Abstract: The invention relates to a process for thermal treatment of gas, in particular for thermal and/or catalytic after-burning of waste gas, in which the gas is conducted through a gas-permeable, in particular fibrous or porous body, which consists at least partly of material which absorbs microwaves, and in which the body is heated by irradiation with microwaves and the gas is heated when flowing through the body, by contact with said body.

Abstract: The invention relates to an arrangement for microwave radiation of materials, in particular of the starting materials for ceramic materials, alloys etc., having a conveying path that is defined at least in part by a trough or pipe arrangement, the wall of which has a specific microwave-absorption capacity, a resonator surrounding at least a length of the wall, and at least one generator for generating the microwave radiation. In order to enable adjustment of the heating and the radiation dosing of the microwave-treated materials independently of one another, it is proposed according to the invention that the wall of the trough or pipe arrangement (1; 9.1 to 9.3) has different microwave-absorption properties along its length.