超临界CO2二元系统相平衡的数值模拟

应用微扰理论,借助微扰状态方程,对超临界CO2 系统相平衡进行了模拟。编制了求解程序,介绍了状态方程中各参数的确定方法和程序模块的设计思想。针对超临界CO2 /非极性体系、超临界CO2 /极性体系,在不同温度、压力条件下的气液相平衡进行了计算,将计算结果与实验结果进行了比较,结果表明:微扰状态方程适合模拟超高压下的CO2 二元体系的相平衡。     

超临界二氧化碳和脂质体系相平衡计算

对超临界CO2和一些脂质体系相平衡计算问题进行了研究.应用Peng-Robinson状态方程及Panagiotopoulos和Reid混合规则,改进能量参数a(T)后,用于计算脂质和超临界CO2组成的二元和三元体系的相平衡,结果与实验数据拟合精度较好.对于一些复杂的混合物如大豆油脱臭馏出物与超临界CO2体系,简化成拟三元、四元等体系进行了计算,计算结果达到一定的精度.     

超临界CO2—共轭亚油酸乙酯萃取体系研究

利用带有视窗的相平衡装置对共轭亚油酸乙酯在超临界CO2中的溶解度进行了测定。并通过对相平衡釜内体系相态变化的观测,进一步研究超临界相行为。采用Chrastil经验方程对共轭亚油酸乙酯在超临界CO2中的溶解度进行模拟。共轭亚油酸乙酯体系计算值与实验值平均误差为2.43%。     

超临界CO2和植物油脱臭馏出物相平衡研究

研究了植物油脱臭馏出物在超临界CO2中的相平衡问题。基于组分的相似性把含有复杂组分的植物油脱臭馏出物简化为两种虚拟组分,用改进的混合规则和超临界组分的能量参数计算式,结合PR状态方程进行计算：理论计算与实验数据相吻合,为间歇式或连续逆流式超临界CO2萃取分离的设计提供了依据。     

超临界流体萃取中的相平衡进展

概述了超临界流体萃取的发展历史。系统地阐明了超临流体－固体系统相平衡的三种关联方法，对其关联精度进行了比较。介绍了超临界流体－低挥发性液体系统相平衡计算中已看到的状态方程和混合规则。论述了超临界流体－低分子量有机化合物－水系统的相平衡研究进展，对这类系统的超临界流体萃取过程的实质进行了探讨。     

超临界CO2中固体溶解度的逆向传播人工神经网络模拟

为了更好地模拟超临界CO2(SC CO2)中固体的溶解度数据,采用逆向传播神经网络(BPANN)对30种固体在超临界CO2中的873个溶解度数据进行了模拟,所得相对误差(AARD)都在10%以下,小于状态方程和经验方程的值,此结果表明BPANN能较好地模拟SC CO2中固体的溶解度数据。     

超临界流体萃取天然产物的过程模拟研究进展

对萃取过程的建模和模拟是超临界流体工业应用的研究重点和难点。本文在阐述溶质在超临界CO2中的相平衡和传质过程的基础上,详细介绍了现有各种模型的科学依据和不足．并指出了这方面研究的发展方向。     

天然气转化深冷分离制CO和H_2模拟研究

重点分析了天然气转化制CO和H_2工艺中CO-H_2分馏装置的组分物性特点,选择P-R方程来计算低温下各组分的相平衡物性,利用Hysys软件模拟了低温下各组分的精馏及闪蒸分离过程,并给出了运行结果。     

CO2-H2O-HAc三组分系统高压相平衡

超临界状态下的CO2在含有有机溶剂的水溶液中可作为萃取剂。这种情况可用于水和有机酸的分离，也可以用于从水溶液中萃取产品。要设计这样的过程，CO2-H2O-有机酸系统相平衡的数据是必不可少的。为此，在实验室建立了一套高压相平衡装置。为了验证这套装置的可靠性，测定了CO2-H2O-HAc体系在313K以及压力在15、20、25和30MPa下的相平衡数据，用Peng-Robinson方程^[1,2]进行了计算，并与文献值进行了比较。     

二元交互参数化PC-SAFT在超临界乙烯配位聚合体系相平衡计算中的应用

超临界烯烃配位聚合技术是近年来国际聚烯烃工业领域中的重要进展之一,超临界体系相平衡计算则是该聚合工艺设计与优化操作的基础。本文以链扰动统计缔合流体理论（PC-SAFT）状态方程描述工业级超临界乙烯配位聚合体系的相平衡,得到了适用于该复杂体系的PC-SAFT二元交互参数。与公开报道的实验数据比较表明,获得的二元交互参数可准确描述该超临界体系在较宽温度、压力范围的相平衡。基于上述二元交互参数,针对2个不同双峰聚乙烯产品牌号,计算了工业装置内多组分的相平衡状态,结果表明,反应器内的[H₂]/[C₂H₄]摩尔比、淤浆密度的计算值与工业数据吻合较好,验证了二元交互参数的适用性。研究结果为进一步的工艺流程模拟与优化奠定了基础。     

A comparison among three equations of state in predicting the solubility of some solids in supercritical carbon dioxide

Equations of state play an important role in chemical engineering designs, and they have assumed an expanding role in the study of the phase equilibria of fluids and fluid mixtures. In this report, a modified Peng-Robinson equation of state by Danesh et al., a modified Peng-Robinson equation of state by Gasem et al., and the Mansoori-Mohsen Nia-Modarress equation of state are used to predict the solubility of some solids in supercritical carbon dioxide. The systems studied were binary mixtures containing supercritical carbon dioxide with Ascorbic acid, Ascorbyl palmitate, Butyl hydroxyl anisole, Dodecyl gallate and Propyl gallate. Interaction parameters for the studied systems are obtained and the percentage of average absolute relative deviation (%AARD) in each calculation is displayed.     

Separation of Alkanes and Aromatics with Supercritical Carbon Dioxide

Abstract

The separation of alkanes and aromatics with supercritical carbon dioxide has been studied by measuring vapour-liquid equilibria and selectivities in the model systems 2-methylnaphthalene/hexadecane/ carbon dioxide and 2-methylnaphthalene/dodecane/carbon dioxide. The results have been modelled with the Peng-Robinson equation of state. In both model systems supercritical carbon dioxide appeared selective for the component with the highest vapour pressure, 2-methylnaphthalene respectively dodecane. Consequently alkanes and aromatics will be separated by supercritical carbon dioxide on basis of their difference in vapour pressure instead of their difference in chemical structure.     

High pressure phase behavior for the binary mixture of pentafluoropropyl methacrylate and poly(pentafluoropropyl methacrylate) in supercritical carbon dioxide and dimethyl ether

Pressure-composition isotherm is obtained for the carbon dioxide+2,2,3,3,3-pentafluoropropyl methacrylate (PFPMA) using static apparatus with a variable volume view cell at temperature range from 40 °C to 120 °C and pressure up to 130 bar. This system exhibits type-I phase behavior with a continuous mixture-critical curve. The experimental result for carbon dioxide+PFPMA mixture was modeled using the Peng-Robinson (P-R) and multi-fluid nonrandom lattice fluid (MF-NLF) equation of state. Experimental cloud-point data of pressure up 470 bar and temperature to 182 °C were reported for the binary mixture of poly(2,2,3,3,3-pentafluoropropyl methacrylate) [Poly(PFPMA)] in supercritical carbon dioxide and dimethyl ether (DME). The Poly(PFPMA)+carbon dioxide and Poly(PFPMA)+DME systems showed LCST behavior.     

α-细辛醚在超临界CO2中溶解度的测定和计算

Solubility of α -asarone in supercritical carbon dioxide was measured and calculated by P-R equation and Chrastil method. Compared with experimental data, the average relative deviation of the calculated solubility of α -asarone is 25% and 8% for P-R equation and Chrastil method respectively,which indicates that the experimental results can be correlated well with Chrastil method.The Chrastil equation for the solubility of α -asarone in supercritical carbon dioxide was subsequently given, which can be applied to the prediction of solubility according to the practical supercritical conditions.     

PR方程用于低温高压含氢体系汽液平衡计算和结果分析

本文用PR状态方程推算低温高压含氢体系汽液相平衡.在计算中,考虑了正、仲氢的转化,并且采用两种方法考虑了量子效应.结果表明比原PR方程更精确地描述了汽液平衡.     

Solubility of some phenolic acids contained in citrus seeds in supercritical carbon dioxide: Comparison of mixing rules, influence of multicomponent mixture and model validation

The solubility prediction of any compound in supercritical carbon dioxide is obtained using the dense gas formulation to calculate the phase equilibria. To achieve this, the Peng-Robinson equation of state with the Stryjek-Vera modification is used. Then, this is coupled with the Wong-Sandler and Van der Waals mixing rules. The latter was included in order to evaluate the influence of the mixing rules in the calculation of the solubility. Therefore, the obtained results from the model are compared with experimental data reported in literature for ferulic acid, p-coumaric acid and caffeic acid contained in citrus seeds. Good agreement was obtained between the model and the experimental data for the phenolic acids, when the Wong-Sandler mixing rules are used. Also the influence of the multicomponent mixture is considered for the prediction of the solubility of phenolic acids in supercritical carbon dioxide.     

超临二氧化碳萃取分离异丙醇-水的相平衡研究

用静态法测定了高压下CO_2-i-C_3H_7OH二元系和CO_2-i-C_3H_7OH-H_2O三元系的相平衡数据.实验证明超临CO_2能从水溶液中萃取分离异丙醇,并打破了常压下异丙醇-水的恒沸组成.用SRK方程和Huran-Vidal混合规则,建立了CO_2-i-C_3H_7OH-H_2O三元系的热力学模型.此模型只用二元作用系数,能成功地预测三元气液平衡和平衡系线随温度压力剧烈变化的行为.最后,通过实验数据分析和模型预测,探讨了影响超临CO_2从水溶液中萃取分离异丙醇的各种条件.