In this article we will discuss about the biogas systems.
Biogas is primarily used for cooking and lighting. In addition, there are numerous additional benefits to installing biogas plants. It is used to power pumps and electric generators in internal combustion engines. As fertilizer, sludge is used. Minimizing environmental pollution and meeting the demand for energy for various purposes are the most cost-effective benefits.
There are two sources of biomass for biogas production: plant and animal matter. The origin of plant biomass is either aquatic or terrestrial, whereas animal biomass includes manure from poultry, goat, sheep, and slaughterhouses, as well as fisheries waste, etc.
Cattle manure is the most effective material for biogas production. In addition to dung (gobar), agricultural residue, apple pomade, and spoiled or discarded wheat grains have been proven to be excellent sources for biogas production.
The process of anaerobic digestion takes place in cylinder-shaped tanks that don’t let air in. These tanks are called digesters. The parts of a digester are concrete bricks, cement, or steel. It has a side opening called a “charge pit” that is used to add organic materials for digestion.
A round container sits on top of the digester to collect the gas. Figure. 1 is a diagram of a single-stage digester for the Gobar gas plant. After 50 days, there is enough gas in the gas tank for household use. Most of the time, digesters are burned in soil so that the soil can act as insulation. When it’s cold, the digester can be warmed up.
Methanogens have strange ways of breaking down. They don’t have the carbon dioxide fixation, Calvin cycle, serine, or hexulose pathways. There are several coenzymes, such as methyl coenzyme M, hydroxymethyl coenzyme M, coenzyme F420, coenzyme F430, component B, methanofuran or carbon dioxide reducing factor, methanopterin, and formaldehyde activating factors.
Figure 1: Biogas systems
The main reaction that makes carbon dioxide is described below
CO + H2O → CO2 + H2
The secondary reaction takes place in the presence of sufficient hydrogen
CO2 + 4H2 → CH4 + 2H2O
Other reactions showing methane formation from various substrates
4CH3OH → 3CH4 + CO2 + 2H2O
4HCOOH → CH4 + 3CO2 + 2H2O
CH3COOH → 12CH4 + 12CO2