Method for recovering energy of incompletely regenerated flue gas generated in process of preparing olefin from methanol

Abstract

The invention relates to a method for recovering the energy of incompletely regenerated flue gas generated in the process of preparing olefin from methanol, which mainly solves the problem that the energy recovery efficiency of the flue gas is low because the incompletely regenerated flue gas generated in the process of preparing the olefin from the methanol has high CO content and low temperature and pressure in the prior art. The method comprises the following steps of: a) heating at least one part of the incompletely regenerated flue gas from which dust is removed to the initial combustiontemperature, and combusting by using O2 contained in the flue gas to obtain flue gas I; b) mixing the flue gas I and the residual unheated incompletely regenerated flue gas, reaching the initial combustion temperature, and continuously combusting in a flue by using the O2 contained in the flue gas to obtain flue gas II; c) making the flue gas II enter a flue gas turbine, expand and do work, and discharging flue gas III; d) making the flue gas III enter a CO combustor, replenishing air and fuel gas for complete combustion, and discharging flue gas IV; and e) recovering the waste heat of the flue gas IV by using a waste heat boiler, and discharging. Through the technical scheme, the problem is well solved, and the method can be applied to the industrial production of preparing the olefin from the methanol.

Description

technical field [0001] The invention relates to a methanol-to-olefin regeneration flue gas energy recovery technology, in particular to a methanol-to-olefin (MTO) incomplete regeneration flue gas energy recovery technology. Background technique [0002] The new process of converting methanol into low-carbon olefins by contacting with molecular sieve catalysts has opened up a new process route for producing low-carbon olefins from natural gas or coal through methanol, so as to partially replace the increasingly scarce petroleum resources and improve the energy structure. [0003] Patent US4,499,327 discloses a process for producing olefins from methanol by using a silicoaluminophosphate (SAPO) molecular sieve catalyst. The method is at a temperature between 300°C and 500°C, at a pressure between 0.1 atmosphere and 100 atmospheres, and between 0.1 and 40 hours -1 The weight hourly space velocity (WHSV) between. The process is highly selective for the production of ethylene a...

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Problems solved by technology

[0009] The technical problem to be solved by the present invention is that in the prior art, the energy recovery efficiency of the hood is low due to the high CO content, low temperatu

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