Agricultural plant residues as potential co-substrates for biogas production

Plant biomass can be used in many directions for bioenergy production. Biogas can be produced from a most diverse group of substrates compared to liquid or solid biofuels. The choice of substrates and technologies is crucial because it will allow getting the expected results. Not without significance is also the price and availability of substrates. Therefore, waste and residues are increasingly being used. Accordingly, the aim of the review was to analyze the potential of biogas production from agricultural plant residues and the effectiveness of using this feedstock as a co-substrate in anaerobic digestion. In this article, selected agricultural plant residues are collected, and their advantages and disadvantages as substrates for biogas production are described. Moreover, the effective technology of biogas production by anaerobic digestion on an industrial scale and calculations to obtain biogas and methane efficiency of the substrates are also included. In addition, the summarized biogas efficiency of selected plant agricultural waste under mesophilic conditions studied by many researchers is shown. On the basis of the analyzed results of this research, it can be concluded that agricultural plant residues have great potential as co-substrates for biogas production. It is important to experimentally determine both the biogas and the methane efficiency of the substrate, representing a potential raw material for the production of gaseous biofuels. The use of artificial neural networks in the prediction of biogas emission is future-proof and should facilitate the management of biogas plants. The use of waste from the cultivation and processing of plant raw materials will not only help to manage this waste rationally, but also contribute to the increase in production of renewable energy sources. Accordingly, the circular economy in terms of the management of agricultural plant residues to produce biogas will have a multi-faceted, positive impact on the environment. On the basis of this review, it can be concluded that numerous agricultural plant residues can be used as potential co-substrates for biogas production.