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Ab Intio Calculations on Reaction Process of Piperazine Absorbing CO 2

Energy Procedia 2017年 114卷 2121-2127页

作者： Tingting Zhang Yunsong Yu Guoxiong Wang Zaoxiao Zhang School of Chemical Engineering and Technology Xi’an Jiaotong University No.28 Xianning West Road Xi’an 710049 P.R. China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University No.28 Xianning West Road Xi’an 710049 P.R. China School of Chemical Engineering University of Queensland Brisbane Qld. 4072 Australia

The increasing amount of CO 2 emitted to the atmosphere has a deep impact on the environment. It is urgent to take effective measures to reduce CO 2 emissions from its intensive emission source. Chemical absorption is an effective way to cover the large reduction of CO 2 , and piperazine (PZ) is one of the amines that have good performance on CO 2 capture. To make a deep understanding of the chemical mechanism of PZ absorbing CO 2 , computational studies on PZ chemically absorbing CO 2 are discussed in this work using Density functional theory (DFT). Possible reaction pathways of PZ absorbing CO 2 are analyzed. Due to the special chemical structure of PZ, the reaction processes can be divided into two parts, the process of (PZ+CO 2 )+PZ and (PZ+2CO 2 )+PZ. To make a good understanding of the reaction process, a comparison of that between PZ and MEA are discussed. The results show that PZ has lower forward and backward energy barriers than MEA in the zwitterion formation, but in the intermolecular hydrogen transfer process, PZ has higher forward and backward barriers than MEA. For the reaction process of PZ+2CO 2 , it can be stated as a two-step zwitterion formation with two transition states. For the following intermolecular hydrogen transfer of PZ(COO) 2 +PZ, the atom movements are similar to that of (PZCOO+PZ). All the discussions provide theoretical information of PZ chemical absorbing CO 2 .

关键词： CO 2 absorption Piperazine Reaction mechanism DFT Energy barriers

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Influence of Geometrical Structure on Inertial Focusing of Particle in the Microchannel

Influence of Geometrical Structure on Inertial Focusing of P...

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2016年大连国际微纳流体和微流控芯片大会(2016 International Conference of Microfluidics, Nanofluidics and Lab-On-A-Chip

作者： Liang-Liang Fan Hong Zhao Qing Yan Jing Guo Liang Zhao Jiang Zhe Fuli School of Food Equipment Engineering and Science (FEES) Xi ''an Jiaotong UniversityXi ''an P.R.China State Key Laboratory of Multiphase Flow in Power Engineering Xi''an Jiaotong UniversityXi ''an P.R.China Department of Mechanical Engineering University of Akron Akron OH USA

Particles subjected to the inertial lift force will be focused in several equilibrium positions in *** to now, most research on inertial focusing of particles have been focused on the microchannel with a constant cros...

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Enhanced Hydrogen Production of Acidified La2nio4 in Water and Seawater by Coupled Piezo-Photocatalysis

SSRN

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SSRN 2022年

作者： Ma, Xinyu Gao, Yangfei Yang, Bian Lou, Xiaojie Huang, Jianbing Ma, Lijing Jing, Dengwei International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Frontier Institute of Science and Technology State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong University Xi’an710049 China School of Materials Science and Engineering Xi’an University of Technology Xi’an710048 China

Photocatalytic water splitting for hydrogen production is more sustainable than traditional desalination and electrocatalysis, because of avoiding electrode corrosion and other problems. Two-dimensional perovskite oxide materials have multiple characteristics such as ferroelectric, piezoelectric and pyroelectric properties, demonstrating good light response and chemical stability, which provides a broad prospect in photo-chemical conversion. In this study, acidified La2NiO4 can greatly improve the amount of hydrogen evolution by coupling its piezocatalysis and photocatalysis. Under the full-spectrum illumination assisted with ultrasonic vibration in seawater, a recordable hydrogen production activity of 1315.44 μmol·g-1·h-1 was obtained in acidified La2NiO4 by 0.006 mol/L HCl, which more than 200 times higher than that of pure La2NiO4 (6.89 μmol·g-1·h-1) in methanol solution. It is found that the significant hydrogen production of La2NiO4 samples treated with acidification lies in the fast separation of charge carriers in comparison with those without acidification. © 2022, The Authors. All rights reserved.

关键词： Hydrogen production

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Enhanced Hydrogen Production of Acidified Ruddlesden-Popper Type Perovskite Oxides in Water and Seawater by Coupled Piezo-Photocatalysis

SSRN

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SSRN 2022年

作者： Ma, Xinyu Gao, Yangfei Yang, Bian Lou, Xiaojie Huang, Jianbing Ma, Lijing Jing, Dengwei International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi'An710049 China Frontier Institute of Science and Technology State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong University Xi'An710049 China School of Materials Science and Engineering Xi’an University of Technology Xi’an Xi'An710048 China

关键词： Hydrogen production

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Effects of Combustor Wall Temperature on the Outer Recirculation Zone Combustion Modes Transition in Lean Premixed Dme/Air Swirl Flames

SSRN

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SSRN 2024年

作者： Lin, Wenjun Zhang, Weijie An, Zhenhua Wang, Jinhua Huang, Zuohua Zhang, Huangwei State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Department of Mechanical Engineering National University of Singapore 9 Engineering Drive 1 Singapore117576 Singapore Department of Mechanical Engineering and Science Kyoto University Kyoto daigakuKatsura Nishikyo-ku Kyoto615-8540 Japan

In this study, the effects of wall thermal conditions on the ORZ combustion modes transition in the DME/air swirl flames are investigated using the Large Eddy Simulation (LES) and Flamelet Generated Manifold (FGM) method. The results show that the ORZ chemistry and temperature are highly sensitive to the wall thermal condition. Based on the correlation between the temperature and species observed in the time-averaged numerical results, the relation between the combustion mode and temperature in the ORZ is discovered. Through temporal analysis of species and heat release rate in the ORZ, the stable Mode II and Mode IV as well as the unstable Mode III are identified. The chemical reaction pathway analysis for typical probe in the ORZ reveals that different combustion modes undergo distinct (lowtemperature or high-temperature) chemical reaction pathways. Afterwards, the definition of combustion modes used in experiments is refined by utilizing the chemical reaction data from the simulations. And it is applied to identify the combustion mode across the entire computational domain. The results confirm the consistency between the combustion modes determined in experiments based on OH and CH2O and those determined in simulations using chemical reaction rates. Finally, this explains the mechanism of the flickering flame in Mode III is the competition between the low-temperature and high-temperature reaction in the ORZ. Whereas the unstable Mode III can be stabilized by changing the wall temperature to reach the Mode II or Mode IV. © 2024, The Authors. All rights reserved.

关键词： Temperature

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Thermal Modulation of Radiation Fields Enhancing the Adaptability of Cpv-Hydrogen Systems to Hot Outdoor Conditions

SSRN

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SSRN 2023年

作者： Zhu, Yizhou Zhang, Ting’an Geng, Jiafeng Jing, Dengwei Xi'an University of Science and Technology China Department of Chemical Engineering School of Water and Environment Chang'an University Shaanxi Xi’an710064 China International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Shaanxi Xi’an710049 China

The efficiency of photovoltaic (PV) modules operating outdoors often subject to significant decrease due to high PV surface temperature under hot outdoor conditions despite of the high irradiation in this period. Meanwhile, the commercial electrolytic water splitting unit requires additional heat sources to preheat the electrolyte, which is neither economical nor energy efficient. This study introduces a proton exchange membrane (PEM) water electrolyzer system coupled with concentrated photovoltaic (CPV) and a pipe-based liquid spectral beam splitting filter acting also as an electrolyte preheater. The results of continuous experiments during local summer daytime show that the average PV surface temperature of the proposed system can be reduced by 23.5 K compared to that without spectral beam splitting filter. Moreover, the average efficiencies of photovoltaic, electrolysis and solar-to-hydrogen can be increased by 7.5%, 8.1% and 5.2%, respectively. Both simulation and experimental results confirm that our design can reduce the sensitivity of system efficiency toward weather factors, especially high-intensity summer irradiation. This work provides a promising option for application of large-scale solar hydrogen production in regions with sufficient sunlight while high outdoor temperature. © 2023, The Authors. All rights reserved.

关键词： Hydrogen production

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Thermal-Hydraulic Characteristics of Helical Cruciform Single Rod Based on Cfd Investigation

SSRN

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SSRN 2024年

作者： Chen, Yiwen Zhang, Dalin Jiang, Dianqiang Deng, Jian Zhang, Xisi Wang, Xinan Tian, Wenxi Qiu, Suizheng Su, Guanghui State Key Laboratory of Multiphase Flow in Power Engineering Shaanxi Key Laboratory of Advanced Nuclear Energy and Technology School of Nuclear Science and Technology Xi’an Jiaotong University Xi’an710049 China Nuclear Power Institute of China 328 Changshun Avenue Chengdu610213 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China China Institute of Atomic Energy Beijing611731 China

To increase power density in nuclear reactors, the helical cruciform fuel (HCF) is designed as a fundamental element. HCF takes advantages of strong mixing effects, self-supporting features, and strengthened heat transfer, potential to increase the fuel performance in nuclear reactors. In this paper, friction factor and heat transfer coefficient empirical correlations of HCF single rod cooled by water were proposed using a geometric dimensionless number based on numerical simulation. The velocity field, and temperature distribution were obtained to discuss influences of geometric sizes on the fuel performance. Finally, correlations with a geometric dimensionless number were validated with various cases, whose application conditions were also proposed and discussed. This paper provides a guide for study of heat transfer and fluid flow in helical structures, and a reference for establishment of reactor system model using helical cruciform fuels. © 2024, The Authors. All rights reserved.

关键词： Heat transfer coefficients

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A New Reduced Reaction Mechanism of the Surrogate Fuel for RP-3 Kerosene

SSRN

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SSRN 2022年

作者： Liu, Jing Hu, Erjiang Zheng, Weilin Zeng, Wen Chang, Yachao State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Shangxi Xi’an710049 China Liaoning Key Lab of Advanced Test Technology for Aerospace Propulsion System Shenyang Aerospace University Liaoning Shenyang110136 China Key Laboratory of Ocean Energy Utilization and Energy Conservation Ministry of Education Dalian University of Technology Dalian116024 China

By combining the reaction class-based global sensitivity analysis (RC-GSA) methodology, species sensitivity analysis (SSA) methodology, decoupling method and genetic algorithm (GA), a reduced reaction mechanism of the surrogate fuel (10% n-dodecane/14% n-decane/30% iso-hexadecane/36% methylcyclohexane/10% toluene, in mole fraction) for RP-3 kerosene was constructed. As an example, the detailed construction process of skeleton mechanism of methylcyclohexane (MCH) was presented, and the skeleton mechanism constructions of other components in the surrogate fuel were similar to that of MCH. First, the dominant reaction classes in the fuel-relevant mechanism of MCH were recognized by the RC-GSA, the representative species in each retained reaction classes were selected by the SSA, and the skeleton fuel-relevant mechanism of MCH was developed. Second, through combining the skeleton fuel-relevant mechanism of MCH with the reduced reaction mechanism of C 0 -C 3 by the decoupling method, the initial skeleton mechanism of MCH was obtained. Third, based on the GA, the rate constants of fuel-relevant reactions in the initial skeleton mechanism of MCH were optimized to enhance the prediction performance. Finally, by coupling the skeleton reaction mechanisms of n-dodecane, n-decane, toluene, iso-hexadecane, MCH, and the reduced reaction mechanism of C 0 -C 3 , a reduced mechanism (containing 121 species and 469 reactions) of the surrogate fuel for RP-3 kerosene was formed. The predicted main species concentrations during the oxidation process in the jet-stirred reactor, the ignition delay times in the shock tube and laminar flame speeds in the constant volume bomb by this reduced mechanism are in good agreement with the corresponding experimental data of RP-3 kerosene. © 2022, The Authors. All rights reserved.

关键词： Sensitivity analysis

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Core/Shell Structured Hematite Nanorod Arrays as Photoanodes for Efficient Solar Water Oxidation

Core/Shell Structured Hematite Nanorod Arrays as Photoanodes...

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IUPAC 9th International Conference on Novel Materials and their Synthesis(NMS-IX) & 23rd International Symposium on Fine Chemistry and Functional Polymers(FCFP-XXIII)(IUPAC第九届新型材料和合成国际会议暨第23届国际精细化工和功能聚合物研讨会)

作者： S.Shen Samuel S.Mao Department of Mechanical Engineering University of California at BerkeleyBerkeley CA 94720 United States Department of Mechanical Engineering University of California at BerkeleyBerkeley CA 94720 United States International Research Center for Renewable State Key Laboratory of Multiphase Flow in Power Engineering Xi''an Jiaotong University Shaanxi 710049 China

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RETRACTED ARTICLE: Numerical Modeling for the Photocatalytic Degradation of Methyl Orange from Aqueous Solution using Cellulose/Zinc Oxide Hybrid Aerogel: Comparison with Experimental Data

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Topics in Catalysis 2024年第19-20期67卷 1415-1415页

作者： Hasanpour, Maryam Motahari, Siamak Jing, Dengwei Hatami, Mohammad Department of Polymer Engineering School of Chemical Engineering College of Engineering University of Tehran Tehran11155-4563 Iran State Key Laboratory of Multiphase Flow in Power Engineering International Research Center for Renewable Energy Xi’an Jiaotong University Xi’an710049 China Department of Mechanical Engineering Ferdowsi University of Mashhad 91775-1111 Mashhad Iran

In the present study, the photodegradation performance of Methyl Orange (MO) by CA/ZnO hybrid aerogel was successfully predicted through numerical and mathematical modeling. A mathematic model and numerical simulation were developed via MATLAB and COMSOL Multiphysics software based on finite difference method (FDM) and finite element method (FEM), respectively. The experimental data were derived from the experimental tests for the photocatalytic degradation efficiency of MO from an aqueous solution in order to validate the simulation. Results demonstrated that there is a good agreement between experimental data and predicted numerical values using COMSOL and mathematical simulation. Also, the effect of diffusion coefficient on the photodegradation efficiency of different dyes such Rhodamine B (RhB) and Methylene Blue (MB) were investigated using FEM method. The FEM numerical results showed that the photodegradation efficiency of MO, MB and RhB dyes, were 94.71%, 92.21% and 90.36%, respectively. The outcomes can be employed as predictive tools for planning the photodegradation efficiency of various pollutants. Graphic Abstract: [Figure not available: see fulltext.] © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

关键词： Cellulose

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