Reasons for the excessive CO level in the purified gas of the low-temperature methanol washing system

The reasons for excessive CO levels may be as follows: 1. In the low-temperature methanol washing system, the CO in the shift gas does not react completely to form CO2, resulting in elevated CO concentrations. 2. In the low-temperature methanol washing system, the conversion gas enters the washing tower at too high a speed, preventing the methanol solution from effectively removing CO from the gas, which results in an excessive CO concentration. 3. In the low-temperature methanol washing system, the methanol concentration in the washing tower is too low, resulting in insufficient washing efficiency and an excessive CO concentration. 4. In the low-temperature methanol washing system, loose packing in the washing tower or improper operation of the equipment prevents the methanol solution from coming into full contact with the shifted gas, which affects the washing efficiency and leads to excessive CO concentrations. An analysis of the specific process parameters and equipment operation conditions is required to determine the cause of the excessive CO levels and make improvements. .

It’s quite unusual that the CO level in your purified air is above the limit. It is usually the carbon dioxide level that is too high. Has the CO content in the raw gas obtained through transformation increased compared to before? Can carbon monoxide levels be high while hydrogen sulfide and carbon dioxide levels remain within acceptable limits? What kind of processing is done in the latter section? We can discuss it together

The CO content after the conversion is within the specified limits; it’s estimated that it’s around 1% after low-temperature methanol washing. Both carbon dioxide and hydrogen sulfide are within normal ranges; only CO exceeds the specified limit. The subsequent processing step involves PSA purification

Shouldn’t a higher CO content increase the purity of PSA? If you reduce the conversion rate of CO, then the purity of the purified gas will naturally decrease as well. Is the pressure in the flash tower appropriate? Is the amount of CO recovered from the flash vapor higher than before?

There may be the following reasons: Catalyst deactivation: CO is an important reaction intermediate; if the catalyst becomes deactivated or its activity decreases, it will result in a lower conversion rate of CO, thereby increasing the CO concentration at the outlet. Improper reaction conditions: CO typically undergoes a water-gas shift reaction with water vapor in the presence of sufficient hydrogen, producing carbon dioxide and methane. If there is a shortage of hydrogen or the reaction temperature is too low, it will lead to a decrease in the CO conversion rate, thereby increasing the CO content. System failure: Issues such as damaged scrubber towers or deformed bed particles can lead to a reduced cleaning efficiency, as well as an increase in CO concentration. Solution: Optimize catalyst selection and treatment processes to ensure stable catalyst activity. Adjust the reaction conditions to ensure an adequate supply of hydrogen, and that the reaction temperature meets the design requirements. Inspect the scrubber tower and related equipment to ensure the proper operation of the system.

The CO content in the shifted gas is above the specified level; the original design called for around 1%, but the actual value is around 3%. Possible reasons: 1. The water-to-gas ratio at the inlet of the shift reactor is too low； 2. Poor catalyst activity ； 3. High temperature at the converter outlet

Please share your process details for review; the main issues are as follows: 1. The catalyst activity does not meet the requirements, or the amount of catalyst used is insufficient. 2. It is unclear whether the process can meet the conversion requirements – only one stage of conversion is sufficient to achieve these requirements. 3. The water vapor content in the converted gas is too low, resulting in a low conversion rate

You said later that the gas resulting from the transformation was all within the specified range. So which specific part has an excessive CO level? 1. It is the poor conversion capacity of the converter. 2. Or else the CO2 vent contains too much CO.