Abstract: The method of catalytic cleaning of exhaust gases from organics and carbon monoxide consists in that an exhaust gas is passed through a bed of deep oxidation catalyst. The process is carried out with a temperature of 250.degree.-700.degree. C. The catalyst is made up of two parts. The exhaust gas is passed through a first part of the catalyst bed, stirred and passed through a second part of the catalyst bed. The stirring is continued until the temperature drop in the stream of the gas which is being cleaned is not over 50.degree. C. at the entrance into the second part of the catalyst bed, and the flow of the gas is reversed at regular intervals during the cleaning.

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.