The physical absorption of CO2 in water containing different types of particles was studied in a microchannel operated under Taylor flow. The maximum enhancement factors of 1.43-2.15 were measured for activated carbon (AcC) particles. The analysis shows that the enhancement effect can be attributed to the shuttle mechanism. Considering the separate contributions of mass transfer from bubble cap and liquid film, a heterogeneous enhancement model is developed. According to this model, the enhancement factors E-cap, E-Film and E-Ov are mainly determined by mass transfer coefficient K-L, (K-L,K-cap and K-L,K-Film), adsorptive capacity of particles m, and coverage fraction of particles at gas-liquid interface zeta. With both effects of particle-to-interface adhesion and apparent viscosity included, the model predicts the enhancement effect of AcC particles reasonably well.