共查询到19条相似文献,搜索用时 78 毫秒
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本文综述了近年来计算复杂体系汽液相平衡的立方型状态方程、扰动硬链理论(PHCT)及基团贡献型状态方程的进展情况,并对每一方程的适用范围和偏差情况进行了讨论。 相似文献
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利用Orbey和Sandler提出的HVOS混合规则,PR状态方程与Larsen的活度系数模型相结合建立了无限压力下汽液平衡模型,模型给定状态方程中不随温度变化的参数C*=-0.623 23。用大量的汽液平衡数据在广泛的温度范围内修正了12组MLUNIFAC基团相互作用参数,并用修正的和原始的参数分别对含醇、酸、酮、水、腈和胺等极性二元体系进行了预测。结果表明,体系预测精度显著提高,大部分体系汽相组成的绝对偏差低于4.00×10-2,压力的相对偏差低于6.00%。 相似文献
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通过考虑醇胺分子间的缔合作用,结合先前开发的非缔合变阱宽链流体状态方程(SWCF-VREOS)建立了一个缔合方阱链流体状态方程,并利用方程模拟了醇胺系统的密度和汽液相平衡。通过关联不同温度下醇胺的饱和蒸气压和液体体积得到了18种醇胺流体的分子参数,新方程计算的饱和蒸气压和液体密度总的平均误差分别为0.94%和0.88%。结合简单的混合规则,将此方程扩展到混合系统。研究发现,建立的方程可预测二元和三元醇胺混合物的密度。当引入一个与温度无关的可调参数时,方程能满意关联二元系统的汽液相平衡数据,并可进一步预测多元混合系统的汽液相平衡,预示着新方程可模拟醇胺系统的相行为。 相似文献
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以胡英等人的密堆积双重格子模型为基础,建立了一个新的高分子溶液汽液平衡预测的基团贡献方法。模型由三部分构成:混合熵和自由体积的贡献,vanderWaals相互作用能的贡献和氢键等特殊相互作用能的贡献。 相似文献
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含N-甲酰吗啉溶液体系的相平衡模型研究 总被引:2,自引:0,他引:2
通过对N甲酰吗啉(NFM)官能团的分析,将其划分为CH2,CNH2,CHO和CH2OCH2四个官能团,根据N甲酰吗啉溶液体系的实验数据对官能团的相互作用参数进行了拟合,并预测了含NFM的三元体系的汽液平衡数据及四种烃类在NFM中的无限稀释活度系数,并将其与已公开发表的三种划分方法预测数据进行比较。结果表明,划分方法较为合理,且应用UNIFAC基团相互作用参数拟合的误差结果较为满意。 相似文献
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汽液相平衡测定技术的研究进展 总被引:1,自引:0,他引:1
徐美倩 《化学工业与工程技术》2007,28(5):40-43
汽液相平衡数据对于化工生产中液体混合物分离工艺参数的确定有着十分重要的意义。选择正确的测定方法,是准确有效地测定汽液相平衡数据的前提。介绍了目前国内外应用汽液相平衡数据测定方法的原理及优缺点。 相似文献
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Vapor-liquid equilibrium (VLE) of the methanol-biodiesel (BDF)/glycerin binary system and liquid-liquid equilibrium (LLE) of the water-BDF binary system and the methanol-BDF-glycerin and methanol-water-BDF ternary systems were predicted using several UNIFAC models: the latest original UNIFAC model, Kikic’s model, Fornari’s model, Dortmund-UNIFAC model, and LLE-UNIFAC model. The former VLE and latter LLE are used to design methanol recovery processes and separation and purification processes of crude BDF, respectively. Unfortunately, LLE data on the water-BDF binary system was not available. Instead, solubility of water in fatty acid methyl ester (one of the BDF constituents) was measured. By examining the deviation between predicted and experimental results, we determined which of the UNIFAC models was more useful for the design of those processes as follows: either the original UNIFAC model or Dortmund-UNIFAC model should be used for the methanol recovery process. The LLE-UNIFAC model and Dortmund-UNIFAC model were more useful for the recovery and water-washing processes of crude BDF and purification process of water-washed BDF, respectively. 相似文献
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甲基二氯硅烷-甲基三氯硅烷-苯三元体系等压汽液平衡 总被引:2,自引:0,他引:2
利用新型泵式沸点仪,在101.3 kPa下测定了甲基二氯硅烷-甲基三氯硅烷-苯体系以及3个二元体系在不同液相组成时的沸点;对所测的二元系数据,采用间接法由TPx推算了与之平衡的汽相组成,再用最小二乘法分别求出了二元体系的Wilson、NRTL、Margules和van Laar 4种模型的最佳配偶液相活度系数模型参数,并由二元最佳配偶参数推算了甲基二氯硅烷-甲基三氯硅烷-苯三元体系的气相组成和泡点温度,与实验测得的温度值进行了比较,其拟合精度良好,关联结果令人满意. 相似文献
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This paper presents the vapor–liquid equilibrium (VLE) data of acetonitrile–water system containing ionic liquids (ILs) at atmospheric pressure (101.3 kPa). Since ionic liquids dissociate into anions and cations, the VLE data for the acetonitrile+water+ILs systems are correlated by salt effect models, Furter model and improved Furter model. The overall average relative deviation of Furter model and improved Furter model is 5.43%and 4.68%, respectively. Thus the salt effect models are applicable for the correlation of IL containing systems. The salting-out effect theory can be used to explain the change of relative volatility of acetonitrile–water system. 相似文献
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In this study,the quasi-static ebulliometric method was used to measure both of the vapor pressures of methyl N-phenyl carbamate(MPC),and the isobaric vapor–liquid equilibrium(VLE) data of the aniline and MPC binary system.The measured vapor pressure data of MPC,at different temperature ranging from 369.60 to 389.54 K,fitted well with the Antoine equation.The VLE data for the aniline and MPC system at(2.00,4.00,6.00,7.00 and 8.00) k Pa were correlated by both of nonrandom two-liquid(NRTL) and Wilson models.The parameters of the two models were obtained by regressing the experimental data,with the absolute temperature deviations of 0.54 K and 0.53 K,respectively.The relative volatility of the binary system calculated was all far more than 1,which gives the conclusion that the high purity MPC can be separated from aniline and MPC binary system by rectification or distillation technology. 相似文献
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Modeling of vapor-liquid equilibrium of gasoline-ethanol blended fuels for flash boiling simulations
K. Neroorkar 《Fuel》2011,90(2):665-673
Flash boiling is a physical phenomenon which governs the non-equilibrium phase change of a high temperature fluid as it is depressurized below its vapor pressure. The modeling of this process is of importance to a number of industrial applications and requires the vapor-liquid equilibrium properties of the fluid under consideration. The highly non-ideal nature of gasoline-ethanol fuel blends makes vapor-liquid equilibrium calculations extremely difficult for such fluids. A simple model known as GEFlash (Gasoline-Ethanol Flash), based on existing literature and fundamental chemical engineering thermodynamics is proposed to calculate the properties of gasoline-ethanol fuel blends that are required to perform flash boiling simulations. In addition, a second model based on the chemical engineering software Aspen Plus is also proposed and the predictions of the two models are validated against experimental data available in open literature. The results indicate that both models reproduce the trend in experimental data for vapor pressures and saturated liquid density for blends with different ethanol contents. The GEFlash model does not match the vapor mole fraction predictions of the Aspen Plus model for fuels with low ethanol content (E20 and E40). However, the vapor mole fractions for high ethanol content fuels (greater than E60) are accurate over the majority of the temperature range tested. 相似文献
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提出一个新的无限稀释活度系数的斜率关联式(dlnγ_1/dx_1)_x_1=0,与适当的过量自由焓G~E模型相结合可用于计算两参数过量自由焓的模型参数,进而预测整个浓度范围的汽液平衡。 分别用本文提出的方法和UNIFAC方法对118个等温互溶二元系和47个等压互溶二元系作了汽液平衡预測,并与有关文献数据进行比较评定。结果表明,本方法预測精度令人满意,绝大多数体系预测结果优于UNIFAC或与之相当。 相似文献