Patent ID: 6495030
Filing Date: 2002-12-17
Classification: C10G,Y10S

Abstract:
A process for the desulfurization of a full boiling range catalytically cracked naphtha comprising the steps of:(a) feeding (1) a full boiling range cracked naphtha containing olefins, diolefins, mercaptans and other organic sulfur compounds and (2) hydrogen to a first distillation column reactor; (b) concurrently in said first distillation column reactor (i) contacting the diolefins and mercaptans in said full boiling range naphtha in the presence of a Group VIII metal catalyst in the rectification section of said distillation column reactor thereby reacting a portion of said mercaptans with a portion of the diolefins to form sulfide products and a distillate product comprising a light naphtha and (ii) fractionating said full boiling range naphtha into said distillate product and a heavier naphtha, said heavier naphtha containing said other organic sulfur compounds and said sulfide product; (c) removing said distillate product as a first overheads from said first distillation column reactor; (d) removing said heavier naphtha from said first distillation column reactor as bottoms; (e) feeding said bottoms and hydrogen to a second distillation column reactor; (f) concurrently in said second distillation column reactor: (i) contacting sulfur compounds comprising the other organic sulfur compounds in said heavier naphtha with hydrogen in the presence of a hydrodesulfurization catalyst in the rectification section of said second distillation column reactor to convert a portion of said other organic sulfur compounds to hydrogen sulfide, and (ii) fractionating said heavier naphtha into an intermediate naphtha and a heavy naphtha; (g) removing said intermediate naphtha and said hydrogen sulfide from said second distillation column reactor as a second overheads; and (h) removing said heavy naphtha containing sulfur compounds comprising said sulfides from said distillation column reactor as a second bottoms; (i) feeding said second bottoms and hydrogen to a third distillation column reactor; (j) concurrently in said third distillation column reactor: (i) contacting sulfur compounds comprising said sulfides contained within said heavy naphtha with hydrogen in the presence of a hydrodesulfurization catalyst in said third distillation column reactor to convert a portion of said sulfides to hydrogen sulfide, and (ii) fractionating said heavy naphtha to remove said hydrogen sulfide produced as overheads from said third distillation column reactor; and (k) removing the heavy naphtha as bottoms from said third distillation column reactor.