No reduction with diesel fuel reformed by nonthermal hyperplasma
AssigneeGeneral Motors Corporation
InventorByong Kwon Cho
Life of this patent
Estimating the term…
Abstract
The reduction of NOx in diesel engine exhaust gas, typically at about 200° C. to 400° C., is accomplished using a dual bed NaY—CuY zeolite reduction catalyst. The effectiveness of the catalyst in reducing the nitrogen oxides is markedly increased by the separate and sequential additions of plasma reformed diesel fuel and ozone to the exhaust before it contacts the powdered catalyst. Reformed diesel fuel is obtained by withdrawing fuel from on-board storage, heating the withdrawn volume and stripping a more volatile fraction with air and passing the air/volatile diesel fuel fraction through a non-thermal plasma reactor. Ozone is obtained by blowing ambient air through a second non-thermal plasma reactor.
Claims11
A method of reducing nitrogen oxides, including NO and NO2, in an exhaust stream at a temperature above about 150° C., said method comprising:
- treating diesel fuel in a non-thermal plasma reactor to make reformed diesel fuel containing oxidized hydrocarbons;
- adding said reformed diesel fuel to said exhaust stream for the reduction of said nitrogen oxides;
- generating an ozone containing plasma separately from the making of the reformed diesel fuel and adding said ozone containing plasma to said exhaust stream for oxidation of NO to NO2, said ozone containing plasma being added to said exhaust stream separately from said plasma treated diesel fuel;
- and, thereafter
- contacting said exhaust stream with a dual bed reduction catalyst comprising at least one of NaY zeolite and BaY zeolite in the first bed and CuY zeolite in the second bed to reduce said nitrogen oxides to N2.
A method of reducing nitrogen oxides, including NO and NO2, in an exhaust stream from a diesel engine when the temperature of said exhaust stream is at a temperature at or above about 200° C., said engine having a source of hydrocarbon containing diesel fuel, said method comprising:
- withdrawing a volume of said fuel from said source and treating it in a first non-thermal plasma reactor to make a reformed diesel fuel containing oxidized hydrocarbons;
- adding said reformed diesel fuel to said exhaust stream for the reduction of said nitrogen oxides;
- generating an ozone containing plasma separately from the making of the reformed diesel fuel and adding said ozone containing plasma to said exhaust stream for oxidation of NO to NO2, said ozone containing plasma being added to said exhaust stream separately from said plasma treated diesel fuel;
- and, thereafter
- contacting said exhaust stream with a dual bed reduction catalyst comprising at least one of NaY zeolite and BaY zeolite in the first bed and CuY zeolite in the second bed to reduce said nitrogen oxides to N2.
Dependencies are inferred from the claim text.