马丁-侯(M-H)状态方程计算二元液液平衡

本文将马丁-侯状态方程用于LLE数据关联.对二元体系,使用两个二元相互作用参数.在较大温度范围,参数处理成温度函数;温度差范围在30-40℃之内,参数可作为常数,取得良好的关联结果.基于二元LLE数据推算了二元低压VLE,结果与实验值符合较好.     

马丁－侯状态方程向固相发展

ＭＨ－８１状态方程式经过进一步改进后，其使用范围可扩展到固相。在该方程中增加了三个常数，Ａ６、Ｂ７和ｂｓ后变为：Ｐ＝ＲＴＶ－ｂ＋Ａ２＋Ｂ２Ｔ＋Ｃ２ｅ－５．４７５ＴＴｃ（Ｖ－ｂ）２＋Ａ３＋Ｂ３Ｔ＋Ｃ３ｅ－５．４７５ＴＴｃ（Ｖ－ｂ）３＋Ａ４＋Ｂ４Ｔ（Ｖ－ｂ）４＋Ｂ５Ｔ（Ｖ－ｂ）５＋Ａ６（Ｖ－ｂｓ）６＋Ｂ７Ｔ（Ｖ－ｂｓ）７改进后的状态方程对于一般物质，如二氧化碳、氩、甲烷及氮等，在三相点到临界点温度、计算的饱和液相、汽相摩尔体积与文献值的偏差基本上保持ＭＨ－８１方程的准确度，而固相摩尔体积的偏差在几千大气压下也在１０％左右，一般压力不太高时都在５％以内，需要增加的输入信息仅三相点（Ｐｔ，Ｔｔ）下的Ｖｓｔ数据。     

用软核微扰理论改进马丁—侯状态方程

采用Ｂａｒｋｅｒ－Ｈｅｎｄｅｒｓｏｎ软核微扰理论的方法改进马丁－侯状态方程，在”多方阱“微扰势的基础上引入一简单的”势，导出了方程本系参数ｂ与温度的函数关系以及新的常数的计算公式。使马丁－侯各参数的物理意义得到进一步解释，初步计算表明改进后的马丁－侯方程的计算精确度有所提高。     

发展马丁-侯方程作为水的专用方程

发展了适用于极性物质水的MH方程。由线性最小二乘法拟合单相区和汽液共存区的PVT及相平衡数据 ,得到方程常数 ,并用统计方法检验了方程的有效性。计算结果表明 ,饱和蒸汽压和摩尔体积误差一般小于0 .6。单相区体积和压力平均误差分别为 0 .3 %和 2 .5 %。与Bender方程相比 ,新方程准确度更高     

对马丁一侯（81）型状态方程的进一步研究 连载

本文对影响 MH-81型方程关联结果的因素(选择不同的蒸汽压点,特性参数T′、m、β、K、T_B,不同的目标函数等)进行了详细的研究,同时讨论了如何判别所求的 MH 常数的合理性、根的情况与求根的方法、MH 方程的适用范围等问题。为更多的人接受与应用这一方程提供良好的基础。     

马丁-侯方程中参数m和B4的直接求取

马丁-侯(M-H)方程在计算液相体积、高压气体的焓熵、以及极性液体的焓熵方面有很好的精度优势,但对其中B4参数的求取需要迭代计算而影响了M-H方程在工程计算中的应用.今首先将M-H方程的m参数和物质的偏心因子ω关联起来,在保持M-H方程计算气相体积精度的条件下得到计算m的普适方法.然后提出参数B4与物质的对比温度Tr以...     

从统计力学推导流体状态方程(Ⅲ)——关于马丁-侯状态方程等的统计力学证明与解释

本文从多方阱非球形势硬粒子微扰理论出发,通过适当的近似与化简,导出了马丁-侯状态方程,从而使这个由经验提出的状态方程得到了统计力学的证明与解释.从多方阱非球形势硬粒子微扰理论出发,通过更粗略的近似也能得到范德华状态方程以及Barner与Adler改进的(?)offie状态方程.由理论分析,马丁-侯方程较为全面,不仅有高级微扰项,保留了多级密度展开式,同时取用了较精确的多级参考流体状态方程.     

方型状态方程在高压相平衡中的研究及应用

对近年来状态方程的研究及其在高压相平衡计算中的应用状况作了综述分析。以ＰＲＳＶ方程为基础，通过实际计算考察和评价不同混合规则在复杂体高压汽液平衡、超临界流体／固体体系相平衡计算中的性能     

立方型状态方程的混合规则在相平衡计算中的研究

对立方型状态方程中所使用的混合规则及其在相平衡计算中的应用状况做了综述分析。将混合规则按二次型、LC型、DDLC型和UNIWAALS型分别进行了介绍和讨论。总结了各种类型混合规则的优缺点和适用范围,并提出了混合规则今后的发展方向。     

用马丁－侯方程理论式计算流体P－V－T性质

本文导出了马丁－侯状态方程理论式常数的计算公式，并用理论式计算了ＣＯ_２的等温曲线和十种非极性和极性物质的汽液饱和曲线，其计算精确度令人满意。     

Estimations of the viscosities of binary mixtures with different equations of state and mixing rules

In this study, the Eyring's kinematic viscosity model was applied with the consideration that the activation free energy of flow was related to the excess free energy of mixtures and estimated with the equation of state (EOS). The effects of the equation of state, mixing rule, and interaction parameter on the viscosity estimations were considered.     

Wong-Sandler新型混合规则应用于MKS状态方程

为了将ＭｏｄｉｆｉｅｄＫｕｍａｒ－Ｓｔａｒｌｉｎｇ立方型状态方程用于近临界及多种类流体混合物的计算，采用作者提出的将Ｗｏｎｇ－Ｓａｎｄｌｅｒ型混合规则推广到普遍化立方型状态方程的方法，建立了改进的ＭＫＳ／２模型。经各类体系的计算考核，ＭＫＳ／２模型对于各类体系的近临界相态行为及非对称体系相平衡计算的改进是显著的。     

应用微扰理论（PHCT）诠释MH—55状态方程

用硬链微扰理论分析了ＭＨ－５５型状态方程。首次改进了该方程中的参考项，以ＣＳ硬球方程替代了原来的ｖａｎｄｅｒＷａａｌｓ斥力项，使改进后的ＭＨ－５５方程计算范围扩大到汽液两相。     

EMPIRICAL TWO-PARAMETER MIXING RULES FOR A CUBIC EQUATION-OF-STATE

Four two-parameter mixing rules are presented along with expressions for the fugacity coefficient and compressibility factor obtained when they are used in conjunction with the Peng-Robinson equation of state. A comparison of the forms of these expressions and results obtained in the prediction of VLE for nine systems with these temperature-, pressure-, density-, and composition-dependent rules provides a guideline for the applicability, advantages and disadvantages of each. Excellent results were obtained, especially in the near critical region, when these simple pressure- and density-dependent rules were used to describe P-x data. The density-dependent mixing rule consistently yielded better predictions of VLE over a range of temperatures (using parameters obtained at a single temperature) than the results obtained by optimizing the interaction parameter of conventional mixing rule at each temperature. The composition-dependent rule was slightly less effective for most systems, but for highly polar, asymmetric systems, this rule was superior     

EXCESS ENTHALPY AND VAPOR-LIQUID EQUILIBRIA WITH THE MHV2 AND SOAVE MIXING RULES

Calculations and predictions of excess enthalpy (H^E) and vapor-liquid equilibrium (VLE) were performed using the Gibbs energy mixing rules MHV2 and a modification of it by Soave. The Soave-Redlich-Kwong equation of state was combined with the UNIQUAC equation. Four sets of parameters estimated in the UNIQUAC model were used for each of seven binary systems: the first estimated from VLE data, the second and the third estimated from H^E data for two versions of the UNIQUAC equation, and the fourth estimated from both H^E and VLE data simultaneously. It was found that H^E calculations can be performed with the mixing rules; the average relative errors fell from around 200% for the conventional mixing rule to around 60% for MHV2 combined with DECHEMA UNIQUAC parameters and was as little as 20% when the UNIQUAC parameters had been estimated from H^E and VLE data simultaneously. However, the approach suffers from the same shortcomings as far as cross-prediction between H^E and VLE data is concerned, as does the UNIQUAC equation used alone. There is a discrepancy between values obtained with the mixing rule and those obtained with the UNIQUAC equation directly. This discrepancy is smaller for the Soave modification of the mixing rule.     

立方型状态方程研究进展

概括了立方型状态方程的进展,介绍了立方型状态方程的特点.分析了各类立方型状态方程存在的问题,提出了解决的方法.对立方型状态方程的应用进行了阐述,指出了其仍然具有很大的研究价值.     

SOLID ADSORBENTS IN BATCH FERMENTATIONS

The addition of a non-specific solid adsorbent reduces the liquid-phase substrate concentration at the start of a batch fermentation. Then, as product is generated, it displaces the substrate from the adsorbent, reducing liquid-phase product concentration. So both substrate and product inhibition can be reduced and the productivity of the fermentation increased. A mathematical model for this process is developed including a modified Langmuir bi-solute adsorption isotherm, and both growth- and non-growth-associated product formation. The model agrees well with experimental data on the effect of Linde JXC activated carbon on the fermentation of glucose to ethanol by S. cerevisiae. Only product inhibition is considered and NH₃ is the sole nitrogen source to avoid complications arising from the adsorption of organic nitrogen compounds. Since ethanol is very hydrophilic and high concentrations of activated carbon are apparently toxic to yeast, there is little increase in volumetric productivity for this fermentation, the gains from reduced inhibition being cancelled by the additional reactor volume needed for the carbon. However, a significant increase is predicted for fermentations where the product and/or substrate is more inhibitory and adsorbs more readily.     

LCVM型混合规则扩展用于多参数状态方程以关联混合物汽液相平衡

基于两参数状态方程提出的LCVM混合规则是将以无穷压力为参考态的HV混合规则与以零压力为参考态的MHV1混合规则线性结合而得的,尽管没有理论基础,但对于计算非极性、极性体系给出了较好的结果.因而研究借鉴获得LCVM混合规则的思路将LCVM混合规则扩展到多参数状态方程中,即将HVOS混合规则与MHV1混合规则进行线性结合,并通过引入两个对比参数λ0,λ∞给出了适合多常数状态方程的新LCVM型混合规则.在新的LCVM型混合规则中,参数δ决定了MHV1和HVOS混合规则的相对贡献,该参数可由模型在高压和低压下拟合二元混合物的泡露点得到,通过拟合得到的值约为0.21;混合规则中的活度系数模型可以利用由低压区关联出的GE模型.采用该新混合规则模型,在较宽的温度与压力范围内,结合Harmens-Knapp(HK)方程对包括非极性体系、极性体系等在内的20种二元混合物进行了相平衡计算.计算的结果与实验数据吻合得很好.该模型与采用VDW混合规则模型的相平衡计算结果比较表明,该模型的关联精度有了很大的提高,可以在较大的温度与压力范围内关联多种体系的汽液相平衡数据.但是在混合规则中,参数b,c是依赖于经验获得,因此还有待于进一步的研究.