The density and speed of sound of the carbon dioxide + n-heptadecane binary system were measured at four selected temperatures from 303.15 to 333.15 K and for various pressures ranging from 10 to 70 MPa over the whole composition range. A vibrating U-tube densimeter was employed to measure the density, whereas a pulse-echo technique using a double path length sensor working at 3 MHz was used to obtain the speed of sound data. Isothermal and isentropic compressibilities were determined from both measurements. Finally, the excess volume, excess isothermal compressibility as well as excess speed of sound and excess isentropic compressibility were estimated in the same p, T range and represented as a function of CO₂ content. The results, in addition to previous data concerning CO₂ + n-heptane and CO₂ + n-dodecane binary systems, were analyzed to determine the effect of pressure, temperature, and alkyl chain length on nonideal behaviors of such asymmetric CO₂ + n-alkane systems.

中文翻译：

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10 至 70 MPa 二氧化碳 + 正十七烷二元混合物的密度、声速、可压缩性和过量特性

在从 303.15 到 333.15 K 的四个选定温度下以及在整个组成范围内从 10 到 70 MPa 的各种压力下测量二氧化碳 +正十七烷二元系统的密度和声速。使用振动 U 形管密度计来测量密度，而使用在 3 MHz 下工作的双路径长度传感器的脉冲回波技术用于获得声速数据。等温和等熵可压缩性由两种测量确定。最后，在相同的p、T范围内估计了过量体积、过量等温压缩性以及过量声速和过量等熵压缩性，并表示为 CO ₂的函数内容。除了先前关于 CO ₂ + n -庚烷和 CO ₂ + n -十二烷二元系统的数据之外，还分析了结果以确定压力、温度和烷基链长度对这种不对称 CO ₂ + n 的非理想行为的影响-烷烃系统。