A high-concentration CO sulfur-resistant conversion process and device that fully utilizes the heat of reaction

Abstract

The invention belongs to the technical field of sulfur tolerance shift, and particularly relates to a high-concentration CO sulfur tolerance shift technology and device fully using reaction heat. The sulfur tolerance shift technology comprises multiple stages of shift, wherein a catalyst bed layer of a one-stage shift reactor is divided into an upper section and a lower section, firstly raw material coal gas subjected to heat transfer and warming enters the upper section of the catalyst bed layer for shift reaction, and then enters the lower section of the catalyst bed layer for shift reaction, and one-stage shift gas at the outlet of the lower section of the catalyst bed layer serves as a heat source of a medium-pressure steam generator. The sulfur tolerance shift technology has the advantages that heat generated by shift reaction can be fully utilized, a pre-reactor does not need to be arranged, and equipment investment is saved; the risk of occurrence of methanation reaction is avoided; the bed temperature of the shift reactor is prevented from being too high; steam is not consumed, and the medium-pressure steam can also be supplied externally; the process is simple, few equipment is needed, the thermal load of the system is reduced, and the CO conversion rate is high; the sulfur tolerance shift technology has strong adaptability to different coal types and gasification technologies.

Description

technical field [0001] The invention belongs to the technical field of sulfur-resistant conversion, and in particular relates to a high-concentration CO sulfur-resistant conversion process and device that fully utilizes reaction heat. Background technique [0002] Among the process gas produced by coal gasification, the dry basis (composition after deducting the moisture content) of CO in the process gas produced by pulverized coal gasification processes represented by Shell, GSP, Dongfang Furnace, Aerospace Furnace, and BGL is roughly 60% to 75%. More than 60% of CO enters the shift reactor. Under the same shift reaction conditions, the reaction temperature in the lower part of the reaction bed is generally close to 500°C, or even exceeds 530°C. This puts special requirements on the material of the reactor and increases the reaction temperature. The cost of device has also increased the unsafety of device operation. [0003] At present, one way to solve the overheating of...

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Problems solved by technology

More than 60% of CO enters the shift reactor. Under the same shift reaction conditions, the reaction temperature in the lower part of the reaction bed is generally close to 500°C, or even exceeds 530°C. This puts special requirements on the material of the reactor and increases the reaction temperature. The cost of the device also increases the unsafe operation of the device

[0003] At present, one way to solve the overheating of high-concentration CO conversion is to use a high water-gas ratio to reduce the bed temperature. For example, increasing the water-gas ratio (the molar ratio of water to other gas components) to about 1.8 can reduce the temperature of the lower part of the bed. The other is to add a pre-reactor before the main shift reactor, and the pre-shift reaction product enters the main shift reactor after being cooled by water spray or heat exchange, which also requires additional equipment; there is another One method is that the first shift reactor uses very low water vapor, such as 0.2 to 0.4, to limit the conversion rate of CO, but as the reaction progresses, the water gas ratio is getting lower and lower, and there are occurrences at high temperature and low water gas ratio. The danger of methanation reaction; moreover, at present, pulverized coal gasification basically adopts chilling process, and the water-gas ratio is 0.8~1.2. down, add water or steam before entering subsequent transitions

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