Abstract: Gaseous products which tend to form at the anode or cathode of an electrolytic or electrochemical system in which the electrolyte is an aqueous medium may be converted into a reduction-oxidation reaction product through the action of a Contacogen. In such electrolytic systems, hydrogen is usually produced at the cathode and oxygen or other gas may be produced at the anode. By placing a Contacogen in gas receiving relation with the electrode at which a gas tends to be produced, and externally introducing a second gas into contact with the electrode gas and the Contacogen in the presence of an aqueous medium, the two gases enter into a reduction-oxidation reaction to produce a product which is electrolytically noninterferring. The Contacogen is particulate in nature and maintained in a static condition and forms the situs of reaction between the two gases in the presence of an aqueous medium.

Abstract: Sodium polysulfide is prepared by the oxidation of sodium sulfide or sodium hydrosulfide, and by using new procedures and systems described, the production of thiosulfate can be markedly reduced and, in some cases, eliminated. The oxidant is air, oxygen or oxygen in mixture with other gases, the reductant is aqueous sodium sulfide or sodium hydrosulfide and the reaction is carried out with both reactants in non-flooded contact with a solid catalyst material, of which a typical example is a particulate carbon treated with polytetrafluoroethylene (PTFE). The reaction is typically conducted at atmospheric pressure and without the application of heat, with the oxidant and the reductant being in interfacial contact with each other, but only, insofar as possible, at sites where both are simultaneously in contact with a catalyst which is prevented from being flooded by either the oxidant or reductant. Sodium polysulfide and sodium hydroxide are produced, and are useable in treatment of lignocellulose materials.

Abstract: Recovery of chemicals from a sodium sulfide containing pulping liquor which is cycled from a digester through a recovery system is effected by separating hydrogen sulfide gas, either from the cooking liquor or from various points in the recovery system, to provide a source of sulfide sulfur which is oxidized to sulfur. When separated from the cooking liquor, it is preferred that the hydrogen sulfide gas be taken from the black liquor, prior to combustion, so as to reduce the sulfidity of the liquor being burned and thereby to reduce sulfur losses in the combustion furnace and effect reduction of sulfur pollutants. Oxidation of the hydrogen sulfide gas is carried out in an aqueous medium, in the presence of a wetproofed catalyst and using air or other oxygen containing gas as the oxidant. Sour hydrocarbon gases containing hydrogen sulfide gas may also be processed in accordance with this invention to convert the sulfide sulfur to products such as elemental sulfur, sodium polysulfide and the like.

Abstract: Gaseous products which tend to form at the anode or cathode of an electrolytic or electrochemical system in which the electrolyte is an aqueous medium may be converted into a reduction-oxidation reaction product through the action of a Contacogen. In such electrolytic systems, hydrogen is usually produced at the cathode and oxygen or other gas may be produced at the anode. By placing a Contacogen in gas receiving relation with the electrode at which a gas tends to be produced, and externally introducing a second gas into contact with the electrode gas and the Contacogen in the presence of an aqueous medium, the two gases enter into a reduction-oxidation reaction to produce a product which is electrolytically noninterferring. The Contacogen is particulate in nature and maintained in a static condition and forms the situs of reaction between the two gases in the presence of an aqueous medium.