Research Article Open Access

Enzymatic Synthesis of Palm Alkyl Ester Using Dialkyl Carbonate as an Alkyl Donors

Roila Awang1 and Choo Yuen May1
  • 1 Malaysian Palm Oil Board, Engineering and Processing Division, No. 6, Persiaran Institute, Bandar Baru Bangi, 43000 Kajang, Selangor, Malaysia

Abstract

Problem statement: Though efficient in terms of reaction yield and time, the chemical approach to synthesizing alkyl ester has drawback such as difficulties in the recovery of glycerol and the need for removal of salt residue. On the other hand, biocatalyst allow for synthesis of specific alkyl esters and easy recovery of glycerol. However, the solvent-free alcoholysis, does not give high conversion. The same problem was also found when ethyl or methyl acetate was used as acyl acceptors. Approach: Lipase catalyzed transesterification of oil and dialkyl carbonate was predicted to give higher conversion in solvent free reaction system. Results: Alkyl esters were synthesized enzymatically to overcome the problems associated with chemical processes. In this study, dialkyl carbonates were used as an alkyl donor for the production of alkyl ester. Nine commercial lipases were tested for their suitability for the reaction system. Among the lipase tested, Novozym 435 was chosen for optimization study because of their higher activity. In a solvent-free reaction system, the ester formation using dialkyl carbonate was 6 times higher than using ethanol and methanol. The effect of various reaction parameters such as temperature, amount of enzyme, organic solvent and structure of substrates were studied to determine optimal condition. The optimal conditions of ester formation were reaction temperature at 60°C, reaction time at 8 h, enzyme amount of 10% (w/w of oil) and 0.2% wt added water. Conclusion: Solvent-free lipase catalyzed transesterification of palm kernel oil and dialkyl carbonates gave higher conversion of ester compared to the reaction using short chain alcohol as an alkyl donors.

American Journal of Applied Sciences
Volume 7 No. 8, 2010, 1083-1086

DOI: https://doi.org/10.3844/ajassp.2010.1083.1086

Submitted On: 21 May 2010 Published On: 31 August 2010

How to Cite: Awang, R. & May, C. Y. (2010). Enzymatic Synthesis of Palm Alkyl Ester Using Dialkyl Carbonate as an Alkyl Donors. American Journal of Applied Sciences, 7(8), 1083-1086. https://doi.org/10.3844/ajassp.2010.1083.1086

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Keywords

  • Transesterification
  • palm kernel oil
  • dialkyl carbonates