Abstract The limited availability of accurate experimental data in wide ranges of pressure, temperature, and composition is the main constraining factor for the proper development and assessment of thermodynamic models and equations of state. In the particular case of carbon capture and storage (CCS) processes, there is a clear need for data sets related to the (carbon dioxide + oxygen) mixtures that this work aims to address. This work provides new experimental (p, ρ, T) data for three binary (CO2 + O2) mixtures with mole fractions of oxygen x(O2) = (0.05, 0.10, and 0.20) mol·mol−1, in the temperature range T = (250 to 375) K and pressure range p = (0.5 to 13) MPa. The measurements were performed with a high-precision single-sinker densimeter with magnetic suspension coupling. The density data were obtained with estimated expanded relative uncertainties of 0.02% for the highest densities and up to 0.3% for the lowest ones.The results were compared to the corresponding results calculated by the current reference equations of state for this kind of mixtures, namely the EOS-CG (combustion gases) and the GERG-2008 equation of state, respectively. The EOS-CG yields better estimations in density than the GERG-2008 equation of state. The results from the EOS-GC model show no systematic temperature dependence. For the GERG-2008 model, however, this criterion is significantly less fulfilled.

中文翻译：

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(CO2 + O2) 二元系统的准确实验 (p, ρ, T) 数据，用于开发 CCS 过程模型

摘要 在广泛的压力、温度和成分范围内，精确实验数据的有限可用性是正确开发和评估热力学模型和状态方程的主要约束因素。在碳捕获和储存 (CCS) 过程的特殊情况下，显然需要与本工作旨在解决的（二氧化碳 + 氧气）混合物相关的数据集。这项工作为三种二元 (CO2 + O2) 混合物提供了新的实验 (p, ρ, T) 数据，其中氧的摩尔分数 x(O2) = (0.05、0.10 和 0.20) mol·mol−1，在温度范围内T = (250 到 375) K 和压力范围 p = (0.5 到 13) MPa。测量是使用具有磁悬浮耦合的高精度单沉降器密度计进行的。密度数据是在最高密度的估计扩展相对不确定度为 0.02% 和最低密度为 0.3% 的情况下获得的。 将结果与通过当前参考状态方程计算的此类混合物的相应结果进行比较，即分别是 EOS-CG（燃烧气体）和 GERG-2008 状态方程。EOS-CG 比 GERG-2008 状态方程产生更好的密度估计。EOS-GC 模型的结果显示没有系统的温度依赖性。然而，对于 GERG-2008 模型，该标准的满足程度明显较低。即分别是 EOS-CG（燃烧气体）和 GERG-2008 状态方程。EOS-CG 比 GERG-2008 状态方程产生更好的密度估计。EOS-GC 模型的结果显示没有系统的温度依赖性。然而，对于 GERG-2008 模型，该标准的满足程度明显较低。即分别是 EOS-CG（燃烧气体）和 GERG-2008 状态方程。EOS-CG 比 GERG-2008 状态方程产生更好的密度估计。EOS-GC 模型的结果显示没有系统的温度依赖性。然而，对于 GERG-2008 模型，该标准的满足程度明显较低。