Diesel microemulsion biofuels

Abstract

A biofuel can include a diesel fuel, a plant oil, an alcohol viscosity reducer that is either a mixture of a butanol and a C 1 -C 3 alcohol or solely butanol, and a surfactant present at no more than about 1.0% v/v. The biofuel exists as a clear, stable microemulsion at from about −10° C. to about 70° C. with the cloud point and pour point lower than −10° C.

What is claimed is: 
     
         1 . A biofuel, comprising:
 a diesel fuel;   a plant oil or derivative thereof;   an alcohol viscosity reducer; and   a surfactant present at no more than about 1.0% v/v,   wherein the biofuel exists as a clear, stable microemulsion at temperatures from about −10° C. to about 70° C. and has a kinematic viscosity of less than about 6 cSt at 37.8° C.   
     
     
         2 . The biofuel of  claim 1 , wherein the plant oil is selected from the group consisting of canola oil, algae oil, jatropha oil, safflower oil, castor oil, linseed oil, tung oil, soy oil, sunflower oil, peanut oil, cottonseed oil, palm oil, coconut oil, rice oil, transesterification product thereof, pyrolysis product thereof, and combinations thereof. 
     
     
         3 . The biofuel of  claim 2 , wherein the plant oil is canola oil. 
     
     
         4 . The biofuel of  claim 1 , wherein the alcohol viscosity reducer is an alcohol mixture comprising a butanol and a C 1 -C 3  alcohol. 
     
     
         5 . The biofuel of  claim 4 , wherein the C 1 -C 3  alcohol is ethanol. 
     
     
         6 . The biofuel of  claim 4 , wherein the butanol is sec-butanol. 
     
     
         5 . The biofuel of  claim 4 , wherein the butanol is n-butanol. 
     
     
         8 . The biofuel of  claim 4 , wherein the alcohol mixture is present at from about 12% v/v to about 30% v/v. 
     
     
         6 . The biofuel of  claim 4 , wherein the butanol and the C 1 -C 3  alcohol are present at a ratio of from about 2:1 to about 6:1. 
     
     
         7 . The biofuel of  claim 4 , wherein the butanol is present at up to 30% v/v. 
     
     
         11 . The biofuel of  claim 1 , wherein the alcohol viscosity reducer consists essentially of a butanol present at no more than 30% v/v. 
     
     
         12 . The biofuel of  claim 1 , wherein the surfactant is a fatty acid having a heating value of from 40 MJ/kg to 46 MJ/kg. 
     
     
         13 . The biofuel of  claim 1 , wherein the surfactant is selected from the group consisting of oleyl amine, oleyl alcohol, 1-octanol, ethyl hexyl nitrate, ethyl hexanol, ethylene glycol butyl ether, and combinations thereof. 
     
     
         14 . The biofuel of  claim 13 , wherein the surfactant comprises 1-octanol. 
     
     
         15 . The biofuel of  claim 13 , wherein the surfactant comprises oleyl amine. 
     
     
         16 . The biofuel of  claim 1 , wherein the surfactant is present at from about 0.5% v/v to about 1.0% v/v. 
     
     
         8 . The biofuel of  claim 1 , wherein the diesel fuel is present at from about 35% v/v to about 99.5% v/v. 
     
     
         9 . The biofuel of  claim 1 , wherein the plant oil and diesel fuel are present at a ratio of from about 1.0:1.0 to about 1.0:3.0. 
     
     
         10 . The biofuel of  claim 1 , further comprising water at no more than about 0.5% v/v but greater than 0% v/v. 
     
     
         20 . A method of making a biofuel, comprising mixing a diesel fuel, a plant oil, an alcohol viscosity reducer, and a surfactant at an amount such that the surfactant constitutes less than 1% v/v of the biofuel, where the biofuel exists as a clear, stable microemulsion at from about −10° C. to about 70° C.