Radial Reactor-Heat Exchanger for Natural Gas Combustion in a Structured Porous Metal Catalyst Bed

Abstract

A compact (0.01 m3 in volume) radial reactor for deep oxidation of methane (with a heat output of 16–30 kW) that is combined with an internal water heat exchanger is designed. The reactor contains the structured porous metal catalyst 5% (0.5% Pt/γ-Al2O3) + 65% Ni + 5% Al. The reactor performance at different heat outputs is experimentally studied. It is demonstrated that, if catalytic methane combustion is virtually complete, the fraction of heat transferred to the internal heat exchanger (to the water) is large (31–53%) and allows the reactor to reach a specific heat output up to 130 kW/m2 (on the outer surface of the catalytic heating element). The coefficients of heat transfer to the internal heat exchanger and the radial thermal conductivity of the catalyst bed are shown to theoretically strongly affect the thermal conditions in the catalyst bed. It is concluded that the proposed mathematical model fits the experimental data well.