초록 ▼

A process for the production of low sulfur, low olefin gasoline wherein a cracked naphtha, such as a full boiling range cracked naphtha, is first separated by fractional distillation into at least two fractions while simultaneously selectively hydrogenating the polyunsaturated compounds contained th

A process for the production of low sulfur, low olefin gasoline wherein a cracked naphtha, such as a full boiling range cracked naphtha, is first separated by fractional distillation into at least two fractions while simultaneously selectively hydrogenating the polyunsaturated compounds contained therein. The mono olefins in the light fraction are then subjected to etherification with alcohol to produce ethers or hydration with water to produce alcohols. The heavy fraction is subjected to sulfur removal by hydrodesulfurization or chemisorption. The two fractions are then combined to produce a low sulfur, low olefin gasoline.

대표청구항 ▼

The invention claimed is: 1. A process for the production of low sulfur, low olefin content gasoline from a cracked naphtha stream containing olefins and organic sulfur compounds, comprising the steps of: (a) separating the cracked naphtha stream into at least three fractions by fractional distilla

The invention claimed is: 1. A process for the production of low sulfur, low olefin content gasoline from a cracked naphtha stream containing olefins and organic sulfur compounds, comprising the steps of: (a) separating the cracked naphtha stream into at least three fractions by fractional distillation, said fractions comprising a light cracked naphtha fraction, a medium cracked naphtha fraction, and a heavy cracked naphtha fraction; (b) treating the light cracked naphtha fraction to convert a portion of the olefins contained therein to oxygenated compounds; (c) treating the heavy cracked naphtha fraction to remove a portion of the organic sulfur compounds contained therein; and (d) treating the medium cracked naphtha fraction to remove sulfur compounds. 2. The process according to claim 1 wherein said cracked naphtha stream contains polyunsaturated compounds and a portion of said polyunsaturated compounds is converted to monoolefins by hydrogenation concurrently with said separation by fractional distillation. 3. The process according to claim 1 wherein a portion of the olefins contained within said light cracked naphtha fraction is converted to ethers by reaction with alcohols. 4. The process according to claim 1 wherein a portion of the olefins contained within said light cracked naphtha fraction is converted to alcohols by reaction with water. 5. The process according to claim 1 wherein the organic sulfur compounds contained within said heavy cracked naphtha fraction are convened to hydrogen sulfide by reaction with hydrogen. 6. The process according to claim 1 wherein the organic sulfur compounds contained within said heavy cracked naphtha fraction are removed by chemisorption. 7. The process according to claim 1 wherein the treated light cracked naphtha fraction and the treated heavy cracked naphtha fraction are combined to form a low sulfur, low olefin gasoline. 8. The process according to claim 1 wherein said cracked naphtha stream contains mercaptans and a portion of said polyunsaturates comprise diolefins and a portion of said diolefins is reacted with a portion of said mercaptans to form sulfides. 9. The process according to claim 2 wherein said cracked naphtha stream contains mercaptans and a portion of said polyunsaturates comprise diolefins and a portion of said diolefins is reacted with a portion of said mercaptans to form sulfides. 10. The process according to claim 1 wherein said cracked naphtha stream is a full boiling range cracked naphtha. 11. A process for the production of low sulfur, low olefin content gasoline from a full boiling range cracked naphtha containing monoolefins, diolefins, polyunsaturated compounds and organic sulfur compounds, comprising the steps of: (a) feeding hydrogen and said full boiling range cracked naphtha to a first distillation column reactor containing a bed of hydrogenation catalyst; (b) concurrently in said first distillation column reactor (i) reacting hydrogen with a portion of said diolefins and polyunsaturated compounds in the presence of said hydrogenation catalyst to selectively hydrogenate said diolefins and polyunsaturated compounds to monooleflins, (ii) separating the full boiling range cracked naphtha into three fractions by fractional distillation, said fractions comprising a light cracked naphtha, a medium cracked naphtha fraction and a heavy cracked naphtha fraction, (iii) removing said light cracked naphtha fraction from said first distillation column reactor as a first overheads, (iv) removing said medium cracked naphtha from said first distillation column reactor as a first side draw, and (v) removing said heavy cracked naphtha fraction from said first distillation column reactor as a first bottoms; (c) feeding said light cracked naphtha and water to a second distillation column reactor containing a bed of hydration catalyst; (d) concurrently in said second distillation column reactor (i) reacting water with monoolefin in the presence of said hydration catalyst to form alcohols; (ii) separating the unreacted water from the unreacted monoolefins and alcohols by fractional distillation; (iii) removing the unreacted water from said second distillation column reactor as a second overheads, and (iv) removing the unreacted monoolefins and alcohols from said second distillation column reactor as a second bottoms; (e) treating said medium cracked naphtha fraction to remove sulfur; (f) feeding hydrogen and said heavy cracked naphtha fraction to a fixed bed single pass downflow reactor containing a bed of hydrodesulfuirization catalyst; (g) reacting hydrogen and the organic sulfur compounds contained within said heavy cracked naphtha fraction to form hydrogen sulfide; (h) removing the hydrogen sulfide and unreacted hydrogen from the effluent from said fixed bed single pass downflow reactor; and (i) combining the effluent from said fixed bed single pass downflow reactor with said second bottoms. 12. The process according to claim 11 wherein hydrogen and said medium cracked naphtha fraction are fed to a fixed bed single pass downflow reactor containing a bed of hydrodesulfurization catalyst wherein hydrogen and the organic sulfur compounds contained within said medium cracked naphtha fraction are reacted to form hydrogen sulfide. 13. The process according to claim 11 wherein said medium cracked naphtha fraction is fed to a thioetherification reactor where diolefins and mercaptans contained within said medium cracked naphtha fraction are reacted to form sulfides. 14. A process for the production of low sulfur, low olefin content gasoline from a full boiling range cracked naphtha containing monoolefins, diolefins, polyunsaturated compounds, mercaptans and organic sulfur compounds, comprising the steps of: (a) feeding hydrogen and said full boiling range cracked naphtha to a first distillation column reactor containing a bed of hydrogenation catalyst; (b) concurrently in said first distillation column reactor (i) reacting hydrogen with a portion of said diolefins and polyunsaturated compounds in the presence of said hydrogenation catalyst to selectively hydrogenate said diolefins and polyunsaturated compounds to monoolefins, (ii) separating the full boiling range cracked naphtha into three fractions by fractional distillation, said fractions comprising a light cracked naphtha fraction, and medium cracked naphtha fraction and a heavy cracked naphtha fraction, (iii) removing said light cracked naphtha fraction from said first distillation column reactor as a first overheads, (iv) removing said medium cracked naphtha fraction from said first distillation column reactor as a first side draw, and (v) removing said heavy cracked naphtha fraction from said first distillation column reactor as a first bottoms; (c) feeding said light cracked naphtha fraction and a C1 to C4 alcohol to a second distillation column reactor containing a bed of etherification catalyst; (d) concurrently in said second distillation column reactor (i) reacting alcohol with monoolefin in the presence of said etherification catalyst to produce ethers, (ii) separating the unreacted alcohol from the unreacted monoolefins and ethers by fractional distillation; (iii) removing the unreacted alcohol from said second distillation column reactor as a second overheads, and (iv) removing the unreacted monoolefins and ethers from said second distillation column reactor as a second bottoms; (e) treating said medium cracked naphtha fraction to remove sulfur compounds; (f) feeding hydrogen and said heavy cracked naphtha fraction to a fixed bed single pass downflow reactor containing a bed of hvdrodesulfuirization catalyst; (g) reacting hydrogen and the organic sulfur compounds contained within said heavy cracked naphtha fraction to form hydrogen sulfide; (h) removing the hydrogen sulfide and unreacted hydrogen from the effluent from said fixed bed single pass downflow reactor; and (i) combining the effluent from said fixed bed single pass downflow reactor with said second bottoms. 15. The process according to claim 14 wherein the alcohol in said second overheads is recycled to said second distillation column reactor as reflux. 16. The process according to claim 14 wherein said medium cracked naphtha fraction is fed to a thioetherification reactor where diolefins and mercaptans contained within said medium cracked naphtha fraction are reacted to form sulfides. 17. The process according to claim 14, wherein hydrogen and said medium cracked naphtha fraction are fed to a fixed single pass downflow reactor containing a bed of hydrodesulfuirization catalyst wherein hydrogen and the organic sulfur compounds contained within said medium cracked naphtha fraction are reacted to form hydrogen sulfide.