Questions regarding the steam drum of the synthesis tower
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What is the principle behind controlling the temperature of the catalyst in the synthesis tower by regulating the pressure in its drum? Hope Haiyou can help!
The water in the shell side of the drum and the synthesis tower circulates naturally. The steam pressure in the drum can be controlled to change the boiling point of water. It is possible to control the temperature of the catalyst. The drum pressure changes by 0.1 MPA, and the temperature changes by 1.5 degrees
For every 0.1MP increase between 2.5 and 4.0MP, the outlet temperature of the synthesis tower rises by 1.35 degrees Celsius.
Methanol synthesis is an exothermic reaction, and a significant portion of the heat released is carried away by the water in the jacket. By controlling the steam pressure, the temperature of the water in the jacket can be increased; as the pressure rises, the temperature also changes accordingly.
The boiler water in the shell side of the synthesis tower absorbs the heat of reaction from methanol in the tube side, turning it into boiling water at a certain temperature. After boiling water rises into the drum, saturated steam is formed at the upper part of the drum, and the pressure indicated by it is the pressure of the saturated steam. The heat of reaction in the synthesis tower is carried away by saturated steam generated as boiling water rises and turns into vapor. Only then can the bed temperature be stabilized; therefore, the bed temperature is directly affected by the boiling water. Although it changes as the temperature of the boiling water changes, for boiling water at a certain temperature in the steam drum, there is a corresponding saturated vapor pressure at that temperature. Experimental results show that for every 0.1 MP change in steam pressure, the bed temperature changes by 1.35 degrees. Therefore, drum pressure control is very important in the synthesis process. Prevent the dry pot from damaging the catalyst.
The water temperature can be controlled by regulating the saturated vapor pressure of water; consequently, the temperature of the catalyst bed can also be controlled in such isothermal reactors.
It was clearly explained on the 5th floor: the synthesis reaction is an exothermic reaction, and as heat is continuously released during this reaction, it can cause the catalyst to sinter. Therefore, the circulating water from the synthesis drum is used to absorb the heat generated by the reaction, thereby maintaining and controlling the temperature of the catalyst bed. A change of 0.1 MPA in the pressure of the synthesis drum corresponds to a temperature change of 1.35 degrees in the catalyst bed, while the temperature of the circulating water changes by 1.5 degrees; this mechanism is used to control the temperature and pressure of the synthesis process!