Hydrogen prodn. from water by cyclic thermochemical process - by reaction with sulphur dioxide, ferroso ferric oxide and iron disulphide

摘要

H2 prodn. from H2O by a cyclic thermochemical process involves the following reactions: (a) reaction of water with SO2 to give S and H2SO4, (b) decompsn. of the latter to SO2 water and oxygen, (c) reaction between Fe3O4, FeS2 and S to produce FeS and SO2 and (d) evolution of hydrogen and regeneration of FeS2 and Fe3O4 by reaction FeS with water. Reaction (a) is exothermic and is carried out at 1-110 bar in the presence of MeOH and/or alkali sulphate (I) or 200-350 bar in the absence of MeOH of (I) and at a temp. at which the S is obtd. in liquid form. The H2 and O2 are removed from the process and the other prods. are recycled. The heat e.g. from a nuclear reactor, can be used more efficiently than in the process employing Fe-Cl cpds and highly pure H2 is obtd.