Exhaust treatment system and method for treatment of an exhaust stream

Patent metadata

Field	Value
Publication number	US-10626769-B2
Application number	US-201816032706-A
Country	US
Kind code	B2
Filing date	Jul 11, 2018
Priority date	Feb 28, 2014
Publication date	Apr 21, 2020
Grant date	Apr 21, 2020

Abstract

An exhaust treatment system comprising: a first dosage device, arranged to supply a first additive into said exhaust stream; a first reduction catalyst device, downstream of said first dosage device arranged for reduction of nitrogen oxides in said exhaust stream through the use of said first additive; a particulate filter, at least partly comprising a catalytically oxidizing coating, which is downstream of said first reduction catalyst device to catch soot particles, and to oxidize one or several of nitrogen oxide and incompletely oxidized carbon compounds in said exhaust stream; a second dosage device, downstream of said particulate filter to supply a second additive into said exhaust stream; and a second reduction catalyst device, downstream of said second dosage device for a reduction of nitrogen oxides in said exhaust stream, with the use of at least one of said first and said second additive.

First claim

What is claimed:

1. An exhaust treatment system, arranged for treatment of an exhaust stream, which results from a combustion in a combustion engine, said system comprising:
a first dosage device, arranged to supply a first additive comprising ammonia (NH 3 ) into said exhaust stream;
a first reduction catalyst device, arranged downstream of said first dosage device, and arranged for reduction of nitrogen oxides NO x in said exhaust stream through the use of said first additive, wherein said first reduction catalyst device comprises a first slip-catalyst (SC1), arranged for at least one of a reduction of nitrogen oxides NO x or an oxidation of a residue of additive in said exhaust stream;
a particulate filter, at least partly comprising a catalytically oxidizing coating, which is arranged downstream of said first reduction catalyst device, and is arranged to catch and oxidize soot particles, and to oxidize one or several of nitrogen oxide NO and incompletely oxidized carbon compounds in said exhaust stream;
a second dosage device, arranged downstream of said particulate filter, and arranged to supply a second additive into said exhaust stream; and
a second reduction catalyst device, arranged downstream of said second dosage device, and arranged for reduction of nitrogen oxides NO x in said exhaust stream through the use of at least one of said first or said second additive.

2. An exhaust treatment system according to claim 1 , wherein said first reduction catalyst device comprises a first selective catalytic reduction catalyst (SCR 1 ) integrated downstream with said first slip-catalyst (SC 1 ), wherein said first slip-catalyst (SC 1 ) is arranged to oxidize a residue of additive and/or to assist said first selective catalytic reduction catalyst (SCR 1 ) with an additional reduction of nitrogen oxides NO x in said exhaust stream.

3. An exhaust treatment system according to claim 1 , wherein said first reduction catalyst device comprises a first selective catalytic reduction catalyst (SCR 1 ), followed downstream by said first slip-catalyst (SC 1 ) arranged separately, wherein said first slip-catalyst (SC 1 ) is arranged to oxidize a residue of additive and/or to assist said first selective catalytic reduction catalyst (SCR 1 ) with an additional reduction of nitrogen oxides NO x in said exhaust stream.

4. An exhaust treatment system according to claim 1 , wherein said first slip-catalyst (SC 1 ) is integrated downstream with a first selective catalytic reduction catalyst (SCR 1 ), wherein said first slip-catalyst (SC 1 ) is arranged to oxidize additive and/or to assist said first selective catalytic reduction catalyst (SCR 1 ) with a reduction of nitrogen oxides NO x in said exhaust stream.

5. An exhaust treatment system according to claim 1 , wherein said first slip-catalyst (SC 1 ) is followed downstream by a separate first selective catalytic reduction catalyst (SCR 1 ), wherein said first slip-catalyst (SC 1 ) is arranged to oxidize additive and/or to assist said first selective catalytic reduction catalyst (SCR 1 ) with a reduction of nitrogen oxides NO x in said exhaust stream.

6. An exhaust treatment system according to claim 1 , wherein said first reduction catalyst device further comprises an additional first slip-catalyst (SC 1b ) arranged for at least one of a reduction of nitrogen oxides NO x or an oxidation of a residue of additive in said exhaust stream.

7. An exhaust treatment system according to claim 6 , wherein said first slip-catalyst (SC 1 ) is integrated downstream with a first selective catalytic reduction catalyst (SCR 1 ) and integrated downstream with the additional first slip-catalyst (SC 1b ), wherein said first slip-catalyst (SC 1 ), and/or said additional first slip-catalyst (SC 1b ), is arranged to oxidize additive, and/or to assist said first selective catalytic reduction catalyst (SCR 1 ) with a reduction of nitrogen oxides NO x in said exhaust stream.

8. An exhaust treatment system according to claim 6 , wherein said first slip-catalyst (SC 1 ) is followed downstream by a separate first selective catalytic reduction catalyst (SCR 1 ) and followed downstream by said additional first slip-catalyst (SC 1b ) arranged separately, wherein said first slip-catalyst (SC 1 ), and/or said additional first slip-catalyst (SC 1b ), is arranged to oxidize additive, and/or to assist said first selective catalytic reduction catalyst (SCR 1 ) with a reduction of nitrogen oxides NO x in said exhaust stream.

9. An exhaust treatment system according to claim 6 , wherein said first slip-catalyst (SC 1 ) is integrated downstream with a first selective catalytic reduction catalyst (SCR 1 ) and followed downstream by said additional first slip-catalyst (SC 1b ) arranged separately, wherein the first slip-catalyst (SC 1 ), and/or the additional first slip-catalyst (SC 1b ), is arranged primarily to reduce nitrogen oxides NO x and secondarily to oxidize additive in the exhaust stream.

10. An exhaust treatment system according to claim 6 , wherein said first slip-catalyst (SC 1 ) is followed downstream by a separate first selective catalytic reduction catalyst (SCR 1 ) integrated downstream with said additional first slip-catalyst (SC 1b ), wherein the first slip-catalyst (SC 1 ), and/or the additional first slip-catalyst (SC 1b ), is arranged primarily to reduce nitrogen oxides (NO x ), and secondarily to oxidize additive in the exhaust stream.

11. A method for treatment of an exhaust stream, which results from a combustion in a combustion engine, said method comprising:
controlling a supply of a first additive comprising ammonia (NH 3 ) into said exhaust stream through the use of a first dosage device, wherein said supply of said first additive impacts a reduction of nitrogen oxides NO x in said exhaust stream, through the use of said first additive in at least one first reduction catalyst device, arranged downstream of said first dosage device, wherein said first reduction catalyst device comprises a first slip-catalyst (SC1), arranged for at least one of a reduction of nitrogen oxides NO x or oxidation of a residue of additive in said exhaust stream;
catching and oxidizing of soot particles, and oxidizing of one or several of nitrogen oxide NO and incompletely oxidized carbon compounds in said exhaust stream, through the use of a particulate filter, at least partly comprising a catalytically oxidizing coating, which is arranged downstream of said first reduction catalyst device; and
controlling supply of a second additive into said exhaust stream through the use of a second dosage device, arranged downstream of said particulate filter, wherein said supply of said second additive impacts a reduction of nitrogen oxides NO x in said exhaust stream, through the use of at least one of said first or said second additive in a second reduction catalyst device, arranged downstream of said second dosage device.

12. A method according to claim 11 , wherein said first reduction catalyst device comprises a first selective catalytic reduction catalyst (SCR 1 ) integrated downstream with said first slip-catalyst (SC 1 ), wherein said first slip-catalyst (SC 1 ) is arranged to oxidize a residue of additive and/or to assist said first selective catalytic reduction catalyst (SCR 1 ) with an additional reduction of nitrogen oxides NO x in said exhaust stream.

13. A method according to claim 11 , wherein said first reduction catalyst device comprises a first selective catalytic reduction catalyst (SCR 1 ), followed downstream by said first slip-catalyst (SC 1 ) arranged separately, wherein said first slip-catalyst (SC 1 ) is arranged to oxidize a residue of additive an

Assignees

• Scania Cv Ab

Inventors

• Nilsson Magnus
• Birgersson Henrik

Classifications

• F01N2900/04

  Methods of control or diagnosing · CPC title

• B01D53/9409

  Nitrogen oxides · CPC title

• F01N13/0093

  the purifying devices are of the same type · CPC title

• F01N2570/14

  Nitrogen oxides · CPC title

• F01N3/2066

  Selective catalytic reduction [SCR] · CPC title