Process for preparing olefins by methanol dehydration

Abstract

The invention discloses a process for preparing olefins by methanol dehydration, which solves the problem that the yield of the olefins is low, the problem that catalysts are easy to inactivate due to carbon deposition in the reaction process and other problems in prior art. The method comprises the following steps of: heating methanol to form steam, and allowing the methanol steam to contact a shape-selective ZSM-5 zeolite molecular sieve catalyst in a catalytic distillation reactor to react; allowing a reaction product to contact the catalyst in a first moving-bed reactor to react; separating the reaction products, and after products of ethylene and propylene are separated, allowing a C4-containing material flow and a C5 to C7-containing material flow to enter two moving-bed reactors which are sequentially perpendicular to a first moving-bed reactor respectively, so that the material flows contact the catalyst and react; and after scorching an inactivation catalyst in the moving-bedreactors for regenerating, recycling the regenerated catalyst. The method has the yield of the olefins and good activity and high stability of the catalyst.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a process for preparing olefins from methanol dehydration. Background technique [0002] Ethylene and propylene are important basic chemical raw materials with huge annual demand, and they are mainly obtained from petroleum processing at present. In recent years, the international oil price has been at a high level above US$50 / barrel. Our country's oil resources are limited, and more than 40% of the oil needed at present depends on imports. Therefore, the catalytic conversion of methanol produced from coal to ethylene and propylene has important strategic significance and application prospects. [0003] The methanol-to-ethylene-based process (MTO) and the propylene-based process (MTP) have entered the eve of large-scale industrialization. The MTO process uses SAPO-34 molecular sieve as a catalyst and a fluidized bed as a reactor. MTP uses ZSM-5 zeolite a...

AI Technical Summary

Problems solved by technology

[0006] The present invention aims at the disadvantages of the prior art, such as low yield of olefins, easy carbonation and deactivation of the catalyst in the reaction process, etc., and proposes a new process for methanol dehydration to olefins, which uses a catalytic distillation reactor and a continuous reaction regeneration The device constitutes the MTP catalytic reaction system, using the method of the present invention, the catalyst can be continuously reacted and regenerated, with less carbon deposition and high olefin yield

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