Poisoning, arsenic, hydrodesulfurization catalysts

The metal function of the catalyst is poison by sulfur, as discussed later. The elimination of sulfur from the naphthas is carried out in the hydrodesulfurization vmit, in which the sulfur compounds are hydrogenolyzed, producing H2S, which is separated. This unit contains a catalyst, usually Co-Mo, Ni-Mo, or Ni-W supported on alumina. This catalyst also eliminates the nitrogen as NH3 and retains the arsenic and metals present in the feed. 

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