Patent ID: 8268629

Claim:
A method for characterizing a liquid hydrocarbon fuel having unknown or variable composition, the method comprising: sensing the solvent relative humidity of the liquid hydrocarbon fuel; sensing the capacitance of the liquid hydrocarbon fuel; determining the amount of water or water-soluble compounds in said liquid hydrocarbon fuel, wherein determining the amount of water or water-soluble compounds includes comparing the solvent relative humidity, and the capacitance of said liquid hydrocarbon fuel to a plurality of pre-determined values of capacitance and solvent relative humidity of the liquid hydrocarbon fuel corresponding to a plurality of concentrations of water or water-soluble compounds in said liquid hydrocarbon fuel; identifying which water-soluble compound or compounds are present in said liquid hydrocarbon fuel, wherein identifying which compound or compounds are present includes comparing the solvent relative humidity and the capacitance of said liquid hydrocarbon fuel to a plurality of pre-determined values of capacitance and solvent relative humidity of the liquid hydrocarbon fuel corresponding to a plurality of water-soluble compounds that may be present; and calculating a temperature threshold for a water or water-soluble phase to form in said liquid hydrocarbon fuel during anticipated temperature conditions of transportation or storage based at least in part on said determining and identifying.