Alumina-supported potassium iodide as a heterogeneous catalyst for biodiesel production from soybean oil

Abstract Biodiesel fuel, a promising alternative diesel fuel produced by a catalytic transesterification of vegetable oils, has become more attractive recently because of its environmental concerns and the fact that it is made from renewable resources. In this work, the transesterification of soybean oil with methanol has been studied in a heterogeneous system, using alumina loaded with potassium iodide as a solid base catalyst. After loading KI of 35 wt.% on alumina followed by calcination at 773 K for 3 h, the catalyst gave the highest basicity and the best catalytic activity for this reaction. The catalysts were characterized by means of XRD, IR, SEM and the Hammett indicator method. Moreover, the dependence of the conversion of soybean oil on the reaction variables such as the catalyst loading, the molar ratio of methanol to oil and the reaction time was studied. The conversion of 96% was achieved under the optimum reaction conditions. Besides, a correlation of the catalyst activity for the transesterification reaction with its basicity was proposed.

[1]  J. F. González,et al.  Biodiesel Fuels from Vegetable Oils: Transesterification of Cynara cardunculus L. Oils with Ethanol , 2002 .

[2]  Yue Fu,et al.  Vapor-phase reactions of catechol with dimethyl carbonate. Part III: Selective synthesis of veratrole over alumina loaded with potassium nitrate , 1999 .

[3]  B. Gates,et al.  Sulfated zirconia and iron- and manganese-promoted sulfated zirconia: do they protonate alkanes? , 1998 .

[4]  J. Clacens,et al.  Correlation between the basicity of solid bases and their catalytic activity towards the synthesis of unsymmetrical organic carbonates , 2005 .

[5]  A. Dalai,et al.  Synthesis and characterization of vegetable oil derived esters: evaluation for their diesel additive properties. , 2004, Bioresource technology.

[6]  T. Baba,et al.  Highly efficient self-condensation of benzaldehyde to benzyl benzoate over KF-loaded alumina , 1998 .

[7]  Sanjib Kumar Karmee,et al.  Preparation of biodiesel from crude oil of Pongamia pinnata. , 2005, Bioresource technology.

[8]  G. Suppes,et al.  Calcium carbonate catalyzed alcoholysis of fats and oils , 2001 .

[9]  Wangy,et al.  Supported K-salts as a New Solid Base Catalyst , 1997 .

[10]  Leon B. Levy,et al.  Deactivation characteristics of an acrolein oxidation catalyst: I. Kinetics of activity loss , 1982 .

[11]  J. Clark,et al.  19F mas NMR and FTIR analysis of the adsorption of alkali metal fluorides onto alumina , 1990 .

[12]  Y. Chun,et al.  An investigation of KF modification to generate strong basic sites on NaY zeolite , 1998 .

[13]  K. J. Harrington,et al.  Transesterification in situ of sunflower seed oil , 1985 .

[14]  G. Pleizier,et al.  Alkali-promoted alumina catalysts: II. Water-gas shift reaction☆ , 1982 .

[15]  Yi Chen,et al.  Surface interaction model ofγ-alumina-supported metal oxides , 1992 .

[16]  J. M. Stevenson,et al.  Characterization of the actual catalytic agent in potassium fluoride on activated alumina systems , 1986 .

[17]  W. Hoelderich,et al.  Preparation of superbases and their use as catalysts for double-bond isomerization , 1999 .

[18]  E. Min,et al.  Structure and basicity of γ-Al2O3-supported MgO and its application to mercaptan oxidation , 2001 .

[19]  K. Nakamoto.  Infrared spectra of inorganic and coordination compounds , 1970 .

[20]  L. Forni.  Comparison of the Methods for the Determination of Surface Acidity of Solid Catalysts , 1974 .

[21]  Y. Amenomiya,et al.  Alkali-promoted alumina catalysts: I. Chemisorption and oxygen exchange of carbon monoxide and carbon dioxide on potassium-promoted alumina catalysts☆ , 1981 .

[22]  K. J. Harrington,et al.  A comparison of conventional and in situ methods of transesterification of seed oil from a series of sunflower cultivars , 1985 .

[23]  U. Schuchardt,et al.  1H nuclear magnetic resonance determination of the yield of the transesterification of rapeseed oil with methanol , 1995 .

[24]  Xiao Wang,et al.  Dispersion of potassium nitrate and the resulting basicity on alumina and zeolite NaY , 1998 .

[25]  A. Tomašević,et al.  Transesterification of sunflower oil in situ , 1998 .

[26]  Hak Joo Kim,et al.  TRANSESTERIFICATION OF VEGETABLE OIL TO BIODIESEL USING HETEROGENEOUS BASE CATALYST , 2004 .

[27]  A. S. Ramadhas,et al.  Biodiesel production from high FFA rubber seed oil , 2005 .

[28]  J. Zhu,et al.  Attempts to create new shape-selective solid strong base catalysts , 1999 .

[29]  W. Stork,et al.  Studies of compound formation on alkali/.gamma.-aluminum oxide catalyst systems using chromium, iron, and manganese luminescence , 1974 .

[30]  J. Clark,et al.  Alumina-supported fluoride reagents for organic synthesis: optimisation of reagent preparation and elucidation of the active species , 1986 .

[31]  G Antolín,et al.  Optimisation of biodiesel production by sunflower oil transesterification. , 2002, Bioresource technology.

[32]  C. Kappenstein,et al.  Surface contribution to the interfacial chemistry of potassium modified oxide catalysts , 1998 .