Synthesis gas purification technology

Abstract

The invention relates to a synthesis gas purification technology, which is characterized by comprising the following steps: subjecting an absorbent to acid gas absorption by an absorption tower, to flashing by a flash tower and to analysis by a re-absorbing tower, raising the temperature of the carbon-rich absorbent output from an flash section of the re-absorbing tower by 2 to 30 DEG C, performing the flashing operation and gas extraction operation to analyze the carbon dioxide in the carbon-rich absorbent, introducing the carbon-rich absorbent subjected to further analysis and serving as a semi-lean absorbent into the absorption tower to be used for washing the acid gas in raw gas. By combining the temperature-raising flashing and gas extraction operation, the content of acid gas in thesemi-lean absorbent is effectively reduced, the absorption effect of the semi-lean absorbent in unit flow is improved, the circulation volume of the semi-lean absorbent is reduced, the energy consumption of a semi-lean absorbent circulation pump is reduced. Meanwhile, part of the semi-lean absorbent subjected to analysis is distributed into a first flashing tower, the flashing steam in the first flashing tower is washed, the yield of the carbon dioxide can be improved to a certain degree and the energy consumption of a thermal regeneration system is reduced.

Description

technical field [0001] The invention relates to the field of chemical technology, in particular to a synthesis gas purification process. Background technique [0002] Syngas purification is mainly used to remove H in raw gas 2 S, COS, CO 2 and other acidic gases to produce purified gas that meets the process requirements. Synthesis gas purification processes commonly used in industry mainly include Selexol process, MDEA process and low-temperature methanol washing process. 2 S and CO 2 Absorption is carried out to achieve the purpose of purifying the synthesis gas. At the same time, a thermal regeneration system is set up to regenerate the liquid phase absorbent. The above three synthesis gas purification methods are generally consistent in terms of process flow, and they all include acid gas absorption and absorbent thermal regeneration. According to the specific requirements of the production device, medium-pressure flash recovery of effective gas and low-pressure fla...

AI Technical Summary

Problems solved by technology

However, the synthesis gas purification process in the prior art all adopts the carbon-rich absorbent that has been flashed by the reabsorption tower and returns it directly as a semi-lean absorbent to the absorption tower for absorption operation, because the acid gas dissolved in the semi-lean absorbent The content is too high, which affects the absorption effect, which in turn leads to a corresponding increase in the circulation volume of the semi-lean absorbent required by the device, and an increase in energy consumption; at the same time, due to the large liquid phase circulation volume, some equipment is relatively large, and the investment in the device increases

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