Highly efficient SCR Solution for Large Engine Application by modular System Set-up - universal and cost efficient

Transcription

1 Highly efficient SCR Solution for Large Engine Application by modular System Set-up - universal and cost efficient Klaus Müller-Haas Rolf Brück Andreas Scheeder EMITEC Gesellschaft für Emissionstechnologie mbh 5 TH AVL LARGE ENGINE TECHDAYS 09 th & 10 th May 2012

2 Introduction Requirements and Demands for Large Engine SCR- Technology Components for DeNOx Technology Multi-Pipe Decomposition System for Large Engines SCR catalyst technology and optimization Outlook Content

3 PM [g/kwh] 0,2 PM [g/kwh] 0,2 NOx [g/kwh] 6 C&I currently no EU limits under consideration 0,1 Stationary currently no EU limits regulated by TA-Luft 8 C&I 2011 Tier 4i 2011 Tier 4i < 900 kw 2016 Stage IV (CCNR) NOx [g/kwh] Tier 4 Tier Stage IIIB 2016 Stage IV NOx (Euromot) [g/kwh] 0, Tier 4i > 900 kw Stationary Tier 4 Tier 4 NOx [g/kwh] 0, Stage IIIB (Euromot) 2012 Stage IIIB (CCNR) 2011 Tier 4i 0, Tier 3 Rail (Switch) Marine Rail (Switch) Marine 0,2 PM [g/kwh] 0,2 PM [g/kwh] (CCNR) Central Commission for Navigation on the Rhine EU and US Emission Legislation for Different Applications EU : S < 15ppm (2014) IMO: S < 5000ppm (2020) Emission Control Area: S < 1000ppm (2015)

4 relative torque nonroad vehicles and industrial equipment relative speed marine engines 1.2 less than 24m; except tug/push boats HD, constant speed for marine propulsion C1 E1 E C C C C high > 500 C constant speed 1.2gensets, pumps Marine: 1.2 for test cycles based on propeller curve C2 E4 E C C C high 0.2 > 500 C C 0.5 constant speed 1.2 Genset, units with intermitted load rail engines D1 D2 high > 500 C C F C C C high 0.2 > 500 C Classification of Test Cycles according to ISO 8178 and Exhaust Gas Boundary Conditions

5 Introduction Requirements and Demands for Large Engine SCR- Technology Components for DeNOx Technology Multi-Pipe Decomposition System for Large Engines SCR catalyst technology and optimization Outlook Content

6 Low Temperature Mid range High Injection of reduction agent C C decomposition of reduction agent high > 500 C Uniformity Substrate/ Catalyst optimization Thermodynamic Challenges for DeNOx-Systems

7 EMITEC Technology Air Assisted Dosing System Airless Dosing Systems Air Supply Exhaust Pipe Diameter Injection of Reduction Agent Needed easy in pipe installation of nozzle Droplet size Small droplets << 50µm Droplet penetration /- distribution Variation based on p, gasflow > 200 mm 400mm Emitec AdBlue-Dosing Systems

8 low gas velocity bigger droplets small droplets Principle Droplet Penetration/ Evaporation of Air-Assisted System as Function of Gas Speed

9 low gas velocity high gas velocity bigger droplets droplet penetration smaller droplets fast evaporation Principle Droplet Penetration/ Evaporation of Air-Assisted System as Function of Gas Speed

10 Air Assisted Dosing System Airless Dosing Systems Air Supply Needed Not needed (Motivation) Exhaust Pipe Diameter Injection of Reduction Agent Nozzle in gas stream e.g. Ø400 mm Nozzle outside in pipe Droplet size < 50 SMD SMD Droplet penetration /- distribution Variation based on p, flow defined spray angle, p, Scope of development for large engines Goal: optimal ammonia distribution at LARGE Ø Pipes at all operation conditions Development Scope for AL-AdBlue-Dosing Systems for Large Engines

11 Injectors (Airless, Watercooled) Inlet Modular Arrangement of Multi Dosing Pipe Outlet Multi-Pipe Decomposition System (e.g kw)

12 Introduction Requirements and Demands for Large Engine SCR Technology Components for DeNOx Technology Multi-Pipe Decomposition System for Large Engines System Layout Universal Dosing Pipe Design Function and Characterization Performance results SCR catalyst technology and optimization Outlook Content

13 Manifold with SAE-Connectors Large Engine Dosing Control Unit LE- DCU.... Dosing Pumps with Urea Pumphead (60 ltr/h and 150 ltr/h)) Injectors (Airless, Watercooled) Large Engine Airless Dosing System

14 Overview of Multi-Pipe Decomposition System

15 Introduction Requirements and Demands for Large Engine SCR Technology Components for DeNOx Technology Multi-Pipe Decomposition System for Large Engines System Layout Universal Dosing Pipe Design Function and Characterization Performance results SCR catalyst technology and optimization Outlook Content

16 Key features: usage of 6- hole injector to increase droplet uniformity penetration of droplets in flow direction towards a hot surface at low cell density MX-Metalit Substrate Design of Decomposition Pipe and Components

17 AdBlue droplet interaction on surface Adblue droplet penetration on surface evaporation & thermolysis reaction steps steps from AdBlue towards ammonia: 1. Step: evaporation of Water: {(NH 2 ) 2 CO 7H 2 O} fl {(NH 2 ) 2 CO} fl + 7 H 2 O 2. Step: thermolysis of Urea: {(NH 2 ) 2 CO} fl HNCO + NH 3 3. Step: hydrolysis of isocyanic acid: HNCO + H 2 O CO 2 + NH 3 Emitec-Technology for Optimization: Optimize Hydrolysis: Usage of Hydrolysis Catalyst / Mixer Optimize NH 3 Distribution: Optimization of Mixing pipe and mixing design Fundamantal Steps for AdBlue Decomposition and Technology for System Optimization

18 Droplet Efficiency [-] 50,8 mm 74,5 mm MX 40 cpsi no droplets Substrate Length [mm] MX-Metalit design Criteria: Influence of Matrix Length on Droplet Efficiency Temperature =300 C, Channel Velocity 10 m/s

19 potential improvement wall enthalpy ~ Characterization of Decomposition Pipe

20 to be avoided Design of Decomposition System Source: AVL

21 wetted MX-front face as function of injector distance 1,0 10 0,8 0,6 0, ~ Distance Injector-Tip to MX-Front Face [mm] l Relative Spray Load at MX-Metalit Front Face depending on Injector Distance

22 Injection on MX-Front Face Basic Investigations without Hydrolysis Catalyst Investigations of Deposit Formation

23 Installation of AdBlue-Injector Flow Straightener Burner MX- Substrate Decomposition Pipe U-Pipe to simulate inlet flow condition Parameter: AdBlue-Dosing Rate Gas Flow Rate Gas Temperature Characterization of Decomposition Pipe MX- Substrate

24 start of deposition dosing rate to high dosing rate reduced after 2 hrs after 8 hrs after 6 hrs no deposition Deposition Test at Dosing Pipe

25 increase of dosing rate long medium short robust to remove more than 7 g/kwh NO x increase of AdBlue-Loading Capacity of Dosing Pipe as Function of Temperature and Injector Distance

26 Key features: usage of 6- hole injector to increase droplet uniformity penetration of droplets in flow direction on hot surface usage of a low cell density MX-Substrate with hydrolysis coating excellent heat transfer reduction of droplet surface tension inlet flow support droplet break up accelerate evaporation start hydrolysis process high degree for NH 3 -NO x -mixing downstram very good heat transfer coefficient at blade TiO 2 -Coating supports droplet break up and hydrolysis process Design of Decomposition Pipe: MX-Metalit with Hydrolysis Catalyst

27 Introduction Requirements and Demands for Large Engine SCR Technology Components for DeNOx Technology Multi-Pipe Decomposition System for Large Engines System Layout Universal Dosing Pipe Design Function and Characterization Performance results SCR catalyst technology and optimization Outlook Content

28 Low Temperature Mid range High Injection of reduction agent C C decomposition of reduction agent high > 500 C Uniformity to be perfect (goal = UI.NH 3 = 1,0) Substrate/ Catalyst optimization Robust System performance over lifetime (degradation) Thermodynamic Challenges for high Efficient DeNOx-Systems

29 92% 90% 88% 86% 84% 82% 80% 78% 76% 74% 72% 70% UI = 1,0 UI = 1,0 UI = 1,0 ALPHA = 0,8 ALPHA = 0,85 ALPHA = 0,9 DeNO x -Function depending on NH 3 -Uniformity and Catalyst Stage (Assumption homogeneous flow distribution)

30 catalyst divided in slices Inlet Outlet eta.nox Alpha = 0,9 UI.NH 3 = 1,0-20% -20% -20% -20% -20% -20% -20% -20% -20% -7% (NH 3 consumed) 90,0% Inlet eta.nox Alpha = 0,9 UI.NH 3 = 0,935 85,2% 4,8% NH 3 Slip Modell to predict System DeNOx Performance as Function of Uniformity and Catalyst Activity

31 92% 90% 88% 86% 84% 82% 80% 78% 76% 74% 72% 70% UI = 1,0 UI = 0,935 UI = 1,0 UI = 0,935 UI = 1,0 UI = 0,935 ALPHA = 0,8 ALPHA = 0,85 ALPHA = 0,9 DeNO x -Function depending on NH 3 -Uniformity and catalyst stage (Assumption homogeneous flow distribution)

32 92% 90% 88% 86% 84% 82% 80% 78% 76% 74% 72% 70% UI = 1,0 UI = 0,935-2,5% UI = 1,0 ALPHA = 0,8 ALPHA = 0,85 ALPHA = 0,9 UI = 0,935-5,0% UI = 1,0 UI = 0,935-8,0% aged with DF = 0,8 NH 3 -uniformity is the key for robust DeNOx Function DeNO x -Function depending on NH 3 -Uniformity and Catalyst Stage (Assumption homogeneous flow distribution)

33 Low Temperature C Mid range C High high > 500 C Injection of reduction agent decomposition of reduction agent Uniformity to be perfect (goal = UI.NH3 = 1,0) Substrate Catalyst formulation Substrate surface area (GSA) Vandium CU- Zeolithe mass transfer and GSA Vanadium Fe-Zheolithe Thermodynamic Challenges for high efficient DeNO x -Systems

34 18 [mm] LS/PE-Foil Flow Position A Position H Concentration Tracer gas [%] Radial Mixing after a substrate length of 18 mm LSPE Tracer Gas injected into a single Channel; 200kg/h; 300 C 0

35 Conversion reaction limited by mass transfer significant boost at higher where overall reaction is controlled by mass transfer Temperature [ C] NO x -Conversion as Function of Substrate Technology Standard Foil and LS-Foil

36 Introduction Requirements and Demands for Large Engine SCR Technology Components for DeNOx Technology Multi-Pipe Decomposition System for Large Engines System Layout Universal Dosing Pipe Design Function and Characterization Performance results SCR catalyst technology and optimization Outlook Content

37 0,25 0,20 Stufe IIIA PM in g/kwh 0,15 0,10 0,05 0,00 Stage IV Stage IIIB SCR > 94% NO X in g/kwh? Outlook: SCR-only with highest Efficiencies

38 NH 3 -Distribution at SCR Catalyst Inlet

39 PM in g/kwh 0,25 0,20 0,15 0,10 0,05 0,00 Stage IV Stage IIIB T [ C] cold Stufe IIIA SCR engine speed engine load T SCR in T SCR out NOx emissions engine out NOx emissions tail pipe t [s] NO X in g/kwh NRTC (α = 1,05) warm T [ C] engine speed engine load T SCR in T SCR out NOx emissions engine out NOx emissions tail pipe t [s] - SCR-only (Va-Typ, w/o EGR, w/o DOC, w/o Slip-Kat - Tailpipe: cold 0,7 g/kwh (>90%) / warm 0,18 g/kwh (>97,5%) break specific NOx [g/kwh]? break specific NOx [g/kwh] Outlook: SCR-only with highest Efficiencies

40 Modular Arrangement of Multi Dosing Pipe Thank you for your attention Dosing Unit with Hydrolysis Catalyst Simulation of the Dosing Unit Injectors (Airless, Watercooled) Dosing Pumps

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