The application of fine TiO2 particles for enhanced gas absorption

The physical absorption of pure CO2 in various liquids (water, hexadecane, and sunflower oil) containing micron sized TiO 2 particles has been investigated. Absorption studies were carried out in a batch stirred cell reactor at 298 K and initial pressures of 0.08 MPa. Solid loading and stirring intensities were varied systematically between 0–15 kg/m 3 and 3.3–12.5 s −1 , respectively. Gas absorption rates are enhanced significantly in the presence of TiO 2 particles. Enhancement factors are a function of the solids loading and stirring intensity. Maximum enhancement factors of about 2 were observed for all solvents at low stirring intensities. The rate of gas absorption was theoretically analyzed using a heterogeneous unsteady state mass transfer model based on the Danckwerts surface renewal theory and a Langmuir-type of particle to interface adhesion isotherm. This model not only predicts the trends in the observed enhancement factors very well but also gives an accurate quantitative picture. © 2002 Elsevier Science B.V. All rights reserved.