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SUMMARY The effects of several modifications on TiO2 P25 in producing hydrogen from glycerol–water mixture have been investigated. Prior to further modification, TiO2 underwent hydrothermal treatment at 130°C for several hours to obtain nanotube shape. TiO2 nanotubes (TiNT) was then doped with platinum (Pt) and nitrogen (N) by employing photo‐deposition and impregnation method, respectively. SEM and XRD results showed that Pt‐N‐TiNT was successfully obtained as pure anatase crystal structure. The effects of glycerol content to photocatalytic activity of hydrogen production have also been studied, result in 50%v of glycerol as the optimum concentration correspond to the stoichiometric volume ratio of glycerol reforming. The results of photo‐production test showed that TiNT (nanotube) could enhance hydrogen generation by two times compared with unmodified P25 (nanoparticle). Meanwhile, simultaneous modification of TiNT by Pt and N dopants (Pt‐N‐TiNT) lead to activity improvement up to 13 times compared with P25. The output of this study may contribute toward finding an alternative pathway to produce H2 from renewable resources. Copyright © 2012 John Wiley & Sons, Ltd.

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Palm oil empty fruit bunches (POEFBs) can be converted into levulinic acid (LA) and furfural, which are among the top building-block chemicals. The purpose of this study was to investigate separate and simultaneous kinetic model parameters for LA and furfural production from POEFBs, which were pretreated by soaking in aqueous ammonia (SAA). The highest LA yield, which was obtained at a reaction temperature of 170°C after 90 min in an acidic solution with a concentration of 1 M, was 52.1 mol%. The highest furfural yield was 27.94 mol%, which was obtained at a reaction temperature of 170°C after 20 min in an acidic solution with a concentration of 0.5 M. SAA pretreatment affected activation energy in glucose degradation reactions and favoured direct conversion of hemicellulose to furfural. The activation energy of LA production (EakHMF) increases with higher acid catalyst concentration, and the activation energy of furfural production (EakXYN) decreases with higher acid concentration. These trends in the activation energy occurred in both separate and simultaneous kinetic models. Simultaneous kinetic model is better to calculate kinetic parameters of LA and furfural production than separate kinetic models because the simultaneous kinetic model had a lower sum of square error (SSE) when estimating kinetic parameters.

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