OP-II-3

OP-I-31USE OF A HIGH-TEMPERATURE GRADIENT AS ATHERMODINAMIC PUMPPerko D. 1 , Hočevar S. 1 , Levec J. 1,21 Laboratory for Catalysis and Chemical Reaction Engineering, National Institute ofChemistry, P.O. Box 660, SI-1001 Ljubljana, Slovenia, david.perko@ki.si2 Faculty of Chemistry and Chemical Technology, University of Ljubljana,P.O. Box 537, SI-1001 Ljubljana, SloveniaBased on the thorough CFD simulations and calculations a catalytic reactor withhigh temperature gradient is constructed. A high temperature gradient shifts thethermodynamic equilibrium of a reversible reaction to the right by continuouslyremoving the formed products from the catalyst surface. We call this type of productremoval the thermodynamic pump. Methanol synthesis is used as a model reaction.The reactor consists of two horizontal plates (120 mm x 240 mm), separated by2-10 mm: the upper one is covered by a thin layer (50-100 µm) of the methanolsynthesis catalyst (Cu/Zn/Al) and heated up to 250-270 deg. C, whilst the lower oneis cooled down to 30-50 deg. C. The gaseous phase flows between the plates in thelaminar flow regime and is exposed to a huge temperature gradient. Thehydrogenation of CO 2 to methanol and reverse water-gas shift reaction take place onthe catalyst surface. The products, methanol and water, are continuously condensedon the cooled plate. This creates lateral gradients in their concentrations (Fig. 1),which drive the gaseous methanol and water from the catalyst surface into the bulkgas phase and further down to the cooled surface.xC 0.8scooledhlajenjembrez isothermal hlajenjaxC vs. ywall0.6ravnotežje equilibriux0xxH2O CH3OH CO2 CO H2y 0 v Cicatalystcondensewall0.40.20.00.00 0.05 0.10 0.15 0.20Fig 1. Schematic view of velocity and concentration Fig 2. Conversion along the length of the reactor.profiles.In order to determine enhancement of the conversion by the thermodynamicpump, its efficiency is going to be studied under different operating parameters (inletgas-phase composition, pressure, temperature, gas-phase velocity, distancebetween plates) and compared with the system in which the bottom plate is notcooled.ym96