【Ten Years of Rapid Development in Chemical Equipment】From 1968 to 2022: Domestic new carbonyl sulfide hydrolysis technology was first put into industrial use
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Witnessing the decade-long rapid development of chemical processing equipment; praising the prosperity and strength of modern China. Replies will be rewarded – discussions are welcome. -------------------------------------------The domestically developed million-cubic-meter-class fixed-bed carbonyl sulfide hydrolysis technology was successfully applied industrially for the first time at the Wanzhou branch of China National Petroleum Corporation’s Southwest Oil and Gas Field Company’s natural gas purification plant. As of 10:00 on December 13, the facility had been operating stably for over 900 hours, marking an important breakthrough in China’s efforts to remove carbonyl sulfide from natural gas to a high degree. It is understood that the complete set of technologies put into use this time features a carbonyl sulfide hydrolysis rate of over 99%; the temperature required for the hydrolysis reaction is 40 degrees Celsius lower than that of similar foreign products. This enables annual savings of around 1.6 million cubic meters of fuel gas, providing critical technical support for the clean and efficient development of sulfur-containing gas fields as well as for ensuring energy security. Carbonyl sulfide is a colorless, odorless, toxic, and flammable gas that is widely present in the production of fossil fuels such as natural gas. Due to technical gaps in core catalysts and associated process packages, China needs to enhance its independent innovation capabilities in the field of deep carbonyl sulfide removal; the localization of such technologies is a key step in overcoming the obstacles to upgrading the quality of natural gas in China. For a long time, the Natural Gas Research Institute of the Southwest Oil and Gas Field has been actively working to advance research on carbonyl sulfide hydrolysis technology. Through stages such as basic research, development of processes and catalysts, and pilot-scale testing, it has successfully developed a complete set of fixed-bed carbonyl sulfide hydrolysis technologies, creating a technological package for this process that possesses independent intellectual property rights. In May 2020, China’s first field test unit for carbonyl sulfide hydrolysis technology was built; it has been operating stably for over two years now, laying the foundation for its industrial application. The independently developed fixed-bed carbonyl sulfide hydrolysis technology package has been put into industrial use for the first time, enhancing China’s competitiveness in the field of efficient removal of organic sulfur from natural gas and providing support for promoting a green transformation in the development of sulfur-containing gas fields.
On November 8, 2022, the project for upgrading the quality of the product gas at the Wanzhou branch of the Natural Gas Purification Plant in the Southwest Oil and Gas Field, as well as the project for treating the exhaust gases from the sulfur recovery units, came online. The product gas met the required standards and could be sent out for use, while the exhaust gases were discharged at levels that complied with regulations. This marked the successful simultaneous implementation of these two projects at the field’s first purification plant with high sulfur content, thereby contributing to the creation of a green enterprise in this area and furthering efforts to protect the ecological environment in the Three Gorges Reservoir region.
For the first time, an independently developed COS hydrolysis process was employed. To address the global challenge of deep desulfurization of raw gas with high organic sulfur content, the Southwest Branch took into account various factors such as the source of the raw gas, its chemical properties, product specifications, and the actual conditions of existing facilities. By comprehensively evaluating various process options, it adopted this independently developed COS hydrolysis process for the first time; this process enables deep conversion of COS in the wet purified gas, with a single-stage hydrolysis conversion rate of over 99%. For the first time, a COS hydrolysis catalyst developed independently in China was used. This catalyst offers advantages such as a low reaction temperature, a small amount required per use, and high conversion efficiency. The use of this COS hydrolysis catalyst **improved the efficiency of sulfur conversion, achieving better quality and higher productivity, and resolved the issue of China’s long-term dependence on imported catalysts. For the first time, the independently developed CPO exhaust gas treatment process was utilized. By optimizing the structure of the quench tower and the process for storing acidic wastewater, this process enables the actual emission concentration of sulfur dioxide in the exhaust gases to be well below the standard requirement of 800 milligrams per cubic meter. It also reduces equipment corrosion and enhances the operational stability of the facility. More importantly, it breaks the Western countries’ long-standing monopoly in this technological field, resulting in savings of over 10 million yuan in costs related to process packages and patent fees. For the first time, a stand-alone chimney for high-sulfur exhaust gases was used. The footprint of such a chimney is reduced from 13 meters by 13 meters for traditional tower chimneys to 4 meters by 4 meters, **which saves land resources and reduces construction safety risks during the operation of existing purification plants.