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Biogas Production in Agriculture: Technological, Environmental, and Socio-Economic Aspects
This review provides a comprehensive analysis of the technological, environmental, economic, regulatory, and social dimensions shaping the development and operation of agricultural biogas plants. The paper adopts a primarily European perspective, reflecting the comparatively high share of agricultural inputs in anaerobic digestion (AD) across EU Member States, while drawing selective comparisons with global contexts to indicate where socio-geographical conditions may lead to different outcomes. It outlines core principles of the AD process and recent innovations—such as enzyme supplementation, microbial carriers, and multistage digestion systems—that enhance process efficiency and cost-effectiveness. The study emphasises substrate optimisation involving both crop- and livestock-derived materials, together with the critical management of water resources and digestate within a circular-economy framework to promote sustainability and minimise environmental risks. Economic viability, regulatory frameworks, and social dynamics are examined as key factors underpinning successful biogas implementation. The paper synthesises evidence on cost–benefit performance, investment drivers, regulatory challenges, and support mechanisms, alongside the importance of community engagement and participatory governance to mitigate land-use conflicts and ensure equitable rural development. Finally, it addresses persistent technical, institutional, environmental, and social barriers that constrain biogas deployment, underscoring the need for integrated solutions that combine technological advances with policy support and stakeholder cooperation. This analysis offers practical insights for advancing sustainable biogas use in agriculture, balancing energy production with environmental stewardship, food security, and rural equity. The review is based on literature identified in Scopus and Web of Science for 2007 to 2025 using predefined keyword sets and supplemented by EU policy and guidance documents and backward- and forward-citation searches.
Anaerobic Digestion of Food Waste—A Short Review
In recent years, growing environmental awareness, the need to reduce greenhouse gas emissions, and the energy crisis have led many countries to seek alternative energy sources. One of the most promising solutions is biogas production via anaerobic digestion (AD), whose substrate can be organic-rich and easily biodegradable food waste (FW). This waste is a significant part of the global waste problem, and its use for energy production is beneficial to both the environment and the economy. This paper presents important issues concerning the monitoring of the AD process, as well as standard and innovative, for the implementation of this process, technological solutions. The aim of the measures taken to optimise the process is to increase AD efficiency and obtain the highest possible methane content in biogas. Two approaches—pretreatment and anaerobic co-digestion (AcoD)—have been integral to the implementation of AD of food waste for years. They are presented in this paper based on a review of recent research developments. Pretreatment methods are discussed with particular emphasis on mechanical, chemical and biological methods. The AcoD of FW with different organic substrates has been extensively reviewed, as confirmed by numerous studies, where higher buffer capacity and optimum nutrient balance enhance the biogas/methane yields. Attention was also paid to the parameters, operating mode and configurations of anaerobic digesters, with a thorough analysis of the advantages and disadvantages of each solution. The article concludes with a brief presentation of the development perspectives for the discussed FW management method and recommendations.
Nośnik diatomit/torf w intensyfikacji fermentacji metanowej odpadów organicznych: efektywność i stabilność procesu oraz zmiany mikrobiomu
Additives Improving the Efficiency of Biogas Production as an Alternative Energy Source - A Review
Additives for anaerobic digestion (AD) can play a significant role in optimizing the process by increasing biogas production, stabilizing the system, and improving digestate quality. The role of additives largely boils down to, among others, enhancing direct interspecies electron transfer (DIET) between microbial communities, resulting in improved syntrophic interactions, adsorption of toxic substances that may inhibit microbial activity, improving microbial activity, and increasing process stability and accelerating the decomposition of complex organic materials, thereby increasing the rate of hydrolysis. Through the aforementioned action, additives can significantly affect AD performance. The function of these materials varies, from enhancing microbial activity to maintaining optimal conditions and protecting the system from inhibitors. The choice of additives should be carefully tailored to the specific needs and conditions of the digester to maximize benefits and ensure sustainability. In light of these considerations, this paper characterizes the most commonly used additives and their combinations based on a comprehensive review of recent scientific publications, including a report on the results of conducted studies. The publication features chapters that describe carbon-based conductive materials, metal oxide nanomaterials, trace metal, and biological additives, including enzymes and microorganisms. It concludes with the chapters summarising reports on various additives and discussing their functional properties, as well as advantages and disadvantages. The presented review is a substantive and concise analysis of the latest knowledge on additives for the AD process. The application of additives in AD is characterized by great potential; hence, the subject matter is very current and future-oriented.
Kinetics and Energy Yield in Anaerobic Digestion: Effects of Substrate Composition and Fundamental Operating Conditions
Operation and challenges of biogas technology: a fundamental overview
The modern world is facing a huge energy crisis related to the depletion of conventional energy sources. Therefore, obtaining energy from alternative sources is sparking increasing interest, expressed by both scientists and entrepreneurs. One such source is biogas, which has great potential to become, along with wind and solar energy, an important renewable energy source (RES). This paper presents the technical and practical aspects of biogas production (mainly agricultural) and extensively discusses the anaerobic digestion (AD) process. The global development of biogas plants and the operation of the most important types of biogas plants are also discussed. In the conclusion section, the benefits of biogas technology development are provided and explained, as well as the challenges and barriers hindering the intensification of biogas plant construction despite the potential and access to adequate resources and waste materials.
The use of sewage sludge in anaerobic digestion process: formation, properties, and implementation.
The effect of municipal wastewater treatment, in addition to improving its quality, is sludge formation. Disposal of sewage sludge (SS) is a critical environmental problem that requires careful management. Under current legislation, SS represents waste requiring stabilisation to eliminate pathogenic microorganisms and substances potentially harmful to the environment. Anaerobic digestion (AD) is an efficient method of treating SS, and it produces biogas as a renewable energy source (RES). The efficiency of the process can be increased by combining SS with other organic wastes as cosubstrates. Therefore, AD allows for a twofold benefit crucial for sustainable waste and energy management, i.e. sludge stabilisation and biogas production. Another equally important consideration in the construction of biogas plants at wastewater treatment plants is reducing the plant's operating costs by using the electricity and heat generated in the cogeneration units for the plant's needs. This paper discusses the formation technology and properties of sewage sludge, the legal aspects of using and disposing of SS, the conditions for employing their anaerobic biodegradation, and the co-digestion systems used.
The Use of Fungi of the Trichoderma Genus in Anaerobic Digestion: A Review
Plant waste biomass is the most abundant renewable energy resource on Earth. The main problem with utilising this biomass in anaerobic digestion is the long and costly stage of degrading its complex structure into simple compounds. One of the promising solutions to this problem is the application of fungi of the Trichoderma genus, which show a high capacity to produce hydrolytic enzymes capable of degrading lignocellulosic biomass before anaerobic digestion. This article discusses the structure of plant waste biomass and the problems resulting from its structure in the digestion process. It presents the methods of pre-treatment of lignocellulose with a particular focus on biological solutions. Based on the latest research findings, key parameters related to the application of Trichoderma sp. as a pre-treatment method are discussed. In addition, the possibility of using the digestate from agricultural biogas plants as a carrier for the multiplication of the Trichoderma sp. fungi, which are widely used in many industries, is discussed.
Biogas Plants: Fundamentals, Operation and Prospects
As the global demand for renewable energy continues to rise, biogas technology has emerged as a promising solution for sustainable energy generation. This review article presents the advantages of biogas technologies and extensively discusses the main principles of biogas production in the methane fermentation process. In this respect, the main parameters of the process, which require monitoring and are at the same time decisive for its course and efficiency are described, the principles of substrate selection are discussed and the necessity and advantages of the use of organic waste according to the model of a circular economy and the concept of sustainable development, are indicated. The part on biogas production is summarised with an explanation of the necessity to treat and purify biogas, taking into account the share of methane extracted. A special place in this paper is devoted to the design, construction, functioning and operation of biogas plants, based on both scientific and practical aspects. In conclusion of this chapter, the economic aspects and profitability of operating biogas plants are discussed, taking into account, in a theoretical balance sheet – in addition to investment and operating costs and the availability and cost of raw materials – the possibilities of producing and using electricity and heat, as well as environmental and social benefits. The article concludes with a discussion of opportunities and barriers to the development of biogas plants, pointing to: financial issues, access to feedstock, political regulations, public awareness and the geopolitical situation as key factors issues related to biogas plants – in different regions of the world.
Polylactide (PLA) as a Cell Carrier in Mesophilic Anaerobic Digestion—A New Strategy in the Management of PLA
The management of waste polylactide (PLA) in various solutions of thermophilic anaerobic digestion (AD) is problematic and often uneconomical. This paper proposes a different approach to the use of PLA in mesophilic AD, used more commonly on the industrial scale, which consists of assigning the function of a microbial carrier to the biopolymer. The study involved the testing of waste wafers and waste wafers and cheese in a co-substrate system, combined with digested sewage sludge. The experiment was conducted on a laboratory scale, in a batch bioreactor mode. They were used as test samples and as samples with the addition of a carrier: WF—control and WFC—control; WF + PLA and WFC + PLA. The main objective of the study was to verify the impact of PLA in the granular (PLAG) and powder (PLAP) forms on the stability and efficiency of the process. The results of the analysis of physicochemical properties of the carriers, including the critical thermal analysis by differential scanning calorimetry (DSC), as well as the amount of cellular biomass of Bacillus amyloliquefaciens obtained in a culture with the addition of the tested PLAG and PLAP, confirmed that PLA can be an effective cell carrier in mesophilic AD. The addition of PLAG produced better results for bacterial proliferation than the addition of powdered PLA. The highest level of dehydrogenase activity was maintained in the WFC + PLAG system. An increase in the volume of the methane produced for the samples digested with the PLA granules carrier was registered in the study. It went up by c.a. 26% for WF, from 356.11 m3 Mg−1 VS (WF—control) to 448.84 m3 Mg−1 VS (WF + PLAG), and for WFC, from 413.46 m3 Mg−1 VS, (WFC—control) to 519.98 m3 Mg−1 VS (WFC + PLAG).
Methods of Handling the Cup Plant (Silphium perfoliatum L.) for Energy Production
The aim of the study was to determine the possibilities of using cup plants (Silphium perfoliatum L.) to generate energy. The energy balances of the combustion and anaerobic digestion were compared. The research showed that cup plants could be used as a raw material for solid fuel and for anaerobic digestion. An energy balance simulation showed that electricity could be generated through the anaerobic digestion of cup plants. The following amounts could be generated in the anaerobic digestion process: 1069 kWhe from 1 Mg of the raw material fragmented with an impact mill, 738.8 kWhe from 1 Mg of the raw material extruded at a temperature of 150 °C, and as much as 850.1 kWhe from 1 Mg of the raw material extruded at 175 °C. The energy balance of the combustion of biofuel in the form of cup plant pellets showed that 858.28 kWht could be generated from 1 Mg of the raw material. The combustion of solid biofuel generated a relatively low amount of heat in comparison with the expected amount of heat from a biogas-powered cogeneration system due to the high energy consumption of the processes of drying and agglomeration of the raw material for the production of pellets.
Bioenergy from Maize Silage by Anaerobic Digestion: Batch Kinetics in Relation to Biochemical Composition
Maize silage can play a key role in policies aimed at stabilising local energy systems, as it constitutes a critical renewable feedstock for European biogas plants. By providing a dense and predictable source of chemical energy, it supports balance and reliability in the agricultural energy sector. To convert this potential into stable energy production, operators require kinetic models that translate routine silage quality indicators into concrete guidance for digester operation and control. Therefore, the aim of this article was to evaluate the batch kinetics of anaerobic digestion (AD) of maize silage and to select an adequate model for describing biochemical methane potential (BMP) profiles and associated energy recovery in the context of start-up, organic loading rate (OLR), hydraulic retention time (HRT) and feedstock preparation. Ten batches of silage (A–J) were examined, covering a realistic range of pH, electrical conductivity (EC), dry and volatile solids, ash, protein–fat–fibre fractions, fibre composition (NDF, ADF and ADL), derived fractions (hemicellulose, cellulose, and residual organic matter (OM)), C/N ratio and macro-/micronutrient profiles, including trace elements relevant to methanogenesis (Ni, Co, Mo, and Se). BMP tests were carried out in batch mode, and the resulting curves were fitted using the modified Gompertz and a first-order kinetic model. Methane yields of approx. 100–120 m3 CH4/Mg fresh matter (FM) and 336–402 m3 CH4/Mg volatile solids (VS), with CH4 contents of 52–57% v/v, were typical for energy-grade maize silage. Kinetic and energetic behaviours were governed mainly by residual OM and hemicellulose (shortening the lag phase and increasing the maximum methane production rate), the ADL/cellulose ratio (controlling the slower hydrolytic tail), EC and Na/Cl/S (extending the lag phase), and C/N together with Ni/Co/Mo/Se (stabilising methanogenesis). The modified Gompertz model reproduced BMP curves with a pronounced lag phase and asymmetry more accurately (lower error and better information criterion values), and its parameters directly support start-up design, OLR ramp-up and energetic performance optimisation in bioenergy reactors. The novelty of this work lies in combining batch BMP tests, comparative kinetic modelling and detailed silage characterisation to establish quantitative links between kinetic parameters and routine maize silage quality indicators that are directly relevant for biogas plant operation and renewable energy production.