Reasons for the high COS content in exhaust gases
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I. Background Introduction CO2 product gas consists of two parts, which originate from the CO2 flashing section and the product section, respectively. CO2 flash section, CO2 product section, exhaust gas: Design value, Actual value; Design value, Actual value; Design value, Actual value. Pressure and temperature (MPa): 0.078, 0.064, 0.048, 0.021, 0.018, 0.028. Temperature (°C): -61.7, -58.1, -65.4, -64.8. Flow rate (Nm3/h): 66797.5, 140908, 206986.5. In actual analytical tests, the H2S content in the CO2 product gas is between 10-20 ppm, while the CO2 content is below 5 ppm. The H2S content in the exhaust gas ranges from 0-20 ppm, showing great instability; the COS content is between 150-200 ppm. CO2 is sent for gasification and reuse, while the exhaust gases are released into the atmosphere; the total sulfur content is above the specified limit. In light of the above situation, I urge the experts to urgently provide good suggestions.
It is necessary to check whether the amount of methanol used in the carbon dioxide product section for spraying sulfur-rich methanol is sufficient. Additionally, the pressure in that section, at 0.021 Mpa, is a bit low; other units operate at 0.07 Mpa. The pressure in the reabsorption tower seems similar to that of other units; check whether the methanol spray is sufficient. Excessive sulfur content in either of these two locations can lead to excessive exhaust emissions.
Considering the previous set of exhaust gas desulfurization units, it is a dry desulfurization method, with the total sulfur content in the exhaust gas being below 1 ppm.
Your device is quite large in scale. Does the effective gas treatment capacity need to reach 250,000 Nm3/h?
Oh, I thought it was low-temperature methanol washing,,, What product is this used to make? . Wouldn’t it be better to carry out direct low-temperature methanol washing in one step? The investment for the previous desulfurization unit was also quite high
The exhaust flow rate is too high; it’s not practical. This post is meant to explore whether there are any good methods from the perspective of adjustment techniques
Does 0.07 MPa refer to the flash section or the product section?
The precision desulfurization unit is mainly added to the purification gas pipeline as well!
Is iron oxide used in dry desulfurization? We used to have this problem: when oxygen or air was introduced during the pre-precise desulfurization stage, it was necessary to strictly control the amount of air or oxygen used, and as a result, the sulfur content at the outlet remained consistently within the specified limits. This method was devised by an engineer who graduated from Dalian University of Technology with a degree in chemical engineering and has been working for decades.
Are there any methods for adjusting COS in exhaust gases?
Has the sulfur content in the gas exiting the desulfurization section of the absorption tower been analyzed? Sometimes, due to issues with the trays or operating conditions, the sulfur-free methanol stream sent to the CO2 product tower contains sulfur, which results in slight excess levels of sulfur in both the CO2 product gas and the exhaust gas.