Biogas Process Overview

Biomethane is produced in anaerobic digesters, in the process called anaerobic digestion. Biomethane is a renewable energy resource, as opposed to natural gas (methane), which is a non-renewable energy resource. Biomethane has similar qualities of methane and both are used in interchangeably, and each may be a substitute for the other. Anaerobic digestion is a biological process that produces a gas principally composed of methane (CH4) and carbon dioxide (CO2) otherwise known as biogas. These gases are produced from organic wastes such as livestock manure, food-processing waste, etc.

As previously stated, Bio methanization is the process of conversion of organic matter in the waste (liquid or solid) to Bio Methane (sometimes referred to as "Biogas) and manure by microbial action in the absence of air, known as "anaerobic digestion."

Anaerobic processes could occur either naturally or in a controlled environment such as a biogas plant. Organic waste such as livestock manure and various types of bacteria are put in an airtight container called digester so the process could occur. Depending on the waste feedstock and the system design, biogas is typically 55 to 75 percent pure methane. State-of-the-art systems report producing biogas that is more than 95 percent pure methane.

Production and disposal of large quantities of organic and biodegradable waste without adequate or proper treatment results in widespread environmental pollution. Some waste streams can be treated by conventional methods like aeration. Compared to the aerobic method, the use of anaerobic digesters in processing these waste streams provides greater economic and environmental benefits and advantages.

Interest in Bio methaination as an economic, environmental and energy-saving waste treatment continues to gain greater interest worldwide and has led to the development of a range of anaerobic reactor designs. These high-rate, high-efficiency anaerobic digesters are also referred to as "retained biomass reactors" since they are based on the concept of retaining viable biomass by sludge immobilization.

Despite popular belief, the amount of waste going in the digester is almost equal to the amount coming out. However the quality of the waste is altered into the better ready to use organic fertilizer.

Waste coming out of the digester can be separated (solid/liquid) to compost the solid part and use the liquid part as fertilizing irrigation or to be treated further for rejection in nature.

The biogas concept we can offer is primarily suitable for farmer's home, small farms, and rural electrification programs. The family size biogas system is composed of one 2m3 biogas digester, a pipe system, a gas purify system, appliances and/or an electricity generator.

The medium size biogas system is designed for small size livestock farms to treat the animal waste, for schools or factories etc. and to treat waste water from toilets. The medium size biogas system is composed of a group of 10m3 biogas digester that are formed into one unit, a pipe system, a gas purify system, appliances and/or an electricity generator.

Raw material needed to produce 1 normal cubic meter biogas


Raw material


Water content (%)

Raw material needed to produce 1 cubic meter biogas in kg

Dry matter

Fresh matter

Pig Manure




Cow Manure




Chicken Manure




Human Manure




Rice Straw




Wheat Straw 




Corn stalks




*From 25 kg of cow dung (organic waste), you get 1 nm3 of biogas (Calorific Value 4500 5500 Kcal/nm3). From one NM3 of biogas, you can generate 1.5 kWe per day.