System and method of preparing propylene tail oil by value-added exploitation of methanol

Abstract

The invention provides a system and a method of preparing propylene tail oil by value-added exploitation of methanol. The comprises a first reactor, a second reactor, a product separation unit, a c 4 hydrocarbon extraction, rectification and separation device and a heating furnace, wherein the first reactor performs dimethyl ether preparation reaction with methanol to form a first product flow; the second reactor synthesizes propylene by using a material from the heating furnace as a raw material to form a second product flow; the product separation unit receives and separates the second product flow to form propylene, c 4 hydrocarbon, a c 5 / c 6 hydrocarbon mixture and ethylene; the c 4 hydrocarbon extraction, rectification and separation device separates at least part of c 4 hydrocarbon to form a butylene product flow; and the heating furnace receives and heats at least part of first product flow, at least part of butylene product flow, at least part of c 5 / c 6 hydrocarbon mixture and at least part of ethylene. The system and the method can reprocess butylene alone, and supplement the removed butane part with the c 5 / c 6 hydrocarbon mixture; the reprocessing quantity of the tail oil is increased; the yield of propylene is increased; the value-added exploitation of the tail oil is achieved; and economic benefits are raised.

Description

technical field

[0001] The invention belongs to the field of methanol-to-propylene technology, in particular to a system and method for value-added utilization of methanol-to-propylene tail oil. Background technique

[0002] Propylene is one of the important basic chemical raw materials in the chemical industry. Methanol to propylene process, that is, using coal or natural gas as a raw material through synthesis gas, methanol, and then to propylene, as a non-petroleum route technology, gets rid of the shackles of oil shortage, and opens up a new raw material route for the production of propylene .

[0003] The methanol-to-propylene technology of Shenhua Ningxia Coal Industry Group, located in Ningdong, Ningxia, is provided by Germany's Lurgi. For this device, the feed amount of the raw material dimethyl ether / methanol and the recycling amount of ethylene, C4 hydrocarbons, and C5 / C6 mixed hydrocarbons (C5 / C6 mixed hydrocarbons are part of the tail oil) Limited by the maxim...

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