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Journal of Thermal Science 2024年第1期33卷 101-113页

作者： YUAN Baoqiang WANG Wei XIN Gongming DU Wenjing School of Energy and Power Engineering Shandong UniversityJi'nan 250061China

Large eddy simulations have been conducted to study upward transitional flows and heat transfer characteristics of Supercritical CO_(2) in a vertical mini-channel.The numerical simulation was carried out on a modified buoyantPimpleFOAM solver in OpenFOAM 7,and was verified using experiment data.Numerical results indicate that increasing the Grashof numbers can reduce the flow stability and make the flow transition earlier.There are four stages of heat transfer in the transition process,i.e.,weakened,improved,recovered and normal heat transfer.These heat transfer phenomena in the transition process were explained from three perspectives:thermal boundary layer theory,turbulent transport and pseudo-boiling theory.Heat transfer enhancement during transition is related to the transport of Supercritical molecular clusters,and these molecular clusters are regarded as pseudo-bubbles in pseudo-boiling theory.The flow pattern of the pseudo-phases in the dia-Widom process contains single-phase flow,steady pseudo-film flow,unsteady pseudo-film flow,partial pseudo-bubbles flow and flocculent pseudo-film flow.Pseudo-bubbles have similar behaviors to subcritical bubbles,i.e.,break-up,deformation,condensation and coalescence.Relevant researches in this work are favorable for understanding the heat transfer mechanism of Supercritical fluids during flow transition.

关键词： Supercritical heat transfer large eddy simulation transition pseudo-boiling

A new approach of CO_(2)separation by applying rapid expansion of Supercritical CO_(2)rich natural gas

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Petroleum Research 2023年第1期8卷 71-76页

作者： Saripudin Tutuka Ariadji Sanggono Adisasmito Leksono Mucharam Doddy Abdassah Department of Petroleum Engineering Faculty of Mining and Petroleum TechnologyBandung Institute of TechnologyJl.Ganesha No.10Bandung40132Indonesia Department of Chemical Engineering Faculty of Industrial TechnologyBandung Institute of TechnologyJl.Ganesha No.10Bandung40132Indonesia Department of Chemical Engineering Politeknik Negeri BandungJl.CiwarugaBandung40559Indonesia

The previous methods for CO_(2)separation from CO_(2)rich natural gas led to expensive production costs.This work was implemented to overcome the problems utilizing a new approach economically.The cooling and rapid expansion processes were integrated for the CO_(2)separation from CO_(2)rich natural gas on the Supercritical condition.The experimental apparatus was newly constructed to perform the experiments,and the results were simulated using a various equation of state.The result reveals that the inlet temperature of Supercritical expansion diminished the outlet temperature and the gas condensed easily.The simulation indicated that the 70%CO_(2)in natural gas was condensed easier than 45%CO_(2).We found that the outlet temperature of42C and the vapor fraction of 0.69 was attained at the CO_(2)composition of 70%.Besides,the pressure drop change influences the vapor fraction at various CO_(2)compositions.The vapor fraction under Supercritical diminished significantly compared with the nonSupercritical condition.The expansion coefficient determined utilizing the equation of state escalates by the enhancement of expansion inlet temperature based on CO_(2)composition in natural gas.The acid gas equation of state was the perfect equation to estimate the expansion coefficient with the absolute average error of 4.83%.This work suggests that the CO_(2)separation from CO_(2)rich natural gas with the cooling and rapid expansion method promotes the new approach to overcome the disadvantages of previous methods.

关键词： Rich natural gas CO_(2)separation Supercritical Cooling Rapid expansion

Molecular dynamics simulation of Supercritical CO2 microemulsion with ionic liquid domains: Structures and properties

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Chinese Journal of Chemical Engineering 2019年第11期27卷 2653-2658页

作者： Hongyue Zhu Ying Li Hongrui Ren Dan Zhou Jianzhong Yin State Key Laboratory of Fine Chemicals School of Chemical Machinery and SafetyDalian University of TechnologyDalian 116024China

Supercritical carbon dioxide microemulsions are great medium to combine two immiscible substances through forming nanoscale polar cores in nonpolar continuous phase with the help of proper surfactants. The properties of microemulsions could be significantly affected by their constituents and structures. In this work, molecular dynamics simulation was implemented to study Supercritical carbon dioxide microemulsions containing ionic liquid [bmim][PF6] and water by adding surfactant Ls-36. Results showed that the above components could form spherical aggregates in CO2 bulk phase with [bmim][PF6] and some water as the inner core, surfactant headgroups and water as the intermediate shell, and surfactant tails as the outer shell. The microstructure information about the outer shell was further investigated by defining an angle between the surfactant tail and the normal direction of the aggregate outer surface, which ranged from 78° to 125°. The influence of the ionic liquid content on the size and structure of microemulsions was explored and the best molar ratio between the ionic liquid and surfactant was around 1.25 for getting maximum water solubility.

关键词： Molecular simulation Supercritical carbon dioxide microemulsion Ionic liquids Microstructure Structure parameters

Adsorption equilibria of paeoniflorin and albiflorin on cyano-silica column from Supercritical carbon dioxide/ethanol

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Chinese Journal of Chemical Engineering 2019年第4期27卷 827-834页

作者： Huisheng Lü Zhi Wang Zhongfeng Geng Yonghui Li Shuangyan Liu Jiatao Liu Key Laboratory for Green Chemical Technology of Ministry of Education R&D Center for Petrochemical Technology Tianjin University Tianjin 300072 China Collaborative Innovation Center of Chemical Science and Engineering Tianjin 300072 China

Adsorption equilibria of paeoniflorin and albiflorin on a cyano-silica column(CN column) from the solution of Supercritical carbon dioxide(scCO2) modified with ethanol were studied. The adsorption capacity at 308.15 K,313.15 K, 318.15 K and 323.15 K under pressures corresponding to carbon dioxide/ethanol densities from0.347 g·cm^-3 to 0.662 g·cm^-3 were determined using the elution by characteristic point method(ECP). The effects of temperature and pressure on the solute loading were investigated. The results showed that the lower the temperature, the higher the adsorption capacity. With the decrease of density of scCO2, the adsorption capacity strengthens. The maximum adsorption capacity of paeoniflorin(albiflorin) on the CN column was15.24 mg·ml^-1(31.14 mg·ml^-1) in the range of 0–1.84 mg·ml^-1(0–1.67 mg·ml^-1) of paeoniflorin(albiflorin)standard solution. The adsorption capacity of albiflorin was twice as much as that of paeoniflorin under the same conditions. Adsorption data of paeoniflorin and albiflorin could be well described by the Langmuir model and Freundlich model. Compared with the two model fitting results, the adsorption of paeoniflorin and albiflorin belonged to the monolayer adsorption under conditions of 308.15–323.15 K and 10–17 MPa.

关键词： Adsorption Supercritical carbon dioxide Paeoniflorin Albiflorin Isotherm model

A comprehensive CFD combustion model for Supercritical CFB boilers

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Particuology 2019年第2期17卷 29-37页

作者： Linjie Xu Leming Cheng JieqiangJi Qinhui Wang Mengxiang Fang Institute for Thermal Power Engineering State Key Laboratory of Clean Energy Utilization Zhejiang University Hangzhou 31002China

A combustion model of a large-scale Supercritical circulati ng fluidized bed (CFB) boiler was developed for comprehensive computational-fluid-dynamics analysis. The model incorporates gas-solid hydrodynamics, coal combustion, heat transfer on heat exchange surfaces in the furnace, and heat transfer between fumace and working medium in the heat transfer tubes. In simulating the dense and dilute phases in the fumace, the gas-solid hydrodynamics is based on the Euler-Euler model and energy-minimization multiscale drag model. Coal combustion entails evaporation, devolatilization, char combustion, gas homoge neous reaction, and pollutant emission. The coefficient ofheat transfer between gas-solid and the waterwall is estimated using the cluster renewal model, and for radiation, the discrete ordinate model is used. Moreover, thermohydraulic processes in the membrane wall are also in eluded in the heat transfer process. The model was successfully applied in simulations of a 350-MW Supercritical CFB boiler. Detailed distributions of solids concentration, oxygen, heat flux, and working medium temperature in the boiler furnace are presented.

关键词： Comprehensive combustion model Computational fluid dynamic Thermal-hydraulics Supercritical circulating fluidized bed Large-scale furnace

A review on catalytic & non-catalytic bio-oil upgrading in Supercritical fluids

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Frontiers of Chemical Science and Engineering 2021年第1期15卷 4-17页

作者： Sainab Omar Yang Yang Jiawei Wang Chemical Engineering and Applied Chemistry Aston UniversityBirminghamB47ETUK

This review article summarizes the key published research on the topic of bio-oil upgrading using catalytic and non-catalytic Supercritical fluid(SCF)conditions.The precious metal catalysts Pd,Ru and Pt on various supports are frequently chosen for catalytic bio-oil upgrading in SCFs.This is reportedly due to their favourable catalytic activity during the process including hydrotreating,hydrocracking,and esterification,which leads to improvements in liquid yield,heating value,and pH of the upgraded bio-oil.Due to the costs associated with precious metal catalysts,some researchers have opted for non-precious metal catalysts such as acidic HZSM-5 which can promote esterification in Supercritical ethanol.On the other hand,SCFs have been effectively used to upgrade crude bio-oil without a catalyst.Supercritical methanol,ethanol,and water are most commonly used and demonstrate catalyst like activities such as facilitating esterification reactions and reducing solid yield by alcoholysis and hydrolysis,respectively.

关键词： bio-oil upgrading Supercritical review

Improving Supercritical water gasification of sludge by oil palm empty fruit bunch addition: Promotion of syngas production and heavy metal stabilization

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Chinese Journal of Chemical Engineering 2020年第1期28卷 293-298页

作者： Zhouchao Weng Ekkachai Kanchanatip Dwi Hantoko Mi Yan Hongcai Su Sicheng Zhang Guobin Wang Institute of Energy and Power Engineering Zhejiang University of TechnologyHangzhou 310014China Department of Chemical Engineering Institut Teknologi BandungBandung 40132Indonesia Center of Excellence in Environmental Catalysis and Adsorption Faculty of EngineeringThammasat UniversityPathumthani 12120Thailand

The co-gasification of sewage sludge and palm oil empty fruit bunch(EFB) in Supercritical water(SCW) was conducted at 400 °C with a pressure of over 25 MPa. This study aimed to investigate the influence of EFB addition on the syngas production and its composition. The heavy metal distribution and the leaching potential of the solid residue were also assessed. The results showed that syngas yield significantly increased with the addition of EFB into the feedstock. The cold gas efficiency(CGE) and carbon efficiency(CE) of co-gasification were higher than those of individual gasification. The actual syngas production from co-gasification of sludge and EFB was 45% higher than the theoretical total volume. The results indicated that the addition of EFB to sludge had the synergetic promotion effect on syngas production from sludge and EFB in Supercritical water. This enhancement might be due to the dissolution of alkali metals from EFB and the adjustment of organic ratio. In addition, higher percentage of heavy metals were deposited and stabilized in the solid residue after SCWG. The leaching concentration of heavy metals from the solid residues was decreased to a level below the standard limit which enables it to be safely disposed of in landfill. In conclusion, the EFB addition has been proved to promote syngas production,as well as, stabilize the heavy metal in solid residues during co-SCWG.

关键词： Co-gasification Supercritical water Sludge Empty fruit bunch Syngas Heavy metal

Advances of Supercritical fluid chromatography in lipid profiling

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Journal of Pharmaceutical Analysis 2019年第1期9卷 1-8页

作者： Yang Yang Yanshan Liang Jina Yang Fengying Ye Ting Zhou Gongke Li School of Biology and Biological Engineering South China University of Technology School of Chemistry Sun Yat-sen University

Supercritical fluid chromatography(SFC) meets with great favor due to its high efficiency, low organic solvent consumption, and the specialty for the identification of the isomeric species. This review describes the advances of SFC in targeted and untargeted lipid profiling. The advancement of the SFC instruments and the stationary phases are summarized. Typical applications of SFC to the targeted and untargeted lipid profiling are discussed in detail. Moreover, the perspectives of SFC in the lipid profiling are also proposed. As a useful and promising tool for investigating lipids in vitro and in vivo, SFC will predictably obtain further development.

关键词： Supercritical fluid chromatography Online SFC technique Untargeted lipid profiling Targeted lipid profiling Lipidomics

Simultaneous determination of amino acids in different teas using Supercritical fluid chromatography coupled with single quadrupole mass spectrometry

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Journal of Pharmaceutical Analysis 2019年第4期9卷 254-258页

作者： Yang Huang Tiejie Wang Marianne Fillet Jacques Crommen Zhengjin Jiang Institute of Pharmaceutical Analysis College of Pharmacy Jinan University Guangzhou 510632 China Shenzhen Institute for Drug Control Shenzhen China Department of Pharmaceutics State Key Laboratory of Natural Medicines China Pharmaceutical University Nanjing China Laboratory for the Analysis of Medicine Department of Pharmaceutical Sciences CIRM University of Liege CHU B36 B-4000 Liege Belgium

Tea is a widely consumed beverage and has many important physiological properties and potential health benefits. In this study, a novel method based on Supercritical fluid chromatography coupled with mass spectrometry (SFC-MS) was developed to simultaneously determine 11 amino acids in different types of tea (green teas, Oolong tea, black tea and Pu-erh tea). The separation conditions for the analysis of the selected amino acids including the column type, temperature and backpressure as well as the type of additive, were carefully optimized. The best separation of the 11 amino acids was obtained by adding water (5%, v/v) and trifluoroacetic acid (0.4%, v/v) to the organic modifier (methanol). Finally, the developed SFC-MS method was fully validated and successfully applied to the determination of these amino acids in six different tea samples. Good linearity (r ≥ 0.993), precision (RSDs≤ 2.99%), accuracy (91.95%-107.09%) as well as good sample stability were observed. The limits of detection ranged from 1.42 to 14.69 ng/mL, while the limits of quantification were between 4.53 and 47.0 ng/mL. The results indicate that the contents of the 11 amino acids in the six different tea samples are greatly influenced by the degree of fermentation. The proposed SFC-MS method shows a great potential for further investigation of tea varieties.

关键词： Amino acids Teas Supercritical fluid chromatography with single quadrupole mass spectrometry (SFCMS)

Production of renewable fuels by blending bio-oil with alcohols and upgrading under Supercritical conditions

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Frontiers of Chemical Science and Engineering 2019年第4期13卷 702-717页

作者： Sainab Omar Suzanne Alsamaq Yang Yang Jiawei Wang Chemical Engineering and Applied Chemistry Aston UniversityBirmingham.B47ETUK European Biocncrgy Research Institute Aston UniversityBirminghamB47ETUK

The work studied a non-catalytic upgrading of fast pyrolysis bio-oil by blending under Supercritical conditions using methanol,ethanol and isopropanol as solvent and hydrogen donor.Characterisation of the bio-oil and the upgraded bio-oils was carried out including moisture content,elemental content,pH,heating value,gas chromatography-mass spectrometry(GCMS),Fourier transform infrared radiation,13C nuclear magnetic resonance spectroscopy,and thermogravimetric analysis to evaluate the effects of blending and Supercritical reactions.The GCMS analysis indicated that the Supercritical methanol reaction removed the acids in the bio-oil consequently the pH increased from 2.39 in the crude bio-oil to 4.04 after the Supercritical methanol reaction.The ester contents increased by 87.49% after the Supercritical methanol reaction indicating ester formation could be the major deacidification mechanism for reducing the acidity of the bio-oil and improving its pH value.Simply blending crude bio-oil with isopropanol was effective in increasing the C and H content,reducing the O content and increasing the heating value to 27.55 from 17.51 MJ·kg^-1 in the crude bio-oil.After the Supercritical isopropanol reaction,the heating value o f the liquid product slightly further increased to 28.85 MJ·kg^-1.

关键词： bio-oil blending Supercritical upgrading characterisation