Reaction heat
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Is the heat released by the reaction gases in the methanol synthesis tower equal to the amount of steam generated in the drum? In other words, is the amount of steam produced equal to the amount of heat released? How to understand it
Is the heat released by the reaction gases in the methanol synthesis tower equal to the amount of steam generated in the drum? In other words, is the amount of steam produced equal to the amount of heat released? How to understand it
For a drum, the synthesis tower is nothing but a heat exchanger! The total heat of the reaction is known; it can be determined based on the volume and composition of the gas at the inlet and outlet of the synthesis tower, or based on the crude methanol produced ； The heat brought into the synthesis tower is known, as is the heat taken out; therefore, the heat transferred can be determined easily. With the heat value known, the gas production volume can then be calculated based on the vaporization heat of water at the drum pressure
That's not correct to say. The heat released during the reaction in the synthesis tower is carried away partly by the gases involved in the reaction, partly by the steam generated in the drum, and another portion is used for heat transfer losses and the endothermic reactions that occur.
I agree with the above view; the steam production varies with the cycle ratio, as a higher cycle ratio results in less steam being produced per ton of alcohol produced.
Then the heat absorbed by intermittent discharge and continuous discharge should also be taken into account
Is the heat released by the reaction gases in the methanol synthesis tower equal to the amount of steam generated in the drum? In other words, is the amount of steam produced equal to the amount of heat released? How to understand it
The heat released is equal to the heat carried away by the air pocket and the water cooler; the heat carried away by the air pocket typically accounts for about 60% of the total heat.
Reply to 8# Shouhou: Then how is the heat released by the synthesis tower calculated? And how did you determine that the steam drum accounts for 60%?
This calculation isn’t difficult. The temperature of the methanol gas in the inlet cooler is T1; you should look up the boiling point T2 of methanol gas at your operating pressure. We denote the temperature of the gas exiting the outlet cooler as T3. The flow rate of methanol is F. By using the specific heat capacity, we can calculate the amount of heat absorbed by the outlet cooler: F*C_gas*（T1_T2）+F*C_liquid*（T2-T3). Isn’t that how you calculate it?
Reply to 9# zjabc: My value was determined by the design institute using the design data provided to you, and it was calculated based on our tower design.