In-Depth Investigations in Bioenergy

Dear Colleagues,

The Special Issue "In-Depth Investigations in Bioenergy" aims to provide a comprehensive exploration of various aspects related to bioenergy production, utilization and sustainability. In addition, it is dedicated to the examination of bioenergy sources, technologies, environmental impacts and policy considerations and aims to provide a thorough understanding of the current state and future opportunities in this field.

The scope of this topic includes, but is not limited to, the following:

(1) Bioenergy sources and conversion technologies:
Examination of the various bioenergy sources such as biomass, biofuels and biogas.
In-depth analysis of conversion technologies, including thermochemical, biochemical and biological processes.

(2) Sustainability and environmental impact:
Assessment of the environmental footprint of bioenergy production and use.
Exploration of sustainable practices, land use considerations and impacts on biodiversity.

(3) Technological advances and innovations:
Investigating the latest technological developments in bioenergy production.
Exploring innovative approaches to increase efficiency, reduce costs and minimize environmental impact.

(4) Economic viability and market dynamics:
Analyzing the economic feasibility and competitiveness of bioenergy projects in the energy market.
Assessment of market trends, challenges and opportunities for the introduction of bioenergy.

(5) Policy framework and regulatory landscape:
Examination of national and international policies influencing bioenergy development.
Discussing the regulatory framework in relation to sustainability, carbon emissions and incentives for bioenergy projects.

(6) Integration with renewable energy systems:
Exploring the integration of bioenergy with other renewable energy sources for a diversified and sustainable energy portfolio.
Evaluation of hybrid energy systems and their potential contribution to the overall energy matrix.

(7) Challenges and research gaps:
Identifying and analyzing the challenges facing the bioenergy sector.
Exploring research gaps and areas requiring further investigation to overcome barriers to widespread adoption.

(8) Future prospects and emerging trends:
Anticipating future developments in bioenergy technologies and their potential impact.
Investigating emerging trends that could shape the path of bioenergy research and implementation.

Dr. Katarzyna Bułkowska
Prof. Dr. Magdalena Zielińska
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• bioenergy sustainability
• thermochemical conversion
• biofuel production
• environmental impact assessment
• renewable energy integration
• challenges in bioenergy
• market dynamics in bioenergy
• bioenergy infrastructure development
• decentralized energy systems
• lignocellulosic biomass utilization
• emerging trends in bioenergy
• cellulosic ethanol pathways
• algal biofuel production
• microbial fuel cell applications

Title: Blockchain-based management of recyclable plastic waste
Authors: Bułkowska Katarzyna; Zielińska Magdalena; Bułkowski Maciej
Affiliation: Department of Environmental Biotechnology, Faculty of Geoengineering, University of Warmia and Mazury in Olsztyn, Sloneczna St. 45G, 10-709 Olsztyn, Poland
Abstract: Our paper deals with the innovative field of blockchain technology applied to the management of recyclable plastic waste. The aim is to provide valuable insights into how this emerging technology can revolutionize the processes related to plastic waste by providing transparency, efficiency, and sustainability.

Title: An overview of pyrolysis as waste treatment to produce eco-energy
Authors: María del Pilar Dorado Pérez
Affiliation: Department of Physical Chemistry and Applied Thermodynamics, Universidad de Córdoba, Spain, Campus de Rabanales, Campus de Excelencia Internacional Agroalimentario ceiA3, 14071 Córdoba, Spain

Title: Techno-economic analysis of biodiesel production by simulation using Aspen Plus
Authors: Abul Kalam Azad; Pedada Sai Swaroop
Affiliation: School of Engineering and Technology, Central Queensland University, Melbourne, Australia

Title: Thermal depolymerization of waste activated sludge
Authors: Katarzyna Bułkowska; Magdalena Zielińsk
Affiliation: University of Warmia and Mazury in Olsztyn, Poland

Title: Refuse Derived Fuel and its Components Thermal Decomposition Kinetics at Low-Temperature Pyrolysis Conditions
Authors: Kacper Świechowski
Affiliation: Department of Applied Bioeconomy, Wrocław University of Environmental and Life Sciences, Chełmońskiego Str 37a, 51-630 Wrocław, Poland
Abstract: In this study, the thermal decomposition by thermogravimetric analysis (TGA) of eight types of basic refuse-derived fuel (RDF) components and two RDF blends made of those components were studied. The RDF components contained two material types organic and synthetic. The thermo-gravimetric analysis conditions were temperature up to 500 °C, heating rates of 5, 10, and 15 °C×min-1 and a nitrogen atmosphere. Based on the TGA data, the kinetic parameters of thermal decomposition according to Coats-Redfern and Kissinger methods were determined. Next, the at-tempt to determine the process kinetics of any RDF based on a weighted average of the share of individual components and their kinetic parameters was taken. The results showed that it is possible to predict the thermal decomposition (mass loss) of the RDF blend and its kinetics parameters based on the weighted average content of individual components and their thermal decomposition. Nevertheless, this approach needs to be taken with caution since some errors depending on the kinetics determination approach and method chosen are present. It was also observed that low-temperature pyrolysis of RDF can be divided into 3 specific decomposition zones related to water evaporation (25-200 °C), organic component decomposition (200-400 °C), and synthetic component decomposition (400-500 °C).

Title: Use of membrane techniques for the removal and recovery of nitrogen and phosphorus from the liquid fraction of anaerobic digestate
Authors: Zielińska M.; Bułkowska K.
Affiliation: Department of Environmental Biotechnology, University of Warmia and Mazury in Olsztyn, Słoneczna St. 45G, 10-709 Olsztyn, Poland
Abstract: Characteristics of digestate from the anaerobic digestion of organic waste; the impact of digestate separation methods on the properties of its liquid fraction. Use of membrane techniques (ultrafiltration, reverse osmosis, membrane distillation) for the treatment of the liquid fraction of digestate; methods to minimize the effects of fouling and scaling of membranes. Different scenarios of handling permeate and retentate with the aim of nitrogen removal; use of nitrification/denitrification, partial nitrification/denitrification, partial nitrification/Anammox. Different scenarios of handling permeate and retentate with the aim of i) recovery of nitrogen; ii) recovery of phosphorus; iii) combined recovery of nitrogen and phosphorus. Evaluation of the use of anaerobic membrane bioreactors to improve the performance of anaerobic digestion in terms of the composition of the liquid fraction of the digestate, the recovery possibilities and the degree of waste valorization. Future prospects for the use of membrane techniques to valorize organic waste by recovering nutrients from digestate.

Title: Combustion of pelletized coffee residues for bioenergy valorization within a circular economy vision
Authors: Antonio Scarfone; Giuseppe Toscano; Angelo Del Giudice; Andrea Acampora; Elisa Fischetti; Thomas Gasperini; Vincenzo Civitarese
Affiliation: 1 Consiglio per la Ricerca in Agricoltura e l’Analisi Dell’Economia Agraria (CREA), Rome, Italy 2 Università Politecnica delle Marche, Ancona, Italy
Abstract: Coffee is one of the most widely consumed beverages in the world; the European Union alone consumes about 2.5 million tons of coffee per year. As millions of tons of coffee are used, millions of tons of waste are generated, becoming an attractive material for circular economy flows. However, exploiting such a resource is challenging from different points of view, including real energy potential, supply chain management, and safety for humans and the environment. This study explores the potential of utilizing pelletized coffee grounds, coffee waste, and wood-coffee mixtures as sustainable bioenergy sources within the framework of a circular economy. By investigating the combustion characteristics and energy output of these materials, the research aims to demonstrate their viability as alternatives to conventional fossil fuels. The findings indicate that coffee residues exhibit favorable combustion properties with respect to heating value, but also high concentrations of elements such as nitrogen (N) and sulfur (S) compared to conventional pellets obtained from other agricultural residues. In conclusion, coffee residues present good energy potential but also some parameters to monitor during combustion due to the risk of generating greenhouse gases and acid rain. The study underscores the importance of innovative waste management strategies in achieving sustainable energy goals and highlights further research challenges in finding optimal solutions for the energetic valorization of food waste.

Title: Bio-Energy production
Authors: João Carlos Moura Bordado
Affiliation: CERENA, Instituto Superior Técnico, University of Lisbon, 1049-001 Lisbon, Portugal
Abstract: Forests have the natural and major process of CO2 capture, and therefor the wood and the forest residues are the key for the future of Bio-Energy production. Unfortunately, the gasification and pyrolysis processes to convert wood into a bio-oil have a rather low overall yield and the produced bio-oil has a doubtful quality, very often with over 20 % water content, and very unstable. The purification and subsequent stabilization by Hydrogenation have unbearable costs… This is why all the industrial units using the Fischer-Tropsch process become broke and the remaining rather small demonstration units survive on the base of subsidies. Our research team followed a different approach, and we made the option to develop a process of simultaneous catalytic depolymerization of lignin and celluloses, in liquid phase, at moderate temperatures to avoid the destruction of the sugar molecular segments. With this process that we call “Direct liquefaction” we recover more than 70 % of the sugar structures present in cellulose and hemicellulose, and with one overall yield of liquefaction of 94 % on a dry basis. ( 1 ton of dry wood converts to 940 Kg of liquid) In the first step of scale-up of the process, we constructed a Pilot Plant (full AISI 316 L) that produces continuously 3 Ton per day of liquified wood. The process is now protected by two patents, and we believe that it will become of relevance in future Bio-refineries.