Plant Feedstocks and their Biogas Production Potentials

Introduction: Nowadays, organic waste utilization and replacement of fossil energy sources with their renewable alternatives pose a challenging problem both for industrially developed and developing countries. Anaerobic digestion of organic biomass into biogas is considered an efficient technology for bioenergy production. Over the period from 2009 to 2018, the global biogas production capacities have more than doubled and are continuing to grow. The composition and the amount of biogas depend strongly on the type of the substrate. Various types of feedstock can be used for the production of biogas such as animal wastes, agricultural residues, and dedicated energy crops. Objective: To review biogas production potentials of energy crops and plant processing raw materials. Results: In the background of historical development and present state, the paper reviews the potential of different plant raw materials to be utilized for biogas production purposes. The potential of energy crops, agricultural residues, and wastes for biogas production is analyzed. International projects concerning energy crops grown on marginal lands are presented and commented on in the article. The approach of implementing crop rotation systems for industrial energy crop cultivation is described and recommended as beneficial for various purposes. The anaerobic degradability of biomass constituents, optimal process parameters, and biomass treatment for biogas production are discussed. C/N ration and lignocelluloses content in the substrate are considered among the most decisive parameters for AD and methane production. Various concepts of biogas bioreactor technologies have been studied depending on the substrate type. Conclusion: Plant feedstock may play a decisive role in biogas production as a renewable energy source. To avoid GHG release into the atmosphere, biogas facilities should be built within the closest vicinities to the places of existing garbage dumps, and waste management practice involving organic fraction separation in households and in the industry should be applied. Construction of biogas facilities is beneficial for environmental, economic, and social reasons.