Hydrogenation of 4-tert-butylphenol (4-TBP) hydrogenation in isopropanol at 433 K and 1-2 MPa of hydrogen pressure was performed in an upflow three-phase reactor. Overall conversion was ca. 90-97% with 4-tert-butylcyclohexanol as the predominant product. The cis/trans ratio in 4-tert-butylcyclohexanol was close to the thermodynamic one (1:2). The data were evaluated with a model, which assumes that at low conversion of organic compound the rate of the process is determined by the hydrogen mass transfer in the liquid film, while at high conversions the transfer of the organic compound to the catalyst surface is the limiting factor. (C) 2003 Elsevier Science B.V. All rights reserved.