Process for removal of mercaptans from hydrocarbon streams
AssigneeCatalytic Distillation Technologies
InventorsDennis Hearn, Gary R. Gildert, Hugh M. Putman
Life of this patent
Estimating the term…
Abstract
A process for treating a light cracked naphtha to be used as an etherification feed stock is disclosed in which mercaptans, H2S and diolefins are removed simultaneously in a distillation column reactor using a reduced nickel catalyst. The mercaptans and H2S are reacted with the diolefins to form sulfides which are higher boiling than that portion of the naphtha which is used as feed to the etherification unit. The higher boiling sulfides are removed as bottoms along with any C6 and heavier materials. Any diolefins not converted to sulfides are selectively hydrogenated to mono-olefins for use in the etherification process.
Claims10
A process for removing mercaptans from a hydrocarbon stream, comprising the steps of:
- (a) feeding a first stream containing diolefins and a hydrocarbon stream containing mercaptans to a distillation column reactor into a feed zone;
- (b) feeding an effective amount of hydrogen to said distillation column reactor
- (c) concurrently in said distillation column reactor
- (i) contacting the diolefins and said mercaptans contained within said hydrocarbon stream in the presence of hydrogen in a distillation reaction zone containing a supported nickel sulfide catalyst prepared in the form to act as a catalytic distillation structure thereby reacting a portion of said mercaptans with a portion of the diolefins to form sulfide products and a distillate product, having a reduced amount of said mercaptans and
- (ii) separating said sulfides from said distillate product by fractional distillation;
- (d) withdrawing distillate product from said distillation column reactor at a point above said distillation reaction zone, said distillate product having a reduced mercaptan content;
- and
- (e) withdrawing sulfide products from said distillation column reactor at a point below said distillation reaction zone.
A process for treating a light cracked naphtha distillate for use as an etherification or alkylation feed stock, comprising the steps of:
- (a) feeding a light cracked naphtha distillate containing mercaptans and diolefins to a distillation column reactor having a stripping zone and distillation reaction zone, said light cracked naphtha having a C6+ fraction and a C5− fraction;
- (b) feeding an effective amount of hydrogen to said distillation column reactor;
- (c) separating said C6+ fraction from said C5− fraction in said stripping zone and distilling said C5− fraction up into said distillation reaction zone;
- (d) concurrently in said distillation reaction zone
- (i) contacting the diolefins and mercaptans contained within said light cracked naphtha in the presence of hydrogen in a distillation reaction zone containing a nickel sulfide catalyst supported on a particulate alumina base prepared in the form to act as a catalytic distillation structure thereby reacting a portion of said mercaptans with a portion of the diolefins to form sulfide products and a distillate product,
- (ii) selectively hydrogenating any remaining diolefins to mono-olefins, and
- (iii) separating said sulfides from said distillate product by fractional distillation;
- (e) withdrawing a C5− distillate product from said distillation column reactor as overheads, said C5− distillate product having a reduced mercaptan and diolefin content;
- and
- (f) withdrawing said sulfide products from said distillation column reactor as bottoms along with said C6+ fraction.
A process for treating a light cracked naphtha distillate for use as an etherification and/or alkylation feed stock, comprising the steps of:
- (a) feeding a light cracked naphtha distillate containing mercaptans and a molar excess of diolefins to said mercaptans to a distillation column reactor having a stripping zone and distillation reaction zone, said light cracked naphtha having a C6+ fraction and a C5− fraction;
- (b) feeding an effective amount of hydrogen to said distillation column reactor;
- (c) separating said C6+ fraction from said C5− fraction in said stripping zone and distilling said C5− fraction up into said distillation reaction zone;
- (d) concurrently in said distillation reaction zone
- (i) contacting the diolefins, mercaptans and hydrogen sulfide contained within said light cracked naphtha in the presence of hydrogen in a distillation reaction zone containing a nickel sulfide catalyst supported on a particulate alumina base prepared in the form to act as a catalytic distillation structure thereby reacting substantially all of said mercaptans with a portion of the diolefins to form sulfide products and a distillate product,
- (ii) selectively hydrogenating the remaining diolefins to mono-olefins, and
- (iii) separating said sulfides from said distillate product by fractional distillation;
- (e) withdrawing a C5− distillate product from said distillation column reactor as overheads, said C5− distillate product having a substantially reduced mercaptan and diolefin content;
- and
- (f) withdrawing said sulfide products from said distillation column reactor as bottoms along with said C6+ fraction.
Dependencies are inferred from the claim text.