Effect of airspeed on synthesis
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What effect does an increase in airspeed have on the pressure drop in the combiner tower? What impact will it have on the entire synthesis section?
In a general sense, space velocity will increase the pressure drop in the synthesis tower and increase the synthesis reaction. And it will increase the pressure difference in the compressor cycle section!
Increase airspeed, pressure drop increases, and production increases. However, the pressure drop increases faster and is related to the third power of the airspeed. After it increases to a certain airspeed, the power consumption caused by the increase in pressure drop will be equal to the benefit of the increase in output.
In methanol production, only a small amount of methanol can be obtained by passing the gas through the synthesis tower at one time. The methanol synthesis rate of fresh gas is not high, so the fresh gas must be recycled. At this time, the airspeed of the synthesis tower is often determined by factors such as cycle power and synthesis system resistance. If a lower space velocity is used, the composition of the gas mixture during the reaction is closer to the equilibrium composition, and the production intensity of the catalyst is lower. However, the amount of circulating gas required per unit methanol product is smaller, the power consumption of gas circulation is less, the heat exchange area required to preheat the unreacted gas to the catalyst inlet temperature is smaller, and the temperature of the gas leaving the reactor is higher, and its heat energy utilization value is higher. If a higher space velocity is used, although the production intensity of the catalyst can be improved, the heat transfer area required for preheating will be increased.
1. Under permitted conditions, increase the space speed as much as possible to obtain high output and improve catalyst production intensity. 2. If conditions do not allow, conditions must be created within a reasonable range, such as increasing the venting volume to reduce the inert gas content. ； Reduce the inert gas content in fresh gas ； Increase system pressure, etc. 3. After increasing the airspeed, the output obtained should be reasonable compared with the increased cost. 4. Increasing the airspeed can prevent gas deviation caused by too low airspeed. 5. The space velocity of the methanol catalyst is about 10000h-1. It cannot be increased blindly and should be stopped in moderation. I have some opinions and if I am wrong, please discuss it more.
The good effects have been mentioned above. Let me talk about the bad effects. By increasing the airspeed, the catalyst may be destroyed and pulverized, which increases the resistance of the tower. If not dealt with in time, a vicious cycle will occur.
Within the operating indicator range! But the product is not up to standard?