Transesterification of soybean oil to biodiesel over kalsilite catalyst

Abstract

The transesterification reaction of soybean oil with methanol over kalsilite-based heterogeneous catalysts was investigated. The kalsilite was synthesized from potassium silicate, potassium hydroxide, and aluminum nitrate aqueous solutions by controlling the pH value at 13. After calcination in air at 1200°C, a very porous kalsilite (KAlSiO₄) was obtained with surface pores ranging from 0.2 to 1.0 µm. However, this kalsilite had relatively low catalytic activity for the transesterification reaction. A biodiesel yield of 54.4% and a kinematic viscosity of 7.06 cSt were obtained at a high reaction temperature of 180°C in a batch reactor. The catalytic activity of kalsilite was significantly enhanced by introducing a small amount of lithium nitrate in the impregnation method. A biodiesel yield of 100% and a kinematic viscosity of 3.84 cSt were achieved at a temperature of only 120°C over this lithium modified catalyst (2.3 wt-% Li). The test of this lithium modified catalyst in pellet form in a laboratory-scale fixed-bed reactor showed that it maintained a stable catalytic performance with a biodiesel yield of 100% over the first 90 min.

Key words： kalsilite; heterogeneous catalyst; transesterification; biodiesel

References

1 Boz N, Degirmenbasi N, Kalyon D. Conversion of biomass to fuel: transesterification of vegetable oil to biodiesel using KF loaded nano-γ-Al₂O₃ as catalyst. Applied Catalysis B: Environmental, 2009, 89(3-4): 590–596

2 Kouzu M, Yamanaka S Y, Hidaka J S, Tsunomori M. Heterogeneous catalysis of calcium oxide used for transesterification of soybean oil with refluxing methanol. Applied Catalysis A: General, 2009, 355(1-2): 94–99

3 Schuchardt U, Sercheli R, Vargas R M. Transesterification of vegetable oils: a review. Journal of the Brazilian Chemical Society, 1998, 9(3): 199–210

4 Peter S K F, Ganswindt R, Neuner H P, Weidner E. Alcoholysis of triacylglycerols by heterogeneous catalysis. European Journal of Lipid Science and Technology, 2002, 104(6): 324–330

5 Bondioli P. The preparation of fatty acid esters by means of catalytic reactions. Topics in Catalysis, 2004, 27(1-4): 77–82

6 Suppes G J, Dasari M A, Doskocil E J, Mankidy P J, Goff M J. Transesterification of soybean oil with zeolite and metal catalysts. Applied Catalysis A: General, 2004, 257(2): 213–223

7 Brito A, Borges M E, Otero N. Zeolite Y as a heterogeneous catalyst in biodiesel fuel production from used vegetable oil. Energy & Fuels, 2007, 21(6): 3280–3283

8 Basu H N, Norris M E. Process for production of esters for use as a diesel fuel substitute using a non-alkaline catalyst. US Patent, <patent>5525126</patent>, 1996

9 Oku T, Nonoguchi M, Moriguchi T. Method of production of fatty acid alkyl esters and/or glycerin and fatty acid alkyl ester-containing composition. WIPO Patent, <patent>021697</patent>, 2005

10 Kim H J, Kang B S, Kim M J, Park Y M, Kim D K, Lee J S, Lee K Y. Transesterification of vegetable oil to biodiesel using heterogeneous base catalyst. Catalysis Today, 2004, 93-95: 315–320

11 Balcão V M, Paiva A L, Malcata F X. Bioreactors with immobilized lipases: state of the art. Enzyme and Microbial Technology, 1996, 18(6): 392–416

12 Abreu F R, Alves M B, Macêdo C C S, Zara L F, Suarez P A Z. New multi-phase catalytic systems based on tin compounds active for vegetable oil transesterification reaction. J Mol Catal A: Chemical, 2005, 227(1-2): 263–267

13 Watkins R S, Lee A F, Wilson K. Li-CaO catalysed triglyceride transesterification for biodiesel applications. Green Chemistry, 2004, 6(7): 335–340

14 Alonso D M, Mariscal R, Granados M L, Maireles-Torres P. Biodiesel preparation using Li/CaO catalysts: activation process and homogeneous contribution. Catalysis Today, 2009, 143(1-2): 167–171

15 Bournay L, Hillion G, Boucot P, Chodorge J A, Bronner C, Forestiere A. Process for producing alkyl esters from a vegetable or animal oil and an aliphatic monoalcohol. US Patent, <patent>6878837</patent>, 2005

16 Xie W, Yang Z, Chun H. Catalytic properties of lithium-doped ZnO catalysts used for biodiesel preparations. Industrial & Engineering Chemistry Research, 2007, 46(24): 7942–7949

17 Ma H, Li S, Wang B, Wang R, Tian S. Transesterification of rapeseed oil for synthesizing biodiesel by K/KOH/γ-Al₂O₃ as heterogeneous base catalyst. Journal of the American Oil Chemists’ Society, 2008, 85(3): 263–270

18 Xie W, Li H. Alumina-supported potassium iodide as a heterogeneous catalyst for biodiesel production from soybean oil. J Mol Catal A: Chemical, 2006, 225(1-2): 1–9