【Ten Years of Great Progress in Chemical Technology】Successful Application of Hydrogenation Catalysts for Non-precious Metal C4 Fractions from 2023 to 2033

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Ten years of rapid development in chemical engineering technology – praising the prosperity and strength of modern China. This is just a starting point; more participation will make things even more interesting. With you here, HaiChuan becomes even better. [Ten years of progress in chemical engineering equipment] – continuous updates and summaries available; feel free to join the discussions at https://bbs.hcbbs.com/thread-3576046-1-1.html. Enhancing quality awareness to promote high-quality development. ----------------------------------------- Non-precious metal catalysts have been used successfully in Guangdong Petrochemical’s 600,000-ton/year alkylation plant for nearly half a year. According to a report from Sinochem News on August 3, the highly active and selective non-precious metal alloy catalysts developed by the China Petroleum Petrochemical Research Institute have been in use in this plant for almost 6 months. These catalysts enable the selective hydrogenation of alkylation feedstocks containing coked tetrahydrocarbons, thereby significantly reducing the costs associated with the pre-treatment of such feedstocks. 　　The selection of hydrogenation as the key step in the alkylation process for alkylating feedstocks containing butene is aimed at removing butadiene from the feedstock, thereby reducing acid consumption during alkylation and the dry point of the alkylated oil. At the same time, it helps to minimize the loss of monoenes, thus increasing the yield of the alkylated oil. 　　Currently, the hydrogenation catalysts used for the alkylation of carbon tetracontane-containing raw materials in both domestic and international industries are all precious metal palladium catalysts. Although they exhibit excellent hydrogenation activity and selectivity, they have weak resistance to poisoning. Trace impurities in the raw materials, such as arsenic and amines, can cause the palladium catalyst to become deactivated rapidly, severely affecting the normal operation of the equipment. At the same time, precious metal prices have remained high in recent years, with palladium catalysts costing 2 million yuan per ton, imposing significant costs on enterprises. 　　The design feed composition of the alkylation unit at Guangdong Petrochemical contains about 35% coker tetrahydrocarbon, and impurities in this compound such as sulfides, basic nitrogen compounds, and coke dust, which are difficult to remove, can significantly affect the hydrogenation activity of palladium catalysts. Industrial application practices by domestic enterprises have shown that once coked tetrahydrocarbons are mixed into alkylating feedstocks containing carbon tetrahydrocarbons, conventional precious metal palladium catalysts will rapidly become poisoned and deactivated. The palladium catalysts specified in the original process package design failed to meet the technical requirements, and palladium catalyst suppliers both domestically and internationally withdrew from the public bidding process organized by Guangdong Petrochemical, leaving the plant without any available catalysts. 　　To address the critical hydrogenation technology issue related to raw material selection for the alkylation unit at Guangdong Petrochemical, the Petrochemical Research Institute and Guangdong Petrochemical jointly undertook the major technical field test project titled \"Industrial Demonstration of Highly Selective Non-precious Metal Catalysts for Selective Hydrogenation of C4 Fractions.\" To address the issues of weak impurity resistance and high cost associated with traditional palladium catalysts, the Petrochemical Research Institute, guided by theoretical calculations, developed an active phase made of a non-precious metal multialloy. By leveraging the geometric properties of the alloy as well as electronic synergistic effects, it was possible to effectively control the selectivity for butadiene hydrogenation as well as the catalyst’s impurity resistance, thereby overcoming the technical challenge of insufficient selectivity for butadiene hydrogenation in non-precious metal catalysts. Ultimately, within 6 months they developed an impurity-resistant, low-cost non-precious metal alloy catalyst for the selective hydrogenation of carbon tetra fraction, suitable for the original operating conditions. Its overall performance was on par with that of palladium catalysts, while the cost was reduced by over 70%, enabling it to serve as a seamless substitute for palladium catalysts. 　　On February 14, the catalyst was successfully used in the initial feeding of the newly built 600,000 tons per year alkylation unit at Guangdong Petrochemical, and industrial calibration was completed. The calibration results show that the dibutene content in the hydrogenated product is no higher than 100 ppm, and the yield of monoenes is no less than 100%. Currently, this catalyst exhibits good hydrogenation activity, high selectivity for single alkenes, and strong resistance to impurities, laying a solid foundation for the ‘stable, efficient, and optimal’ operation of this facility.