The freeze-out of impurities in LNG production can pose significant operational risks and lead to costly blockage-induced plant shutdowns. Study of ternary and higher-order mixtures, which are more analogous to LNG, present the critical tests of thermodynamic models in terms of their utility and predictive accuracy. In this work, a visual CryoSolids apparatus was upgraded to allow analytical measurements of solvent composition in multi-component systems where a solid phase is present at equilibrium. The analytical system, which included a ROLSI sampling valve and capillary together with a gas chromatograph, was successfully commissioned and used to measure melting temperatures and solvent compositions of a ternary mixture containing methane, ethane, and benzene at temperatures down to 125 K and pressures up to 6 MPa. The effect on the solubility of benzene by adding ethane to the solvent was investigated by varying the ethane mole fraction from 0 to 0.96. The resulting temperature at which benzene melted into the liquid solvent decreased from 246 K at 4.7 MPa to 125 K at 5.7 MPa. The comparison of results with the ThermoFAST model showed that it could describe the new data with a deviation less than 1 K for ethane liquid phase mole fractions from 0 < $x_{C_2}$< 0.5, which increased to less than 4 K for 0.85 < $x_{C_2}$< 0.97. This result indicates that ThermoFAST satisfactorily represents SFE conditions in LNG mixtures of industrial relevance but needs improvement to cover wider ranges of composition.

液化天然气生产中的杂质冻结会带来重大的运营风险，并导致昂贵的堵塞导致工厂停工。与LNG更相似的三元和更高阶混合物的研究，从热力学模型的实用性和预测准确性的角度出发，对热力学模型进行了严格的测试。在这项工作中，对可视化的CryoSolids仪器进行了升级，可以对固相处于平衡状态的多组分系统中的溶剂组成进行分析测量。该分析系统包括ROLSI采样阀和毛细管以及气相色谱仪，已成功调试并用于在低至125 K的压力和最高压力下测量包含甲烷，乙烷和苯的三元混合物的熔融温度和溶剂组成。至6 MPa。通过将乙烷的摩尔分数从0更改为0.96，研究了通过将乙烷添加到溶剂中对苯的溶解度的影响。苯熔化成液体溶剂的最终温度从4.7 MPa的246 K降低到5.7 MPa的125K。与ThermoFAST模型的结果比较表明，它可以描述新数据，乙烷液相摩尔分数从0 <$X_{C_{\mathrm{2个}}}$<0.5，对于0.85 <，增加到小于4 K < $X_{C_{\mathrm{2个}}}$<0.97。该结果表明，ThermoFAST可以令人满意地代表具有工业相关性的LNG混合物中的SFE条件，但需要进行改进以涵盖更大范围的组成。