WÄRTSILÄ EXHAUST GAS CLEANING...

WÄRTSILÄ

EXHAUST GAS CLEANING

SOX/Scrubbers

30 March 2015 WÄRTSILÄ ENVIRONMENTAL SOLUTIONS PRODUCTS / MORTEN LETNES 1 © Wärtsilä

NOx

Acid rains

Tier II (2011)

Tier III (2016??)

SOx

Acid rains

3.5% (2012)

ECA 0.1% (2015)

CO2

Greenhouse

gas

Under evaluation

by IMO

Emissions and Environment

2 © Wärtsilä. STRICTLY CONFIDENTIAL. This document is the property of Wärtsilä Corporation and shall not be copied or reproduced without the consent of the owner.

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IMO SOx Emission Control Areas

30 March 2015

Options for SOx

CHANGE TO MGO

Run full time on Marine Gas Oil

(MGO).

Convenient

No change over

High operating cost

Future availability?

CONVERT TO LNG

Convert engines to run on gas

(LNG).

A solution which also reduces

NOx and particulates

Investment cost

LNG availability

USE SCRUBBERS

Install an exhaust gas

cleaning system (scrubber).

Works with high S HFO

Lowest total lifecycle cost

Use everywhere

Easy operation

ROI depends on fuel oil price

difference between low S fuel

oil and high S HFO

FUEL SWITCH

Switch to low sulphur fuel in

SECA.

Flexible

Small investment

High operating cost in SECA

Fuel change over procedures

Lube oil TBN management

Fuel availability?

Seawater scrubbing system chemistry

Engine Exhaust Chemistry:

S + O2 → SO2 (~95%)

SO2 + 1/2 O2 → SO3 (~5%)

Scrubber Chemistry:

SO2 + H2O → H2SO3 (Sulphurous Acid)

SO3 + H2O → H2SO4 (Sulphuric Acid)

Scrubber Reactions:

CaCO3 + H2SO3 → CaSO3 + H2O + CO2

2CaSO3 + O2 → 2CaSO4 (Calsiumsulphate)

Alkalinity (Bicarbonates (HCO3-) and carbonates (CO3

2-))

– neutralize and help to buffer the pH rapidly

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Example alkalinity level

30 March 2015 6 Wärtsilä Scrubber Systems / J.Snickars

Scrubber approval alternatives according to IMO

SCHEME A – Exhaust gas cleaning (EGC) system approval, survey and

certification using parameter and emission checks

• Compliance demonstrated by emission tests

• Possible to obtain for serially manufactured units and for a certain

production range

SCHEME B – Exhaust gas cleaning (EGC), survey and certification using

continuous monitoring of SOx emissions

• Compliance demonstrated in service by continuous exhaust gas

monitoring

Wärtsilä Scrubber Types

Yes No Partly

No Yes Partly

OPEN LOOP

Ocean-going ships

Low-alkalinity waters

and for zero discharge

Ships operating in

both types of waters

or requiring full

flexibility of operations

CLOSED LOOP HYBRID

Seawater NaOH NaOH / Seawater

Dependable on

seawater alkalinity

Zero discharge

possible

Applications

Alkaline reactant

30 March 2015 8 Wärtsilä Scrubber Systems / J.Snickars

Selection according to

the Ship Op Profile

30 March 2015

9

C:/Users/KHI007/Documents/Wartsila Ship Power Products/Exhaust Gas Treatment/SOX Scrubbing/Open loop scrubber.wmv

30 March 2015

Closed Loop Scrubber System

C:/Users/KHI007/Documents/Wartsila Ship Power Products/Exhaust Gas Treatment/SOX Scrubbing/Scrubber_animation.wmv

30 March 2015

SOx Scrubbers and Survey Schemes

12 © Wärtsilä This document is the property of Wärtsilä Corporation and shall not be copied or reproduced without the consent of the owner. © Wärtsilä

Freshwater closed loop Seawater open loop Hybrid (seawater closed

loop)

Not dependent on seawater alkalinity

Dependent on seawater alkalinity (issue for limited

areas such as lakes, few ports close to estuaries,

Northern and Eastern part of Baltic Sea; limitation:

1000 umol / L)

Possibility to operate independently from

seawater alkalinity for a limited period (

limitation: 1000 umol / L)

Zero effluent discharge for some time No possibility for zero discharge Zero effluent discharge for limited period

Needs caustic soda as a reagent

No need of NaOH (and logistics) Needs caustic soda for intended closed

loop operations

Low power demand (0,5-1,0 % additional

engine power demand)

Slightly higher power demand (2,0 % additional

engine power demand)

Slightly higher power demand (2,0 %

additional engine power demand)

Slightly more complex system Simple system Slightly more complex system

Needs FW (possibility to use AWP treated

water)

No need for additional FW No need for additional FW

No issues related to sea chests Sea chest capacity (retrofits) Sea chest capacity (retrofits)

More tank requirements (alkali, buffer tank,

holding tank, sludge tank)

Lower tank space demand (residence tank, sludge

tank)

More tank requirements (alkali, 2x

residence tanks, holding tank, sludge tank)

Types of Scrubber Units

30 March 2015

Scrubber with venturi

• SOx reduction from

3,5% to 0,1%

• PM reduction up to

80%

• By-pass needed

• Existing silencer

recommended to be

kept

Inline scrubber

• Smaller footprint

• No by-pass – can

run hot

• Pressure drop at

design: 150 mm

WG

• SOx reduction

from 2,5% to 0,1%

• Can replace

silencer

Wärtsilä Integrated Scrubber

1

3

4

5

2

6 7

8

9

1. Diesel engine

2. Oil-fired boiler

3. SCR

4. Exhaust gas boiler

5. Silencer

6. By-pass valve

7. Exhaust gas manifold

8. Scrubber unit

9. Exhaust gas fan

Main features

• For diesel engines and oil-fired boilers

• One common scrubber unit with suction fan for all

combustion units onboard

• Suction branches with by-pass valves from all

exhaust gas and flue gas pipes

• Constant under-pressure at scrubber inlet

prevents undue flow of gases

Benefits

• Completely avoids increased exhaust gas back

pressure

• Minimizes the amount of equipment

Ideal for

• Single engine cargo ships with HFO gensets

• Multi engine ships

• Tankers with large boilers

14 © Wärtsilä. STRICTLY CONFIDENTIAL. This document is the property of Wärtsilä Corporation and shall not be copied or reproduced without the consent of the owner.

Sludge Seawater Systems

The collected sludge:

Non-hazardous by legislation

To be disposed of ashore

Can be disposed with the vessels waste oils/sludge

Estimated amount closed loop: 2 l/MWh

Estimated SFOC use ~ 0.1 g/kWh

The amount depends on silt content in water and engine running profile

Sludge is collected in standard 1m3 plastic container

Example – APL England

• Vessel : APL England

• Size of SWS : 1 x 8 MW with 3 inlets

Each inlet for a 2,94 MW

engine

• Installation type Retrofit

• Delivery : January 2011

• Performance :

– 97% SOx Removal

– 85 % Particulate Removal

– 3,5% fuel sulphur content

An installation in cooperation with Port of Long Beach and APL

Wärtsila Inline Scrubber

17 © Wärtsilä This document is the property of Wärtsilä Corporation and shall not be copied or reproduced without the consent of the owner.

Scrubber Retrofit

For existing ships, the retrofit of a scrubber requires tailor-making.

Some aspects to be considered for retrofits are:

• Space; design of exhaust gas funnel

• Ship stability

• Space available for tanks, pumps and water treatment unit(s)

• Power demand for the scrubber system

• Sea chest , capacity of supplying water to the scrubber system

• Fresh water capacity (closed loop and hybrid scrubber only )

NaOH Consumption

Alkali Consumption

References Summary

21

Closed loop Open loop Hybrid Total

10

25

30

65

Scrubber Reference Installations

Closed loop Open loop Hybrid Total

As at End of 2014

WÄRTSILÄ

EXHAUST GAS CLEANING

NOX/SCR

30 March 2015 WÄRTSILÄ ENVIRONMENTAL SOLUTIONS PRODUCTS / MORTEN LETNES 22 © Wärtsilä

Revised Marpol Annex VI Regulation 13

Tier I >130 kW New ships 2000

Tier II >130 kW New ships 2011

Tier III >130 kW Upcoming requirement, New ships inside Emission Control Areas (ECA)

Rated engine speed (rpm)

0

2

4

6

8

10

12

14

16

18

0 200 400 600 800 1000 1200 1400 1600 1800 2000

NOX (g/kWh)

Wärtsilä NOR operation area

Primary methods operation area

Secondary methods operation area

18 February 2014

Wärtsilä standard NOR is dimensioned for reaching the IMO Tier 3 level.

23 © Wärtsilä Wärtsilä NOx Reducer

NOX formation and reduction

• Nitrogen Oxides (NOx) are formed during the combustion process

from oxygen (O2) and nitrogen (N2) in air.

• In atmosphere NOX reacts to form smog, acid rain and ozone.

• The Wärtsilä NOX Reducer SCR catalyst converts NOX molecules

back to harmless water (H20) and nitrogen (N2) molecules by means

of urea.

18 February 2014 Wärtsilä NOx Reducer 24 © Wärtsilä

Engine exhaust

Urea injection

Wärtsilä NOX Reducer – Description

• The Wärtsilä NOx Reducer (NOR) is based on selective

catalytic reduction (SCR) technology.

• The NOR is optimized and validated for Wärtsilä medium

speed engine portfolio for marine applications in terms of

reliability, flexibility and size. It is available for both distillate

and heavy fuel oils.


Main components

Injection and

Mixing unit

Reactor Soot blowing unit

Catalyst elements

Control unit

Pump unit Air unit

Dosing unit

18 February 2014 26 © Wärtsilä Wärtsilä NOx Reducer

Reactors availabe in different shapes for

flexible and easy installation

Short and wide 2 layers

vertical reactor

Long and narrow 3 layers

vertical reactor

Short and wide 2 layers

horizontal reactor Long and narrow 3 layers

horizontal reactor


NOX reduction functional principle (SCR)

Operating temperature

~ 300 – 450 °C

Nitrogen oxides (NOX) are

reduced into nitrogen (N2) and

water vapour (H2O) using

ammonia or urea at a suitable

temperature on the surface of the

catalyst.


Wärtsilä NOx Reducer - System overview


System overview - Multiple installation


The control unit, air unit and pump

unit are centralized units, meaning that same

units can be utilized in multiple NOR installations.

Minimum recommended temperature in the SCR

inlet vs fuel sulphur content


Optimised engines for specific requirements

• Majority of the Wärtsilä engines have been

tuned to fulfill SCR temperature

requirements

• The tuning is done to minimize the effect

on SFOC or thermal load

• Temperature control strategies include:

– Air waste-gate control

– Exhaust gas waste-gate control

– Air by-pass control

– Valve timing

• Majority of the Wärtsilä engines have been

developed to cope with a higher back

pressure tolerance

– Install several exhaust gas equipment

– Install smaller equipment


Wärtsilä NOR performance

• Compact and Flexible design

• Optimized and validated system

• Efficient SCR process

• Durable catalyst elements

• Possibility to integrate NOR reactor

with silencers

Performance

NOx emission levels as per IMO Tier III as standard

Other NOx levels upon request

Urea consumption (40% solution)

Typically 15 l/h / MW

Operation

Fuels: MGO / MDO / HFO

Compatible with SOx scrubber systems

Typical noise reduction for the NOR reactor: 8-10 dB(A)


Integrated silencer

SCR reactor

Integrated SCR reactor + silencer + spark arrestor

Integrated spark arrestor

22 January 2015 34 © Wärtsilä

Urea solution

18 February 2014

• Safe carrier of reducing agent ammonia (NH3)

• Classified as non toxic and non dangerous goods

• Decomposes to ammonia when exposed to heat (+100°C)

• Non flammable

• Odourless or has a slight smell of ammonia

• Delivered as colourless, aqueous solution

• ISO 22241 standard defines the purity and material requirements

Vehicles typically use

32,5 wt-% urea due to

the lowest possible

freezing point (-11 °C)

Marine vessels typically

use 40 wt-% urea due to

lower tank capacity need

and adequate enough

freezing point (0°C)


Exhaust gas equipment arrangement example

18 February 2014

• The NOR mixing duct and reactor are the

first components after the engine due to the

temperature requirement of the NOx

Reducer operation.

• NOR designed for high sulphur HFO is

compatible with SOx Scrubbers.

NOR reactor

Boiler

Silencer

Scrubber

NOR mixing duct


Low Pressure SCR

18 February 2014

First Tier III SCR on 2-S RTFlex58T

Benefits with Wärtsilä NOR solution

• More than 500 Wärtsilä engines with SCR in operation or on order today

• Optimized and validated for Wärtsilä medium speed engines in terms of

reliability and size.

• Fuel flexibility, including high sulphur fuels

• Flexible and optimized size according to engine characteristics and NOx

reduction targets

• Sound attenuation features

• Ability to integrate and optimize engine + SCR (+boiler+silencer+scrubber)

• Pre-fabricated and tested modularity, built in redundancy

• One supplier, single point of responsibility

• Worldwide service network in 70 Countries


Thank You!


51 / © Wärtsilä

What is continuous emission monitoring?

• Continuously measuring concentration of specific components in

the exhaust gas

– Typically NOX, CO and SO2 emissions.

– Normally requires specialized equipment.

– Selecting right equipment is critical for robustness.

• WHY?

– Verification of compliance with

emission limits

– Reporting for emission trading or

taxation schemes

– Process feedback for control purposes

– “Voluntary” monitoring

• Stakeholder reporting

• Green certificates

• Optimisation of operation


51 / © Wärtsilä

CEMS – Extractive systems

• Exhaust gas sample is taken from the exhaust gas stack with a sampling probe

• The sample is conveyed in heated sampling lines to a gas analyser via sample

conditioning

Sampling probe Heated

sampling

lines

Gas sampling

and analysis

Data acquisition

and handling system


51 / © Wärtsilä

Time-sharing principle

• Several stacks are monitored by the same analyser (CEMS)

• Gas intake and measurements are automatically controlled by the analyser /

PLC

• Cost optimised solution as less components are needed

• Suitable for multi-engine installations

• Applicability depending on the regulation

Note: Systems based on timesharing principle are considered continuous monitoring systems.


51 / © Wärtsilä

Measured components

• CO2

– Range: 0-15 %

• CO

• NO – Range: 0-2000 ppm

• NO2

– Range: 0-300 ppm

• H2O – Range: 0-35 %

– Required as measurement is done o a wet-basis

• O2 (optional)

– Range: 0-21 %

• SO2 (optional)

– Range: 0-2000 ppm

• CH4 (optional) All components are

measured with NDIR

technology except O2,

which uses paramagentic

sensor.


Thank You!


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