What are the consequences of operating a catalyst at low space velocities?
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What are the consequences of operating a catalyst at low space velocities? The details of the low-pressure methanol synthesis unit in a certain facility are as follows: the design pressure is 5.5 MPa, the catalyst volume used is 32 cubic meters. At 100% load, the flow rate of fresh gas is 7.8 cubic meters per hour, while the flow rate of gas entering the reactor is 220,000 cubic meters per hour. The carbon monoxide content in the gas entering the reactor is 3.5%, and that of carbon dioxide is 0.8%; the required levels for the gas exiting the reactor are 0.7% carbon monoxide and 0.5% carbon dioxide. To save electricity, with a fresh gas flow rate of 6.2 cubic meters per hour, the recycler is not turned on and the space velocity is 2000. What are the consequences of operating the catalyst at such a low space velocity?
The catalyst operating conditions require an air velocity of generally 4000–20000.
A low air velocity results in slow removal of reaction heat, leading to a decrease in methanol production; this is also related to the performance of the catalyst
It can operate at low speeds as long as the temperature does not exceed the limit
The hotspot temperature is likely to increase significantly; if there are other ways to lower the bed temperature, it should have little impact on the catalyst
The company uses Anchun towers and low-pressure polyol plants, along with the absence of circulation pumps, to achieve energy savings and carbon reduction.
The lower the air velocity, the lower the one-way conversion rate. . . As long as the outlet temperature of the synthesis tower is maintained, there should be no adverse effects. . .
Without recycle gas, the one-way conversion rate is the highest.
Will it have side effects on the catalyst?