Silica Products for the Production of Biodiesel Fuel Precursor and Biodiesel Fuel

Environmental, economic and quality benefits

Carlos Alberto Bravo Grace Davison – Engineered Materials – Latin America

Abstract:

Since their inception in the mid-1980’s, TriSyl Silicas have provided the glyceride oils and fats industry with substantive and innovative processing options. These innovations have proven, case after case, that significant economic, quality and environmental benefits can be realized when the biodiesel producer embraces TriSyl Silica technology combined with the Modified Caustic Refining (MCR) and Modified Physical Refining (MPR) processes.

MCR with TriSyl Silicas provides an economical and environmentally sound alternative to traditional caustic refining. MCR allows Biodiesel Feed Stock producers to caustic refine oils and fats while eliminating the water wash step and the associated high BOD waste stream. TriSyl Silica is used to efficiently adsorb the high quantities of soaps, phospholipids and associated trace metals in the oil fed directly from the primary centrifuge. The removal of these contaminants prior to the trans-esterification reaction improves process rates, biodiesel yields and glycerin quality. Both, liquid and solid wastes are significantly reduced using TriSyl Silica and the MCR process. TriSyl Silica offers also an option for the Biodiesel Feed Stock producer to optimize physical refining process, producing very good quality Biodiesel feed Stock while minimizing the volume of undesired by-products. Unlike bleaching earth, the phospholipids capacity of the silica adsorbents is further enhanced by the presence of soaps. This synergism between soap and phospholipids adsorption is taken advantage of in the new silica refining process called MPR. The MPR process employs the use of soaps generated by addition of small quantities of caustic solution to the degummed oil to enhance the adsorption of phospholipids on silica. In summary, MPR can be used to obtain superior Biodiesel Feed Stock while reducing adsorbent usage, waste volume and operating cost. This in turn ensures a high biodiesel yield and subsequent cost-effective downstream purification of the biodiesel and glycerin products. After glycerin separation and alcohol removal, the alkyl esters have to be further purified by removing soaps and other impurities. Grace´s Silica can adsorb high quantities of soaps in a cost-effective manner. Water washing and associated waste streams can be eliminated. All in all, TriSyl Silica and the modified refining processes can help biodiesel producers to solve environmental problems while improving quality and economics. TriSyl is a trademark of W.R.Grace & Co. – Conn.