Production of Bio-methane Gas as Renewable Energy Source - A Review

Abstract

The present review aims to provide an up-to-date summary of bio-methane (CH 4 ) gas production, which use as is a renewable energy source. Burned bio-methane gas used for water heating, space heating, drying, or cooking. CH 4 is also used in an automotive to produce both heat and electricity. The bio-methane gas is produced by anaerobic digestion (AD) technology of food waste, agricultural waste, municipal waste, green waste, manure, and sewage. AD technolog is promising technology; having the potential to convert several bio-masses into bio-gas rich with methane gas, which is alternative to fossil fuels. The hydrolysis, acidogenesis, acetogenesis, and methanogenesis are essential steps of AD process. The steps are proceeding by different kind of bacteria such as, acidogenic, acetogenic, and methanogenic bacteria. An effective process to increase the productivity of an anaerobic digestion process by combining it with a microbial electrosynthesis system (MES) was developed. Percentage compositions of CH 4 from anaerobic digestion of a different feedstock were between 50% -84%. The various physical, chemical, physiochemical and, biological pretreatments methods were applied to break the complex biomass into easily digested components. The AD system has many advantages, like low energy consumption, low nutrient and chemical requirement, improved sanitation, pathogens reduction, reduction of disease transmission, greenhouse emissions and nitrous oxide emissions reduction, etc. And some of the anaerobic digestion disadvantages are a long start-up, high buffer requirements for pH controlling, higher sensitivity of microorganisms to pH and temperature, etc. More advantages and disadvantages are discussed in this review. In the future, will be solutions to problems that limits production yield.