PREPARASI DAN KAJIAN AKTIVITAS Al3+-BENTONIT UNTUK KATALIS SINTESIS BIODIESEL DARI ASAM-ASAM LEMAK DALAM MINYAK JARAK PAGAR

ABDULLOH, Triyono

2015 | Tesis | FMIPA

Catalyst preparation and characterization of Al3+-bentonite for catalytic synthesis of biodiesel by esterification of palmitic acid, oleic acid, linoleic acid and free fatty acids (FFA) in the oil of Jatropha curcas (Jatropha curcas Linnaeus) has been done. Al3+-bentonite catalyst was prepared from standard bentonite (Sigma-Aldrich) and natural bentonite of Turen Malang through cation exchange reaction using AlCl3 solution. The catalysts obtained were characterized by XRD, XRF, pyridine-FTIR and surface area analyzer using the BET method. Catalyst activity test of Al3+-bentonite for esterification reaction was done at 65oC using molar ratio of metanol-FFA of 30:1 and 0.25 g of Al3+-bentonite catalyst for the period of ½, 1, 2, 3, 4 and 5 hours. Based on the characterization results, the Al3+-bentonite standard catalyst has a d-spacing of 14.98 ?, acid sites of Brönsted and Lewis respectively of 70.12 ?mol/g and 337.45 ?mol/g, surface area of 117.30 m2/g and the average of pore radius of 59.70Å. Meanwhile, the Al3+-bentonite Turen Malang catalyst has a dspacing of 15.63 ?, acid sites of Brönsted and Lewis respectively of 230.79 ?mol/g and 99.39 ?mol/g, surface area of 683.88 m2/g and the average of radius pore of 20.09Å. GC-MS analysis results of the oil phase after esterification reaction showed the formation of methyl esters (biodiesel), namely methyl palmitate, methyl oleate and methyl linoleate. The number of conversions resulted in esterification using Al3+-bentonite standard catalyst was 49.30, 34.33, 18.17% and the esterification using Al3+-bentonite Turen Malang catalyst was 74.61, 37.75, and 20.93% for the esterification of palmitic acid, oleic acid and linoleic acid respectively. The conversion of FFA in jatropha oil was 32.53 and 43.98% respectively for the esterification reaction using of Al3+-bentonite standard and Al3+-bentonite Turen Malang catalyst. Catalyst activity of Al3+-bentonite in reducing FFA content in Jatropha curcas oil is still not comparable with the use of H2SO4 catalyst.

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