Abstract: A process for recycling waste sulfuric acid by decomposing organic contaminants by use of light energy, comprising exposing a waste sulfuric acid containing contaminants to a focused radiation emission having an irradiation intensity within the range of from 0.01 to 100 MW/m.sup.2 in a reaction chamber shaped as a directly-absorbing receiver, wherein the chamber is maintained at a temperature within the range of from 200.degree. C. to 1000.degree. C. to form sulfur trioxide and water as sulfuric acid decomposition products. The process also includes forming sulfur dioxide and oxygen, starting materials for sulfuric acid, by cleavage of the decomposition product sulfur trioxide by maintaining the reaction chamber at a temperature between 400.degree. C. and 1500.degree. C. The process, particularly adapted for irradiations with direct solar radiation.

Abstract: A closed-cycle multi-step thermochemical process is described for the production of hydrogen and oxygen from water. The disclosed process utilizes auxiliary compounds of the system iron-chlorine. By using the following two basic process steps:A. reacting an iron oxide with hydrogen chloride or a mixture of hydrogen chloride and chlorine to form iron (II) chloride or iron (III) chloride andB. reacting iron or iron (II) oxide with water to form iron (II) oxide or iron (II) (III) oxideIt is possible to employ a variety of additional steps so that the sum total of the reaction steps consume water, produce hydrogen and oxygen and regenerate the desired starting materials within the closed system.

Abstract: A process is provided for manufacturing iron(II)chloride from iron(III)chloride. Iron(III)chloride is introduced in dimeric form into a reactor or it is vaporized into the dimeric form in the reactor. The dimeric iron(III)chloride vapor rises into the upper part of the reactor where it is completely condensed to the monomeric form. The condensed monomeric iron(III)chloride falls within the reactor to the lower part of the reactor where it is again vaporized. From this reacting circulating system of iron(III)chloride, solid iron(II)chloride is left in the lower part of the reactor. The solid iron(II)chloride is then removed from the reactor.

Abstract: Decomposition of water to hydrogen and oxygen with the aid of a thermochemical cyclic process based upon the iron/chlorine system by reduction of FeCl.sub.2 in the presence of H.sub.2 to Fe, oxidation of the Fe with steam to Fe.sub.3 O.sub.4, treatment of the hot Fe.sub.3 O.sub.4 with steam and chlorine to obtain oxygen, conversion of themixture of iron oxides so obtained with hydrogen chloride to FeCl.sub.2 and recycling of the FeCl.sub.2 to the reduction stage, wherein a part of the heat required for the process is supplied by heating the hydrogen and steam in indirect heat exchange with a hot coolant from a high temperature nuclear reactor. The conversion of the iron oxides to FeCl.sub.2 is carried out via the intermediate stage of dimeric FeCl.sub.3 and it is thus possible to convey the solid reaction products by free fall through the reaction zones.

Abstract: A process for the dissociation of water into hydrogen and oxygen in a multi-stage closed cycle process using a system involving at least one metallic element having multiple valency and at least one halogen, characterized in that a halide of the multiple valency metallic element is subjected to a mixture of steam and hydrogen converting the halide to a mixture of the metallic element and at least one oxide thereof, said latter mixture is subjected to steam to produce a mixed valency oxide of the metallic element accompanied by the liberation of hydrogen, and said mixed valency oxide is then subjected to a hydrogen halide to convert it back to the said metallic halide with the liberation of oxygen.