Fatty Acid Alkyl Esters as Feedstocks for the Enzymatic Synthesis of Alkyl Methacrylates and Polystyrene-co-alkyl Methacrylates for use as Cold Flow Improvers in Diesel Fuels

Journal of the American Oil Chemists' Society, Volume 88, Number 11, 1727-1736 (2011)
Original Paper
Fatty Acid Alkyl Esters as Feedstocks for the Enzymatic Synthesis of Alkyl Methacrylates and Polystyrene-co-alkyl Methacrylates for use as Cold Flow Improvers in Diesel Fuels
Young-Wun Kim, Gyeong Tae Eom, Jin-Sook Hong and Keun-Wo Chung
Abstract
The enzymatic transesterifications of fatty acid methyl esters (FAME) with hydroxyethyl methacrylate (HEMA) were carried out using the Candida antarctica lipase B immobilized within a porous polymethacrylate resin. The enzymatic activity in the transesterification reaction of FAME with HEMA depended on the polarity of the solvent and the highest yield was obtained in toluene (non-polar). The molar ratio of 1:4 (for methyl laurate:HEMA) and 1:2 (for methyl oleate:HEMA) was most favorable for the transesterification yield. The reaction condition (at 60 °C/24 h), and the enzyme concentration of 5% (w/w) for methyl laurate with HEMA, 2% (w/w) for methyl oleate with HEMA resulted in the highest final yield.
Introduction [Excerpt]
Ultra low sulfur diesel (ULSD) may contain substantial amounts of waxy materials.  When subjected to temperatures below their cloud points, these tend to deposit on cold surfaces or crystallize and agglomerate into a solid gel.  ULSD gelling creates rheological problems that interfere with oil production or pipeline transportation and cause handling problems.  A number of techniques have been used to minimize problems caused by wax deposition in diesel fuel.
Some polymers, known as “comb-like” polymers, have long alkyl side chains which act to decrease the rate of wax formation.  Polymeric modifiers including poly(ethylene-co-vinyl acetate), poly(styrene-co-alkyl methacrylate), poly(fumarate-co-vinyl acetate) poly(alkyl methacrylate-maleic anhydride) polymethylmethacrylate, and their acid amide derivatives have been known for several decades as commercial flow improvers and wax inhibitors of diesel fuel.  However, none of them are sufficiently effective in diesel fuel.  It is necessary to develop new ones.
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