Unleaded gasoline compositions

Abstract

An unleaded gasoline fuel of about 87 octane suitable for use in automobile spark-ignition (internal combustion) engines, the gasoline having a low sulfur content (below 100 ppmw) and a relatively high olefin content (between 15 and 25 vol. %). Gasoline fuels meeting these requirements generally have emissions characteristics satisfying the requirements of RFG under EPA regulations.

We claim:  
     
         1 . An unleaded gasoline fuel suitable for operating a spark ignition internal combustion engine of an automobile having an octane value of about 87, said gasoline fuel comprising a mixture of hydrocarbons with 
 (1) a sulfur content below 100 ppmw    (2) an olefin content of between 15 and 25 vol. %    (3) a 90% D-86 distillation point of greater than 300° F.; and    (4) a Reid vapor pressure of less than 9.0 psi.    
     
     
         2 . The unleaded gasoline of  claim 1  having a 50% D-86 distillation point of less than 230° F.  
     
     
         3 . The unleaded gasoline of  claim 2  having a 10% D-86 distillation point of less than 150° F.  
     
     
         4 . The unleaded gasoline of  claim 1  having an aromatics content between 15 and 35 vol. %.  
     
     
         5 . The unleaded gasoline of  claim 4  having a 50% D-86 distillation point of less than 230° F.  
     
     
         6 . The unleaded gasoline of  claim 5  having a 10% D-86 distillation point of less than 150° F.  
     
     
         7 . The unleaded gasoline of  claim 4  having an RVP less than 8.0 psi.  
     
     
         8 . The unleaded gasoline of  claim 4  having an RVP less than 7.5 psi.  
     
     
         9 . The unleaded gasoline of  claim 1  having a sulfur content of below 75 ppmw.  
     
     
         10 . The unleaded gasoline of  claim 9  having a 50% D-86 distillation point of less than 230° F.  
     
     
         11 . The unleaded gasoline of  claim 10  having a 10% D-86 distillation point of less than 150° F.  
     
     
         12 . The unleaded gasoline of  claim 11  having an aromatics content between 15 and 35 vol. %.  
     
     
         13 . The unleaded gasoline of  claim 12  having an RVP less than 8.0 psi.  
     
     
         14 . The unleaded gasoline of  claim 13  having an RVP less than 7.5 psi.  
     
     
         15 . The unleaded gasoline of  claim 1  having a sulfur content of below 30 ppmw.  
     
     
         16 . The unleaded gasoline of  claim 15  having a 50% D-86 distillation point of less than 230° F.  
     
     
         17 . The unleaded gasoline of  claim 16  having a 10% D-86 distillation point of less than 150° F.  
     
     
         18 . The unleaded gasoline of  claim 17  having an aromatics content between 15 and 35 vol. %.  
     
     
         19 . The unleaded gasoline of  claim 18  having an RVP less than 8.0 psi.  
     
     
         20 . The unleaded gasoline of  claim 18  having an RVP less than 7.5 psi.  
     
     
         21 . A process for making an unleaded gasoline having an octane value of about 87 comprising blending at least two hydrocarbon streams boiling in the range of 10° F. to about 450° F, one of which has an olefin content of at least 15 volume percent, to produce an unleaded gasoline suitable for combustion in an automobile engine, the unleaded gasoline having the following properties: 
 (1) a Reid vapor pressure less than 9.0 psi;  
 (2) a 90% D-86 distillation point greater than 300° F.;  
 (3) an olefin content between 15 and 25 vol. %; and  
 (4) a sulfur content below 100 ppmw.  
 
     
     
         22 . The process of  claim 21  wherein said hydrocarbon streams are selected from the group consisting of an alkylate stream, a catalytically cracked gasoline, a heavy straight run gasoline stream, a dehexanizer bottoms stream, a dehexanizer overheads stream, an aromatic saturated gasoline stream, a light straight run gasoline stream, hydrocracker topper light naphtha and a butane stream.  
     
     
         23 . The process of  claim 22  wherein the unleaded gasoline has a 50% D-86 distillation point of less than 230° F.  
     
     
         24 . The process of  claim 23  wherein the unleaded gasoline has a 10% D-86 distillation point of less than 150° F.  
     
     
         25 . The process of  claim 24  wherein the unleaded gasoline has an aromatics content between 15 and 35 vol. %.  
     
     
         26 . The process of  claim 21  wherein the unleaded gasoline has a sulfur content of below 75 ppmw.  
     
     
         27 . The process of  claim 26  wherein the unleaded gasoline has a 50% D-86 distillation point of less than 230° F.  
     
     
         28 . The process of  claim 27  wherein the unleaded gasoline has a 10% D-86 distillation point of less than 150° F.  
     
     
         29 . The process of  claim 28  wherein the unleaded gasoline has an aromatics content between 15 and 35 vol. %.  
     
     
         30 . The process of  claim 29  wherein the unleaded gasoline has an RVP less than 8.0 psi.  
     
     
         31 . The process of  claim 29  wherein the unleaded gasoline has an RVP less than 7.5 psi.  
     
     
         32 . The process of  claim 21  wherein the unleaded gasoline has a sulfur content of below 30 ppmw.  
     
     
         33 . The process of  claim 32  wherein the unleaded gasoline has a 50% D-86 distillation point of less than 230° F.  
     
     
         34 . The process of  claim 33  wherein the unleaded gasoline has a 10% D-86 distillation point of less than 150° F.  
     
     
         35 . The process of  claim 34  wherein the unleaded gasoline has an aromatics content between 15 and 35 vol. %.  
     
     
         36 . The process of  claim 35  wherein the unleaded gasoline has an RVP less than 8.0 psi.  
     
     
         37 . The process of  claim 35  wherein the unleaded gasoline has an RVP less than 7.5 psi.  
     
     
         38 . A method for operating an automobile having a spark-ignition, internal combustion engine and a catalytic converter comprising: 
 (1) introducing into the engine an unleaded gasoline, suitable for combustion in an automobile engine, said gasoline having a Reid vapor pressure less than 9.0 psi, an octane value of about 87, a 90% D-86 distillation point greater than 300° F., an olefin content between 15 and 25 vol. % and a sulfur content of below 100 ppmw; and thereafter    (2) combusting the unleaded gasoline in said engine;    (3) introducing at least some of the resultant engine exhaust emissions into the catalytic converter; and    (4) discharging emissions from the catalytic converter to the atmosphere.    
     
     
         39 . The method of  claim 38  wherein the unleaded gasoline has a sulfur content of below 75 ppmw.  
     
     
         40 . The method of  claim 39  wherein the unleaded gasoline has a 50% D-86 distillation point of less than 230° F.  
     
     
         41 . The method of  claim 40  wherein the unleaded gasoline has a 10% D-86 distillation point of less than 150° F.  
     
     
         42 . The method of  claim 41  wherein the unleaded gasoline has an aromatics content between 15 and 35 vol. %.  
     
     
         43 . The method of  claim 42  wherein the unleaded gasoline has an RVP less than 8.0 psi.  
     
     
         44 . The method of  claim 42  wherein the unleaded gasoline has an RVP less than 7.5 psi.  
     
     
         45 . The method of  claim 38  wherein the unleaded gasoline has a sulfur content of below 30 ppmw.  
     
     
         46 . The method of  claim 45  wherein the unleaded gasoline has a 50% D-86 distillation point of less than 230° F.  
     
     
         47 . The method of  claim 46  wherein the unleaded gasoline has a 10% D-86 distillation point of less than 150° F.  
     
     
         48 . The method of  claim 47  wherein the unleaded gasoline has an aromatics content between 15 and 35 vol. %.  
     
     
         49 . The method of  claim 48  wherein the unleaded gasoline has an RVP less than 8.0 psi.  
     
     
         50 . The method of  claim 48  wherein the unleaded gasoline has an RVP less than 7.5 psi.