Why Discuss Fossil Fuels in
Sustainable Energ
rgyy?
�
Is improving effic
fficiency to reduce fo
fosssil fu
fue
el
use by 1 TW the same as adding 1 TW of f
renewable energy generation?
– In what ways is it the same? How is it different?
– If cost of efficiency and cost of renewable were
the same, which would you prefer? Why?
– Which approach do you think is cheaper?
�
The importance of f S
SCALE: $6,000B/yr
– Small percent changes are HUGE
– Small percent investment in R&D is HUGE
Wedge View of CO2 problem
Need 7 approaches, each providing a wedge. Many of the
inexpensive options involve improving efficiency of fossil
fuel utilization.
Graph by Carbon Mitigations Initiative, Princeton University.
The McKinsey Curve
Estimating $/ton of CO2 emissions avoided
Courtesy of McKinsey & Company. Used with permission.
One Proposal to stabilize CO2: Efficiency+Biofuel+CO2 CCS
Courtesy of Ronald Prinn. Used with permission.
Fossil
Fo
ssil Fuels III:
Liquid Fuels for Trra
ansportation
nsportation
~30% of fossil fuel use
>50% of energy economics
Diesel, Gasoline, Jet Fuel
and the vehicles that burn them
Liquid Fuels Basics
�
Almost 100% of transportation runs on liquid fuels
(mostly petroleum)
–
– A
And
nd most petroleum is used for transportation
transportation
–
– Well­
Well­e
established
stablished technology: reliable, conve
en
niie
en
ntt
�
�
�
�
No technology in sight to replace liquid fuels for air
No
air
transportation.
Cars,
C
ars, trucks, trains: several future options
options
–
– M
More
ore efficient internal combustion engines
engines
� F
Fuel
uel cells are another type of ‘engine’
‘engine’
–
– A
Alternative
lternative liquid fuels
fuels
–
– G
Gaseous
aseous fuels (natural gas, H2)
H2)
� N
Need
eed to generate the H2 (from natural gas?)
gas?)
–
– E
Electric
lectric (overhead wires or batteries)
batteries)
� N
Need
eed to generate the electricity (from coal?)
coal?)
Liquid
Li
quid Fuel may run short: Since 1990,
Discovering Less Oil than we are Burning
ng
This image from: http://www.usnews.com/usnews/news/graphics/ace060315.pdf
Graph from Fournier, Donald F., and Eileen T. Westervelt. "Energy Trends and their Implications
for U.S. Army Installations." U.S. Army Corps of Engineers (September 2005): ERDC/CERL TR-05-21.
Liquid Fuel Mark
rke
et Changing Drama
ramattically
Extrapolated
Demand
IEA 2002
(big increase
in Middle East
Oil Production)
“…these are considered pessimistic projections. Others predict far higher production for the future…
The optimists premise their estimates for the future entirely on production from the Middle East and
Central Asia.”
- U.S. Army Corps of Engineers
Graph from Fournier, Donald F., and Eileen T. Westervelt. "Energy Trends and their Implications
for U.S. Army Installations." U.S. Army Corps of Engineers (September 2005): ERDC/CERL TR-05-21.
Exxperience
E
perience with Oil Projections
�
Historically, Nothing is Smooth!
–
–
–
–
�
i.e. the smooth projections are No
on
nsense
sense
Wars, economic cycles, natural disasters
P
Po
olitical
litical changes (positive & negative)
Technology changes
Technology
changes
Fuel demand is not very elastic
– prices can climb and fall very quickly
�
High prices will inspire production
–
–
–
–
Big increase in Middle East production
Increases in all sorts of alternatives as well
Lag times of ~5 years in production increases
High price can drive world economy into recession.
Price
Pr
ice is almost impossible to predict.
Fuel taxes, subssiidies
dies & regulations even worse.
Graph of crude oil prices from 1947-2009 removed due to copyright restrictions.
Big T
Trransport
rta
ation Fuels Supply Gap
Extrapolated
Demand
The Gap:
~10 Gb/yr
=27 mbd
“…these are considered pessimistic projections. Others predict far higher production for the future…
The optimists premise their estimates for the future entirely on production from the Middle East and
Central Asia.”
- U.S. Army Corps of Engineers
Graph from Fournier, Donald F., and Eileen T. Westervelt. "Energy Trends and their Implications
for U.S. Army Installations." U.S. Army Corps of Engineers (September 2005): ERDC/CERL TR-05-21.
What cou
oulld fill gap bet
etw
ween tra
ran
nsp
sport
ort
liquid fuel dema
eman
nd & oil
oil prod
rodu
uction
on??
Venezuelan tar (“extra heavy oil”)
Unexpected oil discoveries or production rates
Improved petroleum recovery rates
GasGas-toto-Liquids
Faster than expected development of tar sands
Improved transport system efficiency
CoalCoal-toto-Liquids (methanol?)
Shale oil
Gaseous fuels for transportation (CNG, H2)
Conventional biofuels (from sugars, oils)
Fuels from other biomass (e.g. cellulosic)
Electricity
One way out: don’t use liquid fuels at all!
Photo by IFCAR on Wikimedia Commons.
Chevrolet Volt
“Electric
“E
lectric cars are nearly ready…”
Boston Globe – July 22, 2007
Note electricity probably will come from burngin coal;
might solve oil shortage but not greenhouse gas problem.
Slide from S. Koonin talk at MIT Sept. 2005
Courtesy of Steven E. Koonin. Used with permission.
Orr will
O
will the gap be filled with biofuels?
Photos by Kables on Flickr and Nyttend on Wikimedia Commons.
Will need to convert cellulose too, to significantly close the gap.
Conventional biofuel production uses a lot of natural gas.
Hydro
Hydroge
gen
n in
insstead of
of ba
battterie
riess?
Fuel cells in
insstead of
of heat e
en
ngin
gine
es?
Photo by Anika Malone on Flickr.
Honda FCX Prototype
H2 could be made from natural gas (w/ CO2 emissions):
Price? Distribution? Range of vehicle?
Gaseous Fuels: CNG is simpl
mple and abundant
Photo by Christian Giersing on Wikimedia Commons.
Volvo B10BLE
Hard to achieve acceptable range with gaseous fuels.
Natural Gas supplies are limited in US, EU, China. Maybe better
to use it for heating, chemicals, electricity?
LIQUID FUEL WOULD BE MUCH BETTER!
Opt
ptio
ion
ns fo
forr making
ing liqu
liquid
id fu
fuels
els
GasGas-toto-Syngas
Syngas--toto-Liquids
– Commercial: Sumatra, Qatar
– Requires cheap gas, has to compete with LNG
CoalCoal-toto-SynGas
SynGas--toto-Liquids
– Commercial: South Africa, now China.
Coal Liquefaction
– Commercialized by Germany during war.
Biofuels (Ethanol, treated vegetable oil)
– Commercial: Brazil, USA, EU.
Oil Shale pyrolysis
– Has been commercial in many countries.
Melt tar out of Tar Sands, then upgrade.
– Commercial: Canada
Need to Look at Whole Picture
�
All synfuels processes are complicated
–E
Each
ach step adds expense & reduces efficiency.
efficiency.
– Most processes greatly in
incr
crea
ease
se CO
CO2 emi
miss
ssio
ions
ns!!
–M
Modularize
odularize to deal with complexity, but…
but…
�
What
W
hat do we really
really want?
want?
–G
Gasoline?
asoline? Jet fuel? Diesel? Fuels for new engines?
engines?
–E
Electricity
lectricity??
�
Need
N
eed Integrated View
View
– co­
co­optimize
optimize “independent” module
les.
s.
– IIntegrated
ntegrated View should drive R&D focus.
focus.
–P
Policy:
olicy: CO2 sequestration? Other externalities?
externalities?
Making Liquid Fuels from Nonliquids
�
Converting Tar (or Shale) to ordinary fuels
–
�
2 mbd operational or under construction
Gas­­to­
Gas
to­Liquids (Fischer
(Fischer­­T
Trro
op
psscch diie
esse
ell))
– 0
0.4
.4 mbd operational or under construction.
construction.
�
Coal­­to­
Coal
to­Liquids (F
(F­­T diesel, F­
F­T ga
asso
olliin
ne
e,, o
orr m
me
etth
ha
an
no
oll))
– 0.15 mbd in So
South
S
out
uth A
Africa
fric
fr
ica
a
– P
Planned
lanned construction of ~1 mbd in China
China
�
Common
C
ommon features:
features:
–
–
–
–
–
Huge capital investments in the conversion units
Huge
units
Long
L
ong lead times (~5 years).
years).
Capex
C
apex dominated: once you build a unit, never turn it off.
off.
Conversion losses imply extremely large CO2 em
emis
issi
sion
ons
s
Capturing & sequestering CO2 redu
reduce
ces eff
ffic
icie
ienc
ncy,
y, ad
adds
ds to
to ca
cape
pex.
x.
Research Issues: Chemistry
�
Alternative
Alternativ
e chemical
chemical routes to liquid fuels?
–
– CH4 + air
ir,h
,hea
eatt � so
some
meth
thin
ing con
onde
dens
nsab
able
le??
�
� avoid two­
two­sstep
tep process. Air insstte
ea
ad of O2?
�
� N
Need
eed separation methods that work at reactor T
–
– Coal + H2 � valuab
valuable
le liliqu
quid
idss
�� a
avoid
void syngas step and air separation
separation
�
� N
Need
eed better quality liquid products than made with existing
existing
coal liquefaction processes.
�
� C
Catalysts
atalysts
that more selectively remove N from
from
shale oil, minimize H2 co
cons
nsum
umpt
ptio
ion.
n.
�
� R
Reactions
eactions (and separations) that work at T’s that
that
allow better heat integration.
Pro
P
roperties
perties of a successful new fuel
Liquid, high energy density. C/H//O
O only.
only.
� Volatility of gasoline or light diesel.
� If polar, must be biodegradable to avoid
groundwater contamination.
� If soluble in gasoline/diesel, must be some
me
special advantage in keeping it separate.
�
– Much Better Engine or Emissions Performance
Alternative Liquid Fuels:
The $64,000 Question
�
Currently most new liquid fuels are diluted into
petroleum­­derived
petroleum
derived gasoline
ne or
or di
dies
esel
el
–M
Minimizes
inimizes engine perturbation
perturbation
–N
No
o need for new distribution infrastructure
infrastructure
–N
New
ew fuel valued about same as oil. (Risk: oil price
price
can fall below cost to produce the new fuel).
fuel).
�
In the future, will gas stations stock some
In
some
new 3rd fu
fuel
el in addition gasoline and die
iese
sel?
l?
–W
Would
ould open up many new engine possibilities.
possibilities.
–N
New
ew fuel might command higher price than oil.
oil.
� B
But
ut only if it provides a big advantage!
advantage!
Some possible new fuels
�
Oil insoluble biodegradable fuels
–P
Polyols,
olyols, certain other polyoxygenates
polyoxygenates
–M
Most
ost likely from biomass
biomass
– Relatively
Relatively little is know about this option.
option.
option
�
Alcohols,
A
lcohols, other oil­
oil­ssoluble
oluble oxygenates
oxygenate
–M
Methanol,
ethanol, ethanol (GTL, CTL, or bio)
bio)
�U
Unusual
nusual vaporization & energy density
density
– Heavier oil­
oil­ssoluble
oluble oxygenates (ffrro
om
mb
biio
om
ma
assss))
�S
Similar
imilar to oil, any advantage to keep separate??
separate??
What is n
ne
eeded
ded fo
forr a 3rd Fuel to
beccome e
be
esstablis
blish
hed?
All stakeholders must consent
– Vehicle makers
– Fuel makers/distributors
– Political leaders
– Consumers
Mutual consent must persist for many years
What could prompt such remarkably broad
and longlong-lived consensus?
What could prompt long­
long­lived
consensus on a new fuel?
�
All the stakeholders should derive some
benefit from the new fuel’s introduction.
– There must be a significant advantage to the 3rd
fuel.
fuel
–H
How
ow to share the benefit amongst all
all
shareholders?
shareholders?
�
Most
M
ost challenging for fuels which mix into oil.
oil.
–
– Must be a clear adva
van
ntage in kee
eep
p
i
in
ng the
he
new fuel sepa
parr
ate.
Bo
B
oring
ring version of Dual Fuel:
Fuels are not miscible.
Use Fuel B only if Fuel A is not a
avvailable
ailable
(backup for unreliable distribution syysstem)
tem)
Photo of a diesel/CNG bus in New York City removed due to copyright restrictions.
Dual Fuel Compressed Natural Gas/Diesel
(since CNG is not available everywhere)
Fllexible
F
exible Fuel Vehicles:
Again, vehicle compensattiing
ng for unreliable fuel
distribution system
Photo of an E85 Chevrolet Avalanche at the Chicago Auto Show, February 8, 2006 removed due to copyright restrictions.
No compelling reason to keep E85 separate from the main gasoline stream
Interesting versions of Dual­Fuel:
Performance Advantage from using both fuels
Adjust fuel mix to optimize performance.
Photo of ArvinMeritor test vehicle and Clean Air Power dual-fuel truck removed due to copyright restrictions.
ArvindMeritor bus
running diesel/H2 mix
Clean Air Power truck
running CNG/diesel mix
Many other promising dual fuel concepts, e.g. for SI, HCCI…
Are benefits sufficient to drive wide introduction of a 3rd fuel?
Th
T
hird
ird “fuel” could be Electricity:
e.g. Plug­
Plug­In Hybrids
Photo of plug-in hybrid cars removed due to copyright restrictions.
A pair of plug­in hybrid electric vehicles are tested at Argonne's Transportation Technology R&D Center
Approaching a fork in the road…
�
Huge chan
chang
ge
e in liquid fuel mix is coming:
–T
Th
he
erre is no
ott e
en
no
ou
ug
gh
ho
oiill!! IItt iiss e
exxp
pe
en
nssiivve
e!!
–C
Current
urrent system is not environmentally responsible.
responsible.
–N
No
o one has energy security.
security.
�
Difficult
D
ifficult to predict which fuels will fill gap
gap
–d
depends
epends on policy decisions (climate, security, economics)
economics)
�
Window of opportunity to add a 3rd fu
fuel
el at
at th
the pum
ump
p
– Electricity (e.g. plug­
plug­iin
n hybrid)?. Ga
asse
ess???? P
Po
olla
ar liq
iqui
uids
ds??
??
– A third oil­
oil­ssoluble
oluble fuel could become widely ava
aiilla
abl
ble,
e, if
if…
…
�n
new
ew vehicle technology can deliver big advantages by
by
keeping the third fuel distinct.
�T
The
he benefits of the new fuel are perceived and shared
shared
amongst the many stakeholders.
A taste of R&D
�
Mechanical Engineering, Nov. 2009:
– “Blending Diesel Fuel with Gasoline can
improve diesel engine fuel efficiency by an
average of 20%...the best tests achieved
average
achieve
53% thermal efficiency”
– This engine invented by Rolf Reitz was a dual­
dual­
fuel variant on HCCI
A proposed
proposed new engine: HCCI
(homogeneous charge compre
esssion
sion ignition)
Gasoline SI
Fuel/Air
Diesel
Air
HCCI
Fuel/Air
Premixed?
�
�
�
CI?
�
�
�
Ignition
Spark
Injection
Chemistry
Peak T
Hot: NOx
Hot: NOx
Cool
Temperature Distribution Strongly Affects
Ignition Chemistry
Temperature field (TDC)
1250 K
1200
1150
1100
1050
Side View
�
–
–
–
–
�
Top View
Basis:
Ba
Basis:
sis:
1000
2­d calculation (pancake cylinder)
no chemistry
working fluid is pure air
thermal correction applied later
Mesh:
950
900
850
800
– 160 x 190 grid
– coarser mesh in core
– fine mesh in BL (60 µm spacing)
750
Calcs using KIVA, by A. Amsden, LANL
Ch
C
hemistry
emistry can be quite complex
4500
Popular Kinetic
Models for Fuel Chemistry
Reactions
Number of Reactions
3500
1000
iso-octane
(Curran et al.)
800
3000
n-heptane
(Curran et al.)
2500
600
2000
400
hydrogen
1500
1000
methane
(GRIMech3.0)
propane
(Marinov)
200
n-butane
(ENSIC Nancy)
500
0
0
0
1
2
3
4
5
Carbon Number
6
7
8
9
Species
Number of Species
4000
PRF
(Curran et al.)
Ea
E
ach
ch chemical reaction has its own
(complicated) story
CH3 + H2CO → CH4 + HCO
-11
se
ec
log(k) cc/molec s
c
-12
-13
-14
-15
-16
-17
Susnow et al., Chem. Phys. Lett. 1999
-18
0
0.5
1
1.5
2
2.5
3
3.5
1000/T
Courtesy of Elsevier, Inc., http://www.sciencedirect.com. Used with permission.
Wh
W
hat
at Speed­
Speed­Load Range c
ca
an
n this HCCI engine deliver?
Fuel =
n-heptane
C.R.=9.5
Figure removed due to copyright restrictions. See Figure 14 in Yelvington, Paul E., et al.
"Prediction of Performance Maps for Homogenenous-Charge Complression-Ignition Engines."
Combustion Science and Technology 176 (August 2004): 1243-1282.
Boost =
0.7 bar
Yelvington
et al.,
Combust.
Sci. Tech.
(2004).
Integrating engine’s performance over the driving cycle
Morgan Andreae
PhD thesis 2006
With this information,
can estimate mpg for new engine/fuel combo
MIT OpenCourseWare
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Introduction to Sustainable Energy
Fall 2010
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