蒸汽裂解生产乙烯的原料优化选择与配置

Optimal selection and configuration of feedstock for ethylene by steam cracking

关键词:  乙烯  低碳烯烃  蒸汽裂解  煤基石脑油 

Key words:  ethylene  light olefins  steam cracking  coal-based naphtha

摘要:

目的 对国内乙烯裂解原料的优化配置问题进行分析,为炼化企业提质增效提供相关信息和技术参考。方法 对乙烷裂解制乙烯投资热进行理性分析后,指出国内蒸汽裂解生产乙烯的原料来源广泛,以石脑油为主,兼及少量低碳烃和低辛烷值油品。阐述了石脑油的分离技术及裂解评价试验对乙烯裂解原料优化的重要作用。对煤基石脑油与石油基裂解原料的物性和裂解性能进行对比分析。结果 煤基石脑油中正构烷烃质量分数达到72.83%,其裂解乙烯、丙烯、双烯(乙烯+丙烯)及三烯(双烯+1,3-丁二烯)的收率分别比石油基石脑油高出18.33%~26.27%、5.92%~12.34%、16.50%~21.41%、12.66%~17.53%。煤基石脑油裂解乙烯收率分别比拔头油和油田轻烃高出10.95%和10.74%,双烯收率分别比拔头油和油田轻烃高出4.28%和4.09%,三烯收率分别比拔头油和油田轻烃高出6.89%和6.22%,裂解性能优异。结论 立足于国内“富煤、贫油、少气”的能源结构实际,充分发挥炼化一体化优势,积极盘活石油基乙烯裂解原料,对炼油厂副产低碳烃和低辛烷值油品等适合做乙烯裂解原料的烃类,应该合理利用。以煤基石脑油为突破口拓展新的裂解原料来源,是解决国内乙烯裂解原料短缺问题、实现炼化装置提质增效、推动炼化行业高质量发展,保障能源安全和实现乙烯工业可持续发展的有效途径。 

Abstract:

Objective The aim is to analyze the optimal allocation of domestic ethylene cracking feedstock, and provide relevant information and technical reference for refining and chemical enterprises. Methods After rational analysis of the investment heat of ethylene production from ethane cracking, it was pointed out that the feedstock of ethylene production from steam cracking in China was still mainly naphtha with a small amount of low-carbon hydrocarbon and low-octane oil. The important roles of naphtha separation technology and cracking evaluation test in the optimization of ethylene feedstock were described. The physical properties and cracking properties of coal-based naphtha and petroleum-based cracking feedstock were compared and analyzed. Results The hot investment of the cracking of ethane to ethylene should be cautious and rational, while actively activating naphtha resources, the by-products such as low-carbon hydrocarbons and low-octane oil products, which were suitable for ethylene cracking feedstock, should be selected and used reasonably. The mass fraction of N-alkanes in coal-based naphtha was 72.83%, and the yields of ethylene, propylene, diene and triene were 18.33%-26.27%, 5.92%-12.34%, 16.50%-21.41%, 12.66%-17.53% higher than those of petroleum-based naphtha, respectively. The ethylene yield of coal-based naphtha was 10.95% and 10.74% higher than that of topped oil and light hydrocarbon of oil field, respectively. The yield of diene was 4.28% and 4.09% higher than that of topped oil and light hydrocarbon of oil field respectively. The yield of triene was 6.89% higher than that of topped oil and 6.22% higher than that of light hydrocarbon. Conclusion sBased on the actual domestic energy structure of rich coal, poor oil and lack gas, the superiority of refining and chemical integration to be brought into full play, and the cracking feedstock of petroleum-based ethylene to be brought into active play, taking coal-based naphtha as a breakthrough to develop new sources of cracking feedstock was an effective way to solve the problem of shortage of domestic ethylene cracking feedstock, to improve the quality and efficiency of refining and chemical plants, to promote the high-quality development of refining and chemical industry, and to ensure energy security and realize the sustainable development of ethylene industry.