[Weekly Topic] May 14-20, 2011

Possible reasons: 1. The circulating methanol flow rate is too high, or the fluid is too dirty. Solution: Check the methanol flow for washing, and increase the amount of methanol circulating to the water removal separator. 2. The temperature of lean methanol is too low, resulting in a high density. Solution: Reduce the ammonia flow rate at the inlet of the inter-stage ammonia cooler to decrease the cooling in the system. 3. Blockage or poor flow in the inter-stage cooler, resulting in flooding. Solution: Check for blockages in the inter-stage cooler; if severe, stop the machine for cleaning. 4. The tray is severely clogged or scaled. Treatment method: When the tray is severely clogged, shut down the system for cleaning. 5. The system load fluctuates greatly. Solution: Stabilize the system load and overcome interference. 6. False alarm by the instrument. Solution: Notify the instrument maintenance team.

This post was last edited by ychycmchfx on 2011-5-15 at 13:12. Reason for handling 1: The valve on the cooling pipeline introduced in the final cleaning stage is opened too slightly. 1: Adjust to the appropriate valve position. 2: The amount of lean methanol entering the absorption tower is too large, and the pipe diameter is insufficient. 2: Adjust the appropriate flow rate and replace the pipeline while the machine is stopped. 3: Blockage in the methanol extraction cooler. 3: Stop and clean it up in severe cases. 4: The system load increases or decreases significantly. 4: Load addition and reduction should be done slowly.

Reply 1# sxtblo Linde process flow. The process flow is as follows: The shift gas coming from the shift unit (350°C, 3.6 MPa(A)) has a small amount of methanol injected into it before entering the feed gas cooler (E15201), in order to prevent water vapor in the shift gas from cooling and freezing. The shifted gas is cooled to -220°C by the feed gas cooler (E15201) and then sent to the shifted gas separator (V15201), where methanol and water are separated. It proceeds to the lower section of the methanol scrubber (C15201), where H2S+COS and CO2 are removed sequentially; after that, it exits the scrubber at -420°C. The heat recovered through the feed gas cooler (E15201) is used to raise the temperature to 250°C and a pressure of 3.45 MPa(A), after which the gas is sent to the next processing stage. The CO2 content in the purified gas is approximately 2.94%, along with H2S and COS

Personally, I think there are only two reasons: 1. Methanol has become contaminated and is foaming; 2. There are problems with the internals of the tower; 3. There are issues with the instrumentation used for measurement!