Natural gas to hydrogen, presulfurization

Natural gas contains very little sulfur, so hydrogenation catalysts generally do not require pre-sulfurization

That’s right; previously, hydrogen was produced using natural gas without pre-sulfurization. It has been in operation for a year, and now we plan to switch to light hydrocarbons; pre-sulfurization is required

I just want to know how much of the catalyst turns into a sulfided state over the course of a year

The catalysts used for hydrogen production from natural gas should be nickel-based and should not be sulfided, as this would cause poisoning and deactivation.

I didn’t make it clear enough above; I’m referring to the hydrogen production process using natural gas, and specifically the sulfidation issue in the hydrogenation reactor. The hydrogenation reactor uses cobalt-molybdenum catalysts

The hydrogenation reactor in natural gas-based hydrogen production plants seems to be nothing more than a formality... because the sulfur content in our natural gas is required to be less than 5 ppm. . . . .

The first hydrogenation reactor in natural gas-based hydrogen production is used for the saturation of olefins. When natural gas is used as the feedstock, I think this first hydrogenation reactor is basically useless; its purpose seems to be relevant only in hydrogen production via delayed coking in the petrochemical industry, as dry gas contains a high amount of olefins, and it is only by hydrogenating these olefins to form alkanes that they can be sent to a conversion furnace to be converted into hydrogen. The sulfur in the feed gas is removed using the second and third zinc oxide desulfurization reactors. If hydrogen is originally produced from natural gas, there isn’t much sulfur in it, so sulfidation of the catalysts is likely to be minimal as well. If you decide to use it, it is recommended to vulcanize it again; this won’t result in any waste, and the hydrogen production reactor isn’t very large anyway.