The main purpose of biogas purification is to remove carbon dioxide and obtain high-purity methane. Biogas purification technology mostly comes from the decarbonization technology of natural gas and synthetic ammonia. Because the treatment capacity of biogas is far less than that of natural gas or synthetic ammonia, more attention is paid to miniaturization and energy saving in the selection of decarbonization technology.
Biogas can be purified into biological natural gas, which is a renewable and clean energy. There is a vivid metaphor within the biogas industry, that is, building a small biogas digester is equivalent to building not only a small natural gas plant, but also a small sewage treatment plant, garbage treatment plant, organic fertilizer plant and small forest farm. Known by the masses as "money strings" and "cornucopia", it is a cause with small investment, great role and benefits the country and the people.
Biogas can also control air pollution and river pollution. Using biogas, the indoor concentration of carbon monoxide is 80% lower than that of coal, the concentration of carbon dioxide is 60%, the concentration of hydrogen sulfide is 80% lower, and the concentration of floating dust is 90%. At the same time, it also greatly reduces the total number of bacteria, Escherichia coli, ammonia nitrogen and other indicators of drinking water source, protects the water source and improves the quality of water environment.
As a clean distributed energy, biogas purified natural gas can replace petrochemical natural gas for vehicle fuel and residential gas. It is an important way of high-value and energy utilization of biogas. China is not only rich in biogas resources, but also has great potential for biogas production. The future development of biomass energy is immeasurable. At present, the main route for the further utilization of biogas is power generation and purification.