Outlet temperature of the shell-and-tube synthesis tower
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When a shell-and-tube synthesis tower is first started up, what should the temperature at the outlet of the tower be, and what about the pressure in the drum?
When the engine has just started, the required temperature for the catalyst is low, at 225 degrees, with a steam drum pressure of 25 kilograms
It doesn’t need to be too high; our factory uses 210 degrees with a pressure of 1.7 MPa, operating at low load
The steps for operating the machine are as follows: Contact the compressor team to supply fresh gas to the synthesis system, and constantly monitor the temperature at the outlet of the synthesis tower, keeping it between 210°C and 230°C. The liquid level in the drum should be maintained at 50%. When the system pressure reaches around 4.0 Mpa, venting is initiated to maintain stability in the composition of the gas entering the tower; as the system pressure continues to rise gradually and approaches 4.8 MPa, venting is used to stabilize the system pressure. Gradually increase the amount of fresh air until full load is reached. Once the liquid levels in the two separators are normal, automatic control is activated at around 45%. Depending on the temperature of the thalamic layer, the steam generated by the drum is incorporated into the pipeline network. Once the liquid level in the methanol flash tank is normal, automate control and coordinate with the distillation system to supply liquid. Start the alcohol washing pump to establish circulation for the liquid level in the alcohol washing tower. Gradually adjust various parameters to reach a normal operating state.
If driving in the original condition, it is best to set the outlet temperature at around 210°C and operate under that load for a while, then gradually increase the temperature based on the catalyst’s activity.
It was set at 210 at first, and now it has been increased to 215. The pressure in the drum can be adjusted according to the circumstances, usually up to 2.3 MPa.
Will wax formation occur if it is set at 210 degrees? Please advise. What should be the pressure setting for the steam drum?
TOPSOE’s MK-121 can operate at 190 degrees, and its low-temperature performance is one of its key advantages.
Based on my experience, wax formation has little to do with temperature; it’s mainly related to the catalyst itself. Catalysts these days rarely wax.
For shell-and-tube reactor systems, the inlet temperature for the synthesis of low-temperature catalysts can be set at 190 degrees in foreign countries, while in China it is advisable to use a temperature above 195 degrees. Considering that the space velocity should not be too high, the outlet temperature for synthesis should be around 220 degrees
When the engine has just started running, the required temperature for the catalyst is low, at 225 degrees; the pressure in the steam drum is 25 kilograms. This also depends on the specifications set by the catalyst manufacturer
Is it possible for the pressure in the steam drum to reach 25 kilograms, with an exit temperature of 225 degrees in the synthesis tower?
Is the outlet pressure of the synthesis tower related to the activity of the synthesis catalyst? Does the outlet temperature increase when the activity decreases?
When the engine has just started running, the catalyst is highly active; generally, the peak temperature should be kept as low as possible, but it cannot go below 210 degrees, as it is within the range of 190–210 degrees that paraffin is most likely to form. At the beginning, our factory maintained a temperature of 221 degrees; the pressure in the steam drum was primarily used to control the temperature at the hot spots, and the pressure varied depending on the volume of steam
The outlet temperature is generally between 210 and 255; of course, this depends on the circumstances. For example, if the catalyst is very pure and has high selectivity, the temperature can be kept as low as possible
Our factory uses C306 from the Southwest Research Institute. The outlet temperature when we operate the equipment is 220 degrees; however, when the volume of gas flowing through it is high, the temperature can exceed 230 degrees, which allows for the production of more methanol. The manufacturer states that it is possible to maintain a temperature of 240 degrees for over a year without a significant drop in conversion rate