Variable temperature isothermal shift reaction device

Abstract

The invention relates to a temperature-variable isothermal shift reaction device, comprising a furnace body and a catalyst frame arranged in the furnace body, a synthesis gas collection tube is arranged in the middle of the catalyst frame, a heat exchange tube is arranged in the catalyst frame, and an inlet of the heat exchange tube is connected to The water inlet pipe and the outlet of the heat exchange pipe are connected to the steam pipe; it is characterized in that a plurality of raw material gas preheating pipes are also arranged in the catalyst frame, and the inlet of the raw material gas preheating pipe is connected to the first raw material gas conveying pipe, and the raw material gas preheating pipe The outlet is connected to the cavity between the catalyst frame and the furnace body; the furnace body is provided with a raw material gas inlet, the raw material gas inlet is connected to the second raw material gas conveying pipeline, and the second raw material gas conveying pipeline is connected to the first medium channel of the heat exchanger; The outlet of the synthesis gas collection pipe is connected to the first branch and the second branch, and the second branch is connected to the second medium channel of the heat exchanger; There is a second valve on it.

Description

technical field [0001] The invention relates to chemical equipment, in particular to an isothermal shift reaction device. Background technique [0002] CO shift reaction CO+H 2 O ↔ H 2 +CO 2 It is an exothermic reaction. The temperature of the fully reacted shift gas can reach about 450°C, but the energy barrier (reactivity energy) of the reaction is relatively high. Before the reaction, the reaction raw material, namely crude gas, needs to be heated to 260°C or higher. temperature. Therefore, the previous shift process uses the shift gas and crude gas heat exchanger, which uses the shift gas with higher temperature generated after the shift reaction to exchange heat with the raw gas before the shift reaction. A large amount of energy can be saved, and at the same time, the reaction rate and efficiency can be greatly improved. However, because the outlet temperature of the converter is very high, the pressure of the conversion reaction is very high, usually 3-6 MPa, whi...

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Problems solved by technology

[0005] However, as the reaction progresses, the activity of the catalyst decreases, leading to an increase in the catalyst's active temperature, from about 240°C in the initial stage to about 280°C, which requires the reaction temperature to increase accordingly.

The current solution to this problem is usually to increase the temperature of cooling water and heat exchange steam in the later stage of the reaction, which will inevitably lead to a sharp increase in the pressure in the steam drum and heat exchange tubes; at the same time, the design wall thickness of the steam drum and heat exchange tubes should be increased accordingly

In addition to strict requirements on equipment, this will also lead to a series of other problems. For example, due to the increase in the wall thickness of the heat exchange tube, the heat transfer coefficient of the heat exchange tube will decrease, and the amount of heat exchange in the early stage of the reaction will also need to increase; and, Due to changes in the temperature and pressure of the outlet steam drum, it will inevitably lead to corresponding changes in supporting pipelines and equipment

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