Conversion of lignin oil and hemicellulose derivative into high-density jet fuel

Synthesizing high-density fuel from lignocellulose can not only achieve green and low-carbon development,but also expand the feedstock source of hydrocarbon fuel.Here,we reported a route of producing high-density fuel from lignin oil and hemicellulose derivative cyclopentanol through alkylation and hydrodeoxygenation,HY with SiO_(2)/Al_(2)O_(3) molar ratio of 5.3 was screened as the alkylation catalyst in the reaction of model phenolic compounds and mixtures,and the reaction conditions were optimized to achieve conversion of phenolic compounds higher than 87%and selectivity of bicyclic and tricyclic products higher than 99%.Then two phenolic pools simulating the composition of two typic lignin oils were studied to validate the alkylation and analyze the competition mechanism of phenolic compounds in mixture system.Finally,real lignin oil from depolymerized of beech powder was tested,and notably80%of phenolic monomers in the oil were converted into fuel precursor.After hydrodeoxygenation,the alkylated product was converted to fuel blend with a density of 0.91 g/mL at 20℃and a freezing point lower than-60℃,very promising as high density fuel.This work provides a facile and energyefficient way of synthesizing high-performance jet fuel directly from lignocellulosic derivatives,which decreases processing energy consumption and improve the utilization rate of feedstock.

Tandem hydroalkylation and deoxygenation of lignin-derived phenolics to synthesize high-density fuels

Lignin is the most abundant naturally phenolic biomass,and the synthesis of high-performance renewable fuel from lignin has attracted significant attention.We propose the efficient synthesis of high-density fuels using simulated lignin cracked oil in tandem with hydroalkylation and deoxygenation reactions.First,we investigated the reaction pathway for the hydroalkylation of phenol,which competes with the hydrodeoxygenation form cyclohexane.And then,we investigated the effects of metal catalyst types,the loading amount of metallic,acid dosage,and reactant ratio on the reaction results.The phenol hydroalkylation and hydrodeoxygenation were balanced when 180℃ and 5 MPa H_(2)with the alkanes yield of 95%.By extending the substrate to other lignin-derived phenolics and simulated lignin cracked oil,we obtained the polycyclic alkane fuel with high density of 0.918 g·ml^(-1)and calorific value of41.2 MJ·L^(-1).Besides,the fuel has good low-temperature properties(viscosity of 9.3 mm^(2)·s^(-1)at 20℃ and freezing point below-55℃),which is expected to be used as jet fuel.This work provides a promising way for the easy and green production of high-density fuel directly from real lignin oil.

Theoretical and experimental study on the inhibition of jet fuel oxidation by diarylamine

Antioxidants addition is believed as a facile and effective way to improve jet fuel thermal oxidation stability.However,amine antioxidants,as one of the most important antioxidants,have not received sufficient attention in the field of jet fuel autoxidation yet.Herein,the inhibition efficiency and mechanism of decane and exo-tetrahydrodicyclopentadiene(THDCPD)oxidation by di-4-tert-butylphenylamine(diarylamine)was experimentally and theoretically investigated.The results show that diarylamine can significantly inhibit decane oxidation but is less efficient for THDCPD oxidation,which is attributed to the higher energy barrier of retro-carbonyl-ene reaction(rate-determining step)in THDCPD than that in decane during diarylamine regeneration.However,the addition of diarylamine will cause undesirable color change after accelerated oxidation and produce slightly more deposits during high-temperature thermal oxidative stress for both decane and THDCPD.The results provide significant implications for the future design of effective antioxidant additives for high-performance jet fuel.

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.

Sustainable synthesis of high-density fuel via catalytic cascade cycloaddition reaction

The access to high-density hydrocarbon fuels from biomass for the reduction of dependence on fossil resources has been a research highlight in recent years. It is well known that cycloalkanes are the components of fuels with higher energy density than straight or branched alkanes. Herein, we developed a new catalytic pattern to synthesize dimethyltetradecahydroanthracenes(DMTHA), a kind of tricyclic alkane, from biomass-derived isoprene and p-benzoquinone via a cascade Diels-Alder reaction followed by a hydrodeoxygenation reaction. Vanadium supported on titanium dioxide(V-TiO_(2)) was applied to catalyze the cascade Diels-Alder reaction and it was disclosed that V with appropriate V^(4+)/V^(5+) ratio on the surface of TiO_(2) could activate quinones. Experimental tests showed that the heating value of final products was up to 45.7 MJ/kg. The development of new high-density fuel molecules is a long-term trend for the future renewable and sustainable fuel energy application.

Diesel and Jet Fuels from Bitumen-derived Middle Distillates

Narrow fractions of light gas oils obtained from various upgrading processes of Athabasca oilsands bitumen were investigated as diesel and jet fuels. The relationship among the boiling range, cetane number, smoke point, and other properties such as aromatics content, aniline point, and the sulfur and nitrogen content was also studied. The study reveals that when appropriate processes and distillation boiling ranges are selected, oilsands bitumen can produce diesel and jet fuels that meet stringent environmental regulations and future product specifications. New correlations to predict CN and smoke point were developed as a function of density, boiling ranges by simulated distillation, and mono- and total aromatics by supercritical fluid chromatography. The correlations apply to bitumen-derived middle distillates that have a wide range of boiling points.

Synthesis of jet fuel additive with cyclopentanone

A new route was developed for the synthesis of renewable decalin with cyclopentanone which can be derived from lignocellulose.It was found that 1,2,3,4,5,6,7,8-octahydronaphthalene could be selectively produced by the hydrogenation/dehydration/rearrangement of [1,1-bi(cyclopentylidene)]-2-one(i.e.the selfaldol condensation product of cyclopentanone) over a dual-bed catalyst system.Among the investigated catalysts,the Ru/C and Amberlyst-15 resin exhibited the highest activities for the hydrogenation of [1,1-bi(cyclopentylidene)]-2-one to [1,1-bi(cyclopentan)]-2-ol and the dehydration/rearrangement of [1,1-bi(cyclopentan)]-2-ol to 1,2,3,4,5,6,7,8-octahydronaphthalene,respectively.Using Ru/C and Amberlyst-15 resin as the first bed and the second bed catalysts,1,2,3,4,5,6,7,8-octahydronaphthalene was directly produced in high carbon yield(83.7%) under mild conditions(393 K,1 MPa).After being hydrogenated,the1,2,3,4,5,6,7,8-octahydronaphthalene was converted to decalin which can be used as additive to improve the thermal stability and volumetric heat value of jet fuel.

Regulating the nanoscale intimacy of metal and acidic sites in Ru/γ-Al_(2)O_(3)for the selective conversions of lignin-derived phenols to jet fuels

Catalytic hydrodeoxygenation(HDO)of biomass-derived oxy-compounds to advanced hydrocarbon fuels usually requires bifunctional catalysts containing metals and acidic sites.The appropriate tuning of metal and/or acidic active sites at interfaces of bifunctional catalysts can significantly improve catalyst activity and product selectivity.Here,4-trifuoromethyl salicylic acid(TFMSA),as a hydrothermal stable organic acid,was employed to tailor the bifunctional interface of Ru/γ-Al_(2)O_(3)to enhance the catalytic performance on converting lignin-derived phenols to jet fuel range cycloalkanes.More than 80%phenol was converted into cyclohexane at 230°C for 1 h over Ru/γ-Al_(2)O_(3)modified by TFMSA,which was about three times higher than that over unmodified Ru/γ-Al_(2)O_(3).X-ray diffraction(XRD),Transmission electron microscope(TEM),H2 chemisorption,and energy dispersive X-ray spectroscopy(EDS)elemental mapping results indicated that Ru nanoparticles and TFMSA were well distributed onγ-Al_(2)O_(3),and a nanoscale intimacy between Ru and TFMSA was reached.Meanwhile,Fourier transform infrared spectroscopy after pyridine adsorption(Py-FT-IR)analysis proved that Brønsted acidic sites on the catalytic interfaces of TFMSA modified Ru/γ-Al_(2)O_(3)had been improved.Moreover,the kinetic and density functional theory(DFT)results suggested that the synergistic effects of adjacent Ru nanoparticles and acidic sites were crutial for promoting the rate-limiting conversion step of phenol HDO to cyclohexane.

油脂加氢生产生物喷气燃料(SRJET)技术及工业应用

为了保障中国航空业市场对生物喷气燃料的需求,中国石化镇海炼化分公司(简称镇海炼化)采用中石化石油化工科学研究院有限公司开发的油脂加氢生产生物喷气燃料(SRJET)技术新建一套100 kt a以餐饮废油为原料的生物喷气燃料生产装置,该装置一次开车成功,生产的生物喷气燃料产品满足《3号喷气燃料》(GB 6537-2018)附录C酯类和脂肪酸类加氢改质工艺生产的煤油组分标准中各项指标的要求,成功获得可持续生物材料圆桌会议颁发的可持续认证证书和中国民用航空局审定的生物喷气燃料适航证书,并成功实现商业飞行。

Experimental and Molecular Simulations for Evaluating the Effect of Lubricity Improvers on the Property of Jet Fuel

Since the 1990 s, the kerosene fuel(code: JP-8) had been applied in the ground equipment provided with direct injection compression ignition engines in the U.S. Army, resulting in increased occurrence of injection pump failures. Anti-wear additives must be used in the single fuel due to its poor lubricity. In the present work, lubricity improvers were selected on the basis of molecular simulation theoretically and these agents were evaluated to improve the lubricity of jet fuel using the high frequency reciprocating rig(HFRR) apparatus and the ball-on-cylinder lubricity evaluator(BOCLE). It was revealed that dimer acid with higher value of adsorption energy on the Fe(110) plane surface had more efficient lubricity promoting properties than that of naphthenic acid. The experimental results suggested that the dimer acid had a better tribological behavior compared with that of naphthenic acid used as lubricity improver of jet fuel. And addition of anti-wear additives at a dosage of 15 μg/g was able to promote the lubricity of jet fuel to a required level on BOCLE, while a higher concentration over 80 μg/g was needed to improve the lubricity to a demanded value of diesel on HFRR.

Characteristics of a coherent jet enshrouded in a supersonic fuel gas

Based on a current coherent jet,this study proposes a supersonic combustion(SC)coherent jet in which the main oxygen jet is surrounded by a supersonic fuel gas.The characteristics of the proposed coherent jet are analyzed using experimental methods and numerical simulations in the high-temperature environment of electric arc furnace(EAF)steelmaking.The SC coherent jet achieved stable combustion in the EAF steelmaking environment.The simulated combustion temperature of the supersonic shrouding methane gas was 2930 K,slightly below the theoretical combustion temperature of methane–oxygen gas.The high speed and temperature of the supersonic flame effectively weakened the interaction between the main oxygen jet and the external ambient gas,inhibiting the radial expansion of the main oxygen jet and maintaining its high speed and low turbulence over a long distance.These features improved the impact capacity of the coherent jet and strengthened the stirring intensity in the EAF bath.

Effects of Blending Long-Chain Alcohols with Jet Fuel on the Macroscopic Spray Characteristics

Long-chain alcohols were considered to be promising alternative fuels and fuel additives. This study was aimed at figuring out the influences of blending long-chain alcohols with jet fuel on the macroscopic spray characteristic. n-Butanol and n-pentanol were chosen as tested alternative fuels. A common-rail injection system was used to create high-pressure injection conditions. The Schlieren imaging system was used to capture spray processes. Results showed that with the addition of long-chain alcohols, the spray tip penetration and the peak spray tip velocity increased, whereas the spray cone angle and the spray area decreased. Comparisons between those macroscopic spray characteristics of AKB blends and AKP blends were also conducted. Compared to AKB blends, AKP blends showed similar spray tip penetration, larger peak tip velocity, smaller spray cone angle, and smaller spray area.

An experimental study on RP-3 jet fuel injection on a common rail injection system

RP-3 jet fuel could be an alternative fuel for diesel engines.In this study,the injection characteristics of RP-3jet fuel under single and split injection strategies were investigated and compared with diesel fuel.The experimental results indicate that RP-3 jet fuel has slightly shorter injection delay time than diesel fuel,but this difference is negligible in actual engine operations.Further,although the lower density and viscosity of RP-3 jet fuel lead to higher volumetric injection rates and cycle-based injection quantities,the cycle-based injection mass and the mass injection rates at the stable injection stage of RP-3 jet fuel are close to or slightly lower than those of diesel fuel.Based on these experimental observations,it could be concluded that fuel physical properties are the secondary factor influencing the injection characteristics in both single and split injection strategies,as RP-3 jet fuel and diesel fuel are taken for comparison.

Study on Using Mixed Fuel of Jet Fuel/Gasoline as Fuel of Gasoline Engine

This paper has integrated various methods such as laboratory physical and chemical analysis, engine bench test and actual road test, etc. to conduct a feasibility study on the emergency alternative fuel of gasoline by mixed jet fuel and gasoline. The study shows that both the evaporability and anti-knock quality decrease after mixing jet fuel with gasoline. While the mixing proportion increases, the engine power decreases and the fuel consumption increases gradually. When the proportion reaches 40%, the engine power drops by 5.3% to 11.7%, the fuel consumption rises by an average of 3.8%, and meantime the oil dilution and emission of the engine power become worse. Therefore, as for the gasoline engine, the mixed oil can only be used as emergency alternative fuel due to its harm to the engine.

氨/氢燃料射流点火船用发动机燃烧特性

为突破氨在发动机中的燃烧局限性,促进氨燃料高效快速燃烧,提出了一种利用氢气射流火焰点燃氨燃料的方案。通过向主动式预燃室供给氢气,进气道内预混氨/氢燃料,实现氨在大缸径船用发动机上的稳定高效燃烧。基于数值模拟计算方法,在改进了Otomo氨/氢机理基础上,探究了进气温度、掺混氢气的质量分数和主燃室当量比对氨/氢燃料着火与燃烧特性的影响。研究结果表明,射流火焰可以在主燃烧室形成燃烧所需的热力学环境和高活性热射流。在当量比为0.4、不掺混氢气的条件下,450 K进气温度可以实现氨燃料发动机的稀薄燃烧,在掺混氢气的质量分数较低时,射流点火对火焰发展促进作用更显著;掺混氢气的质量分数提高至10.0%可以使燃烧相位提前18°,但爆震风险增加;在进气温度为320 K和掺混氢气的质量分数为2.5%条件下,主燃室在当量比最小为0.45时可正常着火,但随着更接近理论空燃比的燃烧,指示热效率略有提升,主动预燃室氢射流点火的燃烧模式在实现氨发动机高效快速燃烧方面具有良好的潜力。

静电场作用下航煤氧化结焦过程分析

航空发动机燃烧室工作环境恶劣,导致燃油组分同溶解氧反应引发氧化沉积.通过对金属平板表面沉积的研究,分析电场对氧化结焦过程的影响.搭建了金属平板氧化结焦实验系统,对不同物理条件和电场性质下的结焦情况进行分析.研究表明:随着温度升高、表面粗糙度增加,结焦量增多;金属对焦体有催化作用而改变结焦形貌;电场的加入使焦体颗粒的粒径和融并现象发生变化,采用负电场时,表面结焦量大幅降低,焦体内部元素含量和结构发生改变,电场强度使结焦颗粒间排斥作用增大,抑制结焦过程,采用正电场时由于电场方向的改变促进了沉积向壁面的移动,使结焦量增加.

典型添加剂对3号喷气燃料热氧化安定性的影响原因分析及对策

热氧化安定性是喷气燃料的一项重要性能指标。抗静电剂和抗磨剂是工业喷气燃料调和过程中必须要加入的两种添加剂,而在市场中常用的添加剂分别是抗静电剂Stadis和抗磨剂T-1602。通过研究抗静电剂Stadis和抗磨剂T-1602对喷气燃料热氧化安定性的影响因素,包括空气、光照、存储温度等条件,对喷气燃料在实际生产过程中的调和、存储和使用安全都有非常重要的意义。研究结果表明:抗静电剂Stadis对喷气燃料热氧化安定性基本没有影响。抗磨剂T-1602影响喷气燃料热氧化安定性的因素有含氧的环境、光照、储存温度、添加剂浓度和储存材质等。随着储存温度的升高,含抗磨剂喷气燃料母液的热氧化安定性变差。随着抗磨剂添加浓度逐渐提高,含抗磨剂母液的喷气燃料热氧化安定性逐渐下降。通过采取对喷气燃料配置过程中增加氮封隔绝空气、避免光照、罐存储温度按照不大于40℃等措施,可最大程度降低喷气燃料热氧化安定性超标的质量风险,为喷气燃料的安全使用提供合理保障。

负温度系数区域内RP-3喷气燃料表征燃料化学反应动力学分析

为探究喷气燃料(RP-3)在不同条件下负温度系数(NTC)区域内的反应路径、敏感反应以及小分子基元团的影响规律,以CRECK小分子详细机理为核心,基于解耦法耦合正十二烷、正丁基环己烷、正丁基苯简化机理,构建得到RP-3多组分表征燃料化学反应动力学详细机理;并在不同压力、燃料/空气质量比工况下对其NTC区域内的燃烧过程进行了敏感性分析、组分含量变化分析以及组分间交互作用路径分析。结果表明:NTC区域内反应H_(2)O_(2)(+M)=2OH(+M)(M为反应中第三体)是最重要的着火促进反应;不同反应条件下O_(2)、CH_(4)、C_(2)H_(4)的陡降时刻与CO_(2)的激增时刻均与燃料的着火延迟期表现出极高的吻合度;压力与燃料/空气质量比的改变仅会影响反应路径的占比。

柴油发动机燃油跨/超临界喷射特性数值仿真

针对柴油发动机工作条件下喷雾特性变化复杂的问题,利用计算流体动力学软件CONVERGE,采用大涡模拟(Large Eddy Simulation,LES)方法进行跨/超临界柴油机燃料正庚烷的射流喷雾特性仿真分析,对LES中湍流亚格子模型进行深入研究,并从质量分数、密度和温度三方面对比跨/超临界射流的喷雾特性。研究结果表明:随机湍流分散模型开启会使喷雾贯穿距的预测值更接近试验值,当湍流分散系数c_(ps)=0.16时模型预测的贯穿距比c_(ps)=0.05更加贴合试验的结果;跨临界射流存在更加类似于液态的区域,升温时从环境吸收更多热量;与跨临界射流相比,超临界射流喷雾的温度扩散更加迅速,并且喷雾前端温度接近环境温度;跨临界射流中类似液态区域形成了较大的密度分层,抑制喷雾扩散,超临界射流喷雾外层的絮状结构比跨临界射流出现得更早,絮状结构范围更大,径向扩散作用更强;两种状态下温度、密度和质量分数分布呈现一定的对应关系,即温度、质量分数和密度都在中心轴线靠近喷油器处最大,随着轴向距离和径向扩散的增大而减小。

煤焦油加氢制喷气燃料催化剂的开发及性能研究

以煤焦油中难转化的酚油为原料,采用Ni、W负载的MgO和酸碱耦合剂为催化剂,在高压反应釜内对酚油催化加氢制环烷烃反应性能进行研究。结果表明:P改性MgO(P质量分数为0.8%)与酸碱耦合剂均能有效降低加氢催化剂结晶度、优化孔道结构、提高产物环烷烃和芳烃选择性;在Ni-W活性金属负载量(w)为9.0%时,催化剂选择性加氢活性最高,环烷烃选择性达到57.5%。煤焦油加氢的最佳工艺条件为:氢初压8.0 MPa,温度380℃,反应时间60 min。