Why does Chiga’s recycled hydrogen need to maintain a hydrogen sulfide content of several thousand ppm, while Sigea does not?
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For gasoline processing, Axens’ two-stage hydrogenation process is used; the raw materials for diesel processing are catalyzed diesel and conventional diesel, while the raw material for gasoline processing is catalytic gasoline.
Is a continuous vulcanization environment required?
It’s related to the properties of the catalyst itself; the sulfided catalyst prevents reduction
Well, I think so too, but why isn’t the hydrogen in the steam reforming cycle kept at a high level of hydrogen sulfide?
Gasoline is obtained at the top of the tower, hydrogen sulfide is also there at the top, while diesel is found at the middle section. High hydrogen sulfide levels in gasoline can result in the sulfur content of the final gasoline product not meeting the required standards. For gasoline, even if circulating hydrogen isn’t required, there must still be a certain amount of it at several thousand PPM; it’s impossible to have none at all.
The key lies in the reduction conditions of the two catalysts
It is likely that diesel does not require a high level of hydrogen purity; there is no need to maintain such high purity. Moreover, when the hydrogen purity is too high, the circulation rate of the system becomes low, and if it falls below the intake volume of the compressor, an anti-surge valve must be used. Gasoline, on the other hand, requires a high level of hydrogen purity, especially to suppress CO/CO2 levels, which are involved in the reaction processes
This depends on the catalyst you use; the catalyst manufacturer will provide you with detailed data.
What about hydrogen sulfide! Does a catalyst for steam not need to be protected from high-temperature hydrogen reduction?
The manager said that the hydrogen sulfide level in the gas should be as low as possible; the readings I take myself are usually around 20 to 30 ppm