Hydrogen for Internal Combustion Engines? - Technology€¦ · Hydrogen for Internal Combustion Engines? Roger Cracknell, Harold Walmsley - Shell Global Solutions H2NET Meeting 25th

Hydrogen for Internal Combustion Engines?

Roger Cracknell, Harold Walmsley - Shell Global Solutions

H2NET Meeting 25th April

Acknowledgement to Shell Hydrogen for support.

H2 -Well to Wheels GHG Emissions. Well to TankTank to Wheels

Compressed Hydrogen FC (Elec - Wind)

Compressed Hydrogen ICE (Elec - Wind)

Compressed Hydrogen FC (Elec – EU Mix)

Compressed Hydrogen FC (NG)

Compressed Hydrogen ICE (NG)

Diesel Hybrid

Diesel

Gasoline Hybrid

Gasoline

•Based on 2010 vehicles •Taken from EUCAR /JRC /CONCAWE study (2007)

0 50 100 150GHG Emissions (g/km)

200 250

•Hydrogen gives zero tank to wheels emissions.•Using “Clean” or “Green” Hydrogen as a fuel gives low well to wheel GHG emissions, whether in fuel cells or internal combustion engines.

Strengths and Weaknesses of H2 ICES

……some commonly held viewsStrengthsWeaknesses

• Dual fuelled vehicles a lower infrastructure requirement

• Likely to be affordable sooner than fuel cells?.

• Mass market for H2 as a fuel could occur sooner?.

• Less stringent hydrogen purity requirements?

• Poor Efficiency (c.f. fuel cells)

• Pre-ignition limits regions of operability

• Tailpipe emissions (esp. NOx)

Storage remains a challenge for H2 ICEs and FCVs


StrengthsWeaknesses• Dual fuelled vehicles a

lower infrastructure requirement








JRC/EUCAR/CONCAWE Well to Wheels Study 2006Engine on 2010 Vehicle(Equiv performance to 1.6l gasoline vehicle)

Fuel Consumption* (MJ/100km)

Gasoline ICE 190Diesel ICE w/out DPF 172.1

Compressed H2 ICE 167.5Liquefied H2 ICE 167.5Gasoline ICE Hybrid 161.7Diesel ICE Hybrid 141.4Compressed H2 ICE Hybrid 148.5Liquefied H2 ICE Hybrid 141.4H2 Fuel Cell 94.0H2 Fuel Cell Hybrid 83.7

8.1Effic. ICE HEffic. FC H

2

2 ≈

* Over NEDC

Hydrogen ICEs: The PFI Volumetric Efficiency Problem

82% power compared to gasoline (Source: BMW)

Need larger displacement engines - less efficiency

Cryogenic external injection.

Direct Injection

Higher air intake pressure

Solutions:

Gasoline Hydrogen

Air

Fuel Vapour

Air

H2


H2 (g)+0.5O2(g)+ 1.87N2 (g) H2O (g) +1.87N2(g)

LHV= 0.24 MJ per mole of fuel gas

LHV= 0.071 MJ per mole of all gases before combustion

C8H18(g)+12.5 O2 (g) + 46.63 N2 (g)= 9H2O +8CO2 (g)+ 46.63N2(g)

LHV= 5.07 MJ per mole of fuel gas

LHV=0.10 MJ per mole of all gases before combustion


82% power compared to gasoline (Source: BMW)

Need larger displacement engines - less efficiency

Cryogenic external injection.

Direct Injection

Higher air intake pressure

Solutions:

Gasoline Hydrogen

Air

Fuel Vapour

Air

H2

Optimistic Views on Hydrogen ICEs from OEMs

BMW: Gerbig et al (2004) Fisita F2004V113

"we expect to achieve overall [ICE] drivetrain efficiency of 50% in the best point of operation".

Ford:

Natkin et al (2003) SAE 2003-01-0631(Ford Zetec 2.0L engine5000RPM)

0

0.1

0.2

0.3

0.4

0.5

0.6

0 0.2 0.4 0.6 0.8φ

Ther

mal

Effi

cien

cy

BrakeIndicated

Preliminary Analysis of H2 ICE using Ricardo WAVE

Base case = 2 litre, 4 cylinder SI engine (base case brake thermal efficiency =29% for gasoline)

•Supercharging (up to 4 bar)- taking advantage of octane

•Higher Compression ratio (up to 14) – taking advantage of octane

•Improved volumetric efficiency by

injection of cold gas.

different injector timing

•Run electrical system from PEM FC – reduce parasitic losses

•Faster flame speed – optimised ignition map

Results: H2 efficiency vs. boost pressure

262830323436384042

1 1.5 2 2.5 3 3.5 4Upstream pressure, bar

Bra

ke th

erm

al e

ffici

ency

%

Gasoline H2

With 4 bar boost, engine power is very high - further downsizing possible and further efficiency gains?











Pre-ignition

Pre-ignition is autoignition occurring before the spark. It can be very damaging.

Differs from conventional spark knock because it can not be eliminated by retarding the spark timing.

Thought to be due to “hot spots” or catalytic combustion.

Hydrogen is very susceptible because of wide flammability range and low ignition energy.

Hydrogen Pre-ignition

• low ignition energy• wide flammability limits

prone to pre-ignition

Hydrogen-Air

Methane-Air

Heptane-Air

White, C.M., Steeper, R.R., and Lutz, A.E. The hydrogen-fuelled internal combustion engine: a technical review.Int. J. Hydrogen Energy, 31, 1292 2006.

Limits of Pre-ignition for Hydrogen

0.500.550.600.650.700.750.800.850.900.951.00

7.5 8.5 9.5 10.5 11.5 12.5

compression ratio

equi

vale

nce

ratio

Pre-ignitionregion

Operational region

Engine speed = 25r/sTin = 313 KPin = 1 bar

Al-Baghdadi Maher Asadiq. Development of a preignition submodel for hydrogen engines. Proc. IMechE, 219, Part D: J. Automobile Eng., 2005.

Hydrogen pre-ignition: Effect of intake pressure

0.400.450.500.550.600.650.700.750.800.850.900.951.00

7.5 8.5 9.5 10.5 11.5 12.5

compression ratio

equi

vale

nce

ratio


• Pin = 0.8 bar• Pin = 1.3 bar

Engine speed = 25r/sTin = 313 K

Hydrogen pre-ignition: Effect of Intake temperature

0.400.450.500.550.600.650.700.750.800.850.900.951.00

7.5 8.5 9.5 10.5 11.5 12.5

compression ratio

equi

vale

nce

ratio

Engine speed = 25r/sPin = 1 bar

• Tin = 300 K• Tin = 328 K


Late injection avoids pre-ignition

0

10

20

30

40

50

Crank Angle (Deg CA)

Cyl

inde

r Pre

ssur

e (b

ar)

Early Injection Spark Late Injection

Gerbig et al: FISITA paper F2004V113











Tailpipe emissions can be engineered out

0 1 2 3 4 5

Air/Fuel Ratio (λ)

NO

xem

issi

ons

Stoichiometric(catalyst) Lean burn (no

emissions)Forbidden Region

Source: BMW- Gerbig et al (2004) Fisita F2004V113











Lower Infrastructure Requirements than Fuel Cell Vehicles?

•Hydrogen introduced first in “lighthouse projects” taking advantage of local hydrogen availability.

•Shell/GM study showed that economics of hydrogen roll-out requires smaller number of highly utilised retail stations.

•But customers also want to use vehicle to go away at weekends.

•Assume that IC engine calibrated and optimised for hydrogen, but can also operate on gasoline if required.

•Bi-fuel capacity ensures customers can go anywhere they want.











Likely to be affordable sooner than fuel cells?

US DOE target for fuel cells

‘By 2010, develop a 60% peak-efficient, durable, direct hydrogen fuel cell power system for transportation at a cost of $45/kW; by 2015, a cost of $30/kW.’

Current costs for conventional ICE vehicles: 25$-35$/kW

(Slightly higher costs for H2 ICESs)







• Poor Efficiency (c.f. fuel cells)?




Less stringent hydrogen purity requirements?

Fuel Cell performance degraded by:

•CO ( low ppm levels) Reversible•S compounds (sub ppm levels) Non-reversible•NH3 (sub ppm levels) Non-reversible

ICE purity requirements are dictated by aftertreatment catalyst (e.g.~10ppmw S)

(H2/CNG mixtures can also be used)











Shell is an early leader in hydrogen, with a clear strategy towards commercialisation

• First energy company building hydrogen infrastructure in USA, Europe and Asia

• Four hydrogen demonstration projects• Working to develop mini-networks • Challenges: production/distribution

costs, production process CO2

Iceland – initiative to transformIceland into hydrogen economy

Washington DC - combined petrol/hydrogen filling station

Isolated Demo

“demo” stations

2015

Early Commercial

Mini-networkLimited Corridors

Now

Lighthouse projects

2010

Infrastructure development

In the longer term, hydrogen offers the potential to dramatically reduce emissions and increase energy security

• Most efficiently used in fuel cell vehicles

• Flexible sources of hydrogen can increase energy security

• Zero local emissions

• Requires new infrastructure and vehicles

Lifecycle CO2 production depends on hydrogen source and manufacturing process

Hydrogen Production

“grey” “clean” “green”

CO2 emission intensity

1000000’s

100’s

hydrogen production (tpd H2)

< 10 years 10-30 years 30-50 years

Time from today

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Hydrogen for Internal Combustion Engines? - Technology€¦ · Hydrogen for Internal Combustion Engines? Roger Cracknell, Harold Walmsley - Shell Global Solutions H2NET Meeting 25th