금속염화물을 첨가한 루이스산 이온성 액체 촉매를 이용한 대두유로부터 바이오디젤 합성

Synthesis of Biodiesel from Soybean Oil Using Lewis Acidic Ionic Liquids Containing Metal Chloride Salts

  • 최재형 (부경대학교 화학공학과) ;
  • 박용범 (부경대학교 화학공학과) ;
  • 이석희 (부경대학교 화학공학과) ;
  • 천재기 (부경대학교 화학공학과) ;
  • 최재욱 (부경대학교 안전공학부) ;
  • 우희철 (부경대학교 화학공학과)
  • Choi, Jae Hyung (Department of Chemical Engineering, Pukyong National University) ;
  • Park, Yong Beom (Department of Chemical Engineering, Pukyong National University) ;
  • Lee, Suk Hee (Department of Chemical Engineering, Pukyong National University) ;
  • Cheon, Jae Kee (Department of Chemical Engineering, Pukyong National University) ;
  • Choi, Jae Wook (Department of Safety Engineering, Pukyong National University) ;
  • Woo, Hee Chul (Department of Chemical Engineering, Pukyong National University)
  • 투고 : 2010.05.26
  • 심사 : 2010.06.22
  • 발행 : 2010.10.31

초록

본 연구에서는 이온성 액체인 염화콜린에 5가지의 금속염화물을 첨가하여 루이스산 이온성 액체 촉매를 제조하고, 이 촉매를 사용하여 대두유로부터 바이오디젤을 합성하였다. 먼저 단독의 금속염화물인 염화주석과 염화아연, 염화알루미늄, 염화철(III), 염화구리(I) 촉매에 대하여 363~423 K 온도 범위에서 에스터 교환 반응의 반응성을 조사하였다. 5가지의 금속염화물 중 염화주석이 우수한 촉매 활성을 나타내었고, 이러한 경향과 같이 5가지의 루이스산 이온성 액체 촉매 중 $[Me_3NC_2H_4OH]Cl-2SnCl_2$의 촉매가 403 K에서 14시간 동안 유지:메탄올:촉매의 몰 비율 1:12:0.9인 조건으로 최대 91.1%의 높은 반응수율을 나타내었다. 단독의 염화주석 촉매와는 달리, $[Me_3NC_2H_4OH]Cl-2SnCl_2$의 촉매는 반응 후 액체-액체 이상계를 형성하여 반응물과 생성물로부터 쉽게 분리할 수 있으며, 5회 이상 재사용 후에도 활성이 거의 감소하지 않았다. 이러한 결과는 촉매의 수분에 대해 안정성과 강한 루이스 산성도의 특성에 기인한 것으로 생각된다. 또한 촉매에 대한 반응시간과 촉매 및 메탄올 몰 비율 등의 반응변수들에 대한 영향이 조사되었다.

Production of biodiesel from soybean oil catalyzed by Lewis acidic ionic liquids(ILs) containing metal chloride salts was investigated in this study. Metal chloride salts, such as $SnCl_2$, $ZnCl_2$, $AlCl_3$, $FeCl_3$ and CuCl, were screened for oil transesterification in the range of 363-423 K. Among these metal chlorides, tin chloride showed particularly high catalytic property for the oil transesterification. Similarly, among these Lewis acidic ionic liquid catalysts, $[Me_3NC_2H_4OH]Cl-2SnCl_2$ resulted in a high fatty acid methyl esters(FAMEs) content of 91.1% under the following reaction conditions: 403 K, 14 h, and a molar ratio of 1:12:0.9 (oil:methanol:catalyst). Unlike the pure tin chloride catalysts, Lewis acidic ILs containing tin chloride $[Me_3NC_2H_4OH]Cl-2SnCl_2$ catalyst could be recycled up to five times without any significant loss of activity by separating from the FAMEs with simple decantation. The Lewis acidity and high moisture-stability of this catalyst appeared to be responsible for the excellent catalytic performance. The effects of reaction time and the molar ratio of methanol/catalyst to oil on the FAMEs production were also studied in this work.

키워드

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