Exhaust Gas Cleaning Systems. (Scrubber / SCR) Dual Fuel Engines

Transcription

1 Exhaust Gas Cleaning Systems (Scrubber / SCR) Dual Fuel Engines

2 Agenda Legislation Sulfur Limits Scrubber Systems Legislation NOx SCR System

3 Legislation Sulphur Limit Requirements 5,0% global S u lp h ur C o n ten t in fuel in % 4,5% 4,0% 3,5% 3,0% 2,5% 2,0% 1,5% 1,0% 0,5% actual legislation SOx-ECA EU ports USA 200nm California In SOx-Emission-Control-Areas (SECAs) 1,50 % ( ppm) vor dem ,00 % ( ppm) ab ,10 % (1.000 ppm) ab 2015 Alternative Verfahren (z. B. Scrubber) sind zulässig 0,0% year

4 Actions to reduce SO x emission Primary Action Fuel Conversion Fuel Switching Secondary Action Exhaust Gas Cleaning Systems (Scrubber) The IMO and EPA both recognize Exhaust Gas Cleaning Systems (EGCS) as acceptable alternative to low sulfur fuels.

5 Different Scrubber Systems Wet Scrubber Open loop Closed loop Hybrid system Dry Scrubber

6 Open Loop Scrubber (wet system) Scrubbed Exhaust Gas Control Cabinet Exhaust Gas Pump Control Water / Exhaust Gas Monitoring Venting Water Monitoring De-aeration Water Treatment Water Monitoring Sludge Tank

7 Alkalinity / NO x emission in the Baltic Sea Alkalinity ifs2007/en_gb/ship_emissions/_print/

8 Pros & Cons open loop system Advantages of the Open Loop System The process requires no hazardous chemicals, seawater is the only scrubbing agent. The system has fewer components than other wet systems. Disadvantages of the Open Loop System Operation in brackish or fresh water or in high water temperatures can inhibit scrubbing of SO x. The discharge of effluent with acid ph may be restricted in some regions, therefore it may require a switchover to low sulphur fuel or an alternative scrubbing system.

9 Closed Loop Scrubber (wet system) Scrubbed Exhaust Gas Exhaust Gas Pump Control Water / Exhaust Gas Monitoring Pump (Optional) Fresh Water Control Cabinet NaOH Holding Tank (Optional) Tank Water Treatment Sludge Tank

10 Pros & Cons closed loop system Advantages of the Closed Loop System The system can operate in all regions regardless of seawater alkalinity or temperature. Effluent can be stored on board until a possibility of discharging in the next harbour can be used. Disadvantages of the Closed Loop System The system has more components than an open loop system. The system requires a constant supply of sodium hydroxide solution, a hazardous substance requiring special handling, care and cost. In addition, the use of caustic soda chemicals increase the effort to gain regulatory approval.

11 Hybrid Scrubber (wet system) Scrubbed Exhaust Gas Pump (Optional) Exhaust Gas Pump Control Water / Exhaust Gas Monitoring Close Loop Open Loop Control Cabinet Fresh Water NaOH Water Treatment Tank Sludge Tank

12 Pros & Cons hybrid system Advantages of the Hybrid System The system can operate in all regions regardless of seawater alkalinity or temperature. Disadvantages of the Hybrid System The system requires the most components of any wet option. Highest price of wet systems.

13 Dry System Flow Chart.jpg Granulate

14 Pros & Cons dry system Advantages of the dry system include the following: The system does not produce any liquid effluent for overboard discharge. The system can reduce NO x emissions. Temperature stays constant Possibility to install a SCR after the Scrubber Possibility to use more residual heat Disadvantages of the dry system include the following: The ship must have suitable storage and handling arrangements to accommodate the dry bulk reactants and products, as well as a reliable supply of materials. Increased costs from use of calcium hydroxide for SO x abatement. Size and weight of the scrubber.

15 Dry Scrubber Caterpillar Motoren Rostock CMR 24 MW dry scrubber Marine application MS Timbus 3,6 MW engine power

16 Comparison of different scrubber systems Vessel Type: Cargo Ship Operating Aera: ECA Zone Engine Type: MaK 8 M 25 / 2320 kw Fuel Oil: Heavy Fuel Oil (S = 2,7%) Exhaust gas flow rate: kg/h Exhaust gas temperature: 325 C Specific fuel consumption: 181 g/kwh Operating time: 240 h at 85% engine load

17 Comparison Comparison of: Dry System (C) Wet System (H) Wet System (A) Engine: dimension: MaK 8M25C / kw Height H: 8800 mm 7020 mm 4400 mm Width W: 4680 mm 3300 mm 2900 mm Length L: 3100 mm Ø 1750 mm Ø 1500 mm weight: dry: 42 t 4,32 t 4 t running: 55 t 5,82 t closed loop: operation on 10 hours residence tank: 12 t pumps: 7 t multi-cyclone: 1 t NaOH tank: 2 m³ ~ 2,5 t Holding tank: 10 m³ ~ 12 t Sludge tank: 1 m³ ~ 1,5 t piping, etc. ~ t pumps non In total 6 2 wash water supply (one stand by) 2 wash water return (one stand by) 2 reaction water pump (one stand by) 5 t closed loop: estimated water buffer tank: 5 t pumps: ~ 7 t urea tank: ~ 7 t storage tank: ~ 5 t water cleaning system: ~ 5 t piping etc. ~ t In total 9: SW/FW: 4 pieces High Pressure Pumps: 3 pieces NaOH: 1 Other: 1 material Steel SS / Super Duplex SS SS / Super Duplex SS tank included De-aeration, multi-cyclone, sludge Optional: flocculent dosing, tank, skimming tank, etc. system dry wet / hybrid wet / hybrid bypass existing existing existing operating area world wide world wide world wide energy consumption Low, 20kW several minutes per hour + exhaust gas fan Urea, storage, buffer, water cleaning system, etc. High (~ 70 kw) at 3,5% S High (~ 24 kw SW mode / ~ 14 FW mode) 100 % engine load, add. Cooling water pumps Additionally: cooling water pump

18 Comparison Comparison of: Dry System (C) Wet System (H) Wet System (A) serviceability Good Good Good service requirements Low Low Low service availability Good Good Good safety ++ + Caustic, violent reaction with water additives Lime stone consumption (Ca(OH) 2 ), discharge of gypsum, existing logistics No, only seawater in hybrid mode. SW Mode: discharge of sulphate in the sea FW Mode: caustic soda consumption, need of a discharge water storage tank Global caustic soda suppliers: AGC, Akzo, BASF, consumption 30 kg/h per MW at 3% S to 0,1% S %S (HFO) x 29 l/h per ton HFO %S (HFO) x 29 l/h per ton HFO back pressure mbar 10 mbar max 10 mbar max disposal sea / harbour Sea / harbour sea / harbour PM % reduced up to 80 % reduced up to 80 % reduced environment pollution No, gypsum for industry Sulphate into the sea Sulphate in open loop into the sea advantages SCR installation after the Scrubber if Possibility to change between open and Possibility to change between open and needed (retrofit). Robust, low maintenance, closed loop. Open loop the majority of time closed loop. low energy consumption. SCR service and closed loop while sailing in certain areas. interval longer (PM will be reduced from the scrubber) Control & monitoring Complete control system Connection for fan Temperature control Pressure control Level control Heating control Exhaust gas monitoring unit for CO 2, SO x, NO x, According to resolution MEPC 184 (59) scheme B, Using continuous monitoring SO x, CO 2, and NO x emission. Standard control system. Gas analyser: SO 2, CO 2 and optional NO x Water analyser: PH, PAH, Turbidity The gas analyser do have a probe, particle filter, heated hoze an a gas conditioner cabinet. This analysers are needed to control the exhaust gas cleaning system and monitoring the system to fulfil the requirements of regulations. The pumps are automatically selected based on above mentioned parameters and controlled by the PLC.

19 Consumption Wet scrubber NaOH consumption % S (HFO) x 29 l/h per ton HFO (50 % NaOH solution) 2,7 % S x 29 l/h x 86t HFO (240h at 85%) ~ 6,5 t NaOH Fresh water closed loop: 76 m³/h open loop: 150 m³/h Example data Engine power: 2320 kw Load factor: 85 % Fuel consumption: 181 g/kwh Running hours: 240 h HFO: 2,7% S Sludge 1 t HFO ~ 6,3 kg PM dry ~ 10 kg PM sludge 86 t HFO (240h at 85%) ~ 860 kg sludge (at 85% particle filtration + sulphate) Dry scrubber Lime consumption 27 kg/h MW at 2,7 % S - reduce to - 0,1 % S 27 kg (CaOH) x 2,32 MW x 0,85 load x 240 h ~ kg (CaOH)

20 Challenges to integrate a scrubber system Weight and stability Water handling system Machinery and exhaust pipe arrangements Exhaust back pressure Electric power Failure modes We would like to support you

21 Necessary Information Shipping routes Operating time and load Operating time in ECA Operating time in ports (or special EC Areas) Acceptance of additives like NaOH (caustic soda) or Ca(OH)2 (lime hydrate) X-sectional drawing Ambient conditions

22 NOx reduction Selective Catalytic Reaction SCR 8M43C

23 Legislation NOx IMO, NOx-Kurve 18,0 16,0 MaK Engine Range Tier I, ab 2000 Tier II, ab ,0 Tier III, ab 2016 NOx in g/kwh 12,0 10,0 8,0 6,0 10,5 9,0 4,0 2,0 2,6 2,3 0, Drehzahl in 1/min

24 SCR system overview

25 SCR The Chemistry of NOx reduction Step 1: Hydrolysis of Urea Urea Solution (CO (NH2)2 + H2O ) Step 2: Reduction of NOx Ammonia (NH3) + NOx +O2 temperature Ammonia (NH3) + CO2 SCR Catalyst Elevated N2 + H20

26 SCR Urea Consumption and Cost Calculation Necessary NOx Reduction (IMO II IMO III) appr. 8 g/kwh Urea Consumption (40% solution) l/mwh Urea Cost (300 $/t) 0,27 /kg 3,65 /MWh

27 Important values for future aftertreatment layouts TExhaust = f (TInletAir, Operating Point) Exhaust gas mass flow Engine out emissions Allowed backpressure Fuel (HFO, MDO, MGO, ULSF) Sulfur Content Catalyst poisons Lube oil Ash content catalyst poisons

28 SCR - System 375 SCR- technology for HFO Operation Exhaust Gas Temperature before SCR in c No Problems SCR Fouling 250 0,0 0,5 1,0 1,5 2,0 2,5 3,0 Sulphur Content in Fuel in %

29 Critical / important components

30 Technical Options (After Treatment view) Post Turbo SCR for SSC engines - MDO / MGO (LSF) Solution - Post Turbo SCR for SSC engines - HFO Solution with DryScrubber - Post Turbo SCR for SSC engines - HFO Solution with WetScrubber - Cooler Cooler Cooler Urea SCR Module DryScrubber Urea SCR Module Urea SCR Module Wet Scrubber Advantage lower temperature limit for catalyst operation, when running with low sulfur fuel higher durability and lifetime of catalyst smaller catalyst possible No Sox abatement technologies necessary small plant size compared to scrubber systems Disadvantage only low sulfur fuel < 0,1%-S in ECA possible Advantage High sulfur fuel >0,1%-S in ECA allowed lower temperature limit for catalyst operation, when running with dry scrubber higher durability and lifetime of catalyst smaller catalyst possible Disadvantage SOx abatement technolgie necessary Dry Scrubber large and Heavy Advantage High sulfur fuel >0,1%-S in ECA allowed Disadvantage Sulfur content might be restriced to 1% to to catalyst poising high temperature limit since SCR has to be arranged infront of the scrubbing unit low durability and lifetime of catalyst large size of catalyst due to short individual lifetime necessary SOx abatement technolgie necessary All negative points of a wet scrubbing system

31 THANK YOU For more information, please contact Steen Kjærhus Larsen Account Manager MaK Service Tel: Mobile: