Thread Content
Against the backdrop of environmental energy and sustainability requirements, biogas, as a combustible gas with a high calorific value, has attracted considerable attention. The purified biogas can meet various application requirements, including use as household gas, heat and electricity generation in thermal power plants, fuel for vehicles, and integration into natural gas pipelines. 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. Lvyuan Environmental Protection utilizes PSA (Pressure Swing Adsorption) purification technology, which relies on pressure changes to achieve adsorption and regeneration. This technology enables the effective extraction of methane from biogas, bringing it to quality standards suitable for use as natural gas, while also removing carbon dioxide, thereby facilitating the extraction and utilization of gaseous energy sources. I. 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 whose operation timing is preset. 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 filtered through precision filters to remove any solid particles, before being sent to the pipeline network. The high-boiling-point impurity components remain adsorbed in 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 complete, vacuum pumping is used to further reduce the partial pressure of impurities; once the vacuuming 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 towers 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. II. The core advantages of PSA (Pressure Swing Adsorption) technology are operation at normal temperatures, a simple process flow, a high degree of automation, and the ability to achieve continuous separation and purification of gases. Its specific advantages can be summarized as follows: (1) High separation efficiency with controllable product purity. It is capable of effectively removing impurities such as carbon dioxide or small amounts of hydrogen sulfide from biogas, enabling the methane purity to reach over 95%, which meets the standards required for integrating bionatural gas into utility networks or for high-purity applications. (2) Adjusting process parameters allows for flexible control of gas concentration; by tweaking these parameters, it is possible to regulate the purity of the product gas to meet the requirements of different applications. (3) Flexible process operation with strong adaptability. The equipment is easy to start and stop, and the operating load can be adjusted flexibly according to the biogas production volume or demand. (4) Lower energy consumption and controllable operating costs. Compared to traditional methods such as chemical absorption, it does not require the use of large amounts of chemical reagents; the main energy consumption comes from the pressurization and depressurization processes in the adsorption tower, resulting in low energy usage. (5) High degree of automation and low operating costs: The process features a high level of automation, requiring less manual intervention which reduces labor costs; moreover, equipment maintenance is straightforward. (6) Environmentally friendly with no secondary pollution: The entire process relies primarily on physical adsorption; there is no need to use corrosive or toxic chemical reagents, and no wastewater or waste residues containing pollutants are generated. It has a minimal impact on the environment, meeting the environmental requirements of clean energy. The PSA biogas purification technology developed by Lvyuan Environmental Protection features high efficiency, environmental friendliness, controllable costs, energy savings, ready-to-use design for easy installation, environmental sustainability and convenience, a high degree of automation, and flexible operation. Lvyuan Environmental Protection is well aware that only through continuous innovation can it remain at the forefront in the highly competitive environmental protection industry. In the future, the development of PSA biogas purification technology will focus more on improving efficiency and reducing costs, so as to make greater contributions to gas purification and environmental protection.