Two-stage series pressure swing adsorption biogas purification system capable of improving methane recovery rate

Abstract

The invention discloses a two-stage series pressure swing adsorption biogas purification system capable of improving the methane recovery rate. The system comprises a biogas buffer tank, a first-stagePSA adsorption tank, a product gas buffer tank and a desorption gas buffer tank, a biogas compressor is arranged at one end of the biogas buffer tank, a gas inlet pipe is arranged at one end of the biogas compressor, the gas inlet pipe is provided with a first electric control valve, a return pipe is arranged at the front end of the gas inlet pipe, the return pipe is provided with a second electric control valve, the first-stage PSA adsorption tank is arranged on the other side of the biogas buffer tank, and the desorption gas buffer tank is arranged on one side of the first-stage PSA adsorption tank. The system has a low cost, and allows the methane yield to be easier to control than that of an original two-stage PSA technology, the methane yield is controlled to control the methane emptying amount of a PSA decarburization device, and the higher the yield is, the less the methane is emptied, so the system contributes to the national environmental protection control of carbon emission.

Description

technical field [0001] The invention relates to the field of methane processing, in particular to a two-stage series pressure swing adsorption biogas purification system capable of improving methane recovery. Background technique [0002] Pressure swing adsorption (PSA) is an important and widely used gas separation method. It is an important process for the purification of biogas to natural gas. The main components of biogas are methane and carbon dioxide. The main function of PSA is to use adsorbents to absorb biogas The carbon dioxide component in the gas can increase the concentration of methane gas, make the calorific value reach the standard of natural gas, and realize the utilization of biomass energy. With the shortage of energy in the world, countries and industries pay more and more attention to the development and utilization of low-grade resources. In recent years, countries have higher and higher requirements for environmental pollution control. Compared with th...

AI Technical Summary

Problems solved by technology

Due to the principle of adsorbent adsorption, the small pore walls on the adsorbent are close to the carbon dioxide molecules. The wall diameter is normally distributed with the mean approximate to the particle size of carbon dioxide molecules, which will cause the adsorbent to also adsorb part of the methane molecules, resulting in methane being adsorbed, reducing the overall production yield, and leading to an increase in process production costs

Images