Patent ID: 8876924

Claim:
A method for producing a butanol gasoline blend having good cold start and warm-up (CS&W) driveability performance comprising: (a) providing at least one biologically-sourced butanol isomer; (b) blending the at least one biologically-sourced butanol isomer with gasoline to form a butanol gasoline blend, the butanol gasoline blend having a specific ASTM D4814 Table 1 vapor pressure/volatility class; (c) determining a high butanol driveability index (HBDI a ) value for the butanol gasoline blend wherein the HBDI a value is determined by the equation: BuOH(A 1 +A 2 E200+A 3 RVP); wherein BuOH is the concentration in volume percent of the at least one biologically-sourced butanol isomer in the butanol gasoline blend; E200 is the volume percent of the butanol gasoline blend that distills at temperatures up to about 200° F.; RVP is the Reid Vapor Pressure in psi; and A 1 , A 2 , and A 3 are coefficients selected to give a substantially linear relationship between the values of the linear combination for the butanol gasoline blend containing the at least one butanol isomer and the logarithms of the mean corrected measured total weighted demerits for such blends, at concentrations of the at least one biologically-sourced butanol isomer up to about 80 volume percent; and wherein the total weighted demerits of the butanol gasoline blend is less than about 40; and (d) optionally adjusting the amount of gasoline and the at least one biologically-sourced butanol, or any combination thereof, such that the value of HBDI a is below the maximum limit for driveability index (DI) for the specific class of gasoline as specified in Table 1 of ASTM D 4814.