Effective Separation Of C4 Olefins For Maximizing Propylene Fluid Catalytic Cracking

Aimed at the inefficient reclaim problem of mixed C4 olefin resources due to the lack of effective separation method of alkane and olefin,the author presents a method that firstly alkene is made of highly selective separation and then propylene is produced by cracking olefins based on fluid catalytic cracking unit.The experiment verifies the feasibility of the cracking process of using sec-butyl alcohol to produce propylene.In addition,the author makes the simulation and optimization of the process route with the process simulation software.In the fixed bed micro reactor,the investigation is made into the effect of using the secbutyl alcohol and alkyl ether as cracking feedstock under different catalytic cracking temperature and different catalytic cracking catalyst(USY molecular sieve catalyst,different ratio of silicon and aluminum ZSM-5 molecular sieve catalyst)conditions,the author verifies the feasibility of increasing propylene production process by sec-butyl alcohol,alkyl ether.From the experimental results,the reaction conversion rate of carbon four olefin such as sec-butyl alcohol and alkyl ether in the optimized conditions is close to 100% with the propylene up to 42% and the effective utilization rate of carbon more than 85%.The extremely low carbon content has little effect on the cracking performance of catalyst.The intermediate products of carbon four olefin such as sec-butyl alcohol,alkyl ether can be used as the raw material of propylene.With the comparison of the minimum separation work data of mixed carbon four separation process and different sec-butyl alcohol production process data,the production process of sec-butyl alcohol with the indirect hydration and nitrogen gas stripping process is determined avoiding the regeneration of sulfuric acid.With the ASPEN simulation software,the author makes simulation optimization of the new sec-butyl alcohol production to determine the process parameters.In this way,the energy consumption is reduced by over 70% compared with the current carbon four extractive distillation process.The process of effective separation of C4 olefins for maximizing propylene fluid catalytic cracking has obvious advantage in energy saving.