The dissolution and microfluidic mass transfer of carbon dioxide in water at high-pressure conditions are crucial for a myriad of technological applications, including microreactors, extractions, and carbon capture, utilization, and sequestration (CCUS) processes. In this experimental work, we use a high-pressure microfluidic method to elucidate the mass transfer process of CO${}_2$ in water at high pressure. An intriguing multiphase CO${}_2$ flow and dispersions are observed when operating at the pressure–temperature ($P$–$T$) condition close to the CO${}_2$ gas–liquid phase boundary ($P=6.5$ MPa and $T=23.5\pm 0.5°$C). We propose a series of strategies to unravel this complex multi-phase dynamics by calculating each phase's volume and mass change in a gas–liquid coexistent CO${}_2$ dispersion, estimating the possible CO${}_2$ concentration change in water, and comparing with the CO${}_2$ solubility data. Finally, we quantify the CO${}_2$ mass transfer by directly calculating the CO${}_2$ dissolution rate in water and estimating the volumetric mass transfer coefficient ($k_{L}a$). The results show that the mass transfer may be influenced by the specific area ($a$), CO${}_2$ concentration gradient in the water slug, and the traveling speed of a dispersion.

二氧化碳在高压条件下在水中的溶解和微流体传质对于无数技术应用至关重要，包括微反应器、提取和碳捕获、利用和封存 (CCUS) 过程。在这项实验工作中，我们使用高压微流体方法来阐明 CO 的传质过程${}_2$在高压水中。一个有趣的多相 CO${}_2$ 在压力-温度下操作时观察到流动和分散（$磷$——$吨$) 条件接近 CO${}_2$ 气液相界（$磷=6.5$ 兆帕和 $吨=23.5\pm 0.5°$C）。我们提出了一系列策略，通过计算气液共存 CO 中每一相的体积和质量变化来解开这种复杂的多相动力学${}_2$ 分散，估计可能的 CO${}_2$ 水中的浓度变化，并与CO比较${}_2$溶解度数据。最后，我们量化 CO${}_2$ 通过直接计算 CO 的传质${}_2$ 在水中的溶解速率和估计体积传质系数（${克}_{升}\mathrm{一种}$）。结果表明，传质可能受特定面积的影响（$\mathrm{一种}$), 一氧化碳${}_2$ 水段塞中的浓度梯度和分散体的移动速度。