Ecofriendly emulsifier synthesis from esterified waste vegetable oil for wellbore drilling fluids

Abstract

Ecofriendly emulsifier synthesis from esterified waste vegetable oil for wellbore drilling fluids is described. A raw material waste vegetable oil is esterified to produce a methyl ester of the raw material waste vegetable oil. A caustic soda solution is added to the methyl ester resulting in a mixture. The mixture is thermally treated. A pH of the mixture is adjusted resulting in formation of an aqueous phase and a non-aqueous phase. The aqueous phase is separated from the non-aqueous phase.

The invention claimed is: 
     
       1. A method of cleaving an ester group of a methyl ester of waste vegetable oil to produce an emulsifier of the waste vegetable oil, the method comprising:
 adding a caustic soda solution to the methyl ester resulting in a mixture; 
 thermally treating the mixture; 
 adjusting a pH of the mixture resulting in formation of an aqueous phase and a non-aqueous phase; and 
 separating the aqueous phase from the non-aqueous phase. 
 
     
     
       2. The method of  claim 1 , wherein the caustic soda solution comprises an alkoxide dissolved in a solvent. 
     
     
       3. The method of  claim 1 , wherein the caustic soda solution comprises sodium hydroxide. 
     
     
       4. The method of  claim 2 , wherein the solvent comprises water. 
     
     
       5. The method of  claim 1 , further comprising stirring the mixture during thermally treating the mixture. 
     
     
       6. The method of  claim 1 , wherein the mixture is heated to a temperature greater than room temperature. 
     
     
       7. The method of  claim 6 , wherein the temperature is substantially 60° C. 
     
     
       8. The method of  claim 1 , wherein adjusting the pH of the mixture comprises adding an acid. 
     
     
       9. The method of  claim 8 , wherein the acid is substantially 31% hydrochloric acid. 
     
     
       10. The method of  claim 1 , wherein the adjusted pH of the mixture is substantially between 4 and 5. 
     
     
       11. A method comprising:
 cleaving an ester group of a methyl ester of waste vegetable oil to produce an emulsifier of the waste vegetable oil; 
 adding a caustic soda solution to the methyl ester resulting in a mixture; 
 thermally treating the mixture at substantially 60° C.; 
 adjusting a pH of the mixture by adding an acid; 
 forming of an aqueous phase and a non-aqueous phase in response to adding the acid; and
 separating the aqueous phase from the non-aqueous phase.