Method for cleaning process off- or engine exhaust gas

A method for the removal of particulate matter in the form of soot, ash, metals and metal compounds, together with hydrocarbons and nitrogen oxides being present in process off-gas or engine exhaust gas, comprising the steps of:

• providing a process off-gas or engine exhaust gas containing a nitrogenous reductant or adding the nitrogenous reductant to the off- or exhaust gas;
• passing the off-gas or the exhaust gas at a gas temperature of 225° C. to 550° C. through at least one filter unit each comprising at least one particulate filter and capturing the particulate matter;
• reducing amounts of soot captured on the at least one particulate filter and reducing amounts of nitrogen oxides and hydrocarbons in the off- or exhaust gas by selective catalytic reduction (SCR) with the nitrogenous reductant and by oxidation in contact with at least a first combined SCR and oxidation catalyst being coated on or inside walls at a gas inlet side of the particulate filter;
• periodically disconnecting the at least one filter unit from flow of the off- or exhaust gas;
• applying a pneumatic pulse at an outlet of the at least one particulate filter by pulse injecting air into the outlet in reverse to the previous flow of the exhaust gas and blowing off the captured particulate matter together with the heavy metals and metal compounds from the at least one particulate filter;
• and
• applying suction at the gas inlet side of the at least one particulate filter, and conveying the blown off particulate matter and heavy metals and metal compounds from the at least one particulate filter, optionally through an external auxiliary filter unit, to a container, wherein the at least first combined SCR and oxidation catalyst consists of titanium dioxide, oxides of vanadium and oxides of tungsten, and wherein a second oxidation catalyst is coated at a gas outlet side of the particulate filter, consisting of vanadium oxide and palladium in at least one of metallic form and oxide form, and titania, or consisting of vanadium oxide, tungsten oxide and palladium in at least one of metallic form and oxide form, and titania.