Heat recovery from gas contg. combustible vapour or liquid drops - e.g. exhaust gas by catalytic combustion and heat transfer

摘要

Recovery of thermal energy from gas contg. combustible vapour (I) and/or drops of combustible liquid (II) is effected by contacting the gas with an oxidn. catalyst (III) to oxidise (I)/(II) and simultaneously or gradually transferring (pt. of) the heat originally present in the gas and the heat produced by oxidn. in a heat exchanger (IV). The temp. of the gas on reaching (III) is at least the min. temp. at which oxidn. can begin (i.e. the light-off temp.). (III) is supported on the heat exchange material of (IV) or on an intermediate layer (V) with large surface areas. (III) contains min. 10 wt.% Pt, Rh, Ru, Pd and/or Ir, opt. alloyed with other metals. (IV) can consist of a metal or ceramic, whilst (V) contains refractory metal oxide(s), i.e. BeO, MgO, SiO2, B2O3-Al2O3 or SiO2-Al2O3. The process is useful for recovering heat from exhaust gases.