Membrane assisted fluidized bed reactor: Hydrodynamics, heat transfer and reactor demonstration

• Applicant: Professor Dr.-Ing. Stefan Heinrich
• Subject Area: Chemical and Thermal Process Engineering
• Term: from 2006 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 27255698

Objective:The objective of the project is to develop a new kind of reactor by integration of membranes in the fluidized bed, which will either enable full control of the reaction heat generated by controlled dozing of the limiting reactant (e.g. smart dozing of oxygen in partial oxidation reactions) or enhanced conversions and selectivity to the desired product by selective removal of one of the products (e.g. hydrogen removal in dehydrogenation reactions), and which will also give an optimal balance between the bubble-to-emulsion mass transfer and the tube-to-bed heat transfer in the fluidized bed.Procedure:Microporous non-selective membranes with different configurations (vertical or horizontal) will be integrated in the bubbling fluidized bed. The presence of membranes as internals as well as addition or removal of gas via the membranes can have significant effect on the bubble size, bubble to emulsion mass transfer, emulsion porosity, emulsion heat capacity and tube-to-bed heat transfer coefficient. The effect of presence of membranes and the gas addition or removal via the membranes on the bubble size variation at various fluidization velocities will be studied using pressure fluctuation measurements. Similarly, the effect on the emulsion phase porosity, solid concentration in the emulsion, thickness of the gas film at the heat transfer surface, heat transfer surface renewal rate by emulsion packet will be measured using optical fiber probe and effect of these properties on the immersed surface-to-bed heat transfer will be determined by simultaneous measurements of heat transfer. Finally the reactor concept will be demonstrated for partial oxidation of ethylene to ethylene oxide and the experimental results will be predicted by developing phenomenological models incorporating gas addition via the membranes. Experiments with conventional fluidized bed reactor will be carried out as reference.

• DFG Programme: Research Grants
• Participating Person: Dr.-Ing. Salim Deshmukh