Product line : Marine

Aftertreatment system selection

The problematic emissions from combustion

in Diesel engines are nitrogen oxides [NOX]

and particulate or soot [PM].To reduce these

emissions two types of emission

aftertreatment devices are used:

• Diesel Particulate Filter to trap the PM,

DPF

• Selective Catalytic Reduction to reduce

the NOX, SCR.

The scoped legislations are MARPOL VI

[TIER III] for coasters and sea going vessels,

and Stage 4 for inland shipping in Europe and

EPA TIER 4 for the inland vessels in U.S.A..

To fulfill MARPOL [TIER III], NOX must be

reduced between 60 and 90%.

This can be achieved by the Multronic SCR

and SCR+’ systems.

0,000

0,050

0,100

0,150

0,200

0,250

0,300

0,350

0,400

0,450

0,500

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

9,0

PM

g/k

Wh

NOX g/kWh

Mechanical injection Electronic injection

Ultra modern common rail

D

P

F

SCR

Aftertreatment system selection

To fulfill Stage IV/V and EPA TIER 4 both NOX and

PM must be reduced between 60 and 90%.

This can be achieved by the Multronic EEV and

SCRonDPF systems.

For the marine market, Multronic has developed

dedicated emission systems:

• specific catalytic coatings to be durable with

the different fuels present

• specific heat management and regeneration

technologies for applications like propulsion,

diesel electric and power generation

• designs with low pressure drop, short mixing

distances and airless urea dosing.

• protection methods to allow the usage of

automotive sensors and components in harsh

environments with low fuel qualities.

0

2

4

6

8

10

12

14

16

0 250 500 750 1000 1250 1500 1750 2000

NO

X g

/kW

h

RPM

IMO Tier I IMO Tier II IMO (MARPOL 6) Tier III

Marine Diesel engines

Name Low speed Medium Speed High Speed

Displacement (l/cyl) 200 - 2000 16-120 5 - 16 0,8 - 3 < 0,8

Power range (kW) 4000 – 100000 800 - 40000 kW Up to 10000 kW Up to 800 kW Up to 300 kW

Combustion type 2-stroke & 4 stroke 2-stroke & 4 stroke 2-stroke & 4 stroke 4 stroke 4 stroke

Rotation speed (rpm) 70-300 350 - 850 600 - 2200 600 - 3000 >3000

The marine market is characterized by an enormous variety of engines and power ranges. Each type, application

must fulfill different emission requirements.

Multronic scope

Large cargo vessels, use low speed diesel engines, 2 and 4

stroke, and are powered by heavy fuel oil due to its low cost. This

fuel contains high sulphur levels, phosphor and ash. All the

components of the emission system, catalysts, sensors and

actuator package must be selected specifically for this fuel.

Inland vessels, coasters and luxury yachts have access to good

quality fuels, use mainly medium and high speed diesel engines

and have a load profile allowing the use of high efficient

aftertreatment technology similar to onroad heavy duty emission

systems..

Emission systems for ships

Products for Inland vessels

DOC and Open DPF systems for

propulsion engines For some applicationans a DOC or open DPF systems can be sufficient to reduce PM. The cost is low, the

installation is easy and there is no maintenance. Lowest cost of operation.

0

20

40

60

80

100

CO HC PM NOX

OE DOC Open DPF2

Engin

e

DO

C/D

EC

T

U

R

B

O

Engin

e

Open,DPF

T

U

R

B

O

DPF systems for propulsion engines

Nevertheless Multronic equips all the DPF systems with

a back-up active regeneration system, Diesel Hydro

Carbon Post Injection (DHCPI). In case of long periods

of low engine load, the temperature of the exhaust gas

is raised by the injection of fuel over the catalyst.

The main advantages of the DHCPI system compared

to a burner are:

• very large operational window

• Independent from the engine load

• fuel efficient temperature raise

• stepless temperature regulation

• no air injection needed

Engin

e

DPF

Temp 1 Temp 3

DO

C/D

EC

Diesel

injecton

T

U

R

B

O

Temp 2 Press 1

Driven by local rules, environmental

conscience, ship-owners or transport

companies equip the propulsion engines of

their vessels with DPF systems.

The soot is trapped in the filter and is

oxidised by means of a catalytic reaction

that takes place between 280 and 420°C.

Under normal operation this is the

temperature present after the turbocharger

in the exhaust stack.

0

20

40

60

80

100

CO HC PM NOX NO NO2

OE DPF

DPF systems for generators

The main driver to install DPF’s on ships is to

avoid deposits of soot on the water around the

ship, the hull and on the deck.

The engines responsible for these practical

problems are mainly the auxiliary engines used

for the generators.

Multronic has developed the E-DPF for a

durable solution on generators. The DPF

regenerates passively when the engine is

loaded above 50%.

Engin

e

DPF

Temp 3 Press 1 Temp 2

Heate

r

T

U

R

B

O

Generator

Temp 1

Engin

e

DPF

DO

C/D

EC

T

U

R

B

O

Generator

Temp 1 Temp 4

Hea

ter

Diesel

injecton

Temp 3 Temp 2 Press 1

Under low load conditions the exhaust gas

temperature is artificially raised to oxidise the

trapped soot.

The electrical heater can be combined with a

diesel oxidation catalyst and diesel post injection

(DHCPI) to speed up the regeneration and

enlarge the operational window of the system.

The coating on both the DPF and DOC can be

chosen in function of the fuel quality.

Multronic recommend the use of fuel with a

maximum of 1000PPM sulphur.

SCR systems for propulsion engines

Engin

e

SCR

Temp 2

Urea

dosing

T

U

R

B

O

Temp 1 Press 1

Emission legislation for marine

engines focuses mainly on Nitrogen

oxide reduction.

One of the most effective methods to

reduce NOX is SCR, Selective

Catalytic Reduction.

Adblue / DEF, an aqueous urea

solution is injected in the exhaust gas

upstream of the SCR catalyst.

The urea is transformed into ammonia

and In the catalyst the ammonia reacts

with the NOX and is reduced to

nitrogen and water.

Standard SCR system

0

20

40

60

80

100

CO HC PM NOX NO NO2

OE SCR

SCR+ systems for propulsion engines

Optional

Optional

Engin

e

AdBlue

injection

SCR

Hydro

Cat.

Temp

1

Temp

3

Temp

4

Press

1

NOX

DO

C/D

EC

Diesel

injecton

Temp

2

Mixer Mixer

AS

C

To increase the efficiency of the SCR (SCR+ system) additional catalysts

can be added to the system. A hydrolysing catalyst can help to form the

ammonia at lower temperature, an ammonia slip catalyst can remove

excessive ammonia that can slip through the system when high

efficiencies are needed and an upstream diesel oxidation catalyst

balances the relation between NO and NO2 to improve the system

efficiency and urea consumption. A DOC can also be used, when

needed, for crystal removal within the SCR system.

SCR + system

0 20 40 60 80 100

CO

HC

PM

NOX

NO

NO2

SCR+ OE

Combined DPF and SCR systems

Option 1 : Multronic EEV :DPF + SCR E

ng

ine

C/DPF D

OC

/ D

EC

SCR

AS

C

AdBlue

injecton

Hyd

ro C

at.

Temp 1 Temp 3 Temp 4 Temp 2 Temp 5 Press 1 Press /

Ref 2

NOX

Diesel

injecton

Mixer Mixer

To achieve Stage IV/V and EPA TIER 4 both NOX and PM

must be reduced between 60 and 90%. This can be

achieved with the Multronic EEV and SCRonDPF

solutions.

The Multronic EEV is a combination of 2 Multronic

systems, the DHCPI particle filter and the Multronic SCR+.

The efficiency of the system exceeds 90 % for the full

range of emissions.

0

20

40

60

80

100

CO HC PM NOX NO NO2

OE SCR

Option 2 : SCRonDPF

En

gin

e

AdBlue

injecton

SCRonDPF

Temp 1 Temp 3 Temp 4 Press 1 NOX

DO

C/D

EC

Diesel

injecton

Temp 2

Mixer Mixer

AS

C

En

gin

e

C/DPF D

OC

/ D

EC

SCR

AS

C

AdBlue

injecton

Temp 1 Temp 3 Temp 4 Temp 2 Temp 5 Press 1 Press /

Ref 2

NOX

Diesel

injecton

Mixer Mixer

System layout : combined DPF & SCR

Option 1

DPF => SCR

Option 2

SCR => DPF

Option 3

SCRonDPF

DPF regeneration via NO2 / fuel penalty for

regeneration ++ - +

N° of substrates* *(without hydrolysing catalyst and with end-zone coating for

ASC when applicable)

3 4 2

Total substrate volume / compactness of the

system

Medium

volume

Highest

volume

Lowest

volume

Passive & active heat management / fuel penalty High thermal

inertia

High thermal

inertia

Low thermal

inertia

Complexity of the temperature management High High Medium

N° of cans

N° of temperature sensors

3 cans

minimum

4 (optional 5)

4 cans

minimum

4 (optional 5)

2 cans

minimum

3 (optional 4)

Integration / geometrical freedom

Installation - + ++

Marine specific Low SV – Low Pressure drop

requirement - - +

To reduce the size of the

system Multronic has

developed solutions to

integrate the DPF and

the SCR into the same

substrate.

The results is the SCR

on DPF.

The product was

selected by the Dutch

government in 2011 as

the best potential solution

to reduce emissions from

inland vessels.

This resulted in 2

validation programs, one

on a barge and one on a

patrol vessel.

Validation of SCRonDPF on two ships

Barge

This is considered as a normal

application

Engine: Scania V8 16 liter 450 kW

Police Patrol ship

Considered as a worst case

scenario

Engine : 2 x MTU V2000-01 600 kW

The Barge

The silencer The SCRonDPF

The patrol ship

The housing

SCRonDPF

HC dosing

Urea dosing

DOC

The patrol ship

The silencer The SCRonDPF

The patrol ship

Urea tanks on top of the rudder system

The control cabinet /monitor

Urea dosing & NOX measurements for large cargo vessels

Urea dosers

Urea pressure rail

& urea return rail

NOx sampling

Urea dosing multi nozzle

SCR

T1

NOX2

(Post)

NOX1

(Pre) RPM MAP

Urea

Press

1

Urea

Level

Urea

quality

(option

)

SCR

T2

Urea

Temp

1

Urea

Pump

(1)

cont.

CAN

OBD

Line

Heat

Cool.

valve

Inj 1

Master Slave

Inj 2

Inj 3

Inj 4

Inj 5

Inj 6

Urea

Pump

(2)

Cont.

Urea

Press

2

Urea

Temp

2

NOX2

Protect

Air

NOX1

Protect

Air

NOX2

Calib

Gas

NOX1

Calib.

Gas

Urea dosing multi nozzle