1. Max-Planck-Institut für Kohlenforschung; 45470 Mülheim an der Ruhr Germany
2. Chemical Process Engineering Research Institute; Center for Research and Technology Hellas; P.O. Box 361 57001 Thessaloniki Greece
3. School of Science & Technology; International Hellenic University; P.O. Box 361 57001 Thessaloniki Greece
4. Department of Chemical Engineering; South Kensington Campus; Imperial College London; London SW7 2AZ UK