Biodiesel purification by a continuous regenerable adsorbent process

Abstract

A process for the continuous purification of biodiesel (fatty acid alkyl esters (FAAE)) is described using a powdered, granulated or extruded adsorbent. The adsorbent is contained in a column system and is regenerated for reuse multiple times. The crude biodiesel is contacted with an adsorbent packed into a column, or multiple columns in series, for a sufficient amount of time to remove impurities such as, but not limited to, soaps, metals, free glycerin, sterol glucosides and many of the other impurities that reduce the stability of biodiesel. The resulting finished biodiesel exiting the column(s) is ready for the methanol recovery process. Once the adsorbent no longer removes the desired amount of impurities, it is regenerated for reuse. The solvent used for the regeneration process is reclaimed and reused by recycling it back to the transesterification reaction.

1 .- 27 . (canceled) 
     
     
         28 . A biodiesel fuel purified prepared by the steps of:
 treating fatty acid alkyl esters (FAAE) utilizing one or more adsorbent columns containing an adsorbent material for removing one or more impurities from the fatty acid alkyl esters (FAAE).   
     
     
         29 . A system for purification of fatty acid alkyl esters (FAAE) comprising:
 one or more adsorbent columns containing an adsorbent material for removing one or more impurities from the fatty acid alkyl esters (FAAE).   
     
     
         30 . The system of  claim 29  further comprising:
 means for regenerating the adsorbent material by removing adsorbed impurities from the adsorbent material. 
 
     
     
         31 . The system of  claim 30  wherein the regeneration of the adsorbent material is performed with a solvent. 
     
     
         32 . The system of  claim 31  further comprising:
 means for directly esterfying the FFA in the solvent filtrate using an acid as a catalyst. 
 
     
     
         33 . The system of  claim 32  further comprising:
 means for reclaiming fatty acid alkyl esters (FAAE) produced by the esterification. 
 
     
     
         34 . The system of  claim 29  further comprising:
 one or more ion-exchange resin columns used as a lead column to pre-treat the fatty acid alkyl esters (FAAE) before entering said one or more adsorbent columns. 
 
     
     
         35 . The system of  claim 34  further comprising:
 means for regenerating the ion-exchange resin. 
 
     
     
         36 . The system of  claim 35  wherein the step of regenerating the ion-exchange resin is performed with a solvent. 
     
     
         37 . The system of  claim 36  further comprising:
 means for recycling the solvent to be used in a transesterification reaction.