A method for producing propylene from n-butene

Abstract

The invention discloses a method for producing propylene from n-butene. Under the action of a catalyst, a raw material containing n-butene is subjected to cracking reaction under the reaction temperature of 500-600 DEG C, preferably 500-550 DEG C and the total reaction pressure (the absolute pressure) is 0-0.25MPa; the weight space velocity is 1-10h<-1>, preferably 1-5h<-1>; the catalyst comprises the following components in percentage by weight: 30-60 percent of a phosphorus-modified SAPO-11 molecular sieve, 20-30 percent of a hydrogen type ZSM-5 or ZSM-22 molecular sieve and the balance of an adhesive; the load of the phosphorus-modified SAPO-11 molecular sieve is 0.2-1 percent by weight (not including phosphorus in the SAPO-11 molecular sieve). The method used in the industrial process of producing propylene from the mixed carbon-4 raw material containing n-butene has the advantage of high once-through yield of propylene.

Description

technical field [0001] The present invention relates to a method for producing propylene from n-butene. Background technique [0002] In 2011, the total output of propylene in my country was 14.68 million tons. In 2011, the apparent consumption of propylene in my country was 16.43 million tons, and the self-sufficiency rate was only 89.3%. It is estimated that the apparent consumption of propylene in my country will reach 22 million tons in 2015. [0003] With the lightening of ethylene cracking raw materials and the impact of ethane cracking routes and methanol-to-olefins projects, in recent years, the output of ethylene cracking by-product propylene, which is the main source of propylene, will decrease year by year. On the other hand, the rapid development of the methanol-to-olefins project, and its by-product C4 has provided more n-butene resources for the market. Therefore, using cheap and abundant n-butene as raw material, converting n-butene into propylene through ca...

AI Technical Summary

Problems solved by technology

[0013] The ZSM-5 molecular sieve catalyst adopted in the prior art scheme still has the deficiency that the single-pass yield of the target product propylene is low. Through the catalyst modification method described in the above-mentioned documents, the single-pass yield of propylene can be appropriately improved, but the propylene yield is still low. room for further improvement