Microfluidic-based chemical absorption technology for CO2 capture: Mass transfer dynamics, operating factors and performance intensification

Carbon capture, utilization, and storage (CCUS) is a crucial strategy for achieving CO2 emission reduction targets and mitigating the impacts of global warming and climate change. Among various CCUS technologies, chemical absorption of CO2 has proven to be a mature and widely-used technique in various industrial sectors. However, the current CO2 chemical absorption process involves large-scale equipment with low efficiencies, making it difficult to control. To address these issues, microfluidic devices have emerged as a promising technology to intensify the CO2 absorption process by providing a smaller required volume, enhanced mass transfer, cleaner and safer operations, higher productivity, and more efficient energy use. This paper aims at presenting a comprehensive literature review on research advances of the microfluidic technology for CO2 chemical absorption. The review covers various aspects, including microchannel geometries, two-phase flow patterns, mass transfer models, effects of operating factors, and measures to intensify the CO2 absorption process. In addition, the paper discusses the measurement of interfacial and local parameters, such as liquid film thickness, velocity field, and local CO2 concentration, which are primordial for understanding the transport phenomena and for optimizing the CO2 absorbers. This paper may serve as an essential reference that contributes to the development and exploitation of highly-efficient microfluidic-based CO2 chemical absorption technology for future large-scale industrial applications.