A methanation fluidized bed reactor

Abstract

The invention provides a methanation fluidized bed reactor which is equipment for performing reaction on CO and H2 to generate methane and water and performing reaction on CO2 and H2 to generate methane and water at a certain constant low temperature. The methanation fluidized bed reactor comprises a cylindrical shell and inner parts, wherein a primary gas distributor and a secondary gas distributor are arranged at the bottom, and a catalyst is filled to form a catalyst bed; a heat exchange device consisting of a plurality of groups of heat exchange tubes is arranged in the catalyst bed; the lower ends of the heat exchange tubes in each group are communicated with a water inlet header pipe which is communicated with a water outlet of a steam drum, and the upper ends of the heat exchange tubes in each group are communicated with a steam outlet header pipe which is communicated with a steam inlet of the steam drum. According to the methanation fluidized bed reactor, heat continuously released during methanation reaction can be timely transferred through another medium, and the reaction can be performed at the constant low temperature.

Description

technical field [0001] The invention belongs to the field of chemical industry and relates to a fluidized bed reactor, in particular to a methanation fluidized bed reactor. Background technique [0002] At present, industrially synthesized natural gas mainly includes coke oven gas to natural gas and coal to natural gas. The key reaction of synthetic natural gas is methanation reaction, whose reaction formula is: [0003] CO+3H 2 =CH 4 +H 2 O△H 298 =-206KJ / mol [0004] CO 2 +4H 2 =CH 4 +2H 2 O△H 298 =-165KJ / mol [0005] The methanation reaction is a strongly exothermic reversible reaction. Under typical methanation reaction conditions, the adiabatic temperature rise per 1% CO conversion in the gas is about 72 °C, and every 1% CO 2 The adiabatic temperature rise for the conversion is about 60°C. [0006] In the existing methanation process, the methanation reactor is in the form of adiabatic reaction, that is, after the adiabatic reaction of the catalyst bed, the ...

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Problems solved by technology

[0010] ①The reaction temperature is high, the equipment material requirements are high, and the safety is poor

If CO and CO in the inlet gas of the methanation reactor occur 2 When the content suddenly increases, the reactor is prone to over-temperature accidents, and the safety and reliability are poor

[0012] ② High catalyst cost

When the temperature is above 400°C, it is easy to produce carbon deposition reaction, which will cause carbon deposition on the surface of the catalyst, reduce the activity of the catalyst, and affect the service life of the catalyst

[0016] ④High power consumption

[0022] Current fluidized bed reactors, such as the methanation reaction device disclosed in Chinese patent application No. 20101023120.2, include fluidized bed reactors and fixed bed reactors, wherein in the fluidized bed reactor, the reacted gas and catalyst At the same time, it enters the gas-solid separator for separation. At this time, the separation efficiency is limited, and a large amount of catalyst cannot be recovered, and the gas after the reaction is connected to the output together.

The reactors all have the defects of uneven gas distribution, easy channeling, large bubbles, and high catalyst consumption.

[0023] Patent No. 201110023691.3 further sets up a cooling water spraying device to absorb the heat of reaction on the one hand and form a dilute phase region of solid particles in the upper space on the one hand, but spraying cooling water will make it more difficult to reuse the catalyst, which is not conducive to large-scale continuous production of

The reactor spray device increases the water concentration, which increases the product concentration and reduces the reaction conversion rate

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