GB1399214A - Gas purification - Google Patents

Abstract

1399214 Purification of polluted gases H D WRIGHT 15 Aug 1972 [10 Sept 1971] 38063/72 Heading C1A [Also in Division C7] Pollutants, e.g. H 2 S, SO 2 , aldehydes, mercaptans, organic sulphides, amines, alcohols or mixtures thereof, are removed from gases by reaction with a regenerable oxidizing or reducing agent, e.g. ozone, hydrogen peroxide, hypochlorous acid and salts thereof, chlorous acid and salts thereof, chloric or perchloric acid and salts thereof quinone, chlorine dioxide, chlorine trioxide, Cl 2 , Br 2 , hypobromic acid, bromic acid salts, hypoiodous acid, permanganates, manganic salts, cobaltic salts, ferric salts, thallic salts, ceric salts, bichromates, chloroiridic salts and vanadates to yield inocuous substances by bringing the gas into contact with a semipermeable membrane, e.g. 2, which forms a surface of a chamber, e.g. module 1, to allow it to contact an aqueous solution of the oxidizing or reducing agent, e.g. 3. Preferred apparatus, Fig. 2, has a cylindrical, electrically conductive semipermeable membrane 4, e.g. a polytetrafluoroethylene membrane containing activated carbon or graphite, sealed by non-conductive impermeable end members 5, 6 and axially mounted electrode 7 and annular separator 8. Electrical contact to membrane 4 is preferably made via porous electrically conductive material 9, e.g. metal gauzes and screens or porous graphite and power source 10 regenerates the electrolyte, e.g. an aqueous alkaline H 2 O 2 solution at the same rate as it is consumed by reaction with the pollutant. The semipermeable membrane may comprise an inert, finely divided solid, e.g. activated carbon, graphite, ceria, ZnO, Al 2 O 3 , MgO or mixtures of two or more of these, dispersed through a solid, inert, hydrophobic polymer, e.g. P.T.F.E.