Discussion on reduction pressure of synthetic catalysts
Thread Content
At the end of the year, the reduction catalyst needs to be driven for synthesis, and the reduction pressure used by our factory is 0.7MPa (A). I don’t know what the reduction pressure used by each factory is? Will the level of reduction pressure affect the activity of the catalyst after reduction?
Our factory's is 0.8MPa;
a. Copper-based catalysts must be heated and reduced before use. The reduction pressure is 0.8MPa, the maximum reduction temperature is 230°C, the reducing gas is converted coke oven gas, and the diluting gas is N2. The operation is strictly in accordance with the temperature-raising reduction procedure of the catalyst. The temperature rise and heating of the catalyst in the synthesis tower is completed with steam injector L40001AB. Medium-pressure steam with a pressure of 3.5MPa is added, and the furnace water circulation is driven by starting the steam ejector L40001AB, so that the temperature of the catalyst layer rises evenly and gradually. b. Catalyst temperature control: The boiler water on the shell side of the synthesis tower absorbs the reaction heat of methanol synthesis in the tube side and becomes boiling water. After the boiling water rises into the steam drum, it forms a saturated steam pressure corresponding to the boiling water temperature at the upper part of the steam drum, which is the steam pressure controlled by the steam drum. The temperature of the synthesis tower catalyst is achieved by adjusting the steam pressure of the steam drum. Therefore, by adjusting the drum pressure, the catalyst bed temperature can be adjusted accordingly. Generally, the drum pressure changes by 0.1MPa. The bed temperature will change accordingly by 1.5°C. Therefore, it is necessary to adjust the drum pressure frequently and finely, and the adjustment range is determined according to the production situation. In addition, changes in production load, circulation volume, gas composition, condensation temperature, etc. can cause changes in the catalyst bed temperature. If necessary, the drum pressure should be adjusted in time to maintain its normal operating temperature and avoid large fluctuations.
The reduction pressure is generally 0.8MPa and the temperature is 230 degrees.
0.8 has little effect on the activity of the catalyst, but has an impact on the production conditions
Our company used nitrogen as the heating carrier gas for the first time. In order to meet the start-up conditions of the compressor, the system dropped the pressure to 0.2MPa and started the cycle machine. After normalization, the system slowly increased the pressure and adjusted the dry gas sealing system. After normalization, the system continued to increase the pressure to 0.8MPa and then maintained stable trial operation. The water vapor system was opened for circulation. After a comprehensive inspection of the operating parameters of the system and confirmation of normality, the steam drum was supplied with 3.9MPa steam to raise the temperature. The reduction operating pressure is 0.8MPa, and the final temperature is 230 degrees for two hours before switching to ventilation trial production.