A stirred, high-pressure, visual microscopy-based apparatus was used to investigate solid-formation kinetics in LNG-relevant binary mixtures. The apparatus can detect solid crystals as small as 15 µm in a 3.5 mm field of view and is capable of measurements at temperatures as low as 90 K and pressures up to 20 MPa. The apparatus is described in detail and is presented alongside experimental results for two benzene + methane mixtures. Measurements of the solid-fluid equilibrium temperatures for the benzene + methane mixtures at 10 MPa were determined by raising the temperature of the mixture in (0.5 to 1) K steps and observing whether the crystals were still present after 2 hours. The equilibrium temperatures were consistent with those predicted using the software package ThermoFAST within the combined experimental and model uncertainties. Formation measurements were carried out using a 100 ppm benzene-in-methane sample. Isobaric constant-cooling experiments at pressures of 8 and 10 MPa were used to construct subcooling formation-probability distributions for this mixture by identifying the temperature at which solid crystals were first observed to form on a copper substrate. The subcooling values at formation ranged from (4.4 to 11.0) K and were used to generate a cumulative probability of formation. The measured formation-probability distribution was fit to a model based on Classical Nucleation Theory to yield an estimate of 5 mJ/m² for the effective surface free energy of solid benzene in liquid methane on the copper substrate. These results pave the way to probabilistic estimates of risk for solids formation in cryogenic heat exchangers.

基于搅拌，高压，目镜的设备用于研究与LNG有关的二元混合物中的固体形成动力学。该设备可以在3.5 mm的视场中检测出最小15 µm的固体晶体，并且能够在低至90 K的温度和最高20 MPa的压力下进行测量。对该设备进行了详细说明，并与两种苯+甲烷混合物的实验结果一同显示。苯+甲烷混合物在10 MPa下的固液平衡温度的测量是通过以（0.5到1）K的步骤升高混合物的温度并观察2小时后晶体是否仍然存在来确定的。在组合的实验和模型不确定性范围内，平衡温度与使用ThermoFAST软件包预测的温度一致。使用100 ppm的甲烷中苯样品进行地层测量。通过在8和10 MPa的压力下进行等压恒压实验，通过确定首次观察到在铜基板上形成固态晶体的温度，来构建该混合物的过冷形成概率分布。地层处的过冷值介于（4.4至11.0）K之间，用于生成累积的地层概率。测得的地层概率分布适合基于经典成核理论的模型，得出的估计值为5 mJ / m 通过在8和10 MPa的压力下进行等压恒压实验，通过确定首次观察到在铜基板上形成固态晶体的温度，来构建该混合物的过冷形成概率分布。地层处的过冷值介于（4.4至11.0）K之间，用于生成累积的地层概率。测得的形成概率分布适合基于经典成核理论的模型，得出的估计值为5 mJ / m 通过在8和10 MPa的压力下进行等压恒压实验，通过确定首次观察到在铜基板上形成固态晶体的温度，来构建该混合物的过冷形成概率分布。地层处的过冷值介于（4.4至11.0）K之间，用于生成累积的地层概率。测得的地层概率分布适合基于经典成核理论的模型，得出的估计值为5 mJ / m²为铜基板上液态甲烷中固体苯的有效表面自由能。这些结果为概率估计低温热交换器中固体形成的风险铺平了道路。