Shi Haonan,Gu Xiaoyu,Shi Yinteng,Wang Dandan,Shu Sihao,Wang Zhongze,Chen Jixiang
Porous carbon-encapsulated Ni and Ni–Sn intermetallic compound catalysts were prepared by the one-pot extended Stöber method followed by carbonization and tested for in-situ hydrothermal deoxygenation of methyl palmitate with methanol as the hydrogen donor. During the catalyst preparation, Sn doping reduces the size of carbon spheres, and the formation of Ni–Sn intermetallic compounds restrain the graphitization, contributing to larger pore volume and pore diameter. Consequently, a more facile mass transfer occurs in carbon-encapsulated Ni-Sn intermetallic compound catalysts than in carbon-encapsulated Ni catalysts. During the in-situ hydrothermal deoxygenation, the synergism between Ni and Sn favors palmitic acid hydrogenation to a highly reactive hexadecanal that easily either decarbonylate to n -pentadecane or is hydrogenated to hexadecanol. At high reaction temperature, hexadecanol undergoes dehydrogenation-decarbonylation, generating n -pentadecane. Also, the C-C bond hydrolysis and methanation are suppressed on Ni-Sn intermetallic compounds, favorable for increasing the carbon yield and reducing the H 2 consumption. The n -pentadecane and n -hexadecane yields reached 88.1% and 92.8% on carbon-encapsulated Ni 3 Sn 2 intermetallic compound at 330 °C. After washing and H 2 reduction, the carbon-encapsulated Ni 3 Sn 2 intermetallic compound remains stable during three recycling cycles. This is ascribed to the carbon confinement that effectively suppresses the sintering and loss of metal particles under harsh hydrothermal conditions.
Production of jet fuel precursors from waste kraft lignin through a depolymerization and hydrodeoxygenation (DHDO) method with a complex copper acid catalyst is reported. The kraft lignin undergoes a high degree of depolymerization, deoxygenation, hydrogenation, and C–C coupling. Monomers and dimers with molecular weights in the ranges of <200 Da and 354–452 Da are obtained with optimized yields reaching 93.29 and 39.30 C% at 360 °C for 8 h, while trimers and oligomers with higher molecular weights are also generated with lower contents. The high carbon yields of monomers and dimers are given by the incorporation of methanol solvent. The double bond equivalent (DBE) and polydispersity index (PDI) decrease from 14.77 and 2.77 in kraft lignin to 9.05 and 1.35 in the products, while the high heating value (HHV) increases from 24.53 to 36.47 MJ/kg after reaction. Furthermore, over 45% of the optimized products have boiling points in the range of that of commercial jet fuel (60–280 °C). All these results demonstrate the appropriate properties of the products from kraft lignin DHDO as potential jet fuel precursors.
Yiying Dai,Genkuo Nie,Si Gong,Li Wang,Lun Pan,Yunming Fang,Xiangwen Zhang,Ji-Jun Zou
Synthesis of jet fuel with high density, good low-temperature property and high thermal stability is significant to aerospace industry. Here, a great-performance jet fuel blending including bi- and tri-cyclic hydrocarbons (C10 ~ C16) is synthesized with high yield through reduced graphene oxide (rGO) assisted H 2 SO 4 catalytic one-pot reaction of cyclopentanol and methylcyclopentane. The reaction occurs through a consecutive way of dehydration, alkylation, rearrangement and hydrogen transfer. Carbon-based materials especially rGO are used as additive to increase the carbon yield by promoting the emulsification of reactants in sulfuric acid. Promoted emulsification improves the alkylation of cyclopentanol with methylcyclopentane and makes the hydrogen transfer easier, which highly increases the conversion of methylcyclopentane (54.9%), the carbon yield (83.2%) and the selectivity (97.3%) of products. Finally, a jet-fuel-ranged blending with overall yield of 71.8% is obtained by distillation, which shows high density of 0.90 g/mL, low freezing point of ＜-72 °C and a high oxidation onset temperature of 195.0 °C. This work provides a simple, efficient and low-cost way to synthesize high performance jet fuel from biomass.
危险品化学品经营许可证（带存储）