CO2 recovery from methanol wash tower
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Are there any process operation experiences regarding the recovery of high-pressure CO2 from Section A of the methanol wash T1 scrubber? Could insufficient cooling capacity in the subsequent system result in the purified gas not meeting the required standards?
Yes, the absorption efficiency decreases: Section A of the methanol wash tower requires sufficient cooling capacity to maintain a low temperature environment. If the cooling capacity of the subsequent system is insufficient, the temperature of the scrubber tower rises, reducing methanol’s ability to absorb CO₂, which results in an excessive level of CO₂ in the purified gas. The purified gas does not meet the standards: Insufficient cooling capacity leads to an increase in the levels of impurities such as CO₂ and H₂S in the purified gas, failing to satisfy the quality requirements for this gas in subsequent processes such as liquid nitrogen washing and ammonia synthesis.
The impact is minimal; after carbon dioxide is extracted, the load on the entire tower decreases, the overall amount of methanol in circulation drops, and the amount of nitrogen used for gas stripping also decreases. In other words, once the carbon dioxide extraction is in operation, there is generally enough cooling capacity, although an increase is required during startup