1. Department of Mechanical Engineering, University of Western Macedonia, 50100 Kozani, Greece and Chemical Process and Energy Resources Institute (CPERI), Centre for Research and Technology Hellas (CERTH), 57001 Thermi-Thessaloniki, Greece
2. Department of Chemical Engineering, University of Massachusetts, 159 Goessmann Laboratory, 686 North Pleasant Street, Amherst, Massachusetts 01003-9303, USA