A kind of alkali-modified composite catalyst and the method for producing ethylene by hydrogenation reaction of carbon monoxide

Abstract

Disclosed are an alkali-modified composite catalyst and a method for preparing ethylene by the hydrogenation of carbon monoxide. A conversion reaction is carried out on a fixed bed or a moving bed using a mixed gas of carbon monoxide and hydrogen as a reaction raw material, wherein the catalyst used is a composite catalyst compounded from a component I and a component II by means of mechanical mixing. The active component of the component I is a metallic oxide, and the component II is a molecular sieve of an organic alkali-modified MOR structure, wherein the organic alkali is a heterocyclic compound, and the modification treatment is to disperse the organic alkali into a B acid site within a 12-membered ring pore channel of the molecular sieve; and the weight ratio of the active component of the component I and the component II is 0.1:20. The reaction has a very high product yield and selectivity, wherein the selectivity of a side product of methane is very low and the selectivity and the space-time yield of ethylene are significantly improved, and the reaction has very bright application prospects.

Description

technical field [0001] The invention belongs to the production of low-carbon olefin high-value chemicals by carbon monoxide hydrogenation, in particular to an alkali-modified composite catalyst and a method for producing ethylene by carbon monoxide hydrogenation. Background technique [0002] Ethylene is a very important basic chemical raw material and one of the largest chemical products in the world. The ethylene industry is the core of the petrochemical industry and occupies an important position in the national economy. Low-carbon olefins refer to olefins with carbon atoms 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, my country's ethylene industry has developed rapidly and occupies an important position in the world's ethylene market. For a long time, the low-carbon olefins market has been in short supply. At present, the producti...

AI Technical Summary

Problems solved by technology

But ethylene single selectivity is less than 20%

Bao Xinhe and Pan Xiulian's team at Dalian Institute of Chemical Physics, Chinese Academy of Sciences reported that ZnCr supported on alumina 2 o 4 Oxide and hierarchical porous SAPO-34 molecular sieve composite bifunctional catalyst (Jiao et al., Science 351 (2016) 1065-1068), achieved a selectivity of 80% for low-carbon olefins at a CO conversion rate of 17%, but ethylene Selectivity below 30%

In the patent 201610600945.6 they applied for, a bifunctional catalyst containing oxygen holes and MOR molecular sieves was used for the one-step olefin reaction of syngas, which increased the selectivity of ethylene to 30-75%, but the number of carbon atoms in the by-product exceeded 3 has more hydrocarbons, which affects the application of this technology

Images