Reusing system and processing method for byproduct carbon dioxide in synthetic ammonia process

Abstract

The invention discloses a reusing system and processing method for byproduct carbon dioxide in a synthetic ammonia process. The reusing system comprises a pretreatment unit (1), and the pretreatment unit (1) is connected with a coal powder pressurizing and gasifying device (2); the pretreatment unit (1) comprises a carbon monoxide converting device (3), and the carbon monoxide converting device (3) is connected with a low temperature methanol washing device (4); the coal powder pressurizing and gasifying device (2) comprises a carbon dioxide compressor (5), and the carbon dioxide compressor (5) is connected with a fly ash filter (6). According to the reusing system provided by the invention, the investment and equipment maintenance costs are reduced, scaling on an impeller of the carbon dioxide compressor is avoided, the corrosivity of H2S in raw gas to pipelines and the fly ash filter can be reduced greatly, the stable operation period of the reusing system is prolonged greatly, further, the reusing system and processing method provided by the invention further can lower wastewater treatment quantity and environmental protection pressure.

Description

technical field [0001] The invention relates to a recycling system and treatment method, in particular to a by-product CO produced in ammonia synthesis process. 2 Reuse system and treatment method. Background technique [0002] In the industrial production of synthetic ammonia, in the low-temperature methanol washing process, methanol is used to treat CO at low temperature. 2 The physical absorption of acid gas is used to purify the process gas, making the process gas (CO and CO 2 and other acidic gases) to meet the production requirements of synthetic ammonia. The methanol that absorbs the acid gas is regenerated by flash evaporation and heating, and the regenerated methanol is recycled, and the CO 2 As a regenerative product, through CO 2 After the compressor is pressurized, it is used as purge gas to back-flush and clean the fly ash filter in the coal gasification device. Currently CO 2 The product passes through the CO 2 Before the compressor, CO should be introd...

AI Technical Summary

Problems solved by technology

But through CO 2 The recovery of methanol from the product water washing tower is not only of little economic value (due to the low content of methanol), but also the recovery effect of methanol is not obvious (CO 2 Methanol in the product is 95ppm, after washing with water it is 68ppm)

Not only that, the washed CO 2 Products certified by CO 2 After the compressor is pressurized, the fly ash filter is passed into the fly ash filter for backflushing cleaning, and there are still the following problems: 1) Use boiler feed water to wash CO 2 products, because the boiler feed water contains NH 3 ions, this substance readily reacts with CO under high pressure 2 reaction to form ammonium bicarbonate, in CO 2 Scale on the impeller of the compressor, resulting in clogging, affecting the stability and long-term operation of the device; 2) CO after washing 2 The water vapor content in the product has increased significantly (5ppm before water washing and 1200ppm after water washing), so that the H in the crude gas 2 The corrosiveness of S to pipes and fly ash filters increases significantly in humid environments; 3) Increases wastewater treatment capacity and environmental pressure

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