Fixed bed composite reaction equipment

Abstract

The invention relates to fixed bed combined reaction equipment which mainly comprises a cylindrical shell with an end enclosure, a reaction gas inlet and a reaction gas outlet on the shell, a porous gas distributor, a porous gas collection plate, a catalyst layer and a heat exchange pipe for cooling media to transfer heat; steam headers provided with stream pressure adjusting valves form a cooling medium circular loop of which catalysts in at least one heat exchange reaction area are filled in the pipe. The fixed bed combined reaction equipment ensures that heat transfer is designed according to the requirement on the amount of the reaction heat transfer in the reaction, is used for the synthesis of methanol and dimethyl ether, methanation, F-T reaction, the preparation of phthalic anhydride by ortho-xylene oxidation and other strong-effect reaction processes, reduces the temperature difference, improves the reaction efficiency and the yield, saves energy, reduces consumption and achieves the large-sized aim.

Description

technical field [0001] The invention is a catalytic reaction equipment, which is used for fluid catalytic reaction and heat transfer process, belongs to the field of chemical engineering, and is especially suitable for synthesizing methanol, synthesizing dimethyl ether, Fischer-Tropsch reaction to produce liquid hydrocarbons and methane, o-xylene oxidation to produce ortho Strong reaction processes such as phthalic anhydride. Background technique [0002] For some strong exothermic reactions such as methanol synthesis, synthesis gas to dimethyl ether, Fischer-Tropsch reaction to liquid hydrocarbons and methane, o-xylene oxidation to phthalic anhydride, etc., in order to improve the reaction efficiency, it is necessary to remove the reaction heat at the same time. , For example, the Lurgi shell-and-tube methanol tower uses shell-side water to remove the heat of reaction in the reaction tube. In the shell-and-tube reactor design, the temperature of the coolant does not change ...

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Problems solved by technology

Aiming at this fundamental contradiction, the present invention breaks through the existing use of coolants at the same temperature, and uses coolants of different temperatures in different sections of the reactor to solve the problem, so that the heat exchange in the reaction can be designed according to the size of the reaction heat removed, which can be specifically determined according to the reaction The flow direction of the gas in the catalyst layer is sequentially divided into multiple blocks before and after, and the coolant is used to exchange heat indirectly through the heat exchange tube. For reactions such as methanol synthesis, where the reaction temperature is within the range of 180°C to 300°C, pressurized heating can be used. Water is used as the heat carrier, and the heat absorbed by the vaporization of the liquid in the reactor is much higher than the sensible heat absorbed by the temperature rise of the cooling medium. For a higher reaction temperature, mineral oil with low volatility, heat transfer oil or molten salt should be used as the coolant. The heat is brought to the steam drum through the cooling circulation loop, and the heat is transferred to the water through the heat exchange tube in the steam drum to generate steam and recover the heat

One is to use grouped heat exchange tubes in different catalyst block areas before and after. Each group of heat exchange tubes can be connected to a steam drum with different vaporization pressure and vaporization temperature according to needs. Increase the heat transfer temperature difference to enhance heat transfer, solve the problem of fast reaction speed and large reaction heat at the front of the reaction; reduce the catalytic reaction speed and reaction heat at the rear of the reaction, increase the vaporization pressure and temperature of the water exchange pipe correspondingly, and reduce the heat transfer temperature difference. Avoid excessive heat removal and low reaction temperature due to the reduction of reaction heat at the rear

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