which is essential for biohydrogen production. Table 2 signifies the kinetics constants accomplished through Gompertz modeling of control, SS and SAS samples. SAS shows an uttermost hydrogen production potential and rate (150 mL H2/g COD and 0.91 mL/d) in correlation with SS (119 mL H2/g COD and 0.67 mL/d) and control (40 mL H2/g COD and 0.47 mL/d) expressing the combinative potency of sonication and alkali [49]. It is witnessed that the SAS has a very short preliminary stage (1.5 days) in comparison with control (3.7 days) and SS (2.6 days). An excellent fit was observed in exploratory data as the correlation coefficient of 0.995 was obtained. A similar range of fit was obtained in the work of Tamilarasan et al. (2018) [50]. Based on the above points, it was proved that SAS is more effective in biohydrogen generation than control and SS. Table 3 shows biohydrogen production from different species of marine macroalgae with various combinative pretreatments. From a sustainability point of view, marine macroalgae have emerged as prospective sources for biobased products and biofuel.

#### *3.6. Energy Interpretation*

The overall energy consumed for the operation of the marine macroalgae (1 kg) accounted for energy interpretation. Figure 7 depicts the overall energy interpretation between SS and SAS, which includes optimum condition, total energy spent, energy gained through biohydrogen production, net energy, and energy ratio [28,45,51,52]. For effective pretreatment accomplishment, the exhausted input energy should be compensated by the output biohydrogen production. In the evaluation aspect, the output biohydrogen and input sonication energy of SS and SAS observed at an optimum setup were considered. Solubilization efficiency of 21% was kept as an indicator to derive the energy constants for the appraisal of SS and SAS pretreatment energy efficiency [51,52]. The energy consumed by SS (0.1 kWh/kg solids) and SAS (0.05 kWh/kg solids) was determined based on all these specifications. The output biohydrogen production energy of (0.09 kWh/kg solids) was obtained for both SS and SAS since the SCOD solubilization efficiency was taken as

21% to derive the energy parameters. Net energy and energy ratio are the two fundamental factors that conclude the energy competence and pretreatment efficiency [2,45,53,54]. The net energy (−0.01 kWh) and energy ratio (0.8) for SS were less compared to SAS, where the net energy (0.04 kWh) and an energy ratio of (1.8) were obtained. It is proclaimed that the SAS pretreatment process would benefit when there is an energy ratio greater than 1. This is similar to the work of Rajesh Banu et al. (2020) [55]. This certifies that combinative pretreatment of SAS was a more energy valuable pretreatment than SS.

**Figure 6.** Biohydrogen production in control, SS and SAS.

**Table 2.** Kinetic analysis for various solubilized samples through Gompertz modelling.


**Table 3.** Biohydrogen production from different species of marine macroalgae with various combinative pretreatments.


*Sustainability* **2022**, *14*, 12849


#### **Table 3.** *Cont.*

**Figure 7.** Energy interpretation in SS and SAS.

#### **4. Conclusions and Future Areas of Research**

An exploration was made to generate energy-efficient biohydrogen from marine macroalgae by utilizing chemo sonic pretreatment. SS liberated a SCOD release of 2650 mg/L and COD solubilization of 21%, which was lesser than SAS in which a SCOD release of 3400 mg/L and COD solubilization of about 26% was obtained. In comparison with control (40 mL H2/gCOD) and SS (119 mL H2/gCOD), SAS (150 mL H2/gCOD) showed maximum biohydrogen production. pH 11 was the appropriate range for alkali with 50% sonication intensity and 30 min duration for energy-efficient biohydrogen production. VFA production was higher in SAS (1800 mg/L) when compared to SS (860 mg/L) and control (110 mg/L). SAS stated net energy of 0.04 kWh/kg of marine macroalgae biomass and an energy ratio of 1.8, which was effective when compared to SS, in which net energy of −0.01 kWh/kg and an energy ratio of 0.8 was obtained. Hence, chemo sonic pretreatment was regarded as a promising pretreatment approach for biohydrogen generation from marine macroalgae.

Marine macroalgae have emerged as prospective sources for biobased products and biofuel, making them the most viable and desirable biofuel sources. The development of commercial bio-refinery technologies, which primarily utilize marine macroalgae as feed, may be restricted by a distinct lack of practical concepts that must be addressed before its prototype can be successfully sold. Numerous lab-scale experiments are currently being performed, however, it is uncertain whether these technologies could be implemented in the near future. The efficacy of the bioprocess and output of the bioproduct should be reviewed as a result of the scale-up process in order to keep records of losses that happened. Other challenges include species selection as well as conventional microorganisms' role in hydrolysis, conversion and utilization of particular polysaccharides. The development of marine macroalgal biorefineries may be limited by its inability to scale up the biotechnologies which is now being used to conduct ongoing research. Freshwater utilization rises as the biorefinery process progresses, which leads to a freshwater shortage worldwide. The feasibility of using saltwater in a specific biorefinery process has been demonstrated in some research, but it has not yet been verified in a comprehensive marine macroalgal biorefinery process, which entails a number of interrelated processes and activities.

It is essential to identify the spectrum of potential bioproducts and biofuels for each marine macroalgae variety that may be grown sustainably, as well as the best, most comprehensive and unified bioprocessing methods. This information can depend on the long-term sustainability and financial benefit of the green economy. The marine macroalgal sector develops if all bioprocessing steps and the range of potential bioproducts are maintained in a centralized system that can be accessed globally. A strong collaboration between academics and industries which comprises environmental engineers, marine scientists, skillful laborers and economists should yield effective methods for biofuel production from marine macroalgae. The organization of the bioeconomy in a particular nation could undergo a dramatic change in the following decades due to the effects of global warming. As a result of the rising temperatures brought on by climate change, research has revealed potential changes in the geographical distribution of marine macroalgae in diverse coastal environments. Shifts in marine macroalgal distribution affect the infrastructure, locations, employment opportunities and overall viability of marine macroalgal biorefineries in the bioeconomy. Therefore, it is essential to model and predict the transformation of the commercially significant marine macroalgal species under climate change. Better macroalgae collection techniques to have a high yield of biofuels via genetic alteration will be the future of algal biology. The marine macroalgae chosen for biofuel production should suit all the environmental requirements so that they can be considered as a sustainable feedstock. The bioprocessing characteristics of each marine macroalgal species, such as life cycle evaluation, energy and energy-based modeling, should be accurately examined using various eco-friendly techniques. This could help for better sustainable biorefinery development.

**Author Contributions:** Conceptualization, supervision, T.K.; writing—original draft preparation, S.S.; data curation, R.B.J. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**


**Elvira Tarsitano 1,2,\*, Simona Giordano 3, Gianluigi de Gennaro 4, Annalisa Turi 5, Giovanni Ronco <sup>6</sup> and Lucia Parchitelli <sup>7</sup>**


**Abstract:** In an increasingly complex global economic scenario, sustainability represents a fundamental compass aimed to guide actions of institutions and individuals. A nondissipative use of Earth's resources is feasible through a common effort that reconsiders the actual development system according to the key principles of the bioeconomy. It is vital to start from local contexts to reach the global dimension by exploiting the opportunities available in each territory. Starting from these assumptions, the participatory process activated in the Apulia region has represented the first step towards an intervention strategy in the panorama of the bioeconomy, and has made it possible to increase the awareness of a development based on the adoption of bioeconomy models and, therefore, circular economy ones through an effective inclusion process. A process has given rise to a project allowing all involved actors to reflect on the double economy–environment system, to share good practices and promote the adoption of lifestyles and consumption styles more compatible with the principles of the bioeconomy and to elaborate a proposal for a participatory regional law for the bioeconomy in the Apulia region as an expression of the collaboration between different bodies and institutions (universities, Confindustria and the council of the Puglia region).

**Keywords:** bioeconomy; sustainable development; 2030 Agenda; natural resources; participation

#### **1. Introduction**

In line with the communication to the European parliament, the council, the European economic and social committee and the committee of the regions of 11 March 2020 [1], the European commission has defined a new action plan for the circular economy, entitled "For a cleaner and more competitive Europe", establishing a future-oriented program to reach the cited objective in cocreation with different actors [2]. Furthermore, the plan aims to accelerate the profound changes required by the European Green Deal, based on actions to the circular economy implemented since 2015. This plan aims to rationalize the regulatory framework, making it suitable for a sustainable future, ensuring the optimization of new opportunities arising from the transition and minimizing the burden on people and businesses. The same plan embeds a series of interconnected initiatives designed to establish a strategic framework for sustainable products, services and business models with the goal to help transform consumption patterns so as to avoid, in the first place, waste generation. In fact, the new regulatory framework has the potential to allow for the achievement of the objectives set out by the new directives on waste prevention, recycling and reduction in landfill disposal. At the same time, the same framework needs to support the transition to the circular economy by removing those administrative and

**Citation:** Tarsitano, E.; Giordano, S.; de Gennaro, G.; Turi, A.; Ronco, G.; Parchitelli, L. Participatory Planning for the Drafting of a Regional Law on the Bioeconomy. *Sustainability* **2023**, *15*, 7192. https://doi.org/10.3390/ su15097192

Academic Editors: Idiano D'Adamo and Massimo Gastaldi

Received: 23 February 2023 Revised: 22 April 2023 Accepted: 23 April 2023 Published: 26 April 2023

**Copyright:** © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

procedural criticalities that too often hinder and slow down its development, aiming to overcome the strong territorial inhomogeneities currently existing in the management of the waste cycle in Italy as a whole, as well as through the construction of necessary systems and infrastructures. As a consequence, it appears necessary that the process of drafting legislative decrees be accompanied by extensive discussions with stakeholders and that the deadline set for the transposition of the new directives into national law is respected. In this scenario, the bioeconomy [3–6] represents the answer to a large part of the current global challenges, from global warming to all the issues related to climate change, to smart agriculture limiting the adoption of pesticides. The bioeconomy [7–10], including the mentioned principles of the circular economy, fosters the adoption of a model of sustainable development, not only devoted to mere profits and profitability, but also to social progress, considered the driving force for achieving the objectives of the 2015 Paris Agreement, as well as the United Nations 2030 Agenda for Sustainable Development [11–13]. By virtue of this, Europe, as well as Italy, recognizing its key role, and has strived to implementing a sound strategy for the bioeconomy. As far as Italy is concerned, in May 2019, the update of the "National Bioeconomy Strategy" [14–17] was presented, with the related implementation program in view of the new "European Bioeconomy Strategy", strongly emphasizing the need to orient all sectors of the bioeconomy towards circularity and environmental, economic and social sustainability.

As for Italy, the European Green Deal [18,19] plays an extraordinary role and constitutes a precious opportunity towards development along a path of ecological transition; this necessarily requires that Italy be able to define its own coherent strategic framework and develop actions to effectively increase and use the financial resources made available by the European plan. The start of the process for a National Green Deal constitutes an essential reference from the point of view of the transition to a circular economy. However, this project needs to be significantly strengthened both from the point of view of public and private investments and from the point of view of a more comprehensive and coherent reorientation of all public policies towards the ecological transition and the circular economy, all within the framework of the European Green Deal. The different regions can play a decisive strategic role in the transition to a circular economy, as they have the necessary regulatory skills and responsibilities, in addition to the knowledge and experience on the different territories, capable of defining realistic objectives, to be pursued on a local territorial and differentiated scale, as "the regions are large enough to make a difference and small enough to make it happen". The OECD [12], through "The Bioeconomy to 2030: designing a policy agenda", defines a true industrial revolution capable of innovating mature sectors, such as those of raw materials, waste, energy production and of guaranteeing long-term environmental, economic and social sustainability within the global economic system. Taking into account the territorial processes included in the annual "Program for the participation of the Puglia Region pursuant to LR N.28/2017—Law on Participation" [20], into which the Manifesto for the Bioeconomy in Puglia (MaBiP) project [21] was inserted, it is vital to highlight, with regard to the issue at stake, the importance of participation from all stakeholders vital to combine innovation and environmental protection. Change is a collective action: the public expresses the needs and governs; the private sector provides skills and financial resources. Without collaboration and partnership, sustainability cannot be achieved (Goal 17, Agenda 2030) [11]. In order for the bioeconomy to win the challenge of "re-integrating economy, society and the environment", it is not enough to simply use biomass for industrial applications or to use renewable raw materials instead of fossil ones. It cannot all be considered a mere question of integrating biological knowledge into existing technology; to overcome the described challenge, the transition must also take place at a social level, stimulating awareness and dialogue, as well as supporting innovation in social structures in order to promote more conscious and aware behaviours.

It is, moreover, fundamental to enhance knowledge related to what is consumed (in particular food products and related processes) to favour the improvement of people's health and lifestyle, thus, stimulating a demand that pushes companies towards sustainable innovation. This process of transition in the economy and society, in order to truly benefit from it, requires a systemic approach according to which citizens must become the real protagonists of the social transformation that the bioeconomy can produce [9,10]. Social dialogue and an understanding of the challenges and opportunities related to the bioeconomy both play a decisive role in the level of demand for new products and services, and in the innovations and technological developments associated with them. Activities such as public procurement should be placed in the context of participatory processes, so as to foster involvement, understanding and the potential for replication. Consequently, the bioeconomy also represents a challenging playground for reconnecting with the environment, economy and society, generating economic value together with new social values and a new cultural approach [22–24].

This takes renewed skills in building consensus for both the public and private sectors, and the opening of a social dialogue.

The challenge at stake requires the following:


Starting from the above-described issues, the present contribution aims at deepening the analysis of the participatory process that led to the involvement, in a context such as the south of Italy, of various actors in sharing good practices in line with the principles of the bioeconomy; the final objective, through the same process that is detailed in the following paragraphs, consists of elaborating a proposal for a participatory regional law for the bioeconomy in the Apulia region.

#### **2. Materials and Methods**

#### *2.1. Preliminary Considerations and Scenario Analysis: The "MaBiP" Project*

As part of the public notice for the selection of participatory processes to be admitted to provide regional support within the annual program of participation of the Puglia region, pursuant to LR N.28/2017—Law on Participation-AD n.28 of 21.11.2018 [20]—the University Centre of Excellence for Sustainability of the University of Bari Aldo Moro, in partnership with the University Centre of Excellence for Innovation and Creativity and Confindustria Puglia presented the "Manifesto for the Bioeconomy in Puglia (MaBiP)" proposal [21,25], the winning result with resolution no. 238 of 16 December 2019 of the head of the special institutional communication structure. The MaBiP project was conceived as a continuation of the subscription on 20 March 2019 of the Manifesto for the Bioeconomy in Puglia by the presidency of the Puglia region, research bodies of the territory (including the University of Bari) and Confindustria, thus, involving all business world, a partnership extended to all stakeholders interested in what the OECD [12], through "The Bioeconomy to 2030: designing a policy agenda", defines a true industrial revolution capable of innovating mature sectors, such as raw materials, waste and energy, ensuring long-term environmental, economic and social sustainability within the economic system. As to the analysis conducted up to this point, it is fundamental, in order to increase

awareness of the importance to promote the definition of a new economic model based on the principles of the bioeconomy, especially in industrial areas that have a strong impact on the territory, to favour the promotion, transition, creation and adoption of bioeconomy models, and, therefore, the circular economy. All regional stakeholders need to be involved at various levels in order to: facilitate connection and dialogue between stakeholders belonging to different value chains; promote and disseminate the principles of the bioeconomy at all levels; frame the regional context in the field of bioeconomy for subsequent mapping; draw up a roadmap for the strategic development of the bioeconomy; promote the drafting of a regional law proposal on the bioeconomy [26].

#### *2.2. Phases of the Process and Activities Carried Out*

The entire participation process consisted of four main steps and took a total of six months, from June to December 2020. The activities of the participatory process were carried out in a mixed way: in presence and remotely. Despite the obvious difficulties in carrying out most of the activities foreseen by the project in person, due to the concomitant pandemic caused by the SARS-CoV-2 virus [27], the technological and multimedia support and the various video-calling applications managed to ensure that all the activities foreseen from the project could be realized. The expected methodology for reaching the objectives was to achieve learning content, the effectiveness of the interventions with an integrated assessment system and the active and participatory assessment of learning. The laboratories were carried out with a small group mode with support from expert facilitators.

The working method used was design thinking (DT). The DT approach is characterized by tools and methodologies that support the generation of ideas, such as the "How Might We", in which prototyping plays a very important role. The method is not limited to a mere definition of the steps aimed at conceiving an idea, a solution, but also allows for the work team to reach its realization by drafting a prototype (Table 1).


**Table 1.** Design thinking.

#### *2.3. The Hackathon*

The "Circular Economy Action" [28] Hackathon, a "rally call" to map the best practices of the bioeconomy in Apulia, has represented a positive example of an effective methodology. It aimed at searching through different actions resulting from start-up or company initiatives, from associations or individual citizens, with the objective of narrating the practices capable of generating experiences of new production and consumption models. The process envisaged the following phases: a launch of call; registration on the platform; evaluation; identification of models and mapping of best practices; drafting and processing of documents.

Private and public actors were not mere spectators of the process but, indeed, protagonists within the entire project through moments of discussion, sharing of ideas and good practices already present in the region, with a particular view of innovation and highlighting the essential dimensions of circularity. The training activity, developed in a modular way for a total of 72 h, had the purpose of providing participants with in-depth knowledge related to the bioeconomy with the ultimate goal of activating specialized offices of Confindustria dedicated to the bioeconomy. The awarded operators were granted a free participation in the training course in management systems for sustainable development in the communities, a specialized module of the ISO 37101:2019 standard [29]. Thirty-four organizations participated in the "Circular Economy Action" [28] Hackathon award ceremony; despite the restrictions imposed by the COVID-19 pandemic situation [27], over three hundred people could participate and fruitfully share the experience.

#### *2.4. Participating Laboratories*

The workshops (4), led by expert facilitators, were delivered online through webinars; approximately two hundred people actively took part in them. In the course of the four participatory workshops, four themes considered as fundamental were addressed:

	- 1. Opening plenary, during which the organizers presented the methodology to conduct each workshop;
	- 2. Working groups divided by categories around the target themes in four virtual rooms, one for each of the themes in which the bioeconomy in Apulia had declined;
	- 3. Output: in this phase, each working group was asked to draw up a report embedding the main results that emerged;
	- 4. Closing plenary, during which each of the four working groups gave feedback on what was discussed and defined within the same working group.

The detailed reports for each laboratory were uploaded to the Puglia Partecipa platform.

#### **3. Results**

#### *3.1. Results of the Participating Laboratories*

The participants in the described workshops totalled 202; out of these, 52% were female and had an average age of forty-six. As shown in Figure 1, more than 50% of the participants were between thirty-six and fifty-five years old. Rather marginal was the presence of young people under the age of twenty-five (only 1.2%). However, the youth segment of the Apulian population was still represented, taking into account that almost 18% of the participants were under the age of thirty-five.

Although the participants born in the province of Bari constituted 44% of the total participants, the data collected showed a representativeness of all the Apulian provinces (Figure 2).

The educational level of participants in the workshops was particularly high (Figure 3), with 86% having at least a bachelor's degree; it is worth noting the data related to those who declared to have the title of PhD (22%). Only 14% of participants declared that they held a high school diploma.

**Figure 1.** Age of participants.

**Figure 2.** Province of birth.

Almost 36% of those enrolled in the participatory process took part in all four workshops included in the course. Approximately one point higher was the percentage of those who enrolled in a single laboratory. In total, 17.8% of the participants enrolled in two laboratories, and 9.5% in three laboratories (Figure 4).

Regarding the preference for the themes of each workshop (Figure 5), the recorded data showed that the percentage of those who enrolled in the workshop "Circularity and sustainable development" was slightly higher (29%). However, there was no particularly high percentage difference between this last topic and that of the other laboratories, namely, "Circularity, food, health and lifestyles", "Circularity, waste and climate change" (both at 24%) and "Circularity and new business models" (23%).

**Figure 4.** Number of laboratories.

Participants in the workshops reflected a clear expression of the great variety of organizational structures present in the Apulia region. In addition to the 33% composed of citizens involved in the process, the rest was represented by the following: almost 24% came from the business world, 13.2% represented the world of associations and 10.7% belonged to public research bodies (in particular the ENEA [17] and CNR). Furthermore, albeit in a more limited percentage, the presence of cooperatives with a percentage of 5.9% and public bodies, at 2.4% (representing the Environment Council of the Municipality of Bari) was noted. On the other hand, 1.2% belonged to voluntary organizations.

#### *3.2. Results of the Hackathon*

As above-described, after the Hackathon, the award ceremony was attended by 34 organizations from the region, distributed at a prevalence of those based in Bari or the cities and towns of the same province (53%), followed in percentage by the organizations located in Taranto (17%) and Lecce (16%). Less than 10 was the percentage of the organizations coming from Foggia (9%) and from Brindisi and BAT (3% in both cases) (Figure 6).

The legal form of the organizations that took part in the Hackathon also varied (Figure 7). Companies with limited liability were obviously the most common legal forms among the participants, with a percentage that stood at 41%. Percentages greater than or equal to 15% were reported for cooperative enterprises (17%) or for associations (15%). Within the record "Other", including 18% of participants, social promotion associations, general partnerships and sole proprietorships in less significant percentages were included. In total, 9% of Hackathon participants declared they represented a natural person.

The data collected related to the sectors in which the organizations operated showed the great vivacity of the Apulia region in the field of the bioeconomy. The most represented sector was that of "Recovery, reuse and recycling", with a percentage of participating organizations equal to 32%. This was followed by the sectors of "Culture, Education and Information", with a percentage of organizations equal to 23%, that of "Technologies and solutions for the environment and the territory", with a percentage of 15%, and that of companies in the "Agrifood sector", with a percentage of 12%. Less than 10% were organizations belonging to sectors such as "Fashion and design" and "Food and fight against food waste", both at 6%, and "Sustainable mobility" and "Research and innovation", with a percentage of 3%.

**Figure 7.** Legal forms of participants.

#### *3.3. Outcomes of the Participatory Process*

With regard to the outcomes of the participatory process, it emerged that during the participated workshops, each of the participants in the different working groups, divided into the cited four thematic areas, highlighted the requests/needs that the regional law on bioeconomy should possess, as summarized in Table 2.

The "Circularity, Waste and Climate Change" group carried out a reflection on how it would be possible to overcome the culture of waste, highlighting the need to define a new economic model capable of combining both the health of the environment and that of citizens, to focus on renewable energy and on the circularity of production, especially in the agrifood sector, one of the strengths of the Apulian economic system.

The "Circularity, Food, Health and Lifestyles" group sought to reflect on the promotion of a culture capable of generating new lifestyles aimed at improving the health and wellbeing of citizens, as well as through the enhancement of small production chains.

The "Circularity and New Business Models" group reflected on the need to encourage the transition to a new model of production and sustainable management of businesses, enhancing their role in reaching an effective growth of the territory.

The "Circularity and Sustainable Development of the Territory" group wanted to reflect on the need to promote a widespread and shared awareness of sustainable development, highlighting the complexity of the issue and the need to address it in a multidimensional and multidisciplinary way.

The presentation of the results of the project with the delivery of the participatory proposal document, embedding the law proposal, which took place on 27 November 2020 [11], during the final workshop. A proposal for a participatory regional law on the bioeconomy that was presented during the final meeting was the result of a development vision that should permeate the regional political strategy in order to fully achieve all the described objectives.

#### **Table 2.** Results of participating laboratories.


In order to achieve a circular and sustainable bioeconomy, it is vital that each political and strategic structure absorbs its principles and declines them in its own activities. The joint commitment of politics and citizenship prompted to elaborate, as part of the "Manifesto for the Bioeconomy" project in Apulia (MaBiP) [21], the following recommendations to the presidency of the Puglia region:

• The creation of a regional observatory on the bioeconomy under the guidance of the presidency of the Puglia region, through the participation office, with the objective to take care of relations and dialogue with the various departments and sectors involved in bioeconomy processes;


Starting from the principles of evidence-based policy and participation, the proposed law aims at defining the regulatory principles for the establishment of a place of synergy and institutional capacity capable of facilitating the sustainable development of Apulia, structuring the collaboration between stakeholders. The participatory process produced the draft text entitled "Participatory Proposal Document", containing the proposal for a participatory regional law on the bioeconomy.

#### **4. Conclusions**

Through the described participatory process, it was possible to initiate a path of shared reflection on the double economy–environment system, with related intersections and implications. Economic systems always require positive growth rates and shun both stabilization and immobility; the environment, instead, requires balance and stability. Since there was no spontaneous convergence between the needs of the two systems, the real issue at stake was which of the two should give way to the other, whereas economy and nature should recognize the need for common subsistence and the necessary balance between themselves. A sound answer must be sought in the different degrees of modifiability in order to reach the objective to create an equilibrium in which both experience life and good health. The economy, as a human product, is, by its nature, modifiable through cultural, social, technological and design innovations, including possible changes in lifestyles to such an extent that it is possible to rely on an elasticity factor that is not only economic– technological, but also cultural–behavioural.

As to the case of the environment, it is worth noting that it is different, as natural balances have their own rules (including limits in the carrying capacity of each system) that cannot be modified or neglected by human activities. The natural equilibrium can "endure" up to a certain point, and the permitted threshold level cannot be shifted. There is no elasticity in natural balances with respect to human actions. This implies having to put aside prejudices, interpretations and absolute values, and devote time and energy to the critical and positive rediscovery of the distinctive characteristics that animate the two systems. For these reasons, recognizing the need and the potential that participation can have in the dynamics of sustainability, also in light of the contents of the United Nations 2030 Agenda (in particular Goals 4, 16 and 17) [11], the described process aimed at being innovative and multidisciplinary in order to promote the definition and enhancement of the economic and cultural model of the bioeconomy that was launched.

The participatory process retraced a creative path and a local, collective and inclusive reflection in the different contexts that experienced the same reflection. The "map" created was at the same time a participatory census, a business plan, a self-portrait and a collective biography. As a consequence, a participatory, innovative, inclusive and multidisciplinary methodological process was launched, designed to build the participation path around the four previously analysed themes.

This approach made it possible to favour the identification and sharing of development policies at a territorial level and disseminate success stories that constitute a fundamental example of how to activate bioeconomy processes, starting from existing good practices and outlining new horizons and projects that could contribute to the sustainable development of both the territory of belonging and of the entire regional area, respecting the vocations and specificities of the territories themselves.

The participated events and workshops involved companies, organizations, institutions and representative associations of all the six Apulian provinces, starting from the analysis of the different elements that contributed to the cited process.

The proposed participatory process promoted throughout the Apulian territory [26] the engagement of the main stakeholders and privileged observers in a path with particularly innovative effects; the result of the identification and sharing of new local production and consumption models strongly oriented towards sustainability in order to promote a business model that puts different and complementary sectors of the economy into a mutual dialogue, also in the context of urban policies. Not surprisingly, there was a growing consensus on the idea that to implement sustainable development paths, learning through experience and community-centred approaches is necessary.

By focusing on participation, it was possible to encourage the promotion and identification of effective and replicable bioeconomy models in the entrepreneurial and cooperative institutions that took part in the project, and in view of the setting of a regional strategic development model linked to the bioeconomy.

From an environmental point of view, the bioeconomy contributes both opportunities and challenges. Opportunities are connected to the gradual transition in the context of production processes, from the use of nonrenewable resources to renewable ones, so as to limit the environmental pressure on ecosystems and enhance their value for the purpose of their conservation, not merely considering their intrinsic value or the connection with ecosystem services that are "natural" solutions to combat climate change and hydrogeological risk, but also as a source of relevant services for the whole economy. Furthermore, the bioeconomy implies the possibility of reducing dependence on resources scarcely available in Italy. The strengthening of production activities deriving from renewable sources holds the potential to facilitate waste management, as these sources can be more easily assimilated.

However, the bioeconomy can also amplify a series of challenges as well as highlight the numerous examples of unsustainable management for the environment and human health, particularly in the food and fish industries. Furthermore, it is evident that it is often not necessary to increase the production of raw materials, but rather to increase their added value to society, improving the quality of products (e.g., in agriculture) and processes in response to the requirements of Objective 12 of the 2030 Agenda [11].

As a consequence, it is vital to proceed towards a sustainable economic system that assumes economic growth limited conditionally to the sustainability of material resources and leading to the valorisation of the new economic and cultural model of the bioeconomy in Apulia [26].

This "new" economy, despite being an interconnected whole on a conceptual level, can be divided into two parts. The first, measurable in material and energetic terms, is necessarily limited in its expansion within the natural carrying capacity, which is constant. The second component, on the other hand, being immaterial, keeps its virtually "unlimited" peculiarity. It is based on information in the availability of services in the required times and methods, as well as in the quality, in particular of relationships, both on a global level and on a territorial one.

It necessarily requires institutional and regulatory interventions with respect to the current market. Accelerating the transition towards the bioeconomy is fundamental to increase not only the competitiveness of regional industry, research and training to strengthen the position Apulia deserves in the national and international context, but above all to safeguard the environmental and sociocultural heritage of the territories. Through the dynamics of debate and comparison, the participatory process aimed at simplifying relations between regional actors on the subject of the bioeconomy, favouring transversal connections and allowing for the dissemination and use of good practices and ready-to-use technologies on the territory in order to reach a sound exploitation of the resources that the Apulian context offers.

The described participatory process enabled us to obtain a strategic vision on how to intervene in the main macroareas of the bioeconomy in Apulia (the environment, economic development and agrifood chain) with an approach devoted to effective sustainability and based on a circular logic, one that does not subtract resources from the territory, but maximizes the opportunities for reuse through technological innovation.

The fundamental objective is to generate a change in the mindset and generate a value of all the actors involved, from companies to institutions to individual citizens to such an extent that it is possible, through the participatory process, to implement a shared strategy of the development of the territory not connected to profit but, instead, to the protection of the Apulian context from an environmental and social point of view. A real industrial revolution that, from below, contribution by contribution, had as its objective the drafting of a law on the bioeconomy through a participatory process [13].

As a result, following the participatory process on 20th May at the headquarters of the Puglia regional council, the draft law "Provisions on the Bioeconomy" was presented; a proposal, originating from the described process carried out by the Centres of Excellence for Sustainability of the University of Bari Aldo Moro, in collaboration with Confindustria Puglia, had the aim of recognizing, for the Apulia region, the importance of fostering a territorial development inspired by the principles of the bioeconomy, in line with the objectives of the 2030 Agenda and the NRRP (National Recovery and Resilience Plan) [11].

Europe and Italy, recognizing their key roles, have proceeded to implement a strategy for the bioeconomy. However, being the achievement of global challenges necessarily based on the active involvement of territories and strategic levers for a sustainable revolution, it is fundamental to commit to create an alliance between institutions, research and the industry. A partnership extended to all stakeholders interested in what the OECD, "The Bioeconomy to 2030: designing a policy agenda" [11], defines a true industrial revolution capable of innovating mature sectors such as raw materials, waste, energy ensuring long-term environmental, economic and social sustainability within the economic system.

A participatory process linked to the bioeconomy [30–32], in view of its enormous innovative potential, can be a response to most of the regional and global challenges to be faced in the coming years, from environmental remediation to the problems of climate change, to the invention of new medicines, to the need to feed a world in which food needs are predicted increase by 70% between now and 2050, reconciling the economy, the environment and society.

The "transversal" nature of the bioeconomy offers a unique opportunity to face, in a comprehensive and systemic way, the mentioned cogent social challenges [33,34], as envisaged by the EU The communication "Innovation for sustainable growth: a Bioeconomy for Europe" [35,36].

In the described scenario, it is of particular interest to carry on a reflection on how bioeconomy intertwines with EU policies related to actual cogent challenges.

Among them, it is important to mention climate change; as a matter of fact, the council and the European Parliament set specific goals as to the climate for the near future. In line with these goals, the fit for 55% relates to the objective of cutting down net greenhouse gas emissions by at least 55% by 2030. As a consequence, the fit for the 55% package contains a whole set of legislative proposals to ensure that EU legislation are in line with the cited 2030 reduction goal.

As the described package deals with a comprehensive series of sectors, from agriculture to industry and the energy sector, in the framework of the present contribution, it is of particular relevance, as it addresses all aspects at the core of bioeconomy and, moreover, represents a crucial witness of how participation (at the core of this article) plays a vital role in reaching a sound and effective legislation at different levels, including the regional one [37].

Furthermore, the actual global scenario has been deeply affected by the Russia–Ukraine conflict; consequent challenges relate, as easily understood, to the supplies of gas being weaponised from Russia. The manipulation of energy markets has led to skyrocketing energy prices in the EU. In addition, unpredictable events and connected risks of the discontinuation or even the interruption of supply holds the potential to create additional pressure on energy markets.

The alternative option proposed by the renewable energy technology field has been strongly supported by means of a series of recent policies in other regions, leading to a weak outlook on the competitiveness of the European renewable energy technology industries and value chains.

In the described context, it is vital to address the exposure of consumers and businesses within the EU to increasing and volatile energy prices; this objective could be achieved by means of fostering supplies from renewable sources, thus, as well, increasing the security of the supply itself.

As a matter of fact, regulation 2022/2577 aims at accelerating the deployment of renewable energy sources through the adoption of ad hoc urgent measures mostly effective in the short term. The time frame is connected to the importance of allowing member states to adopt these same measures rapidly and to ease the permit-granting process applicable to renewable energy projects without requiring burdensome changes to their national procedures and legal systems, and ensuring a positive acceleration of the deployment of renewables in the short term. This reflects the important role that renewable energy can play in the decarbonisation of the European Union's energy system, by offering immediate solutions to replace fossil-fuel-based energy and by addressing the aggravated situation in the market [38].

The issue of sustainability is, of course, a huge challenge; it is difficult to promote sustainability, as it implies a broad vision, a strong determination and a great balance. These three characteristics of vision, determination and balance are necessary, and the open challenges appear epochal and require deeper, faster and more ambitious responses and integrated solutions, to initiate the social and economic transformation necessary to achieve the Sustainable Development Goals (SDGs) of the 2030 Agenda [11]. The present contribution, through the described process, carried out a comprehensive analysis of the participatory process that led to the development of a proposal for a participatory regional law for the bioeconomy in the Apulia region through the involvement, in a context such as the south of Italy, of various actors in sharing reflections and good practices. The outlined path represents an important case study both in the local described context and with a broader perspective.

**Author Contributions:** Conceptualization, E.T.; methodology, E.T. and S.G.; validation, L.P. and G.R.; formal analysis, E.T.; investigation, L.P.; resources, A.T.; data curation, G.d.G.; writing—original draft preparation, A.T.; writing—review and editing, S.G.; supervision, G.R. and E.T.; project administration, G.d.G.; funding acquisition, E.T. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the Apulia region—AVVISO DD 28/2018, BURP n.1250/2018.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** We acknowledge the financial support of Apulia region—AVVISO DD 28/2018, BURP n.1250/2018.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**


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