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This review highlights microfluidics as a disruptive platform for advancing carbon capture and storage, enabling rapid testing, enhanced mass transfer, and precise flow control while offering insight into mechanisms, tools, and design strategies. 

This study introduces a carbonate-surface-mimicking microfluidic platform and demonstrates its pore-scale oil displacement behavior using seawater–concrete–CO₂flooding compared with conventional fluids. 

With increasing energy demands and depleting oil accessibility in reservoirs, the investigation of more effective enhanced oil recovery (EOR) methods for deep and tight reservoirs is imminent. This study investigates a novel hybrid EOR method, a synergistic approach of nonionic surfactant flooding with intermediate CO2-based oil swelling. This study is focused on the efficiency of surfactant flooding and low-pressure oil swelling in oil recovery. We conducted a fluorescence-based microscopic analysis in a microchannel to explore the effect of sodium dodecyl sulfate (SDS) surfactant on CO2 diffusion in Texas crude oil. Based on the change in emission intensity of oil, the results revealed that SDS enhanced CO2 diffusion at low pressure in oil, primarily due to SDS aggregation and reduced interfacial tension at the CO2 gas–oil interface. To validate the feasibility of our proposed EOR method, we adopted a ‘reservoir-on-a-chip’ approach, incorporating flooding tests in a polymethylmethacrylate (PMMA)-based micromodel. We estimated the cumulative oil recovery by comparing the results of two-stage surfactant flooding with intermediate CO2 swelling at different pressures. This novel hybrid approach test consisted of a three-stage sequence: an initial flooding stage, followed by intermediate CO2 swelling, and a second flooding stage. The results revealed an increase in cumulative oil recovery by nearly 10% upon a 2% (w/v) solution of SDS and water flooding compared to just water flooding. The results showed the visual phenomenon of oil imbibition during the surfactant flooding process. This innovative approach holds immense potential for future EOR processes, characterized by its unique combination of surfactant flooding and CO2 swelling, yielding higher oil recovery. 

Carbon capture and utilization technology is the research stream dedicated to mitigating the pressing effect of rising atmospheric carbon dioxide (CO2). The present study investigates a potential environmentally conscious solvent to capture and utilize CO2 using waste concrete and seawater under reactor conditions. Although seawater’s CO2 soubility is low due to salinity, waste concrete raises seawater’s pH and alkalinity, acting as a feedstock for CO2 dissolution and offsetting the adverse effects of salinity. To evaluate the performance of the novel natural seawater-concrete solutions for CO2 capture, time-dependent pH changes of solutions exposed to CO2 were measured in a microchannel using fluorescence microscopy. The concentration of dissolved CO2 in the solution was derived from pH change, revealing a 4-fold increase in the total dissolved carbon from 0.034 to 0.13 M and a 57.54% increase in the CO2 dissolution coefficient from 530 to 835 μm2/s in seawater upon concrete addition. Electrolysis further enhanced the CO2 capture capacity of the seawater-concrete solution by increasing the pH, enabling the solid precipitation of carbonate minerals. Raman spectroscopy and scanning electron microscopy showed that electrolysis-driven precipitates are mainly amorphous calcium carbonates, useful building blocks for seashells and coral reefs.