Pressure settings for drying the hydrogenation reaction system and the catalyst
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Check the startup plans for each device. The drying pressure in the reaction systems of low-pressure hydrogenation units such as those used for gasoline and naphtha hydrogenation is generally 0.35–0.5 MPa, while the drying pressure in medium- and high-pressure hydrogenation units used for diesel and wax oil hydrogenation is typically 2.0 MPa–4.0 MPa. The temperature is controlled according to the furnace drying curve ； The drying pressure for catalysts is generally between 1 and 4 MPa, while the temperature is maintained at around 250°C to 300°C at the reactor inlet. May I ask, what is the basis for the pressure control of drying in this system and catalyst drying? It can be said that the lower the pressure, the easier it is for water to vaporize and separate. If the goal of drying a catalyst is to maintain a higher pressure in order to slow down the vaporization of water and thus protect the catalyst, then why isn’t the pressure kept lower during the drying of the entire system?
When the pressure drops, the flow rate also decreases, and thus the drying effect is reduced.
Oh, you mean that the pressure of the circulating hydrogen is low, so the vapor pressure of water inside also decreases, and as a result its ability to carry water drops, right?
There is a fear that water will vaporize inside the catalyst; when water vaporizes, its volume increases by 1,000 times, which can cause significant damage to the catalyst. Therefore, pressure needs to be controlled in order to reduce the rate of water vaporization
When the pressure is low, the circulation volume of the hydrogen circulator cannot be increased; even if the water vapor pressure is high, it still cannot be removed. Therefore, a certain level of pressure is required.
It has nothing to do with the magnitude of the pressure shared with others; no matter how low or high the water vapor pressure is, as long as there is no gas present, the water remains in the catalyst. Only when there is a circulation flow will the water be carried away.
System drying is largely determined by the circulation rate; during system drying, 2 compressors on the hydrogen circulation side are operated to supply hydrogen without any load.
Those who don’t understand can come and ask me. Don’t be shy, just give Gordo a few more points:lol
This temperature won’t reduce the catalyst! Unless nitrogen～
“Xunkai Catalysts boasts a comprehensive range of hydrogenation catalyst products, including those based on Raney nickel, supported nickel, copper-zinc, copper-silicon systems, as well as catalysts on precious metal carriers – both in powder form and for fixed-bed use. These catalysts have been successfully applied in processes such as hydrogenation, dehydrogenation, reductive amination, and desulfurization across industries including those involving 1,4-butanediol, caprolactam, fatty alcohols, organic amines, butyl octanol, HPPO, petroleum resins, dye intermediates, as well as intermediates for pharmaceuticals and pesticides. For technical inquiries, please contact Manager Mei at 17701646014