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Hydrogen production by catalytic gasification of cellulose in supercritical water

Frontiers of Chemical Science and engineering 2008年第2期2卷 176-180页

作者： Yu GUAN Aixia PEI Liejin GUO State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an 710049China

Cellulose,one of the important components of biomass,was gasified in supercritical water to produce hydrogen-rich gas in an autoclave which was operated batch-wise under high-pressure.K_(2)CO_(3) and Ca(OH)2 were selected as the catalysts(or promoters).The temperature was kept between 450uC and 500uC while pressure was maintained at 24–26 *** reaction time was 20 *** results showed that the two catalysts had good catalytic effect and optimum amounts were observed for each *** 0.2 g K_(2)CO_(3) was added,the hydrogen yield could reach 9.456 mol?kg21 which was two times of the H2 amount produced without *** 1.6 g Ca(OH)2 was added,the H2 yield was 8.265 mol?kg21 which is lower than that obtained using K_(2)CO_(3) as catalyst but is still 1.7 times that achieved without *** with the results obtained using K_(2)CO_(3) or Ca(OH)2 alone,the use of a combination of K_(2)CO_(3) and Ca(OH)2 could increase the H2 yield by up to 2.5 times that without catalyst and 25%and 45%more than that obtained using K_(2)CO_(3) and Ca(OH)2 alone,*** was found that methane was the dominant product at relatively low *** the temperature was increased,the methane reacts with water and is converted to hydrogen and carbon dioxide.

关键词： biomass hydrogen production supercritical water gasification hydrogen

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Gas flow in a Stratified Porous Medium with Crossflow

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Journal of Thermal Science 2002年第1期11卷 35-40页

作者： Sun Hedong Gao Chengtai Qian Huanqun Zhou Fangde State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an 710049China Department of Petroleum Engineering Xi’an Petroleum InstituteXi’an 710065China

A new model called semi-permeable wall model is presented for multilayer gas reservoir. The model is used to study the influence of crossflow on pressure transient well tests and other single-phase flow problems. It is suggested here to use this model to approximate the actual multilayer gas reservoir, so that the problem is greatly simplified mathematically. Its differential equation is established here for multilayer gas reservoirs, and is linearized by normalized pseudo pressure and pseudo time. Simulation program is developed by finite-difference method when all layers are perforated. The feature of wellbore pressure and rate is clarified by analyzing the results of numerical simulation.

关键词： multi-layer gas reservoir semi-permeable wall model numerical simulation transient well-test wellbore storage skin factor.

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High tension cyclic hydrocarbons synthesized from biomass-derived platform molecules for aviation fuels in two steps

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Green Energy & Environment 2023年第1期8卷 331-337页

作者： Zhanchao Li Yizhuo Wang Qing Li Liqing Xu Hong Wang Frontier Institute of Science and Technology Xi'an Jiaotong UniversityXi'an710054China State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong UniversityXi'an710054China

Synthesizing ring structure aviation fuels from biomass-derived platform molecules is challenging,especially for bridged ring structure aviation fuels which are typically achieved from fossil-derived ***,we report the synthesis of a series of ring structure biofuels in two steps by a combination of a solvent-free Michael-cyclization reaction and a hydrodeoxygenation(HDO)reaction from lignocellulosederived 5,5-dimethyl-1,*** biofuels are obtained with high overall yields up to 90%,which exhibit high densities of 0.81 g cm^(-3)-0.88 g cm^(-3)and high volumetric neat heat of combustion(VNHOC)values of 36.0 MJ L^(-1)-38.6 MJ L^(-1).More importantly,bridged-ring structure hydrocarbons can also be achieved in two steps by a combination of a Robinson annulation reaction and an HDO reaction to afford the final products at high overall yields up to 90%.The bridged-ring structure products have comparable high densities and high VNHOC values to the best artificial fuel JP-10(0.94 g cm^(-3)and 39.6 MJ L^(-1)).The results demonstrate a promising way for the synthesis of high-density aviation fuels with different fuel properties at high yields.

关键词： Biofuels 5,5-Dimethyl-1,3-cyclohexanedione Solvent-free Michael-cyclization Robinson annulation Green reaction

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Enhanced efficiency in Concentrated Parabolic Solar Collector(CPSC) with a porous absorber tube filled with metal nanoparticle suspension

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Green Energy & Environment 2018年第2期3卷 129-137页

作者： Mohammad Hatami Jiafeng Geng Dengwei Jing Mechanical Engineering Department Esfarayen University of Technology (EUT) International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi'an Jiaotong University

In this study, effects of different nanoparticles and porosity of absorber tube on the performance of a Concentrating Parabolic Solar Collector(CPSC) were investigated. A section of porous-filled absorber tube was modeled as a semi-circular cavity under the solar radiation which is filled by nanofluids and the governing equations were solved by FlexPDE numerical software. The effect of four physical parameters, nanoparticles type, nanoparticles volume fraction(φ), Darcy number(Da) and Rayleigh number(Ra), on the Nusselt number(Nu) was discussed. It turns out that Cu nanoparticle is the most suitable one for such solar collectors, compared to the commonly used Fe_3O_4, Al_2O_3, TiO_*** the increased addition of Cu nanoparticles all the parameters φ, Da and Ra shows a significant increase against the Nu, indicates the enhanced heat transfer in such cases. As a result, low concentration of Cu nanoparticle suspension combined with porous matrix was supposed to be beneficial for the performance enhancement of concentrating parabolic solar collector.

关键词： Concentrating parabolic solar collector Porous absorber tube Nanofluid Nusselt number Finite Element Method

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Experimental Study of Drop Deformation and Breakup in Simple Shear flows

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Chinese Journal of Chemical engineering 2007年第1期15卷 1-5页

作者：林长志郭烈锦 State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University

The experimental results of the deformation and breakup of a single drop immersed in a Newtonian liq-uid and subjected to a constant shear rate which generated by counter rotating Couette apparatus were presented in this paper. From experimental observations, the breakup occurred by three mechanisms, namely, necking, end pinching, and capillary instability. Quantitative results for the deformation and breakup of drop are presented. The maximum diameter and Sauter mean diameter of daughter drops and capillary thread radius are linearly related to the inverse shear rate and independent of the initial drop size, the dimensionless wavelength which is the wave-length divided by the thread width at breakup is independent of the shear rate and initial drop size, and the deforma-tion of threads follows a pseudo-affine deformation for Cai/Cac larger than 2.

关键词： drop deformation breakup Couette shear flow

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Fast design of catalyst layer with optimal electrical-thermal-water performance for proton exchange membrane fuel cells

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Journal of Energy Chemistry 2023年第6期81卷 642-655,I0014页

作者： Jing Yao Yuchen Yang Xiongpo Hou Yikun Yang Fusheng Yang Zhen Wu Zaoxiao Zhang School of Chemical Engineering and Technology Xi’an Jiaotong UniversityXi’an 710049ShaanxiChina State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an 710049ShaanxiChina

The catalyst layer(CL)is the core component in determining the electrical-thermal-water performance and cost of proton exchange membrane fuel cell(PEMFC).Systemic analysis and rapid prediction tools are required to improve the design efficiency of *** this study,a 3D multi-phase model integrated with the multi-level agglomerate model for CL is developed to describe the heat and mass transfer processes inside ***,a research framework combining the response surface method(RSM)and artificial neural network(ANN)model is proposed to conduct a quantitative analysis,and further a rapid and accurate *** the help of this research framework,the effects of CL composition on the electrical-thermal-water performance of PEMFC are *** results show that the mass of platinum,the mass of carbon,and the volume fraction of dry ionomer has a significant impact on the electrical-thermal-water *** the selected points,the sensitivity of the decision variables is ranked:volume fraction of dry ionomer>mass of platinum>mass of carbon>agglomerate *** particular,the sensitivity of the volume fraction of dry ionomer is over 50%at these ***,the comparison results show that the ANN model could implement a more rapid and accurate prediction than the RSM model based on the same sample *** in-depth study is beneficial to provide feasible guidance for high-performance CL design.

关键词： Catalyst layer Agglomerate model Sensitivity analysis Response surface Artificial neural network

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Mxene-Derived Ni/Tio2-X/Ti3c2 Catalyst for Enhanced Photothermal Co2 Methanation: Unraveling the Roles of Photoexcited Carriers

SSRN

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SSRN 2025年

作者： Sun, Fan Xin, Yu Xing, Xueli Lou, Jiahui Wang, Qiliang Hong, Hui International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing100190 China School of Aeronautics and Astronautics University of Chinese Academy of Sciences Beijing100049 China Huaneng Clean Energy Research Institute Beijing102209 China Shandong Institute of Advanced Technology Jinan250100 China Department of Architecture and Built Environment University of Nottingham NottinghamNG7 2RD United Kingdom Institute of Engineering Thermophysics China

Photothermal catalysis has emerged as a promising approach for CO2 conversion, which combines photo and thermal energy to drive catalytic reactions efficiently. While light can lower activation barriers and enhance reaction rates, the interplay between light and heat within the catalytic framework remains largely unexplored. In this study, we investigate the critical role of photoexcited carriers in enhancing catalytic performance under solar irradiation, unraveling their contribution to the CO2-to-CH4 conversion process. A multilayer accordion-like Ni/TiO2-x/Ti3C2 catalyst, which exhibits excellent photothermal and photoelectric response characteristics was fabricated for efficient photothermal CO2 methanation. Experimental results demonstrated that introduction of light during thermal catalysis markedly enhanced the CO2 conversion rate, with a 55% increase achieved at 275 ºC. Furthermore, the required temperature for maximum CO2 conversion rate was reduced by 50 ºC compared to the thermal-driven process. Meanwhile, the effects of concentrated ratio and incident wavelength on CO2 conversion were also examined, revealing a synergistic effect between photogenerated carriers and thermal energy. Further characterizations, including steady-state and transient photoluminescence spectroscopy, in-situ XPS, in-situ EPR, in-situ DRITFs, were employed to elucidate the enhancement mechanisms of photogenerated carriers in the catalytic reaction. At the same time, an outdoor experimental prototype was developed to verify the feasibility of photogenerated carrier-thermal synergistically driven CO2 methanation. The findings provide valuable insights into the role of photo-generated carriers in photothermal CO2 methanation, offering new perspectives for the design of efficient photothermal catalysts and advancing solar catalytic CO2 conversion technologies. © 2025, The Authors. All rights reserved.

关键词： Methanation

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Theoretical investigation on water/metal fuel ramjet motor-thermodynamic cycle and thermodynamic calculation

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航空动力学报 2010年第5期25卷 1129-1138页

作者： YANG Ya-jing HE Mao-gang School of Aerospace Xi'an Jiaotong UniversityXi'an 710049China State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power EngineeringXi'an Jiaotong UniversityXi'an 710049China

For achieving high-speed requirement of underwater vehicle,a conceptual engine,which utilizes the hydroreactive characteristic of several metals under supercavitation environment,has been put forward. Especially,in order to obtain specific impulse as great as possible,a dual water injection system is taken into account. Then thermodynamic cycle model,which lead the improvement of power plant and energy system,is introduced in detail,and thermal efficiency is also analyzed. Furthermore,for investigating the performance of this kind of engine system,detailed thermodynamic calculation and analysis are achieved. Especially,regarding hydroreactive metal fuel Mg/AP/HTPB as our target fuel-rich propellant,considering its obvious deficient oxygen property and the energy property of magnesium/water reaction,theoretical calculation method is established by integrating chemical non-equilibrium with chemical equilibrium. Accordingly,low limit of primary water/fuel ratio is determined. In addition,the qualitative and quantitative relationship of performance parameters,such as theoretical specific impulse,nozzle exit temperature,characteristic velocity,etc.,versus water/fuel ratio is investigated respectively.

关键词： hydroreactive metal fuel water ramjet thermodynamic cycle thermal efficiency specific impulse

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Acoustic Wave Prediction in flowing Steam-Water Two-Phase Mixture

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Journal of Thermal Science 1994年第3期3卷 147-154页

作者： Xu Jinliang Chen Tingkuan (state key laboratory of multiphase flow in Power engineering, Xi’an Jiaotong University, Xi’an 710049,China) 1. State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University 710049 Xi’an China

The transient two-fluid model has been used to develop a general relation for acoustic waves. The analysis is valid in principle over the whole void fraction region. flow pattern transitions from one flow regime to the other are assumed to occur at certain void fractions. Different correlations are used to calculate the interfacial area and interfacial drag force per unit mixture volume for bubbly flow,slug flow and annular flow respectively. The Vapour-liquid interphase heat flux is derived from the one dimensional Fourier heat conduction equation to evaluate the interphase evaporation or condensatior *** on the present theory, a program has been carried out. Calculations are performed for pressure from 0.07 MPa to 16.0 MPa, void fractions from 0.0 to 1.0. The predicted sound speeds are compare with some experimental data for low pressures, good agreement has been achieved between sound speed predictions and experimental data.

关键词： two-phase flow perturbation wave sound speed

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engineering practice and economic analysis of ozone oxidation wet denitrification technology

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Chinese Journal of Chemical engineering 2021年第1期34卷 401-408页

作者： Yang Li Defu Che Chenglong Yang Mingyu Yao Tingwen Zhao Kangli Fu Hanchen Zhao Xi’an Thermal Power Research Institute Co LtdXi’an 710032China State Key Laboratory of Multiphase Flow for Power Engineering Xi’an Jiaotong UniversityXi’an 710049China

SO_(2)and NO emitted from coal-fired power plants have caused serious air pollution in *** this study,a test system for NO oxidation using O_(3)is *** basic characteristics of NO oxidation and products forms are studied.A separate test system for the combined removal of SO_(2)and NO_(x)is also established,and the absorption characteristics of NO_(x)are *** characteristics of NO oxidation and NO_(x)absorption were verified in a 35 t·h^(-1)industrial boiler wet combined desulfurization and denitrification *** operating economy of ozone oxidation wet denitrification technology is *** results show that O_(3)has a high rate and strong selectivity for NO *** O_(3)is insufficient,the primary oxidation product is NO_(2).When O_(3)is present in excess,NO_(2)continues to get oxidized to N_(2)O_(5)or NO_(3).The removal efficiency of NO_(2)in alkaline absorption system is low(only about 15%).NOx removal efficiency can be improved by oxidizing NO_(x)to N_(2)O_(5)or NO_(3)by increasing ozone *** the molar ratio of O_(3)/NO is 1.77,the NOx removal efficiency reaches 90.3%,while the operating cost of removing NO_(x)per kilogram is 6.06 USD(NO_(2)).

关键词： Ozone Denitrification Wet process engineering practice

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