Dear Colleagues,

Anaerobic digestion is a technology that has been used by man for centuries. The production of biogas during anaerobic digestion is considered a useful tool that can generate renewable energy, and there has recently been great interest regarding research in this field. The basic theory of anaerobic digestion has been described and developed for decades, but much ongoing research concerns the optimization of the anaerobic digestion process under various process conditions as well as the optimization of feed (selection of mass for fermentation) and the use of this process for biowaste management. To optimize the anaerobic digestion process and utilize biodegradable waste in the process, many factors associated with the design and operation of the anaerobic digestion process must be taken into account to ensure maximum efficiency and cost-effectiveness.

Current biowaste management practices have led to the significant methane emissions observed around the world. Landfills, animal waste treatment, and wastewater treatment are respectively the third, fourth, and seventh largest sources of methane emissions, which together account for around 45% of methane emissions as carbon dioxide equivalents. Appropriate biogas installations are not only able to reduce greenhouse gas emissions but also to generate renewable energy and reduce waste stored in landfills. There are a number of biogas installations operating worldwide. However, anaerobic digestion still faces a number of technological, social, and economic obstacles that prevent its full potential being exploited, although market conditions are becoming increasingly favorable for anaerobic digestion.

For most modern biogases, the input material is primarily mixtures of manure and plants specially grown for this purpose. Maize silage constitutes the largest share. The production of energy plants is, however, associated with the need to use large amounts of energy for agrotechnical operations, the production and use of fertilizers and plant protection products, and the processes of harvesting and preparing the substrate. Therefore, the use of intentionally cultivated energy crops may have low energy efficiency and significant greenhouse gas emissions per unit of energy obtained. Therefore, the energy use of biowaste has been recently been receiving increasing attention. To date, the most common method of neutralizing such waste has been composting and thermal conversion. However, this process is not very efficient from both an energy and environmental point of view. This aspect of production optimization in terms of energy efficiency and environmental impact is an integral element of all modern quality management systems in primary production. In addition to obtaining energy from waste, it is a strategic element of sustainable waste management. The ecological aspect of the transformation of waste biomass using methane fermentation processes not only relates to obtaining energy from renewable sources but also involves the rational utilization of this waste as well as the reduction of greenhouse gas emissions that are a consequence of the storage of this waste and the production of energy from conventional sources. The byproduct of methane fermentation is post-fermentation mass, which can be a valuable source of elements for plants if it is introduced into the soil. The use of digestate for fertilizing purposes is an action increasing the level of carbon sequestration in soil resources, and is a factor supporting the effective management of soil fertility. Structural and organizational changes in agriculture lead to a reduction in the use of organic materials in fertilization. In research related to the use of waste from the food industry for fertilizing purposes, special attention is paid to phosphorus, whose global resources will be exhausted by the end of the 21st century. The use of this waste for biogas production, followed by the use of the digestate obtained for fertilization, may constitute an important link in the circulation of elements in agroecosystems as part of the implementation of rational agricultural production methods.

This Special Issue entitled “Biogas Production Processes from Biomass” aims to present innovative achievements in the development and use of methane fermentation for the treatment of biowaste. Topics include, but are not limited to:

• Development of new fermentation media using waste biomass and optimization of biogas yield;
• Diagnosis of the impact of using biodegradable waste for methane fermentation considering social, ecological, and economic aspects;
• Utilization of digestate for energy and fertilizing purposes;
• Development of models specific for biogas production in co-fermentation of agricultural biomass with biowaste.

Prof. Dr. Maciej Kubon
Prof. Dr. Jakub Sikora
Prof. Dr. Marcin Niemiec
Guest Editors

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• biogas
• biogas yield
• process optimization
• biogas quality
• digestate
• digestate management
• agricultural biogas plants
• utilization biogas plants