Production of polysulfide with PTFE coated catalyst
US4024229A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 9, 1974 |
| Grant date | May 17, 1977 |
| Priority date | — |
| Expiry date | May 9, 1994 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01D1/04
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
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. Various arrangements, materials and processes are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.