Abstract: A flexible technique for modifying various chemical substances utilizes a confined path to be followed by these substances in gaseous form or in a gaseous medium. Along this path there is positioned electrically energizeable means for establishing an electric field. Also along the path there are positioned electrically energizeable means for heating the gas to crack certain constituents into free elements; for combusting certain constituents; and for attracting certain constituents through affinity. The electrical energization of these means is controllable to provide the appropriate effect on the substances in the path.

Abstract: Undesired emissions from such sources as automobile engines are controlled by providing a confined path to be followed by these, mostly gaseous substances to be controlled. Along this path there is positioned means for establishing an electric field. Preferably, in other portions of the path, there are positioned one or more of the following: means for heating the gas to crack certain constituents into free elements; means for combusting certain constituents; and means for attracting certain constituents through affinity.