A diffusion-limited shrinking spherical particle model was developed to describe cellulose dissolution in carbon dioxide switchable system (CO2-SWS) by assuming an instantaneous reaction of the CO2-SWS on the cellulose surface. CO2, the main precursor of the SWS, was mixed with 1,8-diazabicyclo [5.4.0] undec7-ene, ethylene glycol and dimethyl sulfoxide under various operating pressures (P) and temperatures (T) to yield a CO2 switchable ionic liquid for cellulose dissolution. As dissolution proceeded, the cellulose particle radius decreased because of the disappearance of cellulose. The model-predicted diffusion coefficient (D), completed dissolution time (tau), and dissolution conversion (X-C) were determined under various CO2-SWS operating conditions. The predicted tau and X-C values were in good agreement with the observed results. The influence of the CO2-SWS operating conditions on the predicted numerical D, tau, and X-C values were investigated using Spearman's rho correlation. The results showed that the D values ranged from 10 (20) to 10 (17) m(2) s (1) for the CO2-SWS-cellulose system depending on the system conditions. (C) 2018 Elsevier Ltd. All rights reserved.