Abstract: The present invention relates to the oxidation of organic compounds in a non-uniform fluidized solid catalyst reaction system characterized in that a temperature profile is maintained in the reaction system such that a predominance of the oxidation occurs in a higher temperature zone, unreacted organic compound is adsorbed on the catalyst surface in a lower temperature zone, direct back-circulation of catalyst is restricted between zones and catalyst containing adsorbed organic compound is circulated from the lower temperature zone to the higher temperature zone.

Abstract: A starting hydrogen sulfide-containing gas is purified by way of a two-stage oxidation to elemental sulfur with oxygen which is supplied in an amount of 100-110% of the stoichiometric quantity necessary for oxidizing hydrogen sulfide to elemental sulfur. Oxidation at the first stage is carried out in a fluidized bed of a granular catalyst containing 10-20% by mass of magnesium chromite on aluminium oxide. At the second oxidation stage, the unreacted hydrogen sulfide and oxygen from the first stage are reacted at 140.degree.-155.degree. C. in the presence of a catalyst to form elemental sulfur.The invention may be used in decontamination of natural gases high in hydrogen sulfide, gas releases of oil refinery and coke chemical plants.

Abstract: A method of preparing sulphur trioxide by the oxidation of sulphur dioxide contained in a reaction mixture in a stationary catalyst bed wherein the direction of the movement of the reaction mixture flow along the catalyst bed is reversed periodically each 10-200 minutes, or the temperature of said reaction mixture is changed in front of the catalyst bed from a temperature of 20.degree.-200.degree. C. to a temperature of 350.degree.-600.degree. C. each 10-200 minutes.