Catalyst and method for direct conversion of synthesis gas to ethylene

Abstract

The invention belongs to the direct preparation of low-carbon olefins from synthesis gas, and specifically relates to a catalyst and a method for directly converting synthesis gas into ethylene. The conversion reaction is carried out on a fixed bed or a moving bed with synthesis gas as a reaction raw material, and the catalyst is a composite catalyst. , composed of component I and component II by mechanical mixing, the active ingredient of component I is a metal oxide, and component II is a molecular sieve of MOR structure; the active ingredient in component I and component II The weight ratio is between 0.1-20 times range. The reaction process has high product yield and selectivity. The selectivity of low-carbon olefins can reach 50-90%, among which the selectivity of ethylene can reach 30-75%. At the same time, the selectivity of by-product methane is extremely low (<15%). It has a good application prospect.

Description

technical field [0001] The invention belongs to the preparation of low-carbon olefins from synthesis gas, and specifically relates to a catalyst and a method for directly converting synthesis gas to ethylene. Background technique [0002] Lower olefins refer to olefins with carbon number less than or equal to 4. Low-carbon olefins represented by ethylene and propylene are very important basic organic chemical raw materials. With the rapid growth of my country's economy, the low-carbon olefins market has been in short supply for a long time. At present, the production of low-carbon olefins mainly adopts the petrochemical route of cracking light hydrocarbons (ethane, naphtha, light diesel oil). The tubular cracking furnace process with light hydrocarbons as raw materials will encounter more and more problems with raw materials, and the production process and raw materials of low-carbon olefins must be diversified. The use of synthesis gas to produce olefins can broaden the s...

AI Technical Summary

Problems solved by technology

Recently, the team of Professor de Jong from Utrecht University in the Netherlands has made good progress in using SiC, Fe catalysts supported by inert supports such as carbon nanofibers and Fe catalysts modified by Na, S and other additives, and achieved a selectivity of 61% for low-carbon olefins, but As conversion increases, selectivity decreases

The catalyzer of above-mentioned report adopts metallic iron or iron carbide as active component, and reaction follows the chain growth reaction mechanism of metal surface, and the selectivity of product low-carbon olefin is lower, and the selectivity of especially single product such as ethylene is lower than 30%

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