Biogas production and quality control
Biogas that is primarily methane (CH4) and carbon dioxide (CO2) can be produced by anaerobic digestion (AD) of organic matters, such as crop residues, manure, municipal wastes, and food wastes in landfills, or anaerobic digesters. Various technologies have been developed to enhance biogas production, which include feedstock pretreatment, codigestion, AD microbial management, and trace element supplementation. Codigestion of animal manure and agricultural residues could make AD profitable at current energy prices. Biogas can be used to generate heat and electricity. Methane in biogas can be concentrated to the same standards as natural gas. Biogas can be reformed into cleaner fuels like syngas and hydrogen. There are various biogas purification methods available such as water scrubbing, chemical absorption, pressure swing absorption, membrane separation, and biofilters to remove impurities such as hydrogen sulphide (H2S) and CO2. This chapter is focused on the review of the biogas production principles and processes, and the latest technologies for the enhancement of biogas production and upgrading.