求化工专业英语高手翻译（5）

Question

3.2. Binary systems
The temperature T, the liquid-phase xi and vapour-phase yi mole fractions at 101.3 kPa for the systems dipropyl ether (1) + 2-ethoxyethanol (3) and 1-propyl alcohol (2) + 2-ethoxyethanol (3) are reported in Tables 4 and 5 and plotted in Figs. 2 and 3. The activity coefficients ¦Ãi for these systems were calculated from the following equation:
¦Ãi =yiPxiPoi(3)
where P is the total pressure. In Eq. (3), the vapour phase is assumed to be an ideal gas and the pressure dependence of the liquid phase fugacity is neglected. To calculate activity coefficients, Eq. (3) was selected because the low pressure used in the
present VLE data, makes these simplifications reasonable.

The activity coefficients presented in Tables 4 and 5 indicate that the dipropyl ether (1) + 2-ethoxyethanol (3) system shows positive deviations from ideal behaviour and that the 1-propyl alcohol (2) + 2-ethoxyethanol (3) system exhibits no deviation from ideal behaviour and no additional azeotropes are present.

The VLE data reported in Tables 4 and 5 for the binary systems dipropyl ether (1) + 2-ethoxyethanol (3) and 1-propyl alcohol (2) + 2-ethoxyethanol (3) were found to be thermodynamically consistent by the point-to-point method of Van Ness and Abbott [14], as modified by Fredenslund et al. [15]. The consistency criterium (y(MAD) ¡Ü10?2) was met using Legendre polynomial with three parameters. Table 6 presents the value of the parameters of the Legendre polynomial and the pertinent consistency statistics. The results for both systems at 101.3 kPa show a reasonable random distribution.

Answer 1

3.2. 二元体系
两种二元体系【1，二丙醚 (1) + 2-乙氧基乙醇(3)；2，1－丙醇 (2) + 2-乙氧基乙醇(3)】在常压下的温度T、液相xi和蒸汽相yi 的莫尔比率见表4和表5，以及图2和图3。这些体系的活度系数Ãi 用下述方程计算：Ãi =yiPxiPoi(3)
在这个方程中，P是总压力，蒸汽相假设为理想气体，并忽略液相逸度的压力依赖性。为了计算活度系数，由于当前的气液平衡数值测定中使用的压力较小，故选用方程(3)更加合理。
表4和表5所示的活度系数表明，“二丙醚+2-乙氧基乙醇”体系与理想模型表现出正偏差而“1-丙醇+2-乙氧基乙醇”体系则无偏差，并且不存在其他共沸物。
用Van Ness和Abbott [14]建立的、Fredenslund等[15]改进的点对点法，我们发现表4和表5中的2种二元体系的气液平衡数值具有热动力学的一致性。用带有三个参数的勒让德多项式做一致性检验。表6表示勒让德多项式的参数值以及一致性检验的统计分析。结果表明两种体系在常压下呈随机分布。