Deep cooling in ethylene plants
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I would like to ask everyone: for a pre-cooling system, if the temperatures of the various cold boxes remain unchanged and the flow rate of the pyrolysis gas stays constant, but the methane-to-hydrogen ratio increases, will the loss of ethylene in the high-pressure methane at the top of the demethanization tower increase or decrease? How does the ethylene loss in the medium- and low-pressure methane change?
Ethylene loss decreases. For a detailed analysis, please refer to an article I previously published. Factors affecting the ethylene yield in the demethanizer system.
I would like to ask everyone: for a pre-cooling system, if the temperatures of the various cold boxes remain unchanged and the flow rate of the pyrolysis gas stays constant, but the methane-to-hydrogen ratio increases, will the loss of ethylene in the high-pressure methane at the top of the demethanization tower increase or decrease? How does the ethylene loss in the medium- and low-pressure methane change? Although I don’t understand the process, considering it as a simple cryogenic process, I would say this: as the proportion of hydrogen in methane increases, the dew point temperature of the mixture drops, making it less easy to cool down; as a result, more ethylene will be lost