Biogas Produced from Different Feedstocks in Anaerobic Digesters

Abstract

Anaerobic digestion is a useful method for producing clean fuel from renewable feedstocks. It is a biological process where biodegradable matter is degraded or decomposed by the activity of specific microorganisms in the absence of oxygen, producing biogas used for electricity and heat generation. The anaerobic digestion is affected by the type of raw materials. Co-digestion, the simultaneous digestion of a mixture of two or more substrates, is a technique, by which the bioconversion rate, as well as the methane yield, can be increased. The same effects are produced by the pretreatment of the biomass as pretreatments make the organic substance of smaller size more accessible to microorganisms and methane production. An important parameter used to evaluate the efficiency of anaerobic digestion is the bio-methane potential. Others are the gross energy yields, the cumulative energy demand, the net energy yield, and the energy efficiency. In this chapter, a literature analysis about the diet of anaerobic digestion and related methods to improve the process is carried out. Works report that energy crop is the most used substrate for the biogas production. Mechanical, chemical, thermal, thermochemical, and biological pretreatments can be used. Also, the different configuration of anaerobic digester can be developed to improve the efficiency of the process.