Method of reducing NOx and particulates from internal combustion engines
View Patent ↗Oxides of nitrogen are adsorbed onto the surfaces of, and particulates are trapped in, pores of channels ( 130, 133, 139 - 151 ) in a porous, interdigitated ceramic particulate filter ( 57, 100 ) that has relative rotation with respect to a gas inlet distributor ( 76, 101 ). The distributor has a baffle ( 85 ) or ribs ( 121, 122 ) that causes constantly flowing engine exhaust ( 53 ) to enter the filter channels over a large portion of a revolution of the adsorption bed or the distributor, and causes constantly flowing syngas ( 54 ) to thereafter pass through those passages during a small portion of each revolution. Either the inlet gas distributor ( 101 ) or the filter bed ( 57 ) may be rotated to distribute the gases. Dual, alternately regenerated filters ( 35, 36 ) may be used.
1. A method of reducing both NO x and particulates in the exhaust of hydrocarbon-burning, internal combustion engines, comprising:
providing in the exhaust stream of an internal combustion engine at least one porous, interdigitated ceramic filter including a plurality of inlet channels and a plurality of outlet channels contiguous with said inlet channels, and having NO x adsorbent material and NO x reduction catalyst disposed on or in at least one of (a) on the surfaces of said channels or (b) within the pores of said filter or (c) within the material of which said filter is composed; and
alternatively providing to each of said inlet channels syngas and said exhaust in an interleaved fashion, thereby to regenerate said NO x adsorbing material and to catalytically burn particulates trapped in said filter, wherein both syngas and said exhaust are simultaneously provided to said filter.
2. The method of claim 1 , wherein the NO x adsorbent material comprises barium carbonate.
3. The method of claim 1 , wherein the NO x reduction catalyst comprises platinum.
4. The method of claim 1 , wherein syngas is provided to between 0.5% and 50% of said inlet channels.