Method and means for chemically modifying gases or fumes

A system for chemically modifying material from, or suspended within, gases or fumes fed through a filter, from an inlet side of the filter to an outlet side of the filter, the system comprising:

• a first electrode system positioned at the inlet side of the filter, the first electrode system comprising a first group of electrodes and a second group of electrodes located at the inlet side of the filter, wherein the electrodes of one or both of the first group and the second group are covered by a dielectric barrier, and
• a second electrode system positioned at the outlet side of the filter, the second electrode system comprising a third group of electrodes located at the outlet side of the filter, the first group, second group and third group of electrodes being connected to voltage sources to facilitate applying a high voltage between the first group of electrodes and the second group of electrodes and applying an electric field from the inlet side of the filter to the outlet side of the filter by means of a high voltage between the first and/or second group of electrodes and the third group of electrodes,
• wherein in operation, the filter being submitted to an electric plasma density such that the plasma density of the electric plasma is maximal at the inlet side of the filter.

A method for chemically modifying material from, or suspended within, gases or fumes fed through a filter, from an inlet side of the filter to an outlet side of the filter, the filter being submitted to an electric plasma having a plasma density, the method comprising:

• applying an electric field from the inlet side of the filter to the outlet side of the filter between a first electrode system positioned at the inlet side of the filter and a second electrode system positioned at the outlet side of the filter, the first electrode system comprising a first group of electrodes and a second group of electrodes located at the inlet side of the filter, and the second electrode system comprising a third group of electrodes located at the outlet side of the filter, the first group, second group and third group of electrodes being connected to voltage sources to facilitate applying a high voltage between the first group of electrodes and the second group of electrodes and applying the electric field from the inlet side of the filter to the outlet side of the filter by means of a high voltage between the first and/or second group of electrodes and the third group of electrodes during the applying an electric field,
• wherein the plasma density of the electric plasma is maximal at the inlet side of the filter.