What is the cause of the sudden drop in the inlet temperature of the synthesis tower?
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What is the cause of the sudden drop in the inlet temperature of the synthesis tower? In a methanol production facility, the inlet temperature of the synthesis tower dropped suddenly from 194°C to 180°C, while the temperature of the exhaust gas heat exchanger increased by 14°C. Analysis of the causes of temperature changes: what impact does it have on methanol production?
Consider whether there is a leak in the gas-gas heat exchanger or if the compressor is carrying liquid (methanol).
Can production be maintained in this situation?
First, check the thermocouples and the gas composition at the inlet and outlet of the synthesis tower; only if there are problems with these two aspects will the temperature drop by such a large amount
This is a low-pressure methanol system, not a methanol-ethanol blend.
What is the temperature of the outlet heat exchanger? Why has it suddenly risen by 14°C? This will definitely lead to a significant increase in the alcohol content in the circulating gas, causing the temperature of the catalyst bed in the synthesis tower to drop, to the point where it can no longer be maintained, and as a result the yield of primary alcohol will decrease.
During normal operation: The inlet temperature of the gas-to-gas heat exchanger is 60°C, and the outlet temperature is 194°C℃； Secondary inlet temperature of the gas-to-gas heat exchanger: 235°C, outlet temperature: 100°C. During abnormal operation: The inlet temperature of the gas-to-gas heat exchanger is 60°C, and the outlet temperature is 180°C℃ ； Secondary inlet temperature of the gas-to-gas heat exchanger: 235°C, outlet temperature: 114°C.
From a data perspective, it means that the heat exchange efficiency of the heat exchanger has decreased, with some foreign substance blocking the heat exchange tubes. If it’s considered a leakage issue, then it can only be that the gas entering the tower mixes with the gas exiting the tower; therefore, the temperature of the gas exiting the tower through the heat exchanger should also decrease, right?
The gas entering the tower becomes the gas exiting the tower; from a mixing perspective, the temperature decreases. If it affects the heat exchange efficiency, the temperature should be increased.
As the temperature of the gas entering the tower decreases, side reactions in the synthesis tower increase slightly. The higher temperature after gas-to-gas heat exchange indicates that the heat transfer efficiency of the heat exchanger has decreased. This suggests that there are factors affecting the heat transfer efficiency; with the heat transfer area and specific heat capacity remaining constant, the only remaining factors are the heat transfer coefficient, flow velocity, and temperature difference. Check if there is any change in your recirculation air volume