Use of alcohols in fuels for spark ignition engines

Abstract

The use of at least one C 4 alcohol to increase the vapour pressure of a fuel for spark-ignition engines comprising base fuel and ethanol in which use the at least one C 4 alcohol is added to a fuel comprising base fuel and ethanol to produce a resultant fuel mixture comprising 15-50% by volume of base fuel, 15-65% by volume of ethanol and 15 to 50% C 4 alcohol. The resultant fuel mixture exhibits an adequately high vapour pressure, for example, which meets the specification, and also exhibits a good start behaviour even at winter temperatures

1 - 19 . (canceled) 
     
     
         20 . A method for increasing the vapour pressure of a fuel comprising base fuel and ethanol for spark ignition engines comprising:
 adding at least one C 4  alcohol to a fuel comprising base fuel and ethanol to produce a resultant fuel mixture;   wherein the resultant fuel mixture comprises 15-50% by volume of base fuel, 15-65% by volume of ethanol and 15 to 50% C 4  alcohol.   
     
     
         21 . The method of  claim 20  wherein the resultant fuel mixture comprises:
 20 to 46% by volume of a base fuel   20 to 60% by volume of ethanol, and   20 to 50% by volume of C 4  alcohol.   
     
     
         22 . The method of  claim 20  wherein the resultant fuel mixture comprises:
 19.5 to 44% by volume of a base fuel   21 to 59.5% by volume of ethanol, and   21 to 49% by volume of C 4  alcohol.   
     
     
         23 . The method of  claim 20  wherein the C 4  alcohol is one or more of n-butanol, secondary butanol, and isobutanol. 
     
     
         24 . The method of  claim 20  wherein the C 4  alcohol is isobutanol. 
     
     
         25 . The method of  claim 21  wherein the C 4  alcohol is one or more of n-butanol, secondary butanol, and isobutanol. 
     
     
         26 . The method of  claim 21  wherein the C 4  alcohol is isobutanol. 
     
     
         27 . The method of  claim 20  wherein the ethanol is predominantly of natural origin. 
     
     
         28 . The method of  claim 20  wherein the C 4  alcohol is predominantly of natural origin. 
     
     
         29 . The method of  claim 20  wherein the base fuel comprises predominantly a mixture of hydrocarbons with a Carbon-number predominantly from 4 to 12. 
     
     
         30 . The method of  claim 29  wherein the mixture of hydrocarbons comprises predominantly paraffins, naphthenes, and aromatics. 
     
     
         31 . The method of  claim 29  wherein the base fuel comprises 0-15% by volume of ether. 
     
     
         32 . The method of  claim 31  wherein the ether is tertiary butyl methyl ether, tertiary butyl ethyl ether, or a combination thereof. 
     
     
         33 . The method of  claim 20  wherein the alcohol content of the resultant fuel mixture is at least 50% by volume. 
     
     
         34 . The method of  claim 20  wherein the alcohol content of the resultant fuel mixture is at least 70% by volume. 
     
     
         35 . The method of  claim 21  wherein the base fuel comprises predominantly a mixture of hydrocarbons with a Carbon-number predominantly from 4 to 12. 
     
     
         36 . The method of  claim 35  wherein the mixture of hydrocarbons comprises predominantly paraffins, naphthenes, and aromatics. 
     
     
         37 . The method of  claim 35  wherein the base fuel comprises 0-15% by volume of ether. 
     
     
         38 . The method of  claim 37  wherein the ether is tertiary butyl methyl ether, tertiary butyl ethyl ether, or a combination thereof. 
     
     
         39 . The method of  claim 21  wherein the alcohol content of the resultant fuel mixture is at least 50% by volume. 
     
     
         40 . The method of  claim 21  wherein the alcohol content of the resultant fuel mixture is at least 70% by volume. 
     
     
         41 . The method of  claim 23  wherein the base fuel comprises predominantly a mixture of hydrocarbons with a Carbon-number predominantly from 4 to 12. 
     
     
         42 . The method of  claim 41  wherein the mixture of hydrocarbons comprises predominantly paraffins, naphthenes, and aromatics. 
     
     
         43 . The method of  claim 41  wherein the base fuel comprises 0-15% by volume of ether. 
     
     
         44 . The method of  claim 43  wherein the ether is tertiary butyl methyl ether, tertiary butyl ethyl ether, or a combination thereof. 
     
     
         45 . The method of  claim 23  wherein the alcohol content of the resultant fuel mixture is at least 50% by volume. 
     
     
         46 . The method of  claim 24  wherein the alcohol content of the resultant fuel mixture is at least 50% by volume. 
     
     
         47 . The method of  claim 25  wherein the base fuel comprises predominantly a mixture of hydrocarbons with a Carbon-number predominantly from 4 to 12. 
     
     
         48 . The method of  claim 47  wherein the mixture of hydrocarbons comprises predominantly paraffins, naphthenes, and aromatics. 
     
     
         49 . The method of  claim 47  wherein the base fuel comprises 0-15% by volume of ether. 
     
     
         50 . The method of  claim 49  wherein the ether is tertiary butyl methyl ether, tertiary butyl ethyl ether, or a combination thereof. 
     
     
         51 . The method of  claim 25  wherein the alcohol content of the resultant fuel mixture is at least 50% by volume. 
     
     
         52 . The method of  claim 26  wherein the alcohol content of the resultant fuel mixture is at least 50% by volume. 
     
     
         53 . A method of manufacturing a fuel comprising mixing of a mixture I, comprising 15-30% by volume of a base fuel and 70-85% by volume of ethanol with a mixture II, comprising 30-50% by volume of base fuel and 50 to 70% by volume of C 4  alcohol. 
     
     
         54 . The method of  claim 53  wherein mixture I and mixture II are mixed in the ratio of 1:1 by volume. 
     
     
         55 . The method of  claim 53  wherein mixture I is an E70 or E85 gasoline and mixture II is a B50 or B70 gasoline.