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supercritical fluids technology for clean biofuel production

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Progress in Natural Science:Materials International 2009年第3期19卷 273-284页

作者： Dongsheng Wena,*, H. Jiang a, Kai Zhang b a School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, UK b State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China School of Engineering and Materials Science Queen Mary University of London London E1 4NS UK State Key Laboratory of Heavy Oil Processing China University of Petroleum Beijing 102249 China

Biofuels are liquid or gaseous fuels that are predominantly produced from biomass for transport sector applications. As biofuels are renewable, sustainable, carbon neutral and environmentally benign, they have been proposed as promising alternative fuels for gasoline and diesel engines. This paper reviews state-of-the-art application of the supercritical fluid (SCF) technique in biofuels production that includes biodiesel from vegetable oils via the transesterification process, bio-hydrogen from the gasification and bio-oil from the lique- faction of biomass, with biodiesel production as the main focus. The global biofuel situation and biofuel economics are also reviewed. The SCF has been shown to be a promising technique for future large-scale biofuel production, especially for biodiesel production from waster oil and fat. Compared with conventional biofuel production methods, the SCF technology possesses a number of advantages that includes fast kinetics, high fuel production rate, ease of continuous operation and elimination of the necessity of catalysts. The harsh operation environment, i.e. the high temperature and high pressure, and its request on the materials and associated cost are the main concerns for its wide application.

关键词： supercritical fluids Biomass Transesterification Biofuel Hydrogen Biodiesel Gasification Liquefaction

Hybrid Particle Swarm-Ant Colony Algorithm to Describe the Phase Equilibrium of Systems Containing supercritical fluids with Ionic Liquids

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Communications in Computational Physics 2013年第6期14卷 107-125页

作者： Juan A.Lazzus Departamento de Fisica Universidad de La SerenaCasilla 554La SerenaChile

Based on biologically inspired algorithms,a thermodynamic model to describe the vapor-liquid equilibrium of binary complex mixtures containing supercritical fluids and ionic liquids,is *** Peng-Robinson equation of state with the Wong-Sandler mixing rules are used to evaluate the fugacity coefficient on the ***,a hybrid particle swarm-ant colony optimization was used to minimize the difference between calculated and experimental bubble pressure,and calculate the binary interaction parameters for the excess Gibbs free energy of all systems *** are carried out in nine systems with imidazolium-based ionic *** results show that the bubble pressures were correlated with low deviations between experimental and calculated *** deviations show that the proposed hybrid algorithm is the preferable method to describe the phase equilibrium of these complex mixtures,and can be used for other similar systems.

关键词： Particle swarm optimization ant colony optimization vapor-liquid equilibrium ionic liquids supercritical fluids Peng-Robinson equation of state

Improved dissolution and bioavailability of silymarin delivered by a solid dispersion prepared using supercritical fluids

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Asian Journal of Pharmaceutical Sciences 2015年第3期10卷 194-202页

作者： Gang Yang Yaping Zhao Nianping Feng Yongtai Zhang Ying Liu Beilei Dang School of Pharmacy Shanghai University of Traditional Chinese MedicineShanghai 201203China School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

The objective of this study was to improve the dissolution and bioavailability of silymarin(SM).Solid dispersions(SDs)were prepared using solution-enhanced dispersion by supercritical fluids(SEDS)and evaluated in vitro and in vivo,compared with pure SM *** particle sizes,stability,and contents of residual solvent of the prepared SM-SDs with SEDS and solvent evaporation(SE)were *** polymer matrix materials were evaluated for the preparation of SM-SD-SEDS,and the hydrophilic polymer,polyvinyl pyrrolidone K17,was selected with a ratio of 1:5 between SM and the *** analyses using X-ray diffraction and differential scanning calorimetry indicated that SM was dispersed in SD in an amorphous *** optimized SM-SD-SEDS showed no loss of SM after storage for 6 months and negligible residual solvent(ethanol)was detected using gas *** vitro drug release was increased from the SM-SDSEDS,as compared with pure SM powder or *** vivo,the area under the rat plasma SM concentration-time curve and the maximum plasma SM concentration were 2.4-fold and 1.9-fold higher,respectively,after oral administration of SM-SD-SEDS as compared with an aqueous SM *** results illustrated the potential of using SEDS to prepare SM-SD,further improving the biopharmaceutical properties of this compound.

关键词： Silymarin Solution-enhanced dispersion by supercritical fluids Solid dispersion Dissolution Bioavailability

New Approaches to Porous Polymeric Films:supercritical fluids and Breath Figure Technique

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New Approaches to Porous Polymeric Films:Supercritical Fluid...

Flow instability of supercritical hydrocarbon fuel in a multi-channel cooling system

2010年全国高分子材料科学与工程研讨会

作者： Lei LI,Yawen Zhong,Caikang Chen,Jian Li (College of Materials,Xiamen University,Xiamen,P.R.China,361005)

Porous polymeric films represent a new class of materials that have attracted both industrial and academic *** past years,porous materials have been widely investigated for a variety of applications such as molecular and protein separation,catalysis,and ultralow dielectric devices. Recently,block copolymers have been receiving an increasing attention as a candidate for an ideal template due to their registered ***,we report two novel methods to prepare nanoporous and microporous polymer films by supercritical fluids foaming and breath figure technique,*** films appear with an average diameter ranging from 15 to 30 nm processed by an scCO process at a pressure from 8 to 20 *** polymer films have highly ordered pore arrays,working as template to align ZnO and carbon nanotubes.

关键词： Block copolymer supercritical fluids Reath figure

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Chinese Journal of Aeronautics 2024年第2期37卷 283-295页

作者： Yichao JIN Kun WU Xuejun FAN Institute of Applied Physics and Computational Mathematics Beijing 100094China Institute of Mechanics Chinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Thermally-induced flow instabilities are a critical issue in multi-channel regenerative cooling *** particular,the interactions between Density-Wave Oscillations(DWO)and Flow Maldistribution(FMD)can result in complex and disastrous instability *** study investigates the instability behaviors of hydrocarbon fluid in a four-channel system with a constant heat flux ratio using both frequency-and time-domain *** the heat flux increases,the in-tube flow sequentially destabilizes in each channel and converges to new equilibrium states,leading to the emergence of FMD *** also causes the system eigenvalue to change repeatedly from negative to positive rather than increasing ***,the system eigenvalues are between those of the two most unstable channels,indicating that the stability behavior of the entire system is dictated by the most unstable *** FMD occurs,flow oscillations are activated in channels with weak stability,and the in-tube flow is observed to evolve into various flow patterns,including stable flow,self-sustained oscillation,oscillation divergence,quasiperiodic oscillation,and oscillation *** novel instability mode of oscillation excursion involves a spontaneous transition of operating *** oscillates from an equilibrium state and then stabilizes at a new operational state after oscillation-induced ***,the newfound stable state may also be only temporary,with the in-tube flow regressing to the initial state,resulting in quasi-periodic oscillation.

关键词： Cooling supercritical fluids Hydrocarbons Flow instability Flow maldistribution Density-wave oscillations

Oxidation of Styrene with Molecular Oxygen in supercritical CO_2

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Chinese Chemical Letters 2004年第3期15卷 296-299页

作者： TaoJIANG BuXingHAN GuoYingZHAO ZhongHaoLI YanHongCHANG HaiXiangGAO JunChunLI CenterforMolecularSciences InstituteofChemistryChineseAcademyofSciencesBeijing100080

The oxidation of styrene with molecular oxygen catalyzed by PdCl2+CuCl2 has been investigated in supercritical CO2 with a batch reactor. The oxidative system of styrene contains four components at the beginning and seven components during the reaction. The critical temperature, critical pressure, and critical density at different conversions are determined by using a high-pressure view cell. The effect of phase behavior on the conversion and selectivity were studied. Experimental results showed that the critical parameters of the reaction mixture at fixed initial molar ratio changed with the conversion of reactant. The conversion of styrene reached maximum near the critical density of the reaction mixture. Product selectivity also varied with density of reaction mixture and could be tuned to some degree.

关键词： Styrene supercritical fluids carbon dioxide wacker oxidation molecular oxygen.

Simultaneous Removal of Surfactant Template from MCM-41 and Implantation of Transition Metal Complexes into Mesopores with supercritical Fluid

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Chinese Chemical Letters 2002年第5期13卷 480-483页

作者： XiaoBingLU WenHuaZHANG 等 StateKeylaboratoryoffinechemicals DalianuniverstiyoftechnologyDalian116012 StateKeylaboratoryofCatalysis DalianinstituteofchemicalphysicschineseAcademyofSciencesDalian11602

The simultaneous removal of up to 92% of the surfactant template and chemical implantation of transition metal complexes into mesopores has been successfully achieved by treating as-synthesized pure siliceous MCM-41 with supercritical CO2 modified with CH2Cl2/MeOH mixture, resulting in the formation of functionalized material with uniform pore structure.

关键词： MCM-41 mesoporous supercritical fluids transition metal complexes.

Green Extraction of Bioactive Compounds from Microalgae

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Journal of Analysis and Testing 2018年第2期2卷 109-123页

作者： Rocío Gallego Lidia Montero Alejandro Cifuentes Elena Ibáñez Miguel Herrero Laboratory of Foodomics Institute of Food Science Research(CIALCSIC-UAM)Nicolás Cabrera 928049 MadridSpain Laboratory of Applied Analytical Chemistry University Duisburg-EssenUniversitaetsstr.545141 EssenGermany

At present,there is an increasing demand for natural bioactive compounds able to provide health benefits when included and consumed in a functional food or in a *** this regard,microalgae are promising natural sources with great potential,not only considering that these organisms are largely underexplored,but also because microalgae can be produced at large scale and their chemical composition might be tuned to over-synthesize a particular target *** use of advanced sustainable extraction techniques to recover these bioactive compounds is a must *** work presents an overview on the use of compressed fluid-based extraction techniques to obtain bioactive compounds from microalgae that can be seen also as a first step towards its recovery at larger *** relevant,the description of the analytical procedure used to chemically characterize the bioactive compounds is also included.

关键词： Bioactives Compressed fluids Green extraction techniques Microalgae Pressurized liquids supercritical fluids

Preparation of ibuprofen/lipid composite microparticles by supercritical fluid technique

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Frontiers of Chemical Science and Engineering 2008年第4期2卷 361-367页

作者： Xia WANG Hui CHEN Yanni GUO Yuzhong SU Hongtao WANG Jun LI Department of Chemical and Biochemical Engineering College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China

Using the CO_(2)-and N2-assisted atomization processes,the production of ibuprofen/lipid composite microparticles is investigated,in which the lipid includes myristic acid and *** produced composite particles show similar morphology to that of the pure lipids obtained by the same *** the case of the N2-assisted process,the average size of composite part-icles is slightly larger than that of the pure lipid particles due to the difficulty of solidification when using *** the case of the CO_(2)-assisted process,the average size of com-posite particles is slightly smaller than that of the pure myr-istic acid particles,but slightly larger than that of the pure tripalmitin *** dissolution study reveals that the drug release from the ibuprofen/myristic acid particles is enhanced in comparison with that of the unprocessed *** the particles produced by the N2-assisted pro-cess,the X-ray diffraction(XRD)patterns clearly indicate the encapsulation of ibuprofen into myristic *** obtained ibuprofen/tripalmitin composite particles with 5%or 20%of ibuprofen(in mass)evidently show the con-trolled drug release:only about 20%of the drug is released in 500 min from the ibuprofen/tripalmitin composite part-icles consisting of 20%ibuprofen prepared by the CO_(2)-assisted process,and the same release is obtained from the ibuprofen/tripalmitin composite particles containing 5%ibuprofen prepared by the N2-assisted process.

关键词： supercritical fluids composite microparticles ibuprofen myristic acid tripalmitin