Method for removing iron-based catalyst carried in Fischer-Tropsch synthesis tail gas of slurry-phase bed

Abstract

The invention discloses a method for removing iron-based catalyst carried in Fischer-Tropsch synthesis tail gas of a slurry-phase bed, comprising the following steps of: in a Fischer-Tropsch synthesis reactor of the slurry-phase bed, feeding the non-reacted raw material gas and the generated gas (Fischer-Tropsch synthesis tail gas) with partial fine catalyst powder to a settling section of the Fischer-Tropsch synthesis reactor; due to the action of the horizontal magnetic field in the settling section, collecting the fine catalyst powder carried in the Fischer-Tropsch synthesis tail gas to the wall of the reactor and then returning the fine catalyst powder to the slurry phase so as to further remove the catalyst in the tail gas. By adopting the method, the content of the catalyst in the gas-phase stream at the outlet of the reactor is lower than 1ppm, thereby benefit conditions to the steady operations of the consequent heat exchanger, separator and recycle gas system are provided, and the long-period operation of the Fischer-Tropsch synthesizer is ensued.

Description

technical field [0001] The invention relates to a method for removing the iron-based catalyst carried by the tail gas of a slurry bed Fischer-Tropsch synthesis. Background technique [0002] In order to overcome the problems of easy occurrence of hot spots in the fixed-bed Fischer-Tropsch synthesis catalyst bed, difficulty in catalyst loading and unloading, etc., people have vigorously developed the slurry-state Fischer-Tropsch synthesis technology in recent years. Because the slurry bed reactor requires that the particle size of the catalyst should not be too large, otherwise the catalyst and the product cannot form a slurry phase. At the same time, the catalyst and the heavy fraction of the Fischer-Tropsch synthesis product must be kept to form a slurry without phase separation, and the catalyst is basically distributed along the axial direction of the reactor. Uniformity, there are certain requirements for the feed gas flow rate of the Fischer-Tropsch synthesis reactor. "...

AI Technical Summary

Problems solved by technology

Catalyst particles and powders entrained out of the reactor will be deposited at the turns of heat exchangers, separators and pipelines, which will cause problems such as increased pressure drop of heat exchangers, difficulty in draining liquid from separators, and increased pressure drop of pipelines over time. Due to the high pressure drop of the circulating gas system, the unit will be shut down, which will seriously affect the stable operation of the slurry bed Fischer-Tropsch synthesis unit

[0003] In order to overcome the above problems, people usually expand the diameter of the top of the Fischer-Tropsch synthesis slurry bed reactor, reduce the linear velocity of the gas phase flow, increase the height of the settling section of the slurry bed reactor, etc., and solve the problem of gas phase entrainment of catalyst by means of settling , but the above method does not fundamentally solve the problem

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