The hydrocarbon purification and preparation of CNG adopts the wet desulfurization process to remove the hydrogen sulfide in the biogas to less than 20mg/Nm3, and the pressure decarburization process is used after desulfurization to obtain high-quality compressed natural gas (CNG) with a purity of 97%. The main systems include desulfurization system, biogas compression system, dehydration and pre-cooling system, membrane pack decarburization and purification system and auxiliary system.

1. Technical scheme

2. . Benefit analysis

Sludge biogas is not only a green and clean energy, but also a high-quality resource, purifying sludge biogas to produce compressed natural gas (CNG), which can give full play to the value of biogas, increase product income, and achieve the synergistic effect of pollution reduction and carbon reduction. After purification and compression, the methane concentration of biogas can reach more than 97%, which can be integrated into the natural gas pipeline network as bio-natural gas, and the natural gas supply can be increased or filled for vehicle and civil fuel. At the same time, the high-purity liquid carbon dioxide separated by liquefaction can be sold as an industrial raw material as a by-product. This process breaks the limitations of the traditional biogas industry, opens up a new path for the high value-added utilization technology of biogas, improves the economic and social benefits of traditional biogas projects, and helps China steadily achieve the goal and task of "double carbon", which has broad market prospects.