2 Emissions from Exhaust Aftertreatment Technology by AECC (www.aecc.be) EU Level Workshop on 2 European Commission - DG Environment Brussels, 19 September 26 Outline of the Presentation Introduction. 2 measurement. Emissions Control and 2. Technologies to reduce 2 emissions. 2 measurements during recent AECC Test Programmes. Conclusions. 1
+ ½ O 2 2 Pt - 3 x adsorber Support Red. Pt Support x adsorber Association for Emissions Control by Catalyst (AECC) AECC members: European Emissions Control companies Technology for exhaust emissions control on all new cars (OEM and Aftermarket) and an increasing number of commercial vehicles and motorcycles AECC Core Technologies The chemistry, physics, engineering and production technology for catalysis, media for filtration and catalyst support and speciality materials used in automotive catalysis, filtration and filter regeneration. Three Way Catalyst Oxidation Catalyst x Adsorber Lean x Adsorption Rich - 3 N x 2 x Reduction Selective Catalytic Reduction Particulate Trapping and Regeneration 4 + 4 NH 3 + O 2 4 N 2 + 6 H 2 O 6 2 + 8 NH 3 7 N 2 + 12 H 2 O Regenerated filter NH 3 x Filtration mode Filter Regeneration 2
25 Road Transport emissions Motorcycles, 4-stroke, gasoline Heavy-duty 2-stroke (mopeds etc), gasoline Light-duty Light-duty Motorcycles, 4-stroke, gasoline 4 stroke motorcycles Leaded gasoline exhaust PM1 Light Duty GDI Leaded gasoline exhaust Light Duty GDI Heavy Duty 2 stroke motorcycles/moped Heavy-duty Light duty excluding GDI 4 stroke motorcycles 2-stroke (mopeds etc), gasoline x Heavy Duty uty excluding GDI 2 stroke motorcycles / moped Data Source: IIASA, 24 Low emissions require a whole-system approach Emission control technology Engine technology Sensors & Control Fuel & Lubricant & Reductant Quality 3
Effect of Sampling & Analysis Methods on 2 /x Ratio Source: UK Air Quality Expert Group, 24 Emission Control 2 A Diesel Oxidation Catalyst + Particulate Filter system uses the 2 to oxidise and remove the particulate matter. This can also be achieved through thermal regeneration by oxygen. Combining DOC+DPF and appropriate x reduction systems, low levels of all pollutants can be achieved simultaneously. 4
Role of 2 for Regeneration of the Diesel Particulate Filter (DPF) Engine control To increase exhaust gas temperature Continuously Regenerating CR-DPF Oxidation Catalyst DPF Catalysed C-DPF Catalysed DPF DPF + Fuel-Borne Additive (Off-line electrical regeneration) Emission Control 2 Both x storage and SCR x reduction systems benefit from an appropriate 2 :x ratio. x-storage catalysts remove the initially formed 2 by storage and subsequent reduction. SCR removes 2 by reaction with and ammonia. 5
Role of 2 in the x-storage Process Lean Red. Rich + ½ O 2 3-2 Pt x adsorber - 3 N x 2 x Pt adsorber Support x Adsorption Support x Reduction and 2 are stored as nitrates. The storage efficiency is considerably higher for 2 than for, so an oxidation function is used to increase the fraction of 2 in the feed gas. 2 is then preferentially stored on the catalyst. The stored 2 is then converted to N 2 in the reduction phase. Partial Removal of and 2 x; 2 [ppm] 8 6 4 2 x_vk [ppm] x_nk [ppm] 2_vK_f [ppm] 2_nK_f [ppm] 2 before catalyst Ratio 2/x [%] 25 3 35 4 45 5 55 6 65 7 75 1 time [s] 4 75 3 5 2 25 1 2 after catalyst ratio_2_x_vk_lean [%] ratio_2_x_nk_lean [%] ratio_2_x_nk [%] 25 3 35 4 45 5 55 6 65 7 75 time [ s ] Source: AECC Member 6
Complete Removal of and 2 8 x_vk [ppm] x; 2 [ppm] 6 4 2 2 before catalyst x_nk [ppm] 2_vK_f [ppm] 2_nK_f [ppm] 35 45 55 65 75 85 95 time [s] 2 after catalyst Source: AECC Member SCR Working Principle Source: AECC Member 7
A Heavy-duty SCR catalyst system urea (NH 2 ) 2 CO SCR catalyst (S) 4NH 3 + 4 + O 2 4N 2 + 6H 2 O 2NH 3 + + 2 2N 2 + 3H 2 O 8NH 3 + 6 2 7N 2 + 12H 2 O exhaust gas V H S O Oxidation catalyst (V) 2 + O 2 2 2 4HC + 3O 2 2CO 2 + 2H 2 O 2CO + O 2 2CO 2 Hydrolysis catalyst (H) (NH 2 ) 2 CO + H 2 O 2NH 3 + CO 2 Oxidation catalyst (O) 4NH 3 + 3O 2 2N 2 + 6H 2 O Source: AECC Member Emissions (Post CUC) [g/kw.h] / 2 Emissions form Euro III Heavyduty engine with CR-DPF and Urea SCR 2 18 16 14 12 1 8 6 4 2 IVECO engine with DPF followed by SCR with clean-up catalyst on ETC 2 6 6 12 18 Time [s] Source: AECC HD programme, 22 8
Passenger Car 2 and x Emissions on NEDC Cycle average and 2, NEDC tests at 4km.25.2 2 Euro 4 diesel x limit.15 g/km.1 Euro 4 gasoline x limit.5. Gasoline Diesel A Diesel B Diesel with DPF Source: AECC LD programme, 25 Passenger car 2 and x emissions on Artemis Cycles 12 1 NEDC Artemis Urban Artemis Extra-Urban Artemis Highway 2 8 mg/km 6 4 2 Gasoline Diesel A Diesel B Diesel with DPF Gasoline Diesel A Diesel B Diesel with DPF Gasoline Diesel A Diesel B Diesel with DPF Gasoline Diesel A Diesel B Diesel with DPF Source: AECC LD programme, 25 9
Conclusions Measurement of 2 is an issue. Creation of some 2 in an upstream part of the exhaust system is an essential part of effective emissions control. Systems can be optimised to minimise excess 2 production. x emissions controls will minimise both 2 and total x emissions. Thank you for your attention www.aecc.be 1