Method of monitoring and optimizing denaturant concentration in fuel ethanol

Abstract

Disclosed is a method of monitoring and optimizing the concentration of a denaturant composition in a fuel ethanol. The method includes adding a known amount of the denaturant composition to the fuel ethanol to create a treated fuel ethanol. A measured spectroscopic absorbance or transmittance signal provides information for determining the concentration of the denaturant composition in the fuel ethanol. A component in the denaturant composition is capable of providing the spectroscopic absorbance or transmittance signal or capable of being chemically derivatized to provide a spectroscopic absorbance or transmittance signal. Based upon the measured spectroscopic absorbance or transmittance signal, the concentration of the additive composition in the fuel ethanol may be adjusted.

1 . A method of monitoring and optionally optimizing the concentration of a denaturant composition in a fuel ethanol, the method comprising:
 (a) adding a known amount of the denaturant composition to the fuel ethanol to create a treated fuel ethanol, wherein the known amount is calculated to provide an optimum concentration range for the denaturant composition in the treated fuel ethanol, and wherein the denaturant composition includes at least one component that is either inherently capable of providing a spectroscopic absorbance or transmittance signal or capable of being chemically derivatized to provide the spectroscopic absorbance or transmittance signal;   (b) measuring the spectroscopic absorbance or transmittance signal for the component in the treated fuel ethanol at a point subsequent to adding the known amount of the denaturant composition;   (c) determining the concentration of the denaturant composition in the treated fuel ethanol based upon the measured spectroscopic absorbance or transmittance signal of the component at the point subsequent;   (d) if the determined concentration of the denaturant composition is above the optimum concentration range, optionally diluting the treated fuel ethanol by adding a known additional volume of the fuel ethanol, wherein said additional volume is calculated to bring the concentration of the denaturant composition in the treated fuel ethanol into the optimum concentration range;   (e) if the determined concentration of the denaturant composition is below the optimum concentration range, optionally adding an additional known amount of the denaturant composition, wherein said additional known amount is calculated to bring the concentration of the denaturant composition in the treated fuel ethanol into the optimum concentration range; and   (f) optionally repeating one or more of steps (a) to (e) until the determined concentration of the denaturant composition is within the optimum concentration range.   
     
     
         2 . The method of  claim 1 , wherein the known amount of the denaturant composition is calibrated based upon mathematical derivative treatment and/or multivariate analysis of the spectroscopic absorbance or transmittance signal. 
     
     
         3 . The method of  claim 1 , wherein the spectroscopic absorbance or transmittance signal is derived from a near infrared spectrum. 
     
     
         4 . The method of  claim 1 , wherein the denaturant composition is selected from the group consisting of: a denaturant combined with a corrosion inhibitor; two or more different denaturants; two or more different denaturants plus a corrosion inhibitor; two or more different denaturants plus two or more different corrosion inhibitors; and combinations thereof. 
     
     
         5 . The method of  claim 1 , including measuring the spectroscopic absorbance or transmittance signal using a sample derived from the group consisting of: grab sample; sidestream sample; inline sample; bulk measurement; or combinations thereof. 
     
     
         6 . The method of  claim 1 , including operating the method with a control scheme selected from the group consisting of: manual; automatic; proportional-integrative-derivative or other electronic/computer control; control based upon rate of change of measured signals over time; and combinations thereof. 
     
     
         7 . The method of  claim 1 , including chemically derivatizing the component in a grab sample with a moiety to enable the component to provide the spectroscopic absorbance or transmittance signal, wherein the chemical derivatization optionally produces a covalent bond or complex formation between the component and the moiety. 
     
     
         8 . The method of  claim 1 , wherein the denaturant composition includes a plurality of additional compounds. 
     
     
         9 . The method of  claim 1 , including measuring the spectroscopic absorbance or transmittance signal of the component either continuously or intermittently. 
     
     
         10 . The method of  claim 1 , including measuring the spectroscopic absorbance or transmittance signal of the component at a plurality of points. 
     
     
         11 . The method of  claim 1 , including removing a sample of the treated fuel ethanol after the point subsequent, either automatically or manually, and measuring the spectroscopic absorbance or transmittance signal of the component. 
     
     
         12 . The method of  claim 1 , wherein the treated fuel ethanol is mixed with gasoline to form a fuel ethanol composition. 
     
     
         13 . The method of  claim 12 , wherein the fuel ethanol composition ranges from about E10 to about E95. 
     
     
         14 . The method of  claim 12 , wherein the spectroscopic absorbance or transmittance signal is used to determine total ethanol content in the fuel ethanol composition. 
     
     
         15 . The method of  claim 1 , including operating the method over a network, wherein the network includes one or more sensors, controllers, digital storage mediums, and/or communication means. 
     
     
         16 . A digital storage medium having computer-executable instructions stored thereon, the instructions operable to execute the method of  claim 1 .