000 02463nab a2200205 4500
005 20260520000903.0
008 260224s2010 xxu
245 0 0 _aResponse of titanium-isopropoxide-based heterogeneous amphiphilic polymer ctalysts for transesterification
260 _a
_b
_cjul./ago. 2010
270 _a23/11/2010 ; 23/11/2010
300 _a7 p. ; 4123–4129
520 _aTranscripción del resumen del autor. Transesterification is a widely used reaction in the chemical industry. Currently, industrial-scale transesterification is primarily performed via homogeneous catalysts. Because of downstream separation issues, there is a need for effective heterogeneous catalysts. However, heterogeneous catalysts introduce the drawback of mass-transfer limitations into the reaction system. The substrates associated with transesterification form a three-phase system that is inherently immiscible in each other with liquid/liquid/solid (L/L/S) interfaces. This study was conducted to ascertain the behavior of a solid catalyst that has amphiphilic properties in the transesterification system. It was hypothesized that the amphiphilic catalyst, depending upon its degree of polymerization, would orient itself at the interface of the two immiscible liquids, forming an emulsion. The catalytic active site, in the mean time, would catalyze the transesterification reaction. In this study, the catalytic aspects of the titanium-isopropoxide-based inorganic dendritic polymers were investigated. Titanium isopropoxide catalysts with varying degrees of polymerization were developed by sol-gel water condensation. The degree of polymerization was controlled by the amount of water addition. Five forms of catalysts with varying degrees of polymerization were subjected to transesterification at varying temperatures and time intervals. In this experiment, soybean oil was used as the triglyceride. Isopropanol and titanium isopropoxide were used as the catalyst precursors. The highest yield of 41.56% of propyl esters was obtained at 200 °C after 3 h with 1% (w/w) of the monomeric form of the catalyst. The behavior of the dimeric and higher forms was highly correlated with reaction temperatures and residence times.
581 _a4
773 0 _tEnergy & fuels
_g24
942 _cARTICULO
100 1 _aNawaratna, Gayan
_943779
100 1 _aFernando, Sandun D.
_938271
100 1 _aAdhikari, Sushil
_943780
999 _c172043
_d172043