The Process And Technologies Research On Mixed C4 Hydrogenation For Producing Ethylene Cracking Feedstock

Nowadays, naphtha from refineries is the most important cracking feedstock to produce ethylene in the world. As naphtha resources reducing gradually, it becomes necessary to increase ethylene yield by substituting new cracking feedstock for naphtha. In the process of ethylene and propylene production, the cost of raw material takes 60-80% proportions of total production cost, so that, it will have an influence on the development of petrochemical field to select proper cracking feedstock..Olefin content takes 50-60% proportions in C4 fractions produced by typical catalytic cracking plant of domestic refineries, meanwhile, contains few impurities, such as diene, sulphur, arsenic, etc. Owing to high content olefin, polymerization, cyclization, condensation and coking will occur in cracking furnace tubes if C4 fractions are used as feedstock to produce ethylene. So, C4 components should be analyzed and researched, and issue proper suggestions for comprehensive usage of isobutene and butene-1 components according to treatment cost. Rest C4 components will be transferred to alkane by hydrogenation as cracking feedstock.At present, there are not process technologies and plants by mixed C4 hydrogenation to produce ethylene cracking feedstock in domestic refineries, as well as in other countries. This project uses low pressure hydrogenation to saturate and hydrogenate olefin in C4 fractions and remove impurities from it to make olefin ethylene cracking feedstock with top quality. If this process technology gets success, it will fill the gap in the field for domestic technology.This paper mainly focuses on the following contents:(1) Research and analyze refineries C4 components and C4 usage and market at present in Daqing, issue proper suggestions on comprehensive usage of isobutene and butane-1 components as per treatment cost.(2)Select sutiable catalyst as per component of refineries rest C4 feedstock and impurities.(3) Take pilot for catalyst on the base of small-scale test and then continuous stable test.(4)Optimize process procedure and operating conditions of refineries C4 hydrogenation.(5)Complete C4 pyrolysis simulation optimization research according to pilot result.