Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

POTENTIAL OF WOWEN FIBROUS CATALYTIC CLOTHSIN FLOW REACTORUri Matatov-Meytal and Moshe SheintuchPP-III-13Chemical Engineering, Technion-Israel Institute of Technology, Haifa, Israel 32000Fibrous woven catalytic cloths 1 form a special category of structured catalysts and withtheir unique ability to combine an open macrostructure with mechanical flexibility would besuitable for design of new kinds of reactors. A novel flow reactor with rolled fibrous catalyticcloth was proposed to carry out a gas-liquid reactions with hydrogen pre-dissolved in theliquid-phase at elevated operating pressure prior to entering into catalytic reactor 2 .The hydrogenation of nitrate in water (reaction 1) over most active 2wt%Pd-0.6wt%Cucatalyst supported on activated carbon cloths (ACC, Figure 1a) in this reactor (Figure 1b andc) at 25 C, shows selectivity up to 84% toward nitrogen at nitrate conversion up to 93%.(1)→→a b cFigure 1. Typical SEM image of ACC (a), radial flow reactor with catalytic cloth (b) and schematic diagram ofthe experimental nitrate hydrogenation test unit (c).The aim of this work is to highlight the potential benefits of novel radial-flow reactor withfibrous catalytic cloths as compared to pellet or monolith for water treatment. To comparewoven cloths with pellets or monoliths, we use a merit index that accounts for a tradeoffbetween mass transfer and pressure drop performances:-ln(1-X)/∆P/(ρ u 2 ) =dS v Sh/2f ReSc =dS v k m /2fu (2)where k m – liquid/solid mass-transfer coefficient for liquid reactant (m/s); ∆P – pressure drop(Pa), X – nitrate conversion; ρ – bulk density of catalytic bed (g/cm 3 ); S v – external surfacearea per unit volume of bed (m –1 ) and u – superficial flow velocity (m/s).Woven cloths have a specific geometric structure (Figure 1a), containing tows, which arebundles of arrays of aligned filaments with pores (openings) results from the interlacing oftwo adjacent warp and weft tows. Results of experimental measurements of pressure drop327