A low-temperature methanol washing reformation process

Abstract

The invention belongs to the technical field of low-temperature methanol washing, and specifically relates to a transformation process of low-temperature methanol washing, which solves the problems in the background technology. The following technical scheme is adopted: the direct-supplement high-pressure nitrogen pipeline is connected to the high-pressure nitrogen inlet of the flash tank through a branch, and at the same time, the system pressure of the low-temperature methanol washing unit is reduced by a certain amount; the liquid ammonia pump in the ammonia compressor unit is connected to the inlet separation through a pipeline The spare flange port of the device. The invention supplements nitrogen through the high-pressure nitrogen pipeline, so that the total amount of nitrogen can meet the requirements of the low-temperature methanol washing tower and the cycle gas compressor for start-up operation, meet the minimum operating conditions of the cycle gas compressor, and avoid flashing gas from The vent pipe is directly connected to the flare system for discharge, which greatly reduces carbon emissions and realizes the recycling of nitrogen; it realizes safe, stable and rapid processing of the liquid level of the inlet separator in the ammonia compressor unit under high load conditions, ensuring This ensures the stable operation of the low-temperature methanol washing unit and prevents the tripping of the ammonia compressor.

Description

technical field [0001] The invention relates to the technical field of low-temperature methanol washing, in particular to a transformation process of low-temperature methanol washing. Background technique [0002] The low-temperature methanol washing process is equipped with two sets of large-scale compressor units, the circulating gas compressor 5 and the ammonia compressor 11, which play a vital role in the operation of the overall device. The low-temperature methanol washing unit 1 includes a low-temperature methanol washing tower 3, a flash tank 4 and a recycle gas compressor 5. The inlet of the low-temperature methanol washing tower 3 is connected to the feed gas, and the outlet of the low-temperature methanol washing tower 3 is connected to the flash tank 4 inlet. The flash steam outlet of the flash tank 4 is divided into two routes, one of which is connected to the inlet of the low-temperature methanol washing tower 3 through the recycle gas compressor 5, and the othe...

AI Technical Summary

Problems solved by technology

The reflux effect of the liquid ammonia pump 9 of the existing ammonia compressor unit 2 is not ideal, and the liquefied ammonia entering the pump cannot be refluxed through the return pipeline

The inlet separator 8 of the ammonia compressor unit 2 has a liquid-carrying problem, and the liquid level continues to rise, which will cause the interlocking shutdown of the ammonia compressor 11, affect the acid derefrigeration, and lead to insufficient carbon dioxide by-products, resulting in gasification shutdown and the shutdown of the entire plant , as the production load is gradually increasing, if the rise of the liquid level cannot be effectively controlled, the load production must be reduced, and the liquid level of the inlet separator 8 must be dealt with. In serious cases, it can only be stopped for processing, which will affect long-term stable operation

As the inlet temperature of the ammonia compressor 11 rises, the load of the unit increases, and the steam consumption increases to the maximum design load of the ammonia compressor 11, which has a great impact on the operation of the unit; at the same time, when the working condition is restored, there is a greater risk and it is easy to cause Ammonia compressor 11 overspeed even causes ammonia compressor 11 to trip and damage the unit

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