In this paper, a theoretical optimization of shaped catalyst dimensions with technologically imposed constraints is presented for operating conditions of a typical methanol reformer. A comprehensive two-dimensional mathematical model of a single reformer tube containing physically sound correlations for heat transfer parameters of holed catalyst particles is used. Three-hole pellets and Raschig rings were used as examples. A general conclusion is made that holed steam reforming catalysts should have maximum catalyst height and minimum diameter determined by requirements of uniform catalyst packing. (c) 2007 Elsevier B.V. All rights reserved.