Method of monitoring and optimizing additive concentration in fuel ethanol

Abstract

Disclosed is a method of monitoring and optimizing the concentration of an additive composition in a fuel ethanol. The method includes adding a known amount of the additive composition to the fuel ethanol to create a treated fuel ethanol. A measured fluorescent signal provides information for determining the concentration of the additive composition in the fuel ethanol. A component in the additive composition is capable of providing the fluorescent signal or capable of being chemically derivatized to provide a fluorescent signal or a calorimetric signal. Based upon the measured fluorescent signal or calorimetric 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 an additive composition in a fuel ethanol, the method comprising:
 (a) adding a known amount of the additive 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 additive composition in the treated fuel ethanol, and wherein the additive composition includes a component that is either inherently capable of providing a fluorescent signal or capable of being chemically derivatized to provide the fluorescent signal;   (b) measuring the fluorescent signal for the component in the treated fuel ethanol at a point subsequent to adding the known amount of the additive composition;   (c) determining the concentration of the additive composition in the treated fuel ethanol based upon the measured fluorescent signal of the component at the point subsequent;   (d) if the determined concentration of the additive 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 additive composition in the treated fuel ethanol into the optimum concentration range;   (e) if the determined concentration of the additive composition is below the optimum concentration range, optionally adding an additional known amount of the additive composition, wherein said additional known amount is calculated to bring the concentration of the additive 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 additive composition is within the optimum concentration range.   
     
     
         2 . The method of  claim 1 , wherein the additive composition is selected from the group consisting of: a denaturant combined with a corrosion inhibitor; a corrosion inhibitor; two or more different corrosion inhibitors; and combinations thereof. 
     
     
         3 . The method of  claim 1 , wherein the additive composition includes a corrosion inhibitor and a denaturant, and including measuring the fluorescent signal: (i) after the corrosion inhibitor is added and before the denaturant is added; (ii) after the corrosion inhibitor and the denaturant are added separately; and (iii) after a mixture of the corrosion inhibitor and the denaturant are added. 
     
     
         4 . The method of  claim 1 , wherein the component of the additive composition is an inert fluorescent tracer, which is not normally part of the additive composition and which is added either simultaneously or sequentially with the additive composition in a known proportion. 
     
     
         5 . The method of  claim 1 , wherein an excitation and emission wavelength range for measuring the fluorescent signal of the component is selected from the group consisting of: ultraviolet light excitation and ultraviolet light emission; ultraviolet light excitation and visible light emission; visible light excitation and visible light emission; visible light excitation and near infrared emission; and near infrared excitation and near infrared emission. 
     
     
         6 . The method of  claim 1 , including measuring the fluorescent signal using a sample derived from the group consisting of: grab sample; sidestream sample; inline sample; bulk measurement; or combinations thereof. 
     
     
         7 . 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. 
     
     
         8 . The method of  claim 1 , wherein the component does not inherently provide the fluorescent signal and including chemically derivatizing the component in a grab sample with a moiety to enable the component to provide the fluorescent signal, wherein the chemical derivatization optionally produces a covalent bond or complex formation between the component and the moiety. 
     
     
         9 . The method of  claim 1 , wherein the additive composition includes a plurality of additional compounds. 
     
     
         10 . The method of  claim 1 , including measuring the fluorescent signal of the component either continuously or intermittently. 
     
     
         11 . The method of  claim 1 , including measuring the fluorescent signal of the component at a plurality of points. 
     
     
         12 . 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 fluorescent signal of the component. 
     
     
         13 . The method of  claim 1 , wherein the treated fuel ethanol is mixed with gasoline to form a fuel ethanol composition. 
     
     
         14 . The method of  claim 13 , wherein the fuel ethanol composition ranges from about E10 to about E95. 
     
     
         15 . The method of  claim 14 , wherein the fluorescent signal is used to determine total ethanol content in the fuel ethanol composition. 
     
     
         16 . 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. 
     
     
         17 . The method of  claim 16 , wherein the network is an Internet. 
     
     
         18 . A digital storage medium having computer-executable instructions stored thereon, the instructions operable to execute the method of  claim 1 . 
     
     
         19 . A method of monitoring and optionally optimizing the concentration of an additive composition in a fuel ethanol, the method comprising:
 (a) adding a known amount of the additive 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 additive composition in the treated fuel ethanol, and wherein the additive composition includes a component capable of being chemically derivatized to provide a colorimetric signal;   (b) removing a grab sample from the treated fuel ethanol;   (c) adding to the grab sample an agent to chemically derivatize the component to provide the colorimetric signal;   (d) measuring the calorimetric signal for the derivatized component in the grab sample;   (e) determining the concentration of the additive composition in the treated fuel ethanol based upon the measured calorimetric signal of the derivatized component in the grab sample;   (f) if the determined concentration of the additive 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 additive composition in the treated fuel ethanol into the optimum concentration range; and   (g) if the determined concentration of the additive composition is below the optimum concentration range, optionally adding an additional known amount of the additive composition, wherein said additional known amount is calculated to bring the concentration of the additive composition in the treated fuel ethanol into the optimum concentration range.