Purification and separation method of syngas by full temperature range-pressure swing adsorption (FTrPSA)

Abstract

The invention discloses a purification and separation method of a syngas by FTrPSA, and relates to the technical field of H2 production, CO production and purification and separation for a PSA gas. Compared with the prior art, the purification and separation method of the syngas by FTrPSA disclosed by the invention separates coarse removal and refined removal of impurities of acidic components and the like in the syngas purification process, an intermediate gas is refined by the syngas and subjected to an intermediate temperature PSA separation process to obtain a qualified syngas product or H2 and CO products, the operating temperature and operating pressure are the same as those of an intermediate temperature PSA concentration process, so that the load and energy consumption of the syngas in the refining and intermediate temperature PSA separation are reduced, the integration degree of purification and separation process and the purity of the produces are improved, furthermore, a concentrated gas is subjected to a membrane separation process to obtain further recycled syngas and remove the acidic components, so that the load of the membrane separation process is reduced and the yield of the products is improved.

Description

technical field [0001] The invention belongs to the field of synthesis gas purification and separation, and more specifically relates to a synthesis gas purification and separation method using full temperature range pressure swing adsorption. Background technique [0002] Synthesis gas is a mixed gas with hydrogen (H2) and carbon monoxide (CO) as the main components. It is mainly used to produce synthetic ammonia, methanol, dimethyl ether, ethylene glycol, natural gas, acetic acid (anhydride), butanol, and synthetic oil. , fuel gases, and methanol-based chemicals, synthetic olefins, and materials. Synthesis gas is the basic raw material of C1 chemical industry. [0003] Syngas is mainly obtained through the gasification of fossil raw materials, such as coal, natural gas and oil. In my country, coal resources are relatively abundant, and coal gasification to produce syngas is the main industrialization route, which is the process of converting carbon (C) and hydrogen (H)...

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Problems solved by technology

Cryogenics consumes a lot of energy due to the need for further low-temperature rectification, but the yield and purity are relatively high; the membrane separation process is simple, occupies a small area, and has a high yield, but cannot obtain qualified H2 or CO with high purity

In addition, the investment of membrane separation method is high, the membrane material is expensive, and it needs to be imported and complicated pretreatment to prevent the membrane from being polluted or swollen; Pioneer's patented and proprietary technology for H2 / CO separation by selectively adsorbing CO with loaded active components

Although the PSA method has low energy consumption and simple process, its purity and yield are relatively low, and the purity and yield are greatly affected by the newly introduced large amount of N2 impurities and the original methane, hydrocarbons and other impurities in the purified synthesis gas. , especially a large amount of N2 enters the H2 / CO separation system, which greatly increases the operating load, investment and cost of the PSA process. The purity and yield of H2 products and CO products cannot be increased at the same time. Generally, when the purity of H2 is 99.9%, The yield is only 80~90%, while the purity of CO is only 98%, the yield is lower than 85%

In addition, the PSA method of Peking University Pioneer operates at a temperature range of 60-80°C. It needs to wash and purify low-temperature methanol to obtain syngas at a temperature of -75--34°C and heat it, which greatly increases energy consumption. This is a low temperature The absorption method of methanol washing and pressure swing adsorption (PSA) are too independent to form an organic whole.

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