METHANOL-FUELED

ENGINES: STATE OF THE ART

AND FUTURE POTENTIAL Sebastian Verhelst

DEPARTMENT OF FLOW, HEAT AND COMBUSTION MECHANICS

TRANSPORT TECHNOLOGY RESEARCH GROUP

WHY METHANOL?

3

METHANOL AS A FUEL

1990s: CA methanol program, focused on improving air quality

> 17.000 M85 FFVs sold to public

Now: China main methanol fuel market

Improving air quality & increasing energy security

M5 up to M100, M15&M85 used most

Also large interest in marine (LNG alternative)

2015: 35 billion liters of methanol for energy use

Drop-in possibilities (e.g. EN228 – M3; “GEM blends” for FFVs)

Produced from fossil sources now, but also very interesting bio- or e-fuel

‒ Simplest fuel that is liquid at atmospheric conditions

‒ Liquid fuel that is most easily produced from renewables (wind, solar, …)

‒ H2 + CO/CO2 CH3OH

4

METHANOL (MeOH) AS AN ENGINE FUEL

5

PHYSICOCHEMICAL PROPERTIES

Higher H/C ratio vs. gasoline

specific CO2 emissions (gCO2/MJ) -7% (assuming equal engine effic.)

High Cp of burned products

Lowering peak T and heat losses

Higher laminar burning velocity (burns ~50% faster)

More knock resistant

Higher dilution tolerance

Oxygenate - oxygen constitutes 50m% of CH3OH

Low air/fuel ratio, lower energy content

Slightly lower mixture volumetric energy content

‒ Port Fuel Injection (PFI): P -5%, Direct Injection (DI) P +6%

OH group polar molecule…

6

PHYSICOCHEMICAL PROPERTIES

High heat of vaporization &low AFR:

energy needed to vaporize fuel

= 7 times that of gasoline

Low T throughout engine cycle

&low Tadiab lower wall heat losses, lower NOx

Increased knock resistance: compression ratio (CR)

can go up, optimal spark timing can be used

in wider area of engine map

Charge cooling: mixture‟s volumetric

energy density increases, P↑

Octane numbers: RON = 109, MON = 92 More knock resistant

7

C O

C

O

C

O

C

O

Thus methanol has an

‘effective’ molecular

weight of 128 – i.e. ‘liquid’

NUMBERS – “FFVs”

8

“FLEX-FUEL VEHICLES”: THEN

Note M85 was the fuel for which FFV technology was developed!

E85 only came later.

Note ability for the vehicle to operate on gasoline compromises

the engine design (e.g. compression ratio)

California methanol programme „90s: still, typically about 5%

increase in power and efficiency

Very similar to E85 results

Increased volumetric efficiency, more isochoric combustion,

lower heat losses, lower pumping losses

Remainder of presentation: methanol used pure, i.e. M100

9

“FLEX-FUEL VEHICLES”: NOW

Today‟s engine technology

Knock control ‒ Alcohols don‟t need spark retard at high loads,

ignition can be kept at optimal timing

Component temperature protection (turbine) ‒ No need for enrichment

Direct injection ‒ Making even better use of increased charge cooling

(cooled) Exhaust Gas Recirculation (EGR) ‒ Increased dilution tolerance

Increased potential for efficiency improvement at

highly loaded operation, i.e. downsized engines

10

UGent RESEARCH

Converted engines on test bench

PFI “flexfuel”, VVT: relative to gasoline, efficiency

+10%, NOX up to -10 g/kWh (engine-out)

DI “flexfuel”: relative to gasoline, -20% CO2

Downsized engine (TC DI): In progress…

initial tests already showed up to 5 %pt higher

efficiency (+18% relative), NOx -35%

Further optimization ongoing, supported by

fundamental work on combustion

properties

11

NUMBERS – “DEDICATED”

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PUSHING EGR DILUTION STRATEGY

L4, 1896cc, 2V, CR=19.5, PFI, TC, LPL EGR

i.e. VW AXR TDI converted to SI

Faster, more stable combustion

High CR, turbocharged

Hence, more dilution tolerance

Wider range for wide open throttle operation

(down to 3 bar BMEP)

Lower in-cylinder temperatures

Cooling & dissociation losses ↓

Knock/pre-ignition ↓

Engine-out NOX ↓

13

SAE 2012-01-1283

NOx (ppm)

RESULTS WOT EGR STRATEGY

WOT EGR: diesel-like peak efficiency

Vast engine-out NOx reductions (ppm), l=1 operation

14

42%

Diesel-like efficiencies

while using cheap

aftertreatment systems

WHERETO NEXT?

Ultimate potential dedicated engines?

Increased CR (but not 19.5), DI, TC …

High EGR rates: heat loss ↓ but combustion becomes unstable

Solution? Use other feature of methanol,

i.e. relative ease of fuel reforming

Remember methanol was also studied as a hydrogen carrier for fuel cell

vehicles (1 m³ of MeOH contains more H2 than 1 m³ of liquid H2!)

Thermal decomposition (TD): CH3OH CO + 2H2 Δh298K = +91 kJ.mol-1

Steam reforming (SR): CH3OH + H2O CO2 + 3H2 Δh298K = +49 kJ.mol-1

Waste heat recovery: drive reforming using exhaust heat

+ fuel reforming to support high dilution (faster burning due to H2)

15

M.I.T. CONCEPT

Cfr. alcohol for ORC

“Use fuel as ORC working fluid

but ditch condensor, turbine”

“vs. gasoline PFI: +50% h”

“vs. diesel truck engine: +20-25%”

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Bromberg L, Cedrone K, Cohn DR, 20th ISAF, 2013

Super -efficient Spark Ignition Methanol Engines

Effic

iency g

ain

rela

tive to

sta

ndard

gasolin

e e

ngin

e

20%-

10%-

Removal of knock limit

(higher octane)

50%-

40%-

30%-

exhaust heat recovery

High compression ratio

Turbocharging and downsizing

Diesel engine

55%-

Exhaust heat recovery

Super Efficient Spark Ignition Methanol Engines

Source: MIT

CURRENT METHANOL PROJECTS

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ON-ROAD

Actual use & demo‟s, e.g.:

China

Light & heavy duty

(SI / Dual Fuel CI)

MeOH: 8% of fuel pool

Israel

M15 demo

Australia

No tax on MeOH fuels,

GEM demo

Europe

GEM fuels in Junior WRC

Research projects, e.g.:

Lulea Univ: MeOH production,

vehicle demo

Lund Univ: high efficiency CI MeOH

concepts

Ghent Univ: high efficiency SI MeOH

concepts, GEM blend tests

U.S.: Co-optima – engine-fuel combo

for highest efficiency

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GEM concept: gasoline/ethanol/methanol

blend with same air/fuel ratio as E85

drop-in fuel for FFVs

MARINE

Stena Germanica

Ferry Kiel-Gothenburg, medium speed

engines

Stena, Wärtsilä, ports, Methanex

In operation

LeanShips

WP05: conversion of high speed

marine diesel engine to dual fuel

operation on methanol

Ghent University, Damen Shipyards,

Abeking&Rasmussen, Kant

Marine&Industry (~Volvo Penta),

Methanex Europe, Dredging Int.

2015-2019

GreenPilot

Pilot boat conversion

Swedish Maritime Tech Forum,

ScandiNAOS, SSPA, Swedish

Transport & Maritime Administrations

2016-2018

MethaShip

Medium speed engines, for cruise

vessels and RoPax ferries

Meyer Werft, Flensburger, Lloyds

Register (ass. partners: Caterpillar,

Helm, MAN)

2014-2018

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LEANSHIPS

EU Horizon 2020 Mobility for Growth „innovation action‟

40 partners, 7 demonstrator platforms

UGent: WP05 leader “Demonstrating the potential of methanol as

an alternative fuel” (6 partners)

Conversion of high speed marine diesel engine

to dual fuel operation with methanol

‒Map power, efficiency, emissions

LCA of methanol in shipping

Tools for dissemination and market uptake (pilots)

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CONCLUSION

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CONCLUSION

Methanol is a compelling alternative fuel:

From a production and use point of view…

It‟s liquid; already available (fossil), and can be produced from renewables

Can be blended in (gasoline/ethanol) or used in Dual Fuel (diesel engines)

And methanol is a great engine fuel

Potential for efficiencies exceeding those of diesel engines, with the

low emissions of gasoline engines (using simple aftertreatment), and

with greater performance than both (actual potential still to be proven)

Further boost of (part-load) efficiency through fuel reforming

‒ Waste heat recovery + push dilution (even) further… Work in progress…

Already in the market, + research & demo‟s ongoing

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Sebastian VERHELST Associate Professor of Internal Combustion Engines

DEPT. OF FLOW, HEAT AND

COMBUSTION MECHANICS

E sebastian.verhelst@ugent.be

T +32 9 264 33 06

www.ugent.be/ea/floheacom

Ghent University

@ugent

sebastian-verhelst-0398959

BACKUP SLIDES

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MYTHS&MISCONCEPTIONS

“too corrosive”

Polarity also means MeOH is more corrosive than gasoline

Light metals can be affected by pitting, nylons swell

Well understood and tackled by using compatible materials

<150$ to make a new car methanol compatible

“toxic!”

Yes, so is gasoline… even when gasoline prices were lower than water prices, we

didn‟t need to take actions to prevent people from drinking it…

“dangerous – burns with invisible flame!”

E.P.A. estimated that if all cars ran on methanol rather than gasoline, vehicle fires

would be reduced by 90% (MeOH harder to ignite, less heat radiation, …)

“will contaminate water supplies!”

Methanol is ubiquitous in the environment, and readily bio-degradable. The half-life

for methanol in groundwater is just 1 to 7 days, while e.g. benzene is 10 to 730 days.

Methanol is actually a more environmentally benign fuel than gasoline.

25

CALIFORNIA METHANOL PROGRAMME

Courtesy of Paul Wuebben, CRI

> 17.000 M85 FFVs sold to public

Max fuel volume throughput: 7.5 M liters/month

10 OEMs involved

Toxicity? In the CA Fuel Methanol Program, with over 200

million miles of consumer experience, there was not a single

documented harmful event

By the way, existing commercial products contain significant

amounts of methanol (e.g. windshield washer fluid)

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HYDROGEN VECTORS

27

0

20

40

60

80

100

120

140

Ma

ss

of

Hyd

rog

en

per

m3

of

Co

mp

ou

nd

/ [

kg

] a

nd

Ch

an

ge

ve

rsu

sL

iqu

id H

yd

rog

en

/ [

%]

Mass of Hydrogen per m3 Percentage Increase over Liquid Hydrogen

INTRODUCING METHANOL?

28

HOW TO INTRODUCE METHANOL?

Most successful biofuel presently: bio-ethanol

Which is being used: Mixed into gasoline, in low concentrations (E5, E10)

In high concentrations (E85) in “flex-fuel vehicles” (FFVs)

EtOH lion share of the ~4% share of biofuels in transport,

~40M FFVs worldwide

MeOH miscible with gasoline+EtOH

Hypothesis: gasoline-EtOH-MeOH

blends ~ identical properties to E85

(GEM blends) can be used by FFVs

29

SAE 2011-24-0113

REQUIREMENTS FOR „DROP-IN FUELS‟

30

Turner et al. IMechE

SVT Conference, 2012

WORK ON GEM BLENDS

Experiments on various alcohol blends

(gasoline / methanol / ethanol)

Results indeed identical to E85

i.e.: better efficiency than gasoline, lower (NOx) emissions

Fundamental research into combustion properties

i.e. methanol can be introduced as blend component in drop-

in fuels, i.e. TODAY!

31 Sileghem et al. Fuel 117:286-293

32

72.0 72.0 72.0

15

37 37 37 37

85

21 21 21 21

42 42 42 42

0

10

20

30

40

50

60

70

80

90

100

Gasoline Gasoline Gasoline A C C C C

Blend Designation

Vo

lum

es f

or

Eq

ual

En

erg

y / [

Vo

lum

e U

nit

s]

Gasoline Ethanol Methanol

GASOLINE DISPLACEMENT FOR BLEND C

Equivalent Energy on Each Side

=

72x3+15 = 231 37x4 = 148

36% less gasoline