Patent ID: 11952931
Assignee: FRAUNHOFER GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
Field: Environmental technology (Chemistry)
Classification: CPC F  Y | IPC F

Claim 20:
21. A method for exhaust emission control, the method comprising:
supplying exhaust gas to an exhaust emission control device having at least one exhaust gas line (3) such that the exhaust gas is supplied to at least one particulate filter (31) and/or at least one exhaust gas catalytic converter (32, 33);
providing a heated catalyst assembly (2) upstream of the particulate filter (31) or the exhaust gas catalytic converter (32, 33), the heated catalyst assembly (2) having a catalyst support (5) and being located in a housing (25) which has an inlet (21) and an outlet (22) and which is connected to the exhaust gas line (3) in such a way that a portion of the exhaust gas flowing in the exhaust gas line (3) is supplied through the inlet (21) into the housing (25) and is discharged from the housing (25) through the outlet (22) back into the exhaust gas line (3) downstream of the inlet (21), said portion of the exhaust gas thus traveling through the housing (25) along a path which is parallel to the exhaust gas line (3);
providing a pressure reduction device (7) in the at least one exhaust line (3), between the inlet (21) and the outlet (22) of the heated catalyst assembly (2);
supplying the heated catalyst assembly (2) within the housing (25) with fuel, and said portion of said exhaust gas, said portion of the exhaust gas being supplied to a first side of the catalyst support (5), and the fuel being supplied to a second, opposite side of the catalyst support (5), such that said portion of the exhaust gas and the fuel are supplied in opposite directions;
at least partially reacting said fuel with said portion of the exhaust gas to create reaction products for heating exhaust gas flowing downstream in the exhaust gas line (3); and
supplying the heated exhaust gas to the particulate filter (31) or the exhaust gas catalytic converter (32, 33); the method further comprising;
in a first operating state, predominantly oxidizing the fuel with the exhaust gas; and
in a second operating state, predominantly reacting the fuel to form a reformate;
wherein
the pressure reduction device (7) is configured to be closed after a cold start to establish a pressure difference between the inlet (21) and the outlet (22) to have a partial flow of the exhaust gas flow flows through the housing of the heated catalyst assembly; and
the pressure reduction device (7) is configured to be opened, if a temperature of the exhaust gas is so high such that additional heating of the exhaust emission control device is not required.