CO₂ Dissolution In Water And Ethanol In Parallel Microchannels

This work presents the microfluidic studies of carbon dioxide(CO2)dissolution in liquid solvents conducted in four parallel microfluidic devices.Water and ethanol were the main solvents,and glycerol was used to confer viscosity to the mixtures.Flow rate was manipulated at the inlet of the microchannel and,the flow behaviour was recorded.The main goal of this study was to find feasible option within the study parameters(solvent nature,microchannel design,and glycerol addition)that leads to more CO2 dissolution/absorption,what is very useful for projects related to capture,sequestration and storage of CO2.Parameters such as mass transfer coefficient(kL),dissolution coefficient(kD)and bubble length(d0),were analysed to find the alternative that suits the goal of this study.Results of bubble length variation from its initial value showed that ethanol dissolve about 12% much more CO2 than water.Glycerol additions are not significant in terms of enhancing CO2 dissolution in either solvents(water or ethanol).It did not exceed 1% of its effects if compared to the cases without it.Microfluidics without modifications(as reference device)at the edges offers the best dissolution rate(41 – 45 % in terms of bubble length reduction)than the three others,while the open-entrance device has 13 – 28 % more than opened-outlet.Therefore,modifications reduce performance because they increase pressure drops.Final conclusion is that the solvent nature and the design of the microfluidic devices matters to improve the absorption and dissolution process,whereas the viscosity effects are less pronounceable for carbon dioxide dissolution.