A synthetic natural gas methanation equipment and process

Abstract

The invention belongs to the field of chemical industry, and relates to a device, system and method for the methanation process of synthetic natural gas, which can generate superheated steam at the same time during the methanation process, and can also be equipped with a post-processing system. When the operating load is 30-120% When fluctuating between, the methanation fluidized bed reactor is in a normal fluidized state, and a methanation fluidized bed reactor can complete the reaction; when the operating load fluctuates between 0% and 30%, the methanation fluidized bed reactor The fluidized bed reactor is in an abnormal fluidized state, and the method of adding steam to the feed gas must be used to maintain the normal fluidized state of the catalyst bed. Since steam is added to the feed gas entering the methanation fluidized bed reactor, this will cause the methanation reaction to move in the opposite direction, resulting in CO and CO 2 Conversion rates drop. The gas from the methanation fluidized bed reactor enters the isothermal low-temperature methanation reactor after the water is separated to complete the reaction and produce qualified natural gas.

Description

technical field [0001] The invention belongs to the field of chemical industry and relates to equipment, system and method for synthetic natural gas methanation process. 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

[0020] For the existing methanation fluidized bed reactor, there is a defect of small operating flexibility, and its normal operating load fluctuation range is between 30% and 120%.

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