Tekniske løsninger på NO 2 -forureningen SCR Technology - Selective Catalytic Reduction (SCR) Luft- og støjforureningen i Danmark, 16. november 2011 Ernst Bjerregaard Emitec Denmark A/S ernst.bjerregaard@emitec.com
SCR teknologien Praktiske eksempler på brugen af SCR Omkostningsniveau Indhold 2
SCR teknologien Praktiske eksempler på brugen af SCR Omkostningsniveau 3
Different NOx reduction technologies available, the most important ones being: General improvement of engines Exhaust Gas Recirculation (EGR) Selective Catalytic Reduction (SCR) SCR Basics A means of converting nitrogen oxides (NO and NO 2 ), also referred to as NOx, into nitrogen and water with the aid of a catalyst Technology itself more than 30 years old Typical applications Automotive Marine Locomotive Power plants Built-in from start or retrofit onto existing vehicles NOx reduction technologies 4
60 Engine Technology Euro V/VI Engine Technology Euro IV Fuel Consumption PM [mg/kwh] 30 EU V EU IV EU VI High Efficient SCR 0 1 2 3 4 NO x [g/kwh] 6 Exhaust Emission Legislations & Technologies Example : Commerical Vehicle - ETC
Vertraulich / Confidential Copying of this document and giving it to others is strictly forbidden without express authority of Emitec! 4 NH 3 + 4 NO + O 2 4 N 2 + 6 H 2 O 2 NO 2 + 2 NO + 4 NH 3 4 N 2 + 6 H 2 O Ammonia adsorbs on the surface and reacts with NOx from the gas phase. The final product is nitrogen and water NO x (g) NH 3 (g) N 2 (g) + H 2 O (g) NH 3 (ads) SCR catalyst SCR reaction 6
Urea CO(NH 2 ) 2 Carrier of ammonia AdBlue Quality according to DIN 70070 32,5 % BW dissolved in water Freezing point -11 C Non toxic, used as fertilizer Urea is converted into ammonia and nitrogen Reducing agent 7
SCR System overview 8
Activity, NOx conversion Optimal SCR region Low T region High T region NH 3 oxidation 200 300 400 500 600 Temperature Typical SCR activity window for vanadium based catalyst
Typical NOx conversion ratio for SCR: 80 90 % Test conditions: ESC: European Steady-state Cycle ETC: European Transient Cycle NEDC: New European Driving Cycle Example of measurements done on test bench, ETC test cycle: NOx raw emission NOx out NOx emission(g/kwh) 9.764 1.463 Conversion ratio: 85 % The conversion ratio can be adjusted with the amount of urea injected but has to be balanced with the ammonia slip Conversion ratio 10
SCR teknologien Praktiske eksempler på brugen af SCR Omkostningsniveau 11
In connection with the Olympic Games in Beijing 2008 it was decided to equip the buses for the olympic games with SCR in order to reduce NOx emission Supplier of engines: Yuchai SCR dosing system: Emitec Air Assisted Urea dosing system Buses for the Olympic Games Beijing 2008 12
watercooled injector LS Technology SCR catalyst hydrolysis catalyst Liebherr SCR Production System
Test Car MB Sprinter 315 CDI
SCR Controller Location of AdBlue Dosing Module integrated within the Tank + ECU
cumulative NOx emission [g] 12 10 8 6 4 Start of AdBlue Injection - 32 % 200 100 0-100 -200 AdBlue Inj. [mg/s] 2-300 0 0 200 400 600 800 1000 1200 Time [s] -400 NO X -Reduction and Dosing Strategy in NEDC EHC not Activated 16
cumulative NOx emission [g] 12 10 8 6 4 2 AdBlue Massflow Engine Out Tailpipe - 69 % 200 100 0-100 -200-300 AdBlue Inj. [mg/s] 0 0 200 400 600 800 1000 1200 Time [s] -400 NO X -Reduction and Dosing Strategy in NEDC EHC Activated 18
Vertraulich / Confidential Copying of this document and giving it to others is strictly forbidden without express authority of Emitec! SCR-Demonstrator MB Sprinter 315CDI PEMS Measurements in Berlin City Driving
Vertraulich / Confidential Copying of this document and giving it to others is strictly forbidden without express authority of Emitec! Test Cycle 1 - City Cycle Tiergarten Botan. Garten Test Cycle 2 Reference Cycle Berlin Street Map with the 2 Berlin Test Cycles
Vertraulich / Confidential Copying of this document and giving it to others is strictly forbidden without express authority of Emitec! Vehicle Speed [km/h] 60 50 40 30 20 10 Speed City Cycle 0 Vehicle Speed [km/h] 60 50 40 30 20 10 Speed Reference Cycle 0 0 500 1000 1500 2000 2500 3000 3500 Time [s] Example for the vehicle speed of the two City Test Cycles
Vertraulich / Confidential Copying of this document and giving it to others is strictly forbidden without express authority of Emitec! Temperature [ C] Temperature [ C] 240 220 200 180 160 140 120 100 240 220 200 180 160 140 120 100 T before SCR System T before SCR System City Cycle Reference Cycle 0 500 1000 1500 2000 2500 3000 3500 Time [s] Temperatures in front of the SCR System in the 2 City Test Cycles
Vertraulich / Confidential Copying of this document and giving it to others is strictly forbidden without express authority of Emitec! Berlin City Cycle Distance [km] SCR inactive NO x Emissions SCR active ~ 15.2 32.48 g 12.90 g Efficiency NO x 60,3% Berlin Reference Cycle ~ 14.6 25.55 g 9.40 g Efficiency NO x 63,2% PEMS NO x Results with and without activated SCR System Berlin City Driving
SCR teknologien Praktiske eksempler på brugen af SCR Omkostningsniveau 24
SCR catalyst Urea dosing system Canning Tank with level sensor Basic SCR System Components 25
Omtrentlige omkostninger ved eftermontering af SCR: Light Duty Vehicle: 20 35.000 Kr. Heavy Duty Vehicle: 40 50.000 Kr. Løbende omkostninger: AdBlue forbrug: Ca. 5 % af brændstofforbruget AdBlue pris: 3 6 Kr./l afhængig af volumen Omkostningsniveau 26
Spørgsmål? 27