Topic Editors

Department of Chemistry and Industrial Chemistry, University of Pisa, Via Giuseppe Moruzzi 13, 56124 Pisa, Italy
E.T.S. Ingenieria Industrial, University of Castilla-La Mancha, 13071 Ciudad Real, Spain

Biomass Transformation: Sustainable Development

Abstract submission deadline
31 January 2025
Manuscript submission deadline
31 March 2025
Viewed by
19112

Topic Information

Dear Colleagues,

The exploitation of biomass resources represents an urgent need to produce energy, fuels, and chemical products, to replace the traditional ones, still limitedly obtained from fossil sources. Different valorization strategies are available, grouped as “thermochemical treatments”, including the wet-based ones (e.g., carried out in water and/or in organic solvents, aimed by chemical and/or biochemical catalysis), and the dry-based thermal ones (e.g., pyrolysis and gasification). The available literature on these processes is notoriously extensive, but continuous research is still necessary to improve their efficiency and promote their full development on the industrial scale, really developing the criteria of environmental, economic, and social sustainability. Some questions are not yet answered with certainty and require further investigation. For example, is it possible to develop robust processes, efficiently exploiting waste biomasses, at the same time respecting the environment? Moreover, some hidden technological bottlenecks are still unsolved (e.g., scaling-up of the reactors and work-up units): How is it possible to overcome them? Is it possible to improve the synthesis of catalysts that are active and selective towards the target compound(s), meeting the criteria of low-cost and environmental protection? The proposed topic is wide and challenging, ranging from the development of catalysts to the process intensification, including integrated evaluations via Life Cycle Assessment (LCA). Water is the ideal candidate to meet the sustainability criteria, but also new green bio-based solvents could be attractive to perform biomass transformations (e.g., hydrolysis/dehydration, hydrogenation, oxidation, esterification, ecc.), e.g., working under monophasic or biphasic conditions. To include all these aspects, direct conversion strategies of biomasses will be appreciated, as well as the further upgrade of biomass-derived platform chemicals into more added-value bio-products, even considering the dry-based thermal processes (such as the conversion of biomass to liquid (BTL) transportation fuels via Fischer-Tropsch reaction). Authors are welcome to submit their valuable contributions, demonstrating concrete progress over the current state of the art.

Dr. Domenico Licursi
Prof. Dr. Juan Hernández Adrover
Topic Editors

Keywords

  • hydroprocessing
  • pyrolysis
  • gasification
  • combustion
  • torrefaction
  • esterification
  • hydrogenation
  • oxidation
  • fermentation
  • life cycle assessment

Participating Journals

Journal Name Impact Factor CiteScore Launched Year First Decision (median) APC
Catalysts
catalysts
3.8 6.8 2011 12.9 Days CHF 2700 Submit
Energies
energies
3.0 6.2 2008 17.5 Days CHF 2600 Submit
Molecules
molecules
4.2 7.4 1996 15.1 Days CHF 2700 Submit
Sustainability
sustainability
3.3 6.8 2009 20 Days CHF 2400 Submit
Sustainable Chemistry
suschem
- - 2020 31.2 Days CHF 1000 Submit

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Published Papers (16 papers)

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19 pages, 3315 KiB  
Review
Future Directions of Sustainable Resource Utilization of Residual Sewage Sludge: A Review
by Weicheng Zheng, Yuchao Shao, Shulin Qin and Zhongquan Wang
Sustainability 2024, 16(16), 6710; https://doi.org/10.3390/su16166710 - 6 Aug 2024
Viewed by 471
Abstract
With the simultaneous increase in wastewater generation and wastewater treatment rates in China, the annual production of residual sewage sludge (RSS) has been steadily rising, exceeding 70 million tons with an 80% moisture content. The sustainable resource utilization of RSS will be the [...] Read more.
With the simultaneous increase in wastewater generation and wastewater treatment rates in China, the annual production of residual sewage sludge (RSS) has been steadily rising, exceeding 70 million tons with an 80% moisture content. The sustainable resource utilization of RSS will be the predominant disposal method instead of sanitary landfilling in China. This review aimed to systematically analyze the major sustainable resource utilization technologies for RSS. Firstly, the basic characteristics of RSS in China were analyzed. A comparative analysis was conducted to assess the advantages, disadvantages, and applicability of three primary sustainable resource utilization technologies for RSS: building materials, energy utilization, and phosphorus recovery, aiming to provide clear insights for the development of future strategies. The research findings revealed that no single method can economically and environmentally address all challenges in the utilization of RSS resources. It is necessary to adopt appropriate resource utilization technologies according to the characteristics of RSS from wastewater treatment, achieving integration of pollution control and resource utilization. This review can provide scientific guidance for future sustainable utilization of RSS resources. Full article
(This article belongs to the Topic Biomass Transformation: Sustainable Development)
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30 pages, 18405 KiB  
Article
Co-Pyrolysis of Mushroom Residue Blended with Pine Sawdust/Wheat Straw for Sustainable Utilization of Biomass Wastes: Thermal Characteristics, Kinetic/Thermodynamic Analysis, and Structure Evolution of Co-Pyrolytic Char
by Haiyu Meng, Heng Yang, Zhiqiang Wu, Danting Li, Zhe Wang, Dongqi Wang, Hui Wang, Huaien Li and Jiake Li
Sustainability 2024, 16(15), 6677; https://doi.org/10.3390/su16156677 - 4 Aug 2024
Viewed by 568
Abstract
Co-pyrolysis technology is considered to be one of the most promising methods for the sustainable utilization of biomass wastes, as it can realize waste reduction and convert wastes into high-value-added products with little impact on the environment. The evaluation of thermal characteristics and [...] Read more.
Co-pyrolysis technology is considered to be one of the most promising methods for the sustainable utilization of biomass wastes, as it can realize waste reduction and convert wastes into high-value-added products with little impact on the environment. The evaluation of thermal characteristics and product properties is necessary for understanding this technique. In this paper, thermal characteristics and kinetic and thermodynamic analysis during the co-pyrolysis of mushroom residue (MR) with pine sawdust (PS) or wheat straw (WS) were investigated in a TGA. The carbon structure and surface textures of co-pyrolytic char were explored using Raman spectroscopy and a scanning electron microscope. As the PS or WS mass ratio increased, the devolatilization index increased obviously, indicating that volatile release was promoted and concentrated. Weak interactions were observed between 250 and 400 °C during the co-pyrolysis process, which primarily affected the mass transfer, resulting in a change in the thermal decomposition temperatures and rates. The interactions had no prominent influence on the volatiles’ yields. The non-additive performance of average activation energies for the blends was observed due to the interactions, and the lowest average activation energy was obtained when the PS or WS mass ratio was 50%. The lower average pre-exponential factor of the blends indicated the reduced complicacy of the pyrolysis reaction. The relatively small deviation between the activation energy and enthalpy change (4.94–5.18 kJ·mol−1) signified the energy sensitivity of product formation. PS promoted the formation of small aromatic rings (<6 fused rings) in co-pyrolytic chars, whereas WS favored the production of larger rings (≥6 fused rings). The surface textures of the co-pyrolytic chars became porous, and the greater fractal dimensions of the surface morphology for the co-pyrolytic chars indicated that the char surface became irregular and rough. Full article
(This article belongs to the Topic Biomass Transformation: Sustainable Development)
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19 pages, 8889 KiB  
Article
Valorization of Agave angustifolia Bagasse Biomass from the Bacanora Industry in Sonora, Mexico as a Biochar Material: Preparation, Characterization, and Potential Application in Ibuprofen Removal
by Hylse Aurora Ruiz-Velducea, María de Jesús Moreno-Vásquez, Héctor Guzmán, Javier Esquer, Francisco Rodríguez-Félix, Abril Zoraida Graciano-Verdugo, Irela Santos-Sauceda, Idania Emedith Quintero-Reyes, Carlos Gregorio Barreras-Urbina, Claudia Vásquez-López, Silvia Elena Burruel-Ibarra, Karla Hazel Ozuna-Valencia and José Agustín Tapia-Hernández
Sustain. Chem. 2024, 5(3), 196-214; https://doi.org/10.3390/suschem5030013 - 9 Jul 2024
Viewed by 642
Abstract
The aim of this research was to separate the over-the-counter nonsteroidal anti-inflammatory drug (NSAID), ibuprofen, from an aqueous solution using the adsorption method, as this NSAID is one of the most globally consumed. An adsorbent was crafted from the Agave angustifolia bagasse, a [...] Read more.
The aim of this research was to separate the over-the-counter nonsteroidal anti-inflammatory drug (NSAID), ibuprofen, from an aqueous solution using the adsorption method, as this NSAID is one of the most globally consumed. An adsorbent was crafted from the Agave angustifolia bagasse, a byproduct of the bacanora industry (a representative alcoholic beverage of the state of Sonora, in northwestern Mexico). Three bioadsorbents (BCT1, BCT2, and BCT3) were produced via pyrolysis at a temperature of 550 °C, with slight variations in each process for every bioadsorbent. The bioadsorbents achieved material yields of 25.65%, 31.20%, and 38.28% on dry basis respectively. Characterization of the bagasse and adsorbents involved scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The biomass morphology exhibited a cracked surface with holes induced via the bacanora production process, while the surface of the bioadsorbents before ibuprofen adsorption was highly porous, with a substantial surface area. After adsorption, the surface of the bioadsorbents was transformed into a smoother grayish layer. The macromolecules of cellulose, hemicellulose, and lignin were present in the biomass. According to functional groups, cellulose and hemicellulose degraded to form the resulting bioadsorbents, although traces of lignin persisted after the pyrolysis process was applied to the biomass. In an adsorption study, BCT1 and BCT2 bioadsorbents successfully removed 100% of ibuprofen from aqueous solutions with an initial concentration of 62.6 mg/L. In conclusion, the biocarbon derived from Agave angustifolia bagasse exhibited significant potential for removing ibuprofen via adsorption from aqueous solutions. Full article
(This article belongs to the Topic Biomass Transformation: Sustainable Development)
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31 pages, 3233 KiB  
Systematic Review
Biochars Derived from Olive Mill Byproducts: Typology, Characterization, and Eco-Efficient Application in Agriculture—A Systematic Review
by José Ferreira Lustosa Filho, Ana Paula Ferreira da Silva, Silvana Teixeira Costa, Hélder Teixeira Gomes, Tomás de Figueiredo and Zulimar Hernández
Sustainability 2024, 16(12), 5004; https://doi.org/10.3390/su16125004 - 12 Jun 2024
Viewed by 813
Abstract
In the context of climate change and the circular economy, biochar agricultural and environmental applications have attracted a good deal of attention. Biochar has unique characteristics like surface area, porosity, water-holding capacity, pH, surface charge, and nutrients. This study reviews the biochar production [...] Read more.
In the context of climate change and the circular economy, biochar agricultural and environmental applications have attracted a good deal of attention. Biochar has unique characteristics like surface area, porosity, water-holding capacity, pH, surface charge, and nutrients. This study reviews the biochar production from olive pomace (OP) and olive stone (OS) byproducts, its chemical and physical characterization, and its environmental application. The current review highlights the conditions for biochar production, the effects of pyrolysis temperature, and feedstock type on the physicochemical properties of biochar. High pyrolysis temperature (>500 °C) promotes a high specific surface area, high porosity (especially for OS biochars), and pH as well as the content of ash and fixed carbon, but generates low cation exchange capacity (CEC) and electrical conductivity (EC) and high values of O/C and H/C ratio. OP biochar also presents a high C amount, and ash content, i.e., rich in nutrients and high alkalizing capacity. OP biochar serves as an important source of plant nutrients, especially potassium. After adding both types of biochar, aggregate stability and the amount of water held in soil increase, and bulk density and bioavailability of trace elements decrease. Thus, biochar from olive mill wastes can be a potential plant nutrient reservoir, a good amendment to improve soil properties and long-term carbon sequestration. Results presented in this review can be used to build designer biochars from olive mill wastes to help solve environmental issues (water purification and pollutant remediation) and are suitable for improving soil physical chemistry characteristics and crop growth. Full article
(This article belongs to the Topic Biomass Transformation: Sustainable Development)
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19 pages, 14076 KiB  
Article
Sustainable Production of Chitin Nanowhiskers from Crustacean Biomass Using Cost-Effective Ionic Liquids: Strategies to Avoid Byproduct Formation
by Alexander S. Shkuratov, Reshma Panackal Shibu, Obste Therasme, Paula Berton and Julia L. Shamshina
Sustain. Chem. 2024, 5(2), 130-148; https://doi.org/10.3390/suschem5020010 - 3 Jun 2024
Cited by 1 | Viewed by 805
Abstract
Nanochitin, especially in the form of chitin nanowhiskers (ChNWs), represents a significant advance in biopolymer technology due to its high specific surface area, superior tensile strength, and excellent thermal stability. Derived from crustacean waste, which contains 15–40% of chitin, these materials provide a [...] Read more.
Nanochitin, especially in the form of chitin nanowhiskers (ChNWs), represents a significant advance in biopolymer technology due to its high specific surface area, superior tensile strength, and excellent thermal stability. Derived from crustacean waste, which contains 15–40% of chitin, these materials provide a sustainable option that diverts waste from landfills and contributes to environmental conservation. Traditional methods of isolating nanochitin are energy-intensive and generate substantial waste. This study introduces a more sustainable method using inexpensive ionic liquids (ILs) such as [Hmim][HSO4] and [HN222][HSO4], which bypass the costly and destructive steps of traditional procedures. This study also identified the byproduct in IL-mediated chitin hydrolysis reaction as calcium sulfate dihydrate and presented a solution to circumvent the byproduct formation. The effectiveness of the [HN222][HSO4] IL in producing ChNWs from both purified chitin and crustacean biomass was assessed, showing a high yield and maintaining the purity and structural integrity of chitin, thereby demonstrating a significant reduction in the environmental footprint of ChNW production. Full article
(This article belongs to the Topic Biomass Transformation: Sustainable Development)
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13 pages, 1668 KiB  
Article
Potential Use of Andean Tuber Waste for the Generation of Environmentally Sustainable Bioelectricity
by Segundo Rojas-Flores, Magaly De La Cruz-Noriega, Luis Cabanillas-Chirinos, Nélida Milly Otiniano, Nancy Soto-Deza, Nicole Terrones-Rodriguez and Mayra De La Cruz-Cerquin
Molecules 2024, 29(9), 1978; https://doi.org/10.3390/molecules29091978 - 25 Apr 2024
Viewed by 575
Abstract
The growing demand for agricultural products has increased exponentially, causing their waste to increase and become a problem for society. Searching for sustainable solutions for organic waste management is increasingly urgent. This research focuses on considering the waste of an Andean tuber, such [...] Read more.
The growing demand for agricultural products has increased exponentially, causing their waste to increase and become a problem for society. Searching for sustainable solutions for organic waste management is increasingly urgent. This research focuses on considering the waste of an Andean tuber, such as Olluco, as a fuel source for generating electricity and becoming a potential sustainable energy source for companies dedicated to this area. This research used Olluco waste as fuel in single-chamber microbial fuel cells using carbon and zinc electrodes. An electric current and electric potential of 6.4 ± 0.4 mA and 0.99 ± 0.09 V were generated, operating with an electrical conductivity of 142.3 ± 6.1 mS/cm and a pH of 7.1 ± 0.2. It was possible to obtain a 94% decrease in COD and an internal resistance of 24.9 ± 2.8 Ω. The power density found was 373.8 ± 28.8 mW/cm2 and the current density was 4.96 A/cm2. On day 14, the cells were connected in earnest, achieving a power of 2.92 V and generating enough current to light an LED light bulb, thus demonstrating the potential that Olluco waste has to be used as fuel in microbial fuel cells. Full article
(This article belongs to the Topic Biomass Transformation: Sustainable Development)
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25 pages, 2543 KiB  
Review
Coconut Waste: Discovering Sustainable Approaches to Advance a Circular Economy
by Fabrícia Vieira, Hortência E. P. Santana, Meirielly Jesus, Joana Santos, Preciosa Pires, Manuela Vaz-Velho, Daniel Pereira Silva and Denise Santos Ruzene
Sustainability 2024, 16(7), 3066; https://doi.org/10.3390/su16073066 - 7 Apr 2024
Cited by 1 | Viewed by 2659
Abstract
The coconut tree (Cocos nucifera) stands as a pivotal resource in tropical regions, playing a crucial role in both subsistence and economic activities across Asia, the Pacific Islands, and South America. While the harvesting of coconut fruit is essential for producing globally [...] Read more.
The coconut tree (Cocos nucifera) stands as a pivotal resource in tropical regions, playing a crucial role in both subsistence and economic activities across Asia, the Pacific Islands, and South America. While the harvesting of coconut fruit is essential for producing globally utilized edible products, such as coconut oil, by small owners and large producers around the world in the food, cosmetics, and pharmaceutical industries, concerns have arisen due to the substantial amount of agro-industrial residue generated in this process, posing environmental risks if they are not properly managed. Recognizing the environmental challenges, this paper emphasizes the transformative potential inherent in coconut waste, characterized by its lignocellulosic composition rich in lignin and multifunctional groups. By delving into the historical context of coconut economic exploration and its chemical composition, this review explores the diverse applications of coconut products, focusing on the utilization and processing of residues to generate sustainable products and byproducts. Ultimately, this comprehensive review underscores the significance of repurposing coconut waste, not only to mitigate the environmental impact but also as a valuable contributor to a circular economy, promoting the use of the lignocellulosic biomass in research and bolstering its role as a raw material in the chemical and energy sectors. Full article
(This article belongs to the Topic Biomass Transformation: Sustainable Development)
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27 pages, 8160 KiB  
Article
Liquid Hot Water (LHW) and Hydrothermal Carbonization (HTC) of Coffee Berry Waste: Kinetics, Catalysis, and Optimization for the Synthesis of Platform Chemicals
by Alejandra Sophia Lozano-Pérez and Carlos Alberto Guerrero-Fajardo
Sustainability 2024, 16(7), 2854; https://doi.org/10.3390/su16072854 - 29 Mar 2024
Cited by 1 | Viewed by 790
Abstract
Colombia is the world’s leading producer of mildly washed arabica coffee and produces 12.6 million bags of green coffee, but at the same time, 784,000 tons of waste biomass are dumped in open fields, of which only 5% is recovered or used. The [...] Read more.
Colombia is the world’s leading producer of mildly washed arabica coffee and produces 12.6 million bags of green coffee, but at the same time, 784,000 tons of waste biomass are dumped in open fields, of which only 5% is recovered or used. The objective of this project was to evaluate the production of platform chemicals from these coffee wastes for sustainable resource management. To achieve this, biomass characterization was carried out using proximate analysis, ultimate analysis, and structural analysis. Hydrothermal valorization was carried out at a temperature range of 120–180 °C (LHW) and 180–260 °C (HTC) for one hour. The platform chemicals obtained were quantified by HPLC-RI and monitored by pH and conductivity, and the solid fraction was characterized by monitoring the functional groups in IR spectroscopy and elemental analysis. Hydrolysis processes were obtained at 150 °C, production of platform chemicals at 180 °C, and maximum concentration at 180 °C-4 h; over 200 °C, degradation of the products in the liquid fraction starts to take place. Homogeneous basic and acid catalysts were used to improve the yields of the reaction. The kinetics of the hydrolysis of lignocellulosic structures to sugars were also analyzed and described, and reaction orders of 1 (LHW), 3 (HTC), and their respective reaction rate equations were reported. Full article
(This article belongs to the Topic Biomass Transformation: Sustainable Development)
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12 pages, 3209 KiB  
Article
Waste Lignocellulosic Biomass as a Source for Bioethanol Production
by Klemen Rola, Sven Gruber, Darko Goričanec and Danijela Urbancl
Sustain. Chem. 2024, 5(1), 1-12; https://doi.org/10.3390/suschem5010001 - 28 Feb 2024
Viewed by 856
Abstract
Synthetically produced biofuels play a critical role in the energy transition away from fossil fuels. Biofuels could effectively lower greenhouse gas (GHG) emissions and contribute to better air quality. One of these biofuels is bioethanol, which could act as a gasoline replacement. For [...] Read more.
Synthetically produced biofuels play a critical role in the energy transition away from fossil fuels. Biofuels could effectively lower greenhouse gas (GHG) emissions and contribute to better air quality. One of these biofuels is bioethanol, which could act as a gasoline replacement. For this purpose, a simulation of bioethanol production through lignocellulosic biomass fermentation, focused on distillation, was carried out in simulation software Aspen Plus. Since the possibility of absolute ethanol production through distillation is limited by the ethanol–water azeotrope, pressure swing distillation (PSD) was used to obtain fuel-grade ethanol (EtOH) with a fraction of 99.60 wt.%. The flowsheet was optimised with NQ analysis, which is a simple optimisation method for distillation columns. We found that the PSD has the potential to concentrate the EtOH to a desired value, while simultaneously removing other unwanted impurities whose presence is a consequence of pretreatment and fermentation processes. Full article
(This article belongs to the Topic Biomass Transformation: Sustainable Development)
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25 pages, 6961 KiB  
Article
Catalytic Degradation of Lignin over Sulfonyl-Chloride-Modified Lignin-Based Porous Carbon-Supported Metal Phthalocyanine: Effect of Catalyst Concentrations
by Fangli Du, Xuequan Xian, Peiduo Tang and Yanming Li
Molecules 2024, 29(2), 347; https://doi.org/10.3390/molecules29020347 - 10 Jan 2024
Viewed by 960
Abstract
A sulfonyl-chloride-modified lignin-based porous carbon-supported metal phthalocyanine catalyst was prepared and used to replace the traditional Fenton’s reagent for lignin degradation. The catalyst underwent a detailed characterization analysis in terms of functional group distributions, surface area, morphological structure, via FT-IR, XPS, BET, and [...] Read more.
A sulfonyl-chloride-modified lignin-based porous carbon-supported metal phthalocyanine catalyst was prepared and used to replace the traditional Fenton’s reagent for lignin degradation. The catalyst underwent a detailed characterization analysis in terms of functional group distributions, surface area, morphological structure, via FT-IR, XPS, BET, and SEM. The catalyst possessed a specific surface area of 638.98 m2/g and a pore volume of 0.291 cm3/g. The prepared catalyst was studied for its ability of oxidative degradation of lignin under different reaction conditions. By optimizing the reaction conditions, a maximum liquid product yield of 38.94% was obtained at 135 °C with 3.5 wt% of catalyst and 15 × 10−2 mol/L H2O2; at the same time, a maximum phenols selectivity of 32.58% was achieved. The compositions and properties of liquid products obtained from lignin degradation using different catalyst concentrations were studied comparatively via GC-MS, FT-IR, 1H-NMR, and EA. Furthermore, the structure changes of solid residues are also discussed. Full article
(This article belongs to the Topic Biomass Transformation: Sustainable Development)
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26 pages, 7463 KiB  
Article
Energy and Business Synergy: Leveraging Biogenic Resources from Agriculture, Waste, and Wastewater in German Rural Areas
by Moritz Pollack, Andrea Lück, Mario Wolf, Eckhard Kraft and Conrad Völker
Sustainability 2023, 15(24), 16573; https://doi.org/10.3390/su152416573 - 5 Dec 2023
Viewed by 1016
Abstract
The imperative to transform current energy provisions is widely acknowledged. However, scant attention has hitherto been directed toward rural municipalities and their innate resources, notably biogenic resources. In this paper, a methodological framework is developed to interconnect resources from waste, wastewater, and agricultural [...] Read more.
The imperative to transform current energy provisions is widely acknowledged. However, scant attention has hitherto been directed toward rural municipalities and their innate resources, notably biogenic resources. In this paper, a methodological framework is developed to interconnect resources from waste, wastewater, and agricultural domains for energy utilization. This entails cataloging existing resources, delineating their potential via quantitative assessments utilizing diverse technologies, and encapsulating them in a conceptual model. The formulated models underwent iterative evaluation with engagement from diverse stakeholders. Consequently, 3 main concepts, complemented by 72 sub-concepts, were delineated, all fostering positive contributions to climate protection and providing heat supply in the rural study area. The outcomes’ replicability is underscored by the study area’s generic structure and the employed methodology. Through these inquiries, a framework for the requisite energy transition, with a pronounced emphasis on the coupling of waste, wastewater, and agriculture sectors in rural environments, is robustly analyzed. Full article
(This article belongs to the Topic Biomass Transformation: Sustainable Development)
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27 pages, 4510 KiB  
Article
Comparison of the Techno-Economic and Environmental Assessment of Hydrodynamic Cavitation and Mechanical Stirring Reactors for the Production of Sustainable Hevea brasiliensis Ethyl Ester
by Olusegun David Samuel, Peter A. Aigba, Thien Khanh Tran, H. Fayaz, Carlo Pastore, Oguzhan Der, Ali Erçetin, Christopher C. Enweremadu and Ahmad Mustafa
Sustainability 2023, 15(23), 16287; https://doi.org/10.3390/su152316287 - 24 Nov 2023
Cited by 9 | Viewed by 1176
Abstract
Even though the hydrodynamic cavitation reactor (HCR) performs better than the mechanical stirring reactor (MSR) at producing biodiesel, and the ethylic process of biodiesel production is entirely bio-based and environmentally friendly, non-homogeneous ethanol with the triglyceride of underutilized oil, despite the many technical [...] Read more.
Even though the hydrodynamic cavitation reactor (HCR) performs better than the mechanical stirring reactor (MSR) at producing biodiesel, and the ethylic process of biodiesel production is entirely bio-based and environmentally friendly, non-homogeneous ethanol with the triglyceride of underutilized oil, despite the many technical advantages, has discouraged the biodiesel industry and stakeholders from producing ethylic biodiesel in HCRs. This study examines the generation of biodiesel from rubber seed oil (RSO) by comparing the ethyl-based HCR and MSR. Despite ethyl’s technical advantages and environmental friendliness, a lack of scalable protocols for various feedstocks hinders its global adoption. The research employs Aspen HYSYS simulations to investigate the ethanolysis process for RSO in both HCRs and MSRs. The HCR proves more productive, converting 99.01% of RSO compared to the MSR’s 94.85%. The HCR’s exergetic efficiency is 89.56% vs. the MSR’s 54.92%, with significantly lower energy usage. Removing catalytic and glycerin purification stages impacts both processes, with HC showing lower exergy destruction. Economic analysis reveals the HCR’s lower investment cost and higher net present value (USD 57.2 million) and return on investment (176%) compared to the MSR’s. The HCR also has a much smaller carbon footprint, emitting 7.2 t CO2 eq./year, while the MSR emits 172 t CO2 eq./year. This study provides database information for quickly scaling up the production of ethanolic biodiesel from non-edible and third-generation feedstocks in the HCR and MSR. Full article
(This article belongs to the Topic Biomass Transformation: Sustainable Development)
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21 pages, 2931 KiB  
Article
Solketal Production Using Eco-Friendly Reduced Graphene Oxide as the Catalyst
by Vinicius Rossa, Sancler da Costa Vasconcelos, Gisel Chenard Díaz, Josué de Almeida Resende, João Pedro Reys Mattos, Vinicius Gomes da Costa Madriaga, Fernanda Franco Massante, Yordanka Reyes Cruz, Juan Lucas Nachez, Yutao Xing, Eduardo Ariel Ponzio and Thiago de Melo Lima
Catalysts 2023, 13(11), 1427; https://doi.org/10.3390/catal13111427 - 10 Nov 2023
Cited by 1 | Viewed by 1245
Abstract
In this study, two materials based on reduced graphene oxide (rGOH or rGOE) were synthesized through the Hummers methodology and a more sustainable electrochemical method. These materials were extensively characterized and tested as catalysts in solketal production. Both rGOH [...] Read more.
In this study, two materials based on reduced graphene oxide (rGOH or rGOE) were synthesized through the Hummers methodology and a more sustainable electrochemical method. These materials were extensively characterized and tested as catalysts in solketal production. Both rGOH and rGOE demonstrated significant catalytic activity, achieving 66.18% and 63.97% conversion rates, respectively. The catalytic activity of the synthesized materials was 30 times more efficient than the homogeneous catalyst p-Toluenesulfonic acid. Pseudo-homogeneous and heterogeneous kinetic models were employed to gain further insights into the glycerol ketalization reaction with acetone. The pseudo-homogeneous model suggested that the direct rate constant was lower than the reverse rate constant. In this sense, a reversible bimolecular reaction was proposed. The heterogeneous kinetic models revealed that in the Langmuir-Hinshelwood-Hougen-Watson mechanism, the controlling step of the reaction was the glycerol-acetone surface reaction on the catalyst. In contrast, in the Eley-Rideal mechanism, the reaction was controlled by the adsorbed glycerol on the reaction surface reacting with the available acetone in the bulk fluid. In the reusability tests, the rGOE catalyst demonstrated superior performance over five consecutive cycles, maintaining the highest activity without needing post-reaction washing or treatment. Full article
(This article belongs to the Topic Biomass Transformation: Sustainable Development)
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14 pages, 1386 KiB  
Article
Hydraulic Retention Time as an Operational Tool for the Production of Short-Chain Carboxylates via Anaerobic Fermentation of Carbohydrate-Rich Waste
by Kaoutar Aboudi, Silvia Greses and Cristina González-Fernández
Molecules 2023, 28(18), 6635; https://doi.org/10.3390/molecules28186635 - 15 Sep 2023
Viewed by 1130
Abstract
The carboxylate platform is a sustainable and cost-effective way to valorize wastes into biochemicals that replace those of fossil origin. Short-chain fatty acids (SCFAs) are intermediates generated during anaerobic fermentation (AF) and are considered high-value-added biochemicals among carboxylates. This investigation aimed to produce [...] Read more.
The carboxylate platform is a sustainable and cost-effective way to valorize wastes into biochemicals that replace those of fossil origin. Short-chain fatty acids (SCFAs) are intermediates generated during anaerobic fermentation (AF) and are considered high-value-added biochemicals among carboxylates. This investigation aimed to produce SCFAs through the AF of sugar beet molasses at 25 °C and semi-continuous feeding mode in completely stirred tank reactors. A particular focus was devoted to the role of hydraulic retention time (HRT) variation in SCFAs production and distribution profile. The highest SCFAs concentration (44.1 ± 2.3 gCOD/L) was reached at the HRT of 30 days. Caproic acid accounted for 32.5–35.5% (COD-concentration basis) at the long HRTs of 20 and 30 days due to the carbon chain elongation of shorter carboxylic acids. The findings of this study proved that HRT could be used to steer the anaerobic process toward the targeted SCFAs for specific uses. Furthermore, the successful operation at low-temperature conditions (i.e., 25 °C) makes the process economically promising. Full article
(This article belongs to the Topic Biomass Transformation: Sustainable Development)
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12 pages, 3546 KiB  
Article
Sodium Silicates Modified Calcium Oxide as a High-Performance Solid Base Catalyst for Biodiesel Production
by Shunpan Zhang, Junying Fu, Shiyou Xing, Ming Li, Xiaochun Liu, Lingmei Yang and Pengmei Lv
Catalysts 2023, 13(4), 775; https://doi.org/10.3390/catal13040775 - 20 Apr 2023
Cited by 4 | Viewed by 2096
Abstract
Under the energy crisis and with greenhouse gases causing an ecological imbalance, biofuel has attracted worldwide attention due to its sustainability and low net-carbon emission. For years, the traditional biodiesel industry has been demanding a high-performance solid base catalyst. Its poor reusability is [...] Read more.
Under the energy crisis and with greenhouse gases causing an ecological imbalance, biofuel has attracted worldwide attention due to its sustainability and low net-carbon emission. For years, the traditional biodiesel industry has been demanding a high-performance solid base catalyst. Its poor reusability is the bottleneck for a promising calcium-based solid-base catalyst. In this work, we successfully adopted a new silicate-strength strategy to improve the stability while preserving the activity of the catalyst. The newly synthesized catalyst, NCSO, had two main catalytic phases, Na2CaSiO4 and CaO, and showed a 98.2% FAMEs yield in 60 min at 80 °C with a methanol/oil molar ratio of 9:1 and 5 wt.% catalyst loading. After 12 consecutive reuses, a 57.3% FAMEs yield could still be achieved. The effect of the reaction temperature, methanol ratio, catalyst loading, and reaction time on the FAMEs yield was also investigated. With a combined characterization of XRD, XPS, and SEM, etc., we confirmed that Na2CaSiO4 and CaO showed a synergistic effect in catalyzing the transesterification reaction: the addition of the Na2CaSiO4 phase in NCSO could significantly improve the activity of CaO, while the CaO phase, in turn, helps to stabilize the Na2CaSiO4 phase. This silicate-strength strategy provides a new route to synthesize stable and highly active solid base catalysts. Full article
(This article belongs to the Topic Biomass Transformation: Sustainable Development)
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13 pages, 2620 KiB  
Article
Pyrolytic Conversion of Cellulosic Pulps from “Lignin-First” Biomass Fractionation
by Charles A. Mullen, Candice Ellison and Yaseen Elkasabi
Energies 2023, 16(7), 3236; https://doi.org/10.3390/en16073236 - 4 Apr 2023
Cited by 1 | Viewed by 1467
Abstract
Utilization of lignin is among the most pressing problems for biorefineries that convert lignocellulosic biomass to fuels and chemicals. Recently “lignin-first” biomass fractionation has received increasing attention. In most biorefining concepts, carbohydrate portions of the biomass are separated, and their monomeric sugar components [...] Read more.
Utilization of lignin is among the most pressing problems for biorefineries that convert lignocellulosic biomass to fuels and chemicals. Recently “lignin-first” biomass fractionation has received increasing attention. In most biorefining concepts, carbohydrate portions of the biomass are separated, and their monomeric sugar components released, while the relatively chemically stable lignin rich byproduct remains underutilized. Conversely, in lignin-first processes, a one-pot fractionation and depolymerization is performed, leading to an oil rich in phenolic compounds and a cellulosic pulp. Usually, the pulp is considered as a fermentation feedstock to produce ethanol. Herein, the results of a study where various cellulosic pulps are tested for their potential to produce valuable products via pyrolysis processes, assessed via analytical pyrolysis (py-GC), are presented. Samples of herbaceous (switchgrass) and woody biomass (oak) were subjected to both an acid-catalyzed and a supported-metal-catalyzed reductive lignin-first depolymerization, and the pulps were compared. Fast pyrolysis of the pulps produced levoglucosan in yields of up to about 35 wt %. When normalized for the amount of biomass entering the entire process, performing the lignin-first reductive depolymerization resulted in 4.0–4.6 times the yield of levoglucosan than pyrolysis of raw biomass. Pulps derived from switchgrass were better feedstocks for levoglucosan production compared with pulps from oak, and pulps produced from metal-on-carbon catalyzed depolymerization produced more levoglucosan than those from acid-catalyzed depolymerization. Catalytic pyrolysis over HZSM-5 produced aromatic hydrocarbons from the pulps. In this case, the yields were similar from both feedstocks and catalyst types, suggesting that there is no advantage to lignin fractionation prior to zeolite-catalyzed catalytic pyrolysis for hydrocarbons. Full article
(This article belongs to the Topic Biomass Transformation: Sustainable Development)
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