摘要
在能源紧张和环境问题突出的今天,利用太阳能和工业废热的吸收式制冷技术方兴未艾,而目前工业上广泛应用的吸收式制冷工质对氨-水溶液和溴化锂-水溶液的先天缺陷(冷剂氨有毒、易爆、与吸收剂水的沸点差较小;溴化锂-水溶液易结晶、对设备腐蚀、无法获得0℃以下的低温)制约着制冷技术的发展,所以寻找适应范围广,效率高的新工质对成为吸收式制冷技术的发展方向。
离子液体具有蒸汽压近似等于零、可设计性(通过改变阴阳离子)、较低的腐蚀性、对许多极性和非极性物质均有良好的溶解性、热力学性质稳定、在200℃以下仍能稳定以液体形式存在等特性,使其有成为吸收式制冷新型工质的潜能。本文提出将离子液体1-乙基-3-甲基咪唑磷酸二甲酯([EMIM][DMP])+醇类+水的三元混合溶液作为吸收式制冷机的新型工质,对其热力学性质进行了实验研究和数据关联。
采用沸点仪法测量离子液体[EMIM][DMP]+甲醇/乙醇+水所组成的二个三元体系不同浓度和温度下的汽液相平衡实验数据,结果表明两体系均对Raoult定律呈负偏差。并采用NRTL模型对本实验两个三元体系汽液相平衡进行预测,实验值与预测值的平均相对误差分别为3.09%,3.89%。
采用绝热量热法测量了温度为298.15K时,[EMIM][DMP]分别与水/乙醇/甲醇所组成的三个三元体系的混合热,结果显示三个体系均为放热过程。实验结果采用Nagata-Tamura和Cibulka提出的多元方程进行拟合,用NRTL和UNIQUAC方程预测,得到了超额混合焓与组成之间的关系。
采用绝热量热法测量了[EMIM][DMP]+甲醇乙醇/+水组成的二个三元体系在常压、温度范围为298.15K-323.15K、不同浓度下的比热容。本文还对实验数据进行拟合,得到定压比热容与组成、温度之间的关系,结果显示比热容与温度大体呈线性关系,随着温度的升高而增大。
The technology of absorption refrigeration by employing solar energy and industrial waste heat is developing rapidly in today's society, which is confronted with great energy strain. However, the development of technology of absorption refrigeration is held back due to the inherent weaknesses of widely used working pairs, LiBr-H2O and NH3-H2O for absorption refrigeration at present, with the features of strong corrosion to equipment, easy crystallization, toxicity etc, to name just a few. Therefore, it leads the direction of development to seek new working pairs with wider application and higher efficiency. Many unique properties of Ionic Liquid (IL), such as a nearly zero vapor pressure, ability to be designed (by changing the anion or cation), lower corrosion, strong solubility, thermal stability, consistency in existence under200℃, make it probable to be used as working pairs for absorption refrigeration. The author of this paper put forward ternary systems, with ionic liquid1-ethyl-3-methylimidazolium dimethylphosphate ([EMIM][DMP]), methanol/ethanol and water in it, as the new working pairs for absorption refrigeration, and conducted the experimental study on its thermodynamic properties.
The ebulliometer was used to measure the experimental data of gas-liquid equilibrium of the two ternary systems, which contain [EMIM][DMP] and methanol/ethanol and water with different concentrations and under different temperatures. The results reveal that the two systems show negative deviation in terms of Raoult's law. NRTL model was used to predict the data of the gas-liquid equilibrium of these two ternary systems. The average relative errors of the experimental and predicted values are3.09%and3.89%, respectively,
the excess molar enthalpies (HE) of three ternary mixtures for [EMIM][DMP]+methanol/ethanol/water were measured with an isothermal calorimeter made by the author at298.15K and under the normal atmospheric pressure, which show that all the three mixed processes are exothermic. The experimental results have been correlated with the polynomial proposed by Nagata and Tamura (NT) and Cibulka. Meanwhile, NRTL and UNIQUAC equations were employed to predict the ternary systems, and found the relation between HE and the components.
The specific heat capacity of ternary mixtures for [EMIM][DMP]+methanol/ethanol+water were measured by the isothermal calorimeter at the temperature ranging from298.15K to323.15K, under the constant atmospheric pressure, and with different concentrations. The data were correlated to find that the relationship between the heat capacity and the temperature.
引文
[1]张乃文,陈嘉宾,于志家.化工热力学[M].大连理工出版社.2006.
[2]王建召,郑丹星.吸收式循环构型及含咪唑类离子液体工质对的研究[M].北京:北京化工大学,2009.
[3]KAUSHIK S C, Arora A. Energy and exergy analysis of single effect and series flow double effect water-lithiunbromide absorption refrigeration systems [J]. International Journal of Refrigeration,2009,32:1247-1258.
[4]COLONNA P, GABRIELLI S. Industrial trigeneration using ammonia-water absorption refrigeration systems (AAR) [J]. Applied Thermal Engineering,2003,23:381-396.
[5]MISRA R D, SAHOO P K, GUPTA A. Thermoeconomic evaluation and optimization of a double-effect H20/LiBr vapour-absorption refrigeration system [J]. Inernational Journal of Refrigeration,2002,25:999-1007.
[6](日)高田秋一著,耿惠彬等译.吸收式制冷机[M].机械工业出版社.1987:16-22.
[7]ZHUO C Z, MACHIELSEN C H M. Themophysical properties of the trifluorcethanol-pyrrolidme system for absorption heat transformers [J]. Rev. Int. Froid.1993,16:357-363.
[8]陈曙辉,陈光明,吸收式制冷工质的发展[J].制冷学报,1998,2:45-52.
[9]蒋伏广,张根成,路柱。钼酸锂的制备及其对碳钢在溴化锂溶液中的缓蚀作用[J].腐蚀科学与防护技术,2004,16(14):233-235
[10]ZEHIOUA R, COQUELET C, Soo C B, et al. Experimental and predicted excess molar enthalpies of some working pairs for absorption cycles [J]. Thermochemical Acta, 2009,495(1-2):72-80.
[11]ALBERTO CORONAS, MANEL VALLRS, SHRIRANG K, et al. ABSORPTION HEAT PUMP WITH THE TFE-TEGDME ANDTFE-H20-TEGDME SYSTEMS [J]. Applied Thermal Engineering,1996,16 (4):335-345.
[12]王建召,郑丹星.以TFE-[BMIm][Br]为工质对的吸收式制冷循环性能分析[J].工热物理学报,2008,29(11):1813-1816.
[13]赵宗昌,周方伟,李凇平TFE-E181高温型第二类吸收式热泵热力学过程分析[J].大连理工大学学报,2005,44:651-656.
[14]张锁江,吕兴梅.离子液体-从基础研究到工业应用[M].北京:科学出版社,2006.
[15]邓友全。离子液体-性质、制备与应用[M].北京:中国石化出版社,2006.
[16]BONHOTE P, DIAS A P, PAPAGEORGIOU N K, et al. Hydrophobic, highly conductive ambient-temperature molten salts. Inorganic Chemistry [J].1996,35:1168-1178.
[17]NGO H L, LECOMPTE K, HARGENS L, et al. Thermal properties of imidazolium ionic liquids Thermochim Acta [J].2000,357,97.
[18]HUDDLESTON J G, VISSER A E, REICHERT W M, et al. Characterization and comparison of hydrophilic and hydrophobic room temperature ionic liquids incorporating the imidazolium cation [J]. Green Chemistry,2001,3:156-164.
[19]FAMMIN A A J, FLOREANI D A, KING L A, et al. Proerties of 1,3-Dialkylimldazollum Chloride-Aluminum Chloride Ionic Liquids. Phase Transitions, Densities, Electrical Conductivities, and Viscosities [J]. Journal of Physical Chemistry, 1984,88:2614.
[20]HYUN B, DZYUBA S V, BARTSCH R A. Intermolecular Dynamics of Room-Temperature Ionic Liquids:Femtosecond Optical Kerr Effect Measurements on 1-Alky1-3-methylimidazolium Bis((trifluoromethyl)sulfonyl)imides[J]. Journal of Physical Chemistry.2002,106:7579-7585
[21]SEDDON K R, STARK A, TORRES M J. Influence of chloride, water, and organic solvents on the physical properties of ionic liquids [J].Pure Appl. Chem.,2000,72:2275-2287.
[22]FREDLAKE C P, CROSTHWAITE J M, HERT D G, et al. Thermiphysical properties of imidazolium-based ionic liquids [J].Journal of Chemical Engineering Data,2004, 49:954-964.
[23]CROSTHWAITE J M, MULDOON M J, DIXON J K, et al. Phase transition and decomposition temperatures, heat capacities and viscosities of pyridinium ionic liquids [J]. Journal of chemical thermodynamics,2005,37(6):559-568.
[24]WELTON. Room-Temperature Ionic Liquids. Solvents for Synthesis for Synthesis and Catalysis[J], T. Chem. Rev.,1999,99:2071-2083
[25]KOCH V R, MILLER L L, OSTERYOUNG R A. Electroinitiated Friedel-Crafts transalkylations in a room-temperature molten-salt medium [J], J. Am. Chem. Soc., 1976,98:5277-5284
[26]LAALI K K, GETTWERT V J. Electrophilic Nitration of Aromatics in Ionic liquids Solvents [J], J. Org. Chem.,2001,66(1):35-40
[27]乔煜,邓友全.氯铝酸室温离子液体介质中Blanc氯甲基化反应的研究[J],化学学报,2003,6(11):133-136
[28]ZHAO D B, WU M, KOU Y, et al. Ionic liquids:applications in catalysis[J]. Catalysis Today,2002,74:157-189.
[29]HOWARTH J. OXIDATION of aromatic aldehydes in the ionic liquid [bmim][PF6] [J]. TETRAHEDRON Lett.,2000,41(34):6627-6629.
[30]KEIM W, VOGT D, WAFFENSCHMIDT H, et al. New method to recycle homogeneous catalysts from monophasic reaction mixtures by using an ionic lipuid exemplified for the Rh-catalysed hydroformylation of methyl-3-pentenoate [J]. Journal of Catalysis, 1999,186(2):481-484.
[31]PERRIER S, DAVIS T P, CARMICHAEL A J, HADDLETON D M. First report of reversible addition-fragmentation chain transfer (RAFT) polymerization in room temperature ionic liquids [J]. Chemical Communications,2002, (19):2226-2227.
[32]WONG D S H, CHEM J P, CHANG J M, et al. Phase equilibria of water and ionic liquids [EMIM] PF6 [J], Fluid Phase Equilibria,2002,194-197,1089-1095.
[33]CECILIA D W, CHONG F K, ZAKARIA M, et al. Extraction of dibenzothiophene from dodecane using ionic liquids[J]. Fuel Processing Technology,2012,93:85-89.
[34]HUDDLESTOU J G, WILLAUER H D, ROGERS R D. Hydrophobic ionic liquids as novel media for clean liquid-liquid extraction[J], Chemical Communications,1998,1765-1766.
[35]VISSER A E, HOLBREY J D, ROGERS R D. Hydrophobic ionic liquids incorporating N-alkyllisoquinolinium cations and their utilization in liquid-liquid separations [J], Chemical Commynications,2001,2484-2485.
[36]SCHROEDER U, WADHAWAN J, COMPTON R, et al. Water-induced accelerated ion difusion: voltammetric stydied in 1-methyl-3-[2,6-(S)-dimethylocten-2-yl] imidazolium tetrauoroborate, 1-butyl-3-methylimidazolium tetrauoroborate and hexauorophosphate ionic liquids[J]. New Journal of Chemistry,2000,24:1009-1015.
[37]BONHOTE P, DIAS A, PAPAGEORGIOU N, et al. Hydrophobic, Highly Conductibe Ambient-Temperature Molten Salts[J]. Inorganic Chemistry,1996,35:1168-1178.
[38]KIM K S, SHIN B K, LEE H, et al. Refractive index and heat capacity of 1-butyl-3-methylimidazolium bromide and 1-butyl-3-methylimidazolium tetrafluoroborate, and vapor pressure of binary systems for 1-butyl-3-methylimidazolium bromide+trifluoroethanol and 1-butyl-3-methylimidazolium tetrafluoroborate+trifluoroethanol[J]. Fluid Phase Equilibria,2004,218:215-220.
[39]SEN M, PAOLUEE S. Using carbon dioxide and ionic liquids for absorption refrigeration [C].7th IIR Gustav Lorentzen Conference on Natural Working Fluids, Trondheim, Norway,2006.
[40]SHIFLETT M B, YOKLZEKI A. Absorption eycle utilizing ionic liquids and water as working fluids[P]. USP, US2007/0144186AI.2007-06-28.
[41]YOKLZEKI A, SHIFLETT M B. Vapor-liquid equilibria of amonia+ionic liquid mixtures[J]. Applied Energy,2007,84:1258-1273.
[42]赵杰,梁世强,王立.[bmim]Cl-CH3OH作为吸收式制冷工质对的潜能分析[J].化工学报,2009,60(12):2957-2962.
[43]HE Z B, ZHAO Z C, ZHANG X, et al. Thermodynamic properties of new heat pump working pairs:1,3-Dimethylimidazolium dimethylphosphate and water, ethanol and methanol [J]. Fluid Phase Equilibria,2010,298(1):83-91.
[44]ZUO G L, ZHAO Z C, YAN S H, Zhang XD. Thermodynamic properties of a new working pair:1-Ethyl-3-methylimidazolium ethylsulfate and water [J].Chem Eng J,2010, 156(3):613-617.
[45]赵宗昌,晏双华,张晓冬等.[EMIM] [DEP]+水/乙醇工质对蒸汽压测定与关联[M].大连理工大学学报,2010,50(5):638-642.
[46]JASTORFF B, STORMANN R, RANKE J, et al. How hazardous are ionic liquids? Strcture-activity relationships and biological testing as important elements for sustainability evaluation[C]. Green Chemistry,2003,5:136-142.
[47]WILKES J S. Properties of ionic liquid solvents for catalysis[J]. Journal of Molecular Catalysis A:Chemical,2004,214:11-17.
[48]STOCK F, HOFFMANN J, RANKE J, et al. Effects of ionic liquids on the ACetylcholinesterase-a structure-activity relationship consideration[J]. Green Chemistry,2004,6:286-290.
[49]RANKE J, MOLTER K, STOCK F, et al. Biological effects of imidazolium ionic liquids with varying chain lengths in acute Vibrio fischeri and WST-1 cell viability assays [J]. Ecotoxicology and Environmental Safety,2004,58:396-404.
[50]SWATLOSKI R P, HOLBREY J D, MEMON S B, et al. Using Caenorhabditis elegans to probe toxicity of 1-alkyl-3-methylimidazolium chloride based ionic liquids[J]. Chemical Communications,2004,6:668-669.
[51]SWATLOSKI R P, HOLBREY J D, ROGERS R D. Ionic liquid are not always green:hydrolysis of 1-butyl-3-methylimidazolium hexafluorophosphate[J]. Green Chemistry,2003,5: 361-363.
[52]WILSON G M, Vapor-Liquid Equilibrium. XI. A New Expression for the Excess Free Energy of Mixing [J], J. Am. Chem.Soc,1964,86(2):127-130.
[53]ABRAMS D S, PRAYSNITZ J M. Statistical Thermodynamics of Liquid Mixtures:A New Expression for the Excess GibbsEnergy of Partly or Completely Miscibl Systems [J]. AIChEJ,1975,21:116~128.
[54]李秀丽.UNIFAC及其修正模型的评价研究[D].青岛:青岛理工大学,2009.
[55]任晶.甲基乙基咪唑磷酸二甲酯+水/醇新工质研究[D].大连:大连理工大学,2010.
[56]JIANG X C, NIE Y, LI C X, et al. Imidazolium-based alkylphosphate ionic liquids A potential solvent for extractive desulfurization of fuel [J]. Fuel,2008,87:79-84.
[57]CLAUDIA C, CASSOL, GUNTER E, et al. A simple and practical method for the preparation and purity determination of halide-free imidazolium ionic liquids [J]. Adv. Synth. Catal.2006,348:43-248.
[58]陈庚华,杜志强,韩世庚.纯物质饱和蒸汽压数据的关联一用线性优化法求Antoine公式中 的常数[J].浙江大学学报,1985,8(19):92-97.
[59]LAMA R F, BENJAMIN C Y. Excess Thermodynamics properties of aqueous alcohol solutions[J]. Journal of Chemical and Engineering Data.1965,10(3):217-219.
[60]PFLUG H D, POPE A E, BENSON G C. Heats of mixing of normal alcohols at 25℃[J], J. Chem. Eng. Data,1968,13:408-410.
[61]PINEIRO M M, COMINGES B E. Application of group contribution models and empirical methods to excess enthalpies of ternary mixtures [J]. Journal of Thermal Analysis, 1998,52:799-814.
[62]许金凤.磷酸三甲酯与醇、水混合体系的热力学研究[D].长沙:中南大学,2008.
[63]RILBIA S S, GEORMENNY R S, MATIN A. UNIQUAC correlation of liquid-liquid equilibrium in systems involving ionic liquids:The DFT-PCM approach [J]. Fluid Phase Equilibria.2009,278:54-61.
[64]WANG J F, SUN W. Correlation of infinite dilution activity coefficient of solute in ionic liquid using UNIFAC model[J]. Fluid Phase Equilibria.2008,264:235-241.
[65]刘光启,马连香,刘杰.化学化工物性数据手册(有机卷)[M].北京:化学工业出版社,2002.
[66]OSBORNE N S, SITMSON H F, GINNINGS D C. J. Res. Nat. Bur. Stand.1939,23: 197-260.
[67]LI C K, SORIANO A N, LI M H. Heat capacities of the mixed-solvents desiccants (glycols+water+salts) [J]. Thermochimica Acta,2009,487:26-32.
[68]Patterson M R, Blanco H P. Numerical fits of properties of lithium-bromide water solutions [J].ASHRAE Trans.1988,94(2):2059-2077.
[69]SALAN E M H, GEORGE C B, KUMARAN M K. Excess enthalpies of water+diethylene glycol and water+triethylene glycol [J]. Journal of Chemical Thermodynamics,1985, 17:973-976.