Biodiesel production by sulfated mesoporous titania–silica catalysts synthesized by the sol–gel process from less expensive precursors

Synthesis of Ti(SO 4 )O solid acid nano-catalyst and its application for biodiesel production from used cooking oil

“…The obtained titanium sulphate oxide or titanium oxysulfate nano-catalyst has a unique and different chemical structure than titanium dioxide (see figure 1) and those from published work on sulphated metal oxides [30,34,41,83,95,96]. This obvious change in the chemical structure makes the prepared Ti(SO4)O nano-catalyst more stable compared to all reported sulphated metal oxide [41] as in previous catalysis the sulphate species located on the surface of metal oxides which makes the molecule unstable [30,34]. The stability of synthesised Ti(SO4)O nano-catalyst is due to the formation of polydentate sulphate species inside the structure of TiO2 which also leads to a higher tolerance to high percentage of FFAs in raw material for biodiesel production.…”

“…It was also reported that the SO /TiO2-SiO2 catalyst can be re-used up to 4 times without reducing the catalytic activity. Recently, an inexpensive precursor was used in the synthesis of SO /TiO2-SiO2 catalyst by Shao and co-workers [41]. They reported 88% yield for biodiesel production under 20:1 methanol to UCO molar ratio, 10wt% catalyst concentration and 3hrs reaction time at 120 o C with constant stirring at 400rpm.…”

“…Several synthetic routes were applied for the preparation of heterogeneous catalysts including sol-gel [24][25][26][27], solvent-free [28,29] and hydrothermal methods [30][31][32][33]. Examples of heterogeneous catalysts include SO /TiO2 [30,[34][35][36][37],, SO /TiO2-SiO2 [38][39][40][41], SrO/SO -ZrO2 [29], SO /ZrO2 [17,[42][43][44], SO /TiO2-ZrO2 [45] and SO /SnO2 [17,46], which were considered for a good catalytic activity for the raw materials containing large amounts of FFA in biodiesel production. Among these, sulphated doped TiO2 is a good example of a solid super-acidic catalyst which is also used in the petrochemical industry and petroleum refining process [24,47] and showed better performances as compared to other sulphated metal oxides.…”

Sol–gel synthesis of photoactive kaolinite-titania: Effect of the preparation method and their photocatalytic properties

“…Our research group has been providing a sequel clarifying the use of TiOCl 2 solution (rarely reported TiO 2 precursor) to fabricate various photocatalysts with desirable properties for degradation of organic contaminants [10][11][12][28][29][30]. Using TiOCl 2 solution as a TiO 2 precursor yields a homogeneous product with even distribution of primary particles and high TiO 2 loadings.…”

Application of Microwave Irradiation for Preparation of a KOH/Calcium Aluminate Nanocatalyst and Biodiesel

“…The stability of a solid‐base catalyst is a highly important factor for its industrial application . The reusability of 0.20KCA‐1.5‐800 as the best nanocatalyst and the effect of recalcination of the used catalyst on its reusability were evaluated.…”