Continuous algal biodiesel production facility

Abstract

Embodiments of the present invention concern methods, compositions, and apparatus for the continuous conversion of algal lipids into biodiesel. In some embodiments, the biodiesel is formed in a multi-step sequence, the first steps occurring in the presence of water and a strong acid wherein the lipids are released from the algae by means of mechanical and chemical action and are then hydrolyzed to free fatty acids. In a subsequent step, this free fatty acid mixture is reacted with methanol to generate fatty acid methyl esters (also known as biodiesel). Such methods produce biodiesel from algal lipids without the requirement for separate algal cell lysis or lipid extraction or purification prior to the acid catalysis sequence. In other embodiments, the multi-step acid catalysis sequence occurs at 100° C. at two atmospheres of pressure.

1 . A method for continuous production of biodiesel from algae comprising:
 a. continuously feeding an aqueous suspension comprising algae into a biodiesel production plant; and   b. converting lipids from the algae into biodiesel without an initial purification or extraction step.   
     
     
         2 . The method of  claim 1 , wherein the algal lipids are converted into biodiesel using an acid catalyzed reaction at 100° C. and 2 atmospheres of pressure. 
     
     
         3 . The method of  claim 2 , wherein the acid catalyzed hydrolysis step produces free fatty acids from the algal lipids. 
     
     
         4 . The method of  claim 2 , wherein the acid catalyzed hydrolysis step breaks down algae cell walls and releases the algal lipids. 
     
     
         5 . The method of  claim 3 , further comprising adding methanol to the fatty acids to form fatty acid methyl esters (FAME). 
     
     
         6 . The method of  claim 5 , wherein the amount of methanol added is twice the amount of free fatty acid. 
     
     
         7 . The method of  claim 6 , wherein there is an eighty-five percent conversion of free fatty acids to FAME in one hour of reaction. 
     
     
         8 . The method of  claim 5 , further comprising centrifuging the suspension to form liquid and solid components. 
     
     
         9 . The method of  claim 8 , further comprising decanting the liquid component by a phase separation procedure to form a heavy phase and a light phase. 
     
     
         10 . The method of  claim 9 , wherein the heavy phase comprises water, glycerol, acid and methanol. 
     
     
         11 . The method of  claim 9 , wherein the light phase comprises FAME and free fatty acids (FFA). 
     
     
         12 . The method of  claim 10 , wherein the heavy phase is preheated by flashing to separate glycerol and acid from water and methanol. 
     
     
         13 . The method of  claim 12 , further comprising removing the glycerol and acid in a liquid bottoms stream. 
     
     
         14 . The method of  claim 12 , wherein the water and methanol are distilled to separate the methanol from the water. 
     
     
         15 . The method of  claim 14 , further comprising recycling the distilled methanol to react with free fatty acids. 
     
     
         16 . The method of  claim 11 , wherein the FFA and FAME are reacted with additional acid and methanol to complete the production of FAME from FFA. 
     
     
         17 . The method of  claim 16 , wherein over ninety-five percent of the FFA are converted into FAME.