High-concentration CO sulfur-tolerant conversion process and its device

Abstract

The invention relates to a high-concentration CO sulfur tolerant shift process and a device thereof. The high-concentration CO sulfur tolerant shift process comprises at least two stages of shift; the raw material water gas is divided into two branches; one branch of the water gas passes through a low-pressure waste heat boiler so that the water-gas mol ratio is reduced to (0.2-0.5): 1, is subjected to heat exchange and temperature rising in a gas-gas heat exchanger after water is separated, and further enters a first shift reactor for a shift reaction; the process gas coming out of the outlet of the first shift reactor is cooled, and then mixed with the other branch of raw material water gas and enters a second shift reactor for a second shift reaction. The process is capable of skillfully controlling and balancing the water-gas ratio and heat in each shift reactor, so that the first shift reactor and the second shift reactor both are capable of reacting in the way of getting close to chemical reaction balance; the process has no need for a pre-reactor, and also is capable of effectively preventing overhigh temperature of the bed layers of the shift reactors; under different loads, the first shift reactor is low in a risk of having a methanation reaction; therefore, the process is a high-concentration CO, low water-has ratio sulfur tolerant shift process.

Description

technical field [0001] The invention relates to a high-concentration carbon monoxide sulfur-resistant conversion process and its device, in particular to a high-concentration carbon monoxide resistant conversion process for producing oxo synthesis gas, F-T synthesis gas and methane synthesis gas under low water-gas ratio conditions using crude gas as raw material. Sulfur shift process. Background technique [0002] The dry basis composition of CO in the process gas produced by pulverized coal gasification and chilling processes represented by GSP, Dongfang Furnace, Aerospace Furnace, BGL, etc. (the molar composition after deducting the contained moisture) is roughly 60% to 75%. The water-gas ratio (the molar ratio of water to other gas components) is 0.8 to 1.2. 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 sp...

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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 to about 1.8 can reduce the temperature of the lower part of the bed to below 460 °C; A pre-reactor is added 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; another method is that the first shift reactor adopts a very low The water-gas ratio, such as 0.2-0.4, is used to limit the conversion rate of CO, but as the reaction progresses, the water-gas ratio is getting lower and lower, and there is a danger of methanation reaction at high temperature and low water-gas ratio; and in practice During the production operation, because the load of the device will change, it is necessary to continuously adjust and control the parameters such as the temperature and water-gas ratio of the first and second shift reactors, which brings difficulties to the stable operation of the device

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