A method for reducing particulate emissions

Abstract

A method for reducing particulate emissions from a direct injection spark-ignition engine, wherein the method comprises fuelling the engine with a gasoline composition, wherein the gasoline composition comprises a hydrocarbon base fuel comprising not greater than 5% v aromatics of at least 9 carbon atoms, based on the base fuel, a T90 of up to 150° C. and a final boiling point not greater than 190° C.

1 . A method for reducing particulate emissions from a direct injection spark-ignition engine, wherein the method comprises fuelling the engine with a gasoline composition, wherein the gasoline composition comprises a hydrocarbon base fuel comprising not greater than 5% v aromatics of at least 9 carbon atoms, based on the base fuel, a T90 of up to 150° C. and a final boiling point not greater than 190° C. 
     
     
         2 . The method of  claim 1  wherein the hydrocarbon base fuel has a final boiling point of not greater than 180° C. 
     
     
         3 . The method of  claim 1  or  2  wherein the reduction of particulate emissions is measured by a decrease in PM index (SAE Technical Paper 2010-01-2115) of the gasoline composition. 
     
     
         4 . The method of any of  claims 1  to  3  wherein the gasoline composition has a PM index of 1.0 or less. 
     
     
         5 . The method of any of  claims 1  to  4  wherein the gasoline composition contains 0 to 10% v of at least one oxygenate selected from methanol, ethanol, isopropanol and isobutanol, diethylcarbonate. 
     
     
         6 . The method of any of  claims 1  to  5  wherein the hydrocarbon base fuel contains 10 to 20% v olefins. 
     
     
         7 . The method of any of  claims 1  to  6  wherein the hydrocarbon base fuel contains 12 to 18% v olefins. 
     
     
         8 . The method of any of  claims 1  to  7  wherein the hydrocarbon base fuel contains not greater than 5% v olefins of at least 10 carbon atoms, based on the base fuel. 
     
     
         9 . The method of any of  claims 1  to  8  wherein the base fuel has initial boiling point in the range 30 to 40° C., T10 in the range 45 to 57° C., T50 in the range 82 to 104° C., T90 in the range 140 to 150° C. 
     
     
         10 . The method of any of  claims 1  to  9  wherein the fuel composition comprises one or more antioxidants. 
     
     
         11 . Use of a gasoline composition for reducing particulate emissions from a direct injection spark-ignition engine, wherein the gasoline composition comprises a hydrocarbon base fuel comprising not greater than 5% v aromatics of at least 9 carbon atoms, based on the base fuel, a T90 of up to 150° C. and a final boiling point not greater than 190° C.