【Ten Years of Rapid Development in Chemical Equipment】From 2013 to 2025, the pressure swing adsorption technology developed by the Southwest Research Institute for the recovery and utilization of industrial by-gas has been applied in over 1,000 units
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Let’s give praise and encouragement to the achievements made in China’s chemical engineering technology and equipment; your participation in discussions is the greatest encouragement. **********************【Ten Years of Progress in Chemical Engineering Equipment】Continuous updates and summaries available; feel free to join the discussions: https://bbs.hcbbs.com/thread-3576046-1-1.html ***************** Achieving the resource utilization of industrial by-product gases – A look at the pressure swing adsorption technology developed by Southwest Research Institute for recovering such gases. April 23, 2025. Recently, the “pressure swing adsorption technology for recovering industrial by-product gases,” developed independently by Southwest Chemical Engineering Research and Design Institute Co., Ltd. (hereinafter referred to as Southwest Institute), was included in the first list of advanced and applicable technologies announced by the Ministry of Industry and Information Technology. This technology addresses the challenges related to key processes, adsorption materials, essential equipment, and control techniques in large-scale gas separation and purification. It enables the thorough purification, efficient refinement, and resource utilization of industrial by-gases, thereby contributing to the achievement of the **\"dual carbon\" goals**. Process industries such as steel production generate large amounts of industrial by-gas each year, and either direct emission or combustion of this gas leads to waste of resources and air pollution. Due to technical limitations, a significant portion of industrial by-gas is not recycled, and the greenhouse gases and harmful components within it are not effectively treated. Therefore, it is crucial to develop advanced purification and efficient separation technologies for industrial by-product gases that are highly efficient, precise, and low in energy consumption. In the early 1980s, the first generation of pressure swing adsorption technology developed by the Southwest Research Institute was successfully applied in small fertilizer plants, earning it the **First Prize for Scientific and Technological Progress**. Since then, the Southwest Research Institute has continued to intensify its research efforts; the pressure swing adsorption technology has been upgraded to the sixth generation, resulting in a technology for recovering industrial by-gas using pressure swing adsorption that possesses independent intellectual property rights. This technology introduces a number of innovations: compared to foreign companies’ 45-second \"one-shot multiple processes\" technology, it introduces a 45-second \"two-tank sequential placement–interleaved washing\" pressure swing adsorption process, which significantly reduces the adsorption cycle time and equipment size. It overcomes the limitations associated with increased scale in pressure swing adsorption, such as higher demands for adsorbent usage and lower product recovery rates, thereby improving the efficiency of adsorbent utilization and product recovery. It also introduces a 6.0 megapascal high-pressure adsorption technology to meet the needs of hydrogen production through high-pressure gasification. Furthermore, it develops a \"adsorption–catalysis\" deep purification technology for the characteristic impurities present in industrial by-gas, addressing the challenges of impurity removal under complex conditions in such gases. Currently, this technology has been applied to over 1,000 pressure swing adsorption units for the recovery of industrial by-gases, including hydrogen purification, light hydrocarbon recovery, carbon monoxide purification, methane recovery, and carbon dioxide capture. These units feature low operational energy consumption, low investment costs, and a high level of intelligence, offering broad market prospects. Since the 1970s, the Southwest Research Institute has been dedicated to gas purification and separation, chemical catalysis, as well as the research, development, and promotion of related technologies. It has made numerous innovations in key areas such as the purification and upgrading of typical industrial by-product gases and their resource utilization, enabling the targeted removal of characteristic impurities from industrial by-product gases such as refinery gases, yellow phosphorus off-gases, and converter gas. The valuable components obtained through this process are then concentrated and reused to produce carbon-1 chemical products, and these technologies have been successfully put into industrial application. The pressure swing adsorption technology for recycling industrial by-gas, which has been selected this time, also won the First Prize for Scientific and Technological Progress from the China Petroleum and Chemical Industry Federation in 2022.
In view of the characteristics of hydrogen-rich mixtures in the petrochemical industry – such as reforming off-gases, catalytic dry gas, and hydrogenation off-gases – which contain a large number of hydrocarbon components including high-carbon hydrocarbons like C5+ – extensive experimental research has led to the development of a specialized adsorbent capable of removing all impurities other than hydrogen in just one step. This adsorbent features high adsorption capacity, low mass transfer resistance, and good regeneration properties; it enables an increased frequency of switching during PSA operations, reduces the duration of each operating cycle, improves the utilization rate of the adsorbent, eliminates the need for the traditional TSA pretreatment process, enhances the capacity of each unit of adsorbent to process feed gas and increase the yield of hydrogen, simplifies the process, and reduces the investment required for the installation. These technological advancements have led to an increasing use of PSA technology in hydrogen separation and recovery in refineries. Thanks to advances in adsorbents, along with process technologies such as cross-flushing that provides excellent regeneration effects, the range of feed gases that PSA units can process has greatly increased. With the rapid development of China’s petrochemical industry and the insufficient supply of hydrogen, PSA units can purify hydrogen not only from shift gas but also from catalytic dry gas, reforming off-gas, hydrogenation off-gas, medium shift gas, and styrene off-gas. With the advancement of adsorbents and process technologies, compared to traditional processes, the hydrogen recovery rate can be significantly improved through appropriate pressure equalization cycles and the use of evacuation techniques. Currently, the hydrogen recovery rate of PSA units can reach 95%. Refineries produce catalytic dry gas with a complex composition and a low hydrogen content (25–45% hydrogen). By using evacuation processes, the hydrogen yield from such gas can reach 87–90%, while with normal-pressure washing processes, the hydrogen yield for medium-transformed gas can also exceed 90%. Thanks to the rapid development of airflow distribution in adsorbers, programmable valves, and control systems, researchers have developed self-diagnosis systems for PSA units, as well as timing switching systems that enable online repair of faulty programmable valves. It has gradually evolved into large-scale PSA hydrogen production plants with 8, 10, 12, 14 towers, etc.; in the petrochemical industry, the hydrogen production capacity of a single PSA unit has reached 200,000 Nm³/h.