Transcript Power From Coal Without Emissions

Sustainable Fossil Fuels?
Klaus S. Lackner
Columbia University
April 2004
World Needs Low Cost Energy
• person)
50,000
U.K.
20,000
AFFLUENCE
Fossil Energy
contributes 80 to
90% of the total
World Energy
U.S.A.
Japan
France
Mean Gross Domestic Product Per Capita ($/yr
10,000
South Korea
5000
U.S.S.R.
2000
Poland
SLOPE = 23¢/kW•hr
Mexico
1000
500
China
200
100
Bangladesh
POVERTY
0.01
0.10
1.0
10
100
Cannot eliminate
the biggest
resource from
the world market
Mean Power Consumption Per Capita, kW/person
10 billion people trying to consume energy as US citizens
do today would raise world energy demand 10 fold
Fossil Fuels Vital
For World Economy
Solar
1%
Nuclear
6%
HydroElectric
7%
Coal
25%
Natural Gas
22%
Petroleum
39%
… but this does not make them sustainable
Fossil Carbon Accumulates in the Air
CO2 increase in the atmosphere accounts for 58% of all fossil CO2 emissions
Atmospheric Carbon Dioxide
Changes in the industrial
age are large on a
geological scale
at Mauna Loa Hawaii
370
360
+4
350
Industrial
age CO2
increase
340
330
320
310
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
Year
Anthropogenic increase of
carbon dioxide is well
documented for 20th century.
CO2 (ppmV)
350
+2
300
0
-2
250
-4
-6
200
-8
150
-400000
-300000
Petit et al., Nature 399
Vostok, Antarctica Ice Core data
-200000
-100000
Age (years)
0
-10
Temperature Changes (ºC)
Carbon Dioxide Level
(ppmv)
380
Coal
Scales of Potential
Carbon Sinks
21st
Century’s
Emissions
???
Atmosphere
2000
1800
Soil &
Detritus
Ocean
pH
< 0.3
39,000
Gt
Plants
8,000 Gt
Gt
???
7,000 Gt

Carbon Sources and Sinks
Oil, Gas,
Tars &
Shales
50,000
6,000 Gt
Methane
Hydrates
5,000 Gt
4,000 Gt
3,000 Gt
4
2,000 Gt
3
2
1,000 Gt
constant
20th
Century
0 Gt
Carbon Resources
5
4
3
2
180ppm
increase in
the air
The
Mismatch
in Carbon
Sources
and Sinks
1
50%
increase
in
biomass
30% of
the Ocean
30%
increase in acidified
Soil Carbon
1800
2000
Fossil Carbon
Consumption to date
Hydrogen economy cannot run
on electricity
There are no hydrogen wells
Wind, photovoltaics and
nuclear energy cannot.
$30.00
Price per GJ
Tar, coal, shale and biomass
could support a hydrogen
economy.
Price Ranges for Raw
Fossil Energy Resources
$25.00
$20.00
$15.00
$10.00
$5.00
$0.00
Coal
Gas
Oil
Electricity
Net Zero Carbon Economy
CO2 from
concentrated
sources
CO2
extraction
from air
Capture of distributed emissions
electricity or hydrogen
Permanent &
safe
disposal
Mineral carbonate disposal
Sustainability
A technology or process is sustainable at
a specific scale and for a specific time,
if no intended or unintended
consequences will force a premature
abandonment
Public Institutions
and Government
guidance
Carbon Board
certification
Private Sector
Carbon
Extraction
Farming, Manufacturing, Service,
etc.
Certified Carbon Accounting
certificates
Carbon
Sequestration
Net Zero Carbon Economy
CO2 from
concentrated
sources
CO2
extraction
from air
Permanent &
safe
disposal
Lake Michigan
21st century carbon
dioxide emissions
could exceed the mass
of water in Lake
Michigan
Short Term Answers
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Enhanced Oil Recovery
Coal Bed Methane Extraction
Injection into abandoned wells
Injection into deep saline reservoirs
Ultimately carbonic acid must be neutralized
Constraints on Disposal Methods

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Safe Disposal
Minimum Environmental Impact
No Legacy for Future Generations
Permanent and Complete Solution
Economic Viability
Slow Leak (0.1%/yr)
Economically tolerable:
1 cent/kWh
$20/t of CO2
Nuclear Energy Limit:
$60/t of CO2
$10/ton of CO2:
 8.5¢/gallon
5 Gt/yr for 1000 years
Storage
Fast leaks are catastrophic (Lake Nyos)
Slow leaks cause greenhouse emissions
Dilution causes irrevocable change
5000 Gt of C
200 years at 4 times current rates of emission
Current Emissions: 6Gt/year
Energy States of Carbon
The ground state of
carbon is a mineral
carbonate
Carbon
400 kJ/mole
Carbon Dioxide
60...180 kJ/mole
Carbonate
Net Carbonation Reaction for
Serpentine
Mg3Si2O5(OH)4 + 3CO2(g)  3MgCO3 + 2SiO2 +2H2O(l)
heat/mol CO2 = -63.6 kJ
Accelerated from 100,000 years to 30 minutes
P e rid o tite a n d S e rp e n tin ite O re B o d ie s
Magnesium resources that far exceed
world fossil fuel supplies
Rockville Quarry
ZECA Process
1 GW Electricity
Coal Strip
Mine
Earth Moving ~40 kt/day
28 kt/day
36% MgO
Zero Emission
Coal Power Plant CO2
Coal
4.3 kt/day
Mineral
Carbonation
Plant
Open Pit Serpentine
Mine
Sand & Magnesite
~35 kt/day
70% Efficiency
11 ktons/day
Heat
~1.4 kt/day Fe
~0.2 kt/day Ni, Cr, Mn
Mining, crushing & grinding: $7/t CO2 — Processing: $10/t CO2 — No credit for byproducts
Serpentine and Olivine
are decomposed by acids
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Carbonic Acid - Requires Pretreatment
Chromic Acid
Sulfuric Acid, Bisulfates
Oxalic Acid
Citric Acid
…
ALBANY’S SUCCESS
W.K. O’Conner, D.C. Dahlin, D. N. Nilsen, R. P. Walters & P.C. Turner
Albany Research Center, Albany OR
Mg3Si2O5(OH)4+3CO2(g)  3MgCO3+2SiO2+2H2O(l)
200,000 years reduced to 30 minutes
Suggests simple cost-effective implementation
Acid Recovery: Solvay Process
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
Neutralize with ammonia
Recover through heating
Net Zero Carbon Economy
CO2 from
concentrated
sources
CO2
extraction
from air
Permanent &
safe
disposal
Zero Emission
Principle
Air
Carbon
 
CO2
N2
H2O
SOx, NOx and
other
Pollutants
Need better
sources of
oxygen
Power Plant
Solid Waste
CaO as an enthalpy carrier
CaO + C + 2H2O  2H2 + CaCO3 + 0.6 kJ
O2 + 2H2  2H2O + 571.7 kJ
CaCO3 + heat  CaO + CO2
Compare to
C + O2  CO2 + 393.5 kJ
392.9 kJ
Output
Zero Emission Coal
H2O
CO2
H2O
H2O
Cleanup
H2O
Air
H2O
CaO + C + 2H2O  CaCO3 + 2H2
Gas Cleanup
CH4, H2O
CaCO3
De-
Gasifier
Calciner
carbonizer
Coal
Slurry
CO2
Heat
CaO
H2
Fuel
Cell
CO2
Lime/Limestone Cycle
Polishing Step
Ash
H2
H2
Closed Cycle for Gas
N2
Net Zero Carbon Economy
CO2 from
concentrated
sources
CO2
extraction
from air
Permanent &
safe
disposal
Ca(OH)2 as an absorbent
Air Flow
CO2 diffusion
Ca(OH)2 solution
CaCO3 precipitate
CO2 mass transfer is limited by diffusion in air boundary layer
1 m3of Air
40 moles of gas, 1.16 kg
wind speed 6 m/s
mv
2
 20 J
2
CO2
0.015 moles of CO2
produced by 10,000 J of
gasoline
Volumes are drawn to scale
How much wind?
(6m/sec)
Wind area that
carries 10 kW
0.2 m 2
for CO2
Wind area that
carries 22 tons
of CO2 per year
80 m 2
for Wind Energy
Wind Energy
v = 6m/s
130 W/m2
Extraction from Air
Power Equivalent
from gasoline
Sunshine
200 W/m2
v = 6 m/s
60,000 W/m2
Biomass
3 W/m2
Areas are drawn to scale
60m by 50m
3kg of CO2 per second
90,000 tons per year
4,000 people or
15,000 cars
Would feed EOR for 800
barrels a day.
250,000 units for
worldwide CO2 emissions
Boundary Layer
Wind Energy - CO2 Collection
Wind Energy
CO2 Collection
• Convection tower,
Wind Mill etc.
• Convection tower,
absorbing “leaves”, etc.
• Extract kinetic energy
• Extract CO2
• Wind Turbines
• Sorbent Filters
• 30% extraction efficiency
• 30% extraction efficiency
• Throughput
130W/m2 @ 6m/s wind
• Cost
$0.05/kWh
• Throughput
0.64g/(s·m2) @ 6m/s wind
• Cost by analogy
$0.50/ton of CO2
Additional Cost in Sorbent Recovery
Ion exchanger:
A First Attempt
Na2CO3 + Ca(OH)2 
2Na(OH) + CaCO3
Calciner:
Air contactor:
2Na(OH) + CO2  Na2 CO3
CaCO3CaO+CO2
Objections

CO2 in air is too dilute
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Cross section of structure is affordable
Binding energy of sorbent scales logarithmically
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G = RT log P/P0
Liquid absorbers will saturate
Energy consumption diverges
Cost of sorbent recovery
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CaCO3+ 180 kJ CaO + CO2
CaO + H2O  Ca(OH)2 + 65 kJ
15
km3/day
of air
115m
15 km3/day of air
300m
Cross section
10,000 m2
As
electricity
producer
the tower
generates
3-4MWe
Water sprayed
into the air at
the top of the
tower cools
the air and
generates a
downdraft.
air fall velocity
~15m/s
9,500t of
CO2 pass
through
the tower
daily.
Half of it
could be
collected
Cooling Tower Design
Diameter ratio of
smoke stack to
capture tower is
3001/2 =17
Any design
that moves air
can be used
for CO2capture
Exotic Designs
Process Schematic
Ca(OH)2
NaOH
Hydroxylation
Reactor
(4)
CaO
Fluidized
Bed
CO2
H 2O
H 2O
(1)
Na2CO3
Capture
Device
(2)
Trona
Process
CaCO3
(6)
CaCO3
Limestone
Precipitate
Dryer
Oxygen Depleted Air
Source: Frank Zeman
(3)
O2
(5)
Combined
CombustionSeparation
CH4
Solid Oxide
Membrane
Air
(O2, N2)
Net Zero Carbon Economy
CO2 from
concentrated
sources
CO2
extraction
from air
Capture of distributed emissions
electricity or hydrogen
Permanent &
safe
disposal
Mineral carbonate disposal
Materially Closed Energy Cycles
O2
CO2
CO2
O2
Energy
Source
H2
H2 CH2
H2O
H2O
Energy
Consumer
Sustainable on indefinite
time scales