Sustainable Biorefineries for the Valorization of Agricultural By-Products and Waste Streams

Dear Colleagues,

The circular economy plays an essential role in reintegrating materials into the production chain, offering a supportive approach to achieving economic growth and shifting away from the linear economy, which is reliant on fossil resources. By reusing by-products from traditional industrial processes as feedstock in innovative technological pathways, we can promote the sustainable development of biorefineries within the circular economy framework. The development of integrated close-to-zero waste processes based on fermentation technologies can be proposed as an exemplary model for biomass valorization. Implementing new biorefineries serves as a strategic solution for managing by-products and recovering value-added products and bioenergy, contributing to reductions in greenhouse gas emissions from an environmental standpoint. However, several aspects should be better elucidated, such as the techno-economic and environmental aspects of biomass pretreatment. Therefore, the development of a new management system has the potential to serve as a sustainable model for advancing the agriculture and food sectors. By minimizing the generation of by-products, reducing greenhouse gas emissions, and producing renewable resources and marketable products, this approach aligns with the goals of the circular bioeconomy.

The aim of this Special Issue is to describe the recent advances and trends in the development of sustainable biorefineries for the recovery of value-added products and bioenergy from agricultural by-products and waste streams. We invite authors to submit their original articles and review papers focused on advances, gaps, and perspectives, including, but not limited to, the following:

(i) Novel approaches for the valorization of biomass by-products:

• Exploring integrated biorefinery systems that maximize the production of bio-based materials, chemicals, and fuels from biomass by-products;
• Investigating the use of microorganisms and enzymes for the direct conversion of biomass by-products into valuable products;
• Exploring innovative advanced conversion technologies to efficiently improve the application of biomass by-products.

(ii) Sustainable pretreatment techniques of biomass by-products:

• Developing pretreatment techniques with eco-friendly solvents to improve the accessibility of cellulose, hemicellulose, and lignin while minimizing the environmental impact;
• Investigating the use of specific enzymes or enzyme cocktails to selectively break down the lignocellulosic structure and enhance the conversion of biomass by-products, leading to higher sugar yields for biofuel production;
• Exploring innovative technologies like microwave, ultrasound, subcritical water, hydrothermal liquefaction, gasification, and electrochemical as non-conventional pretreatments to efficiently convert biomass by-products.

(iii) Aerobic and anaerobic fermentation of biomass by-products:

• Studying the microbial conversion by aerobic and anaerobic fermentation processes to produce bioethanol, biogas, and platform chemicals;
• Investigating the use of microbial fuel cells as a sustainable technology to directly convert biomass by-products into hydrogen, providing an alternative energy source.

(iv) Techno-economic assessment of bioprocesses using biomass by-products:

• Conducting comprehensive techno-economic analyses to evaluate the feasibility and scalability of bioprocesses utilizing biomass by-products, considering factors such as raw material costs, process efficiency, product value, and market demand;
• Exploring the integration of bioprocesses utilizing biomass by-products with other industries, such as agriculture, forestry, and waste management, to create novel biorefinery synergies and enhance resource utilization.

(v) Environmental analysis of bioprocesses involving biomass by-products:

• Quantifying the greenhouse gas emissions associated with bioprocesses utilizing biomass by-products, considering the entire life cycle from raw material production to end-product utilization, to assess their environmental impact and potential contribution to mitigating climate change;
• Analyzing the environmental benefits of bioprocesses in terms of reducing waste generation and recovering valuable resources from biomass by-products, optimizing the overall sustainability of the processes;
• Investigating the potential ecological impacts on air, soil, water, and ecosystems, and identifying strategies to minimize any adverse effects and ensure the long-term sustainability of novel bioprocesses.

We look forward to receiving your contributions.

Dr. William Gustavo Sganzerla
Prof. Dr. Giovani Leone Zabot
Guest Editors

Manuscript Submission Information

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• biomass
• circular economy
• biorefinery
• by-products
• waste
• agri-food industry
• fermentation
• bioproducts
• bioenergy