The liquid fuel (made of C 5 /C 6 alkanes) was obtained directly from the hydrogenolysis of microcrystalline cellulose (MCC) with Ir-VO x /SiO 2 combined with HZSM-5 as the composite catalyst in a biphasic system (n-dodecane + H 2 O). The performance of the catalyst was investigated by carrying out a series of experiments using various V/Ir molar ratios , catalyst dosages, reaction temperatures, reaction time, hydrogen pressure and substrates. At the optimized conditions, the cellulose was almost completely converted, and at the same time, a high C 5 /C 6 yield of 85.1% was obtained at 210 °C for 24 h and 6 MPa with the V/Ir molar ratio being 0.13. These results not only proved that Ir-VO x /SiO 2 (V/Ir = 0.13) has excellent performance for the hydrogenolysis of MCC to liquid alkanes, but also indicated that vanadium is a good metal promoter for iridium . In addition, it was proven the C5/C6 alkanes were obtained via sorbitol through the combined effect of Ir-VO x /SiO 2 and HZSM-5.
Lele Jin,Wenzhi Li,Qiying Liu,Longlong Ma,Chao Hu,Ajibola T. Ogunbiyi,Mingwei Wu,Qi Zhang
In this study, the Mo-promoted Ir/SiO 2 (Ir-MoO x /SiO 2 ) catalysts combined with the zeolite HZSM-5 were used for the direct conversion of microcrystalline cellulose (MCC) to liquid fuel (C 5 /C 6 alkanes) in n-dodecane/H 2 O system. A synergistic effect was formed between the partially reduced MoO x species and the Ir particles, which effectively promoted the catalytic activity of Ir/SiO 2 catalyst. When the Mo/Ir molar ratio was 0.5, a high yield of C 5 /C 6 alkanes (91.7%) was achieved at 210 ℃ for 12 h. In addition, the main component of C 5 /C 6 alkanes was n-hexane, which was proven to be obtained by the hydrogenolysis of the key intermediate, sorbitol, formed from the hydrolysis and hydrogenation of MCC.
Yujing Weng,Songbai Qiu,Chenguang Wang,Lungang Chen,Zhengqiu Yuan,Mingyue Ding,Qi Zhang,Longlong Ma,Tiejun Wang
In this work, a dual-bed aqueous catalysis system with Ru/C as catalyst was proposed for the liquid alkane (pentane/hexane: C5/C6) production from acid biomass hydrolysate. The low temperature (413 K) hydrogenation of biomass-derived carbohydrates into polyols was carried out in the first fixed-bed. The high temperature (523 K) hydrodeoxygenation (HDO) of polyols into alkanes was carried out in the down-stream bed. To screen the optimal reaction conditions, glucose and sorbitol were chosen for model tests. Whereby, reactor types, solution pH value, mineral acid, reaction temperature, pressure and sorbitol concentrations were studied. A maximum C5/C6 alkane yield of 61.9% was achieved from 20 wt% sorbitol solution (pH = 1.5) under 523 K and 4 MPa H 2 pressure in the fixed-bed reactor. For cassava and corncob hydrolysate, C5/C6 alkane yield of 38.8% and 44.1% were obtained, respectively.