Synthesis of high density and low freezing point jet fuels range cycloalkanes with cyclopentanone and lignin-derived vanillins

In this work,a“cyclopentanone-vanillin”strategy was proposed for the preparation of jet fuel range cycloalkanes from lignocellulose-derived ketones and lignin-derived aldehydes via aldol condensation and hydrodeoxygenation(HDO).Ethanolamine lactate ionic liquid(LAIL)exhibited excellent catalytic activity in the aldol condensation of cyclopentanone and vanillin.Desired mono-condensation and bicondensation products were obtained with yield of 95.2%at 100℃.It is found that the synergy effects between amino group of ethanolamine and hydroxyl group of lactic acid play a key role in the aldol condensation.The condensation products were converted into cycloalkanes by HDO over 5%Pd/Nb_(2)O_(5)catalyst.The density of the obtained HDO products is 0.89 g/cm^(3)and the freezing point is lower than-60℃.These results suggest that the resulted cycloalkanes can be used as additives to improve the density and low-temperature fluidity of the jet fuels.

Fabrication of a sinter-resistant Fe-MFI zeolite dragonfruit-like catalyst for syngas to aromatics conversion

Direct conversion of syngas to aromatics has great potential to decrease fossil fuel dependence.Here,a unique structured hybrid catalyst composed of Fe_(3)O_(4) nanoparticles intimately dispersed inside an acidic zeolite is developed.1 to 4 nm sized Fe_(3)O_(4) nanoparticles end up evenly dispersed in an acidic and slightly mesoporous Al-ZSM-5 based on Fe_(3)O_(4) restructuring during co-hydro thermal synthesis using organosilane modification.A very high aromatic productivity of 214 mmolaromatics h^(-1) gFe^(-1) can be obtained with a remarkable 62%aromatic selectivity in hydrocarbons.This catalyst has excellent sintering resistance ability and maintains stable aromatics production over 570 h.The synthetic insights that postulate a mechanism for the metastable oxide-zeolite reorganization during hydrothermal synthesis could serve as a generic route to sinter-resistant oxide-zeolite composite materials with uniform,well-dispersed oxide nanoparticles in close intimacy with-and partially confined in-a zeolite matrix.

Efficient production of ethyl levulinate from cassava over Al2(SO4)3 catalyst in ethanol–water system

One-pot achievement of ethyl levulinate from cassava was conducted in ethanol–water system over several simple sulfate salt catalysts. Al2(SO4)3catalyst had the best performance in synthesizing ethyl levulinate comparing with those of a series of sulfate salts. The highest yields of ethyl levulinate was up to 39.27% as well as 7.78% levulinate acid when cassava was catalyzed in ethanol medium by adding 10 wt% water.13C and1H NMR spectroscopic investigations confirmed that isomerization of glucose to fructose over Al2(SO4)3catalyst is an important step in producing ethyl levulinate and levulinate acid. Due to aggregations of Al3+under hydrothermal conditions, tiny amount of Al3+were detected in filtrate at the percentage of 0.32% even if in absolute water. Brønsted and Lewis acids could improve the yield of ethyl levulinate and levulinate acid by synergistic effect. All results suggested that Al2(SO4)3was a simple and efficient catalyst for ethyl levulinate and levulinate acid production. © 2016 Science Press

In situ synthesis of biomass-derived Ni/C catalyst by self-reduction for the hydrogenation of levulinic acid to γ-valerolactone

Herein,we reported in situ synthesis of biomass-derived Ni/C catalyst by self-reduction with pomelo peel.Compared with the conventional method, which includes carbonization, activation, impregnation and reduction, the entire preparation process was simplified to two steps, which was more straightforward. This synthesis method was green as Ni/C can be prepared without any additional chemical and the self-reduction process was realized in N2, which can avoid using H2 thus averting some problems such as storage, transportation and safety of H2. Meanwhile, the size and dispersion of Ni particles can be controlled by changing carbonization temperature.The synthesis mechanism of Ni/C catalyst with selfreduction was investigated, which was mainly attributed to the carbon and reducing gas produced during the carbonization process.For the catalytic performance of GVL synthesis, a high yield (94.5%) can be obtained and it exhibited good stability up to 5 cycles without obvious loss of catalytic activity.

基于木质纤维素的生物基材料

随着化石能源的不断消耗和生态环境的不断破坏,开发环境友好型的可再生电化学储能装置与生物医疗材料尤为迫切。木质纤维素类生物质作为重要的可再生资源,具有成本低、易于获得、环境友好、孔隙结构丰富等优势,其作为一种可再生、可生物降解、具有生物相容性的优秀改性材料基质,具有广泛的应用前景。生物质材料的处理已经从传统方法(包括燃烧法、饲料化、肥料化与基质化处理),逐步走向能源化、生态化、材料改性,以及制备新型生物基功能与智能材料产品,如:高性能储能装置与生物医疗装备。总之,以生物质材料为主要原料,开发新型基质与功能材料是发展趋势。本文对制备用于高性能储能装置与生物医疗领域的生物质衍生材料的最新研究进展进行了总结与展望,同时指出面临的问题与挑战。

高热沉碳氢喷气燃料吸热反应研究进展

高超音速飞行器是空天领域的重要发展方向,是国家整体科技实力的重要标志。吸热型碳氢燃料为兼具冷却与推进功能,需要具备高热沉、高密度、高热值、高热安定性、低冰点、低结焦和低成本的“四高三低”的基本特征。本文总结了吸热型碳氢燃料吸热反应研究进展,重点关注热裂解、催化裂解和催化蒸汽重整对于热沉的影响,分析了温度、压力和停留时间等热解条件对热沉的影响,考察了燃料组成、分子结构与热裂解间的关联规律,总结了分子筛、纳米颗粒和引发剂对吸热型碳氢燃料催化裂解行为和热沉的影响特性,并对吸热反应过程中的结焦及抑制技术进行了总结,结合发展现状提出了吸热型碳氢燃料未来的研究方向。

Numerical research on biomass wastewater treatment using doublepartition vessel with off-centered impellers

Limited by single function,it is difficult for the traditional stirred vessels to meet the requirements of mixing system in biomass wastewater treatment processes.The estimation of biomass wastewater stirring reactor performance by computational fluid dynamics(CFD)during multiphase reactions is important,due to the uncertainty in the numerical results.In this study,a novel double-partition stirred vessel with eccentrically located impellers was developed for the special subject.In addition,many simulations were carried out with the wastewater from biomass ethanol production as the medium to ensure the high reactor performance.The fluid flow was simulated and analyzed using the turbulent RNG k-ε model and multi reference frames.A good agreement is found between the simulation results and the confirmatory experiment.Moreover,the weir crest and interconnected pore were specially designed for the establishment of the circulation of fluid to maintain different technological conditions in the two regions.The distributions of radial velocities and tangential velocities were concentrated near the stirring blade.From the velocity profile,it is deduced that the flow pattern in the stirred vessel is insensitive to Reynolds number.Finally,this simulation study could contribute to the improvement and optimization of the structure,as well as the operation of the novel stirred vessel.