| 摘要 |
1. A spark ignition motor fuel composition consisting essentially of: a hydrocarbon component consisting essentially of one or more hydrocarbons selected from the group consisting of four to eight hydrocarbon atom straight-chained or branched alkanes, wherein said hydrocarbon component has a minimum anti-knock index of 65 as measured by ASTM D-2699 and D-2700 and a maximum Dry Vapor Pressure Equivalent of 15 psi ( one atmosphere) as measured by ASTM D-5191, a fuel grade alcohol; and a co-solvent miscible in both said hydricarbon component and said fuel grade alcohol wherein said hydrocarbon component, said fuel grade alcohol and said co-solvent are present in amounts effective to provide a motor fuel with a minimum anti-shock index of 87 as measured by ASTM D-2699 and ASTM d-2700, and wherein said fuel composition is essentially free from olefins, aromatics and sulfur. 2. The fuel composition of claim 1, wherein said hydrocarbon consisits essentially of one or more hydrocarbonsselected from natural gasoline or coal gas liquid hydrocarbons. 3. The fuel composition of claim 2, wherein said hydrocarbon consisits essentially of natural gasoline or pentanes plus. 4. The fuel composition of claim 1, wherein said hydrocarbon component includes n-butane and said hydrocarbon component, said fuel grade alcohol and said co-solvent are present in amounts effective to provide a DVPE between about 12 psi (0,8 atm.) and about 15 psi (1 atm.). 5. The fuel composition of claim 1, wherein said fuel grade alcohol is ethanol or methanol. 6. The fuel composition of claim 1, wherein said co-solvent is a saturated five to seven atom heterocyclic ring compound which is essentially alkyl-substituted. 7. The fuel composition of claim 6, wherein said co-solvent is 2-methyltetrahydrofuran (MTHF) or 2-ethyltetrahydrofuran (ETHF). 8. The fuel composition of claim 6, wherein said ring heteroatom is oxygen. 9. The fuel composition of claim 6, wherein said hydrocarbon component consists esentially of one or more hydrocarbons selected from natural gasoline, said fuel grade alcohol comprises ethanol and said co-solvent is MTHF. 10. The fuel composition of claim 9 comprising between about 10 and about 50% by volume of said natural gasoline, between about 25 and about 55% by volume of said ethanol, between about 15 and about 55% by volume of said MTHF, and between zero and about 15% by volume of n-butane. 11. The fuel composition of claim 10 comprising between about 25and about 40% by volume of pentane plus, between about 25 and about 40% by volume of said ethanol, between about 20 and about 35% by volume of said MTHF, and between zero and about 10% by volume of n-butane. 12. The fuel composition of claim 1 having said minimum anti-shock index of 89.0, preferably of 92.5. 13. A method for lowering the vapor pressure of a hydrocarbon-alcohol blend with an amount of a co-solvent for said alcohol and said hydrocarbons so that a ternary blend is obtained having a dry vapor pressere equivalent lower than dry vapor pressere equivalent for a binary blend of said alcohol and said hydrocarbon component, wherein said hydrocarbon component consists essentially of one or more hydrocarbons selected from the group consisting of four to eight hydrocarbon atom straight-chained or branched alkanes, and wherein said ternary blend is essentially free of olefins, aromatics and sulfur. 14. The method of claim 13, wherein said alcohol, said hydrocarbons and said co-solvent are present in amounts to provide a motor fuel with a minimum anti-shock index of 87 as measured by ASTM D-2699 and D-2700, and a maximum DVPE of 15 psi (1 atm.). 15. The method of claim 13, wherein, said hydrocarbons and said co-solvent are pre-blended together before being blended with said alcohol. 16. The method of claim 13, wherein, said hydrocarbons comprise pentane plus, said alcohol comprises ethanol and said co-solvent is MTHP. 17. The method of claim 13, wherein, said hydrocarbon component consists essentially of one or more hydrocarbons selected from the group consisting of natural gasoline and coal gas liquid hydrocarbons. |
