【Ten Years of Great Progress in Chemical Technology】005-2023: Technology for Producing Propylene Oxide via Propylene Glycol Peroxide (CHP) using Independent Intellectual Property Rights

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This post was last edited by Desert Fish on 2023-3-3 06:59. Sinopec’s proprietary technology for producing propylene oxide using the cumene hydroperoxide (CHP) process has been successfully applied in industry for the first time. As of February 10, 2023, the first unit – Tianjin Petrochemical’s 150,000-ton/year propylene oxide industrial demonstration plant – had operated stably for 28 days, with an operating load of 60%, and it is gradually being adjusted toward full capacity. This project is one of Sinopec’s “Ten Dragon” scientific and technological research projects, developed jointly by the Shanghai Research Institute of Petrochemical Technology, Tianjin Petrochemical Company, Shanghai Engineering Corporation, and Qingdao Safety Engineering Research Institute. 　　“This is a green manufacturing technology for propylene oxide that does not involve by-products. ”Jin Guojie, a professor-level senior engineer at the Shanghai Research Institute of Petrochemicals and senior supervisor of Research Department 8, said in an interview with reporters, “This technology focuses on the production of propylene oxide, which helps to better coordinate and arrange production processes, thereby achieving higher atom economic efficiency.” ” 　　It is reported that this technology uses propylene and CHP as raw materials to produce propylene oxide, involving three main reactions: the first is the air oxidation of isopropylbenzene to produce CHP; the second is the reaction of propylene with CHP in the presence of an epoxidation catalyst to yield propylene oxide and α,α-dimethylbenzyl alcohol; the third is the catalytic hydrogenolysis of α,α-dimethylbenzyl alcohol to produce isopropylbenzene. “By looking at the flow diagram, it can be seen that this is a reaction process in a closed-loop cycle. ”Jin Guojie said. 　　“In previous years, there was virtually no advanced and green production technology for propylene oxide in China; most companies used the chlorohydrin method or formed joint ventures with foreign companies that held a technological monopoly. ”Jin Guojie told reporters that in order to overcome the key technical challenges, the research team developed a super-hydrophobic titanium-containing mesoporous molecular sieve epoxy catalyst, as well as a dual-functional dehydrogenation catalyst for dehydration and hydrogenation. The former addresses the ‘see-saw’ problem between catalyst selectivity and conversion rate by fundamentally improving the stability of mesoporous materials, thereby achieving simultaneous improvements in the stability, selectivity, and conversion rate of the epoxidation reaction; the latter combines the dehydration and hydrogenation reactions of α,α-dimethylbenzyl alcohol into a single process, allowing for efficient conversion within one reactor. 　　Given the tendency of peroxides to decompose and the associated potential safety risks, the research team developed an innovative multi-stage series-connected propylene epoxidation process along with system control techniques that enable heat removal between stages, thus ensuring controllable reaction temperatures and complete conversion of CHP, and facilitating the safe and stable operation of the facility over extended periods at full capacity. 　　Furthermore, the propylene oxide purification technology developed by the R&D team can significantly improve product quality. According to GB/T 14491-2015 Industrial Propylene Oxide, the mass proportion of aldehydes (acetaldehyde + propionaldehyde) in top-quality propylene oxide should be less than or equal to 50 ppm. “For propylene oxide produced using the CHP method, the mass fraction of aldehydes can be kept below 10 ppm. ”Jin Guojie said, “Whether used to produce highly active polyethers, bimetallic-catalyzed polyethers, or ordinary polyethers, downstream companies that use our products as raw materials give them very high evaluations.” ” 　　It is reported that 70% to 80% of propylene oxide in China is used to produce polyethers, which are then used to manufacture polyurethanes. Polyurethane materials are widely used in automotive interiors, seats, and interior decorations. To achieve a \"odor-free\" condition, it is necessary to improve the quality of the propylene oxide raw material. It is also reported that the 300,000 tons per year propylene oxide production facility at Zhenhai Refining & Chemical Co., which will utilize this technology, is under construction, with completion expected in 2024.