Methanol washing system adopting work quantity exchange and process thereof

Abstract

The invention relates to a methanol washing system adopting work quantity exchange and a process thereof. After impurities are removed in an absorption tower, roughly synthesized gas is sent to the next working section, and after the work quantity is transferred to a methanol solution, the obtained pregnant solution enters a separator; a liquid phase of the separator enters a desorber after the work quantity is released; CO2 produced by desorption is sent out after being reheated, and the liquid phase is sent to a concentration tower; gas obtained through concentration is evacuated, and the liquid phase is sent to a methanol regenerating tower after the work quantity is recovered; a gas phase on the tower top of the regenerating tower is sent to a sulfur recovering working section, and the methanol solution is sent to the absorption tower or a methanol-water separation tower after the work quantity is recovered; a gas phase stream of the tower top of the methanol-water separation tower is returned to the regenerating tower, the liquid phase is sent for sewage treatment, work quantity exchange is carried out between the pregnant solution of the absorption tower and the methanol solution in a positive displacement mode, one stream of the liquid phase of the separator outputs work quantity outwards in a turbine and positive displacement combined mode, and pressure energy contained in the other two streams is output outwards as electric energy in a turbine mode. The system disclosed by the invention has high energy recovery efficiency, is low in energy consumption and operates stably.

Description

technical field [0001] The invention relates to the technical field of synthesis gas purification, in particular to a methanol washing and purification system and process using work-quantity exchange. Background technique [0002] Syngas is a basic intermediate product in the chemical process, and its main components are CO and H 2 , mostly produced by partial oxidation of coal, oil, natural gas, etc. The purification of syngas has an important impact on the safe operation and efficient production of downstream devices. Common purification processes include low-temperature methanol washing, low-temperature liquid nitrogen washing, and copper washing. Due to the advantages of purification effect, economy and many other aspects, methanol washing has increasingly become the preferred purification method of people, and has a wide range of applications in the world. [0003] The low-temperature methanol washing process is a purification process commonly used in the coal chemic...

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Problems solved by technology

[0004] The disadvantages of this process are as follows: the pressure energy of the rich liquid in the absorption tower is not effectively utilized in the process, and it is wasted on the pressure reducing valve, and there is a large room for improvement in the energy utilization efficiency of the entire process

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