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With the growing demand for renewable energy, biogas, as a combustible gas with a high calorific value, is receiving increasing attention. The purified biogas can meet the requirements of various high-end applications, such as cogeneration, environmental protection, industry, chemical and agricultural sectors, as well as vehicle fuel. Biogas purification refers to the process of removing impurities from biogas (mainly carbon dioxide) in order to increase the methane concentration, thereby improving energy efficiency and contributing to environmental protection. Tangshan Lvyuan Environmental Protection Technology Co., Ltd. employs the H-PSA carbon removal technology for biogas purification, which enables the effective extraction of methane from biogas to meet the quality standards required for natural gas. This process also removes carbon dioxide, thereby facilitating the extraction and utilization of biogas as an energy source and promoting the use of clean energy. So, what is the working principle of PSA purification technology, and what are its advantages? Working principle of PSA purification technology: PSA purification technology is a gas separation method based on pressure changes. The gas coming from the desulfurization system is compressed by a compressor to 0.6 MPa; this biogas then enters a cold dryer to have its moisture removed. After that, it goes into a gas-liquid separator. From the bottom of the adsorption tower, it enters a methane decarburization purification unit with a pre-set control timing. The components in the feed gas that are easily adsorbed (CO2) are captured by the adsorbent, while those that are not easily adsorbed (CH4) emerge as the product gas. This gas undergoes pressure regulation at the top of the adsorption tower and is further processed through a precision filter to remove any solid particles, before being sent to the pipeline network. High-boiling-point impurity components remain adsorbed within the adsorbent. The PSA purification technique uses pressure reduction or evacuation for desorption, that is, a portion is separated by reducing the pressure through pressure equalization. To ensure thorough regeneration of the adsorbent, after the pressure equalization process is completed, vacuum pumping is used to further reduce the partial pressure of impurities; once the evacuation process is finished, the regeneration of the adsorbent is complete. After the adsorbent regeneration is completed, the pressure in the adsorption tower is -0.07 to -0.09. To ensure the adsorption efficiency and stabilize system pressure, it is necessary to pressurize the adsorption tower to reach the specified adsorption pressure; simultaneously with this pressure increase, the effective components (CH4) present in the dead spaces of other adsorption towers are recovered, and pressure equilibrium is achieved between the towers in a pair-wise manner. Then, the product gas is used to raise the pressure in the adsorption tower to the adsorption pressure; at this point, the preparation for adsorption in the tower is complete, and the next cycle can begin. Through the above process, continuous, stable, and safe operation of the methane purification unit is achieved. Advantages of PSA purification technology: 1. High product purity, capable of meeting automotive fuel standards ； 2. Operation at normal temperature and low pressure results in lower energy consumption, and no additional heating is required for bed regeneration ； 3. The equipment structure is relatively simple, making operation and maintenance convenient ； 4. It can achieve fully automatic continuous operation ； 5. Environmentally friendly, as it does not generate secondary pollutants such as wastewater.