Method used for heat liberation pressurization catalytic reaction

Abstract

The invention provides a method for exothermic catalytic reaction under increased pressure and a reactor thereof. The method and the reactor are characterized in that: a round pressure vessel (7) with a catalytic bed (4) is used; a gas inlet (1) is positioned on an end cover of the vessel (7) and connected with an internal distribution drum (5) to form a shunt passage (2) for reacting gases; a gas outlet (11) is communicated with a space that is formed between the wall of the vessel (7) and an external distribution drum (6), to form a concentration passage (3) for the reacting gases, the catalytic bed (4) is defined between the external distribution drum (6) and the internal distribution drum (5) and is filled with catalysts; the reacting gases flow axially in a centrifugal manner from the internal distribution drum (5) to the external distribution drum (6). The method and the reactor have the advantages of axial and uniform distribution of the reaction gases, optimum distribution of bed temperature, high utilization rate of catalysts, and low pressure drop of fluids passing through the reactor. The invention is suitable for catalytic reactions in methanol, ammonia and dimethyl ether synthesis, as well as other exothermic gas-solid catalytic reactions under increased pressure.

Description

technical field [0001] The invention belongs to the technical field of chemical reaction engineering, specifically, it relates to a method for exothermic pressurized catalytic reaction and its reactor, in particular to a method for synthesizing methanol, ammonia, dimethyl ether and other catalytic reactions and its reactor. Background technique [0002] As we all know, fixed-bed catalytic reactors are generally used for the catalytic reaction process of synthesizing methanol, ammonia, dimethyl ether, etc. In order to reduce the resistance of the reactor bed, increase the space velocity and increase the production capacity, a fixed bed radial catalytic reactor is used. In addition, for gas-solid phase catalytic exothermic reactions such as synthesis of methanol, ammonia and dimethyl ether under pressure, as the reaction process progresses, the continuously released heat of reaction will increase the temperature of the catalyst layer. In order to improve the reaction process ...

AI Technical Summary

Problems solved by technology

U.S. Patent No. 4,321,234 discloses a radial flow fixed-bed catalytic reactor, which provides the flow mode of the fluid and the arrangement of the cooling tubes, overcomes the shortcomings of the large bed resistance of the tube-and-tube fixed-bed reactor, and can effectively Use the heat of reaction, but there is a serious problem of uneven fluid distribution in the reactor, and the catalyst cannot be fully utilized

Japanese patent JP59162942 and Chinese patent CN1054430 disclose a radial flow fixed-bed catalytic reactor utilizing intubation heat exchange. There is also uneven distribution of fluid in the radial bed layer, which relatively affects the utilization rate of the catalyst. The structure of the reactor is complex, and the catalyst Defects such as difficulty in loading and unloading

U.S. Patent US7055583 and Chinese Patent CN1571697 disclose a heat exchange unit in a radial flow isothermal fixed bed catalytic reactor, which adopts a plate heat exchanger and has an integrated design of the heat exchange unit, but the structure is complex and the engineering implementation is quite difficult

Chinese patent CN1788835 discloses a transverse flow tube heat exchange reaction equipment, the reactor is placed horizontally, the heat exchange tubes are arranged horizontally, the reactant stream flows laterally from top to bottom and exchanges heat with it, which reduces the resistance of the reactor, but Uneven distribution of reactant flow, difficult loading and unloading of catalyst, and difficult sealing of sliding tube sheets in the reactor

Chinese patent CN2880821 discloses a suspended water pipe isothermal radial reactor, which also has defects such as complex reactor structure and difficult loading and unloading of catalysts.

Chinese patents CN2291201 and CN2355787 disclose a fixed-bed catalytic reactor with radial flow by-product steam. The cold pipes are straight pipes or coiled pipes. Achieving the right temperature distribution

[0008] 1. The reaction gas flows from the outside to the inside and from the top to the bottom in a centripetal Z shape. The radial flow process of the fluid is controlled by the central pipe distributor. Therefore, it is difficult to achieve uniform fluid distribution in the entire bed, or it has to be used Controlling a gas distributor with a large pressure drop will largely lose the low pressure drop characteristic of a radial reactor

Horizontal setup of transverse tube heat exchange, fluid distribution is more difficult to be uniform

[0009] 2. The radial heat transfer effect of traditional heat exchange tubes in the reactor is poor; it is difficult to manufacture the large diameter of the radial reactor with intubation heat exchange; and the structure of the plate heat exchange unit is complex and difficult to process, which will make the radial reaction The characteristics that the device is suitable for large-scale are lost

[0010] 3. The traditional radial reactor adopts the centripetal type from the outside to the inside. The reaction gas flows in the shunt channel between the cylinder and the outer distribution cylinder. Due to the heat loss, the temperature difference changes, which will cause a considerable axial displacement of the bed. temperature difference

[0011] 4. Most radial reactors adopt centripetal flow, and the fluid flow speed gradually increases along the radial direction. For those chemical reactions that are seriously restricted by equilibrium, the reaction speed slows down significantly in the later stage. The two do not match, and the Can affect radial reactor efficiency

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