Patent ID: 7404411

Claim:
A process for the control of biodiesel content in a complex mixture comprising hydrocarbons and/or substituted hydrocarbons and at least one type of biodiesel material, by near infrared spectroscopy, comprising predicting said biodiesel content by: a) measuring the near infrared absorbance of at least one wavelength in a portion of the range of 800-2500 nm; which are used to quantify the biodiesel content, b) outputting a periodic or continuous signal indicative of a derivative of said absorbance in said wavelength, or wavelengths in said one or more bands or a combination of mathematical functions comprising a derivative thereof, c) mathematically converting said signal to an output signal indicative of the biodiesel content of said mixture; and d) controlling a blending or other process which correlates with biodiesel content by apparatus responsive to said output signal; wherein said mathematically converting includes taking a first or higher derivative, and wherein said output signal is used to control proportioning pumps, automatic control valves, or other flow control means to control the addition rate of each of a series of components fed from different sources to provide a target biodiesel content in a finished blended mixture.