Potential Contributions of Biomass Toward Sustainable...
Transcript of Potential Contributions of Biomass Toward Sustainable...
Potential Contributions of Biomass Toward Sustainable Energy
Larry BaxterBrigham Young University
Provo, UT 84602
GCEP Conference Beijing, China
August 22-23, 2005
Global and Detailed Overivew
• Energy Industry (10 km)• Biomass Resource Characteristics (3 km)• Overview of Technical Issues (1 m)• Fuel Conversion Issues (1 mm)• Desirable process characteristics (3 km)• Conclusions (40 Mm)
US Energy Flow Diagram - 2001
Combustion fraction of total energy (85%)Source: Energy Information Administration, Annual Energy Review 2001
Units in Quads
International Energy Supplies
0.75
0.8
0.85
0.9
0.95
1
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001Year
Com
bust
ion
Frac
tion
of E
nerg
y C
onsu
mpt
ion
OECD Non OECD OPEC
EU IEA World Total
Energy and Economy
90
80
70
60
50
40Ene
rgy
Con
sum
ptio
n (Q
uadr
illio
n B
TU)
200019901980197019601950
Year
8000
6000
4000
2000
GD
P (B
illion
199
6 D
olla
rs)
Energy GDP
(linear correlation coefficient = 0.95)
Environmental Impacts
Impacts Quantified
Resource Depletion Climate change Health Impactsden Uil et al., 2002
Impacts Quantified
Smog, Haze, VOCs, etc.
Acid Rain, etc. Water Pollution, etc.
den Uil et al., 2002
US CO2 Emissions
• Coal Facts and Figures:• 1 Billion Tons of Coal
Consumed
• Coal generates 54% of US Electricity
• ~ 1200 Coal-Fired Power Plants
15% of Coal Emissions
Transportation32%Electric
Other 4%
ElectricCoal 30%
Industrial21%
Other13%
Biomass Availability• Wood waste: logging residues,
sawdust, nonrecyclable paper
• Crop residues: wheat/rice straw,bagasse, almond shells
• Energy crops: poplar,switchgrass, willow
18.7 Quads of Coal
WoodResidues
~ 10%Paper~ 4%
AgriculturalResidues
~ 14%
Potential Biomass Contribution
400
450
500
550
600
650
1990 1995 2000 2005 2010
Car
bon
Em
issi
ons
(106 m
etri
c to
ns)
Year
Kyoto Protocol
Cofiring Scenario
Status Quo
Cofiring Reduces Net CO2 Emissions
1
1.5
2
2.5
3
3.5
4
0% 20% 40% 60% 80% 100%
40%
60%
80%
100%
120%
140%
Eff
icie
ncy
Mul
tiplie
r
Effective Reduction in CO2 Emissions
Po
wer
Pla
nt E
ffic
ienc
y
Thermodynamic Limit
FutureTechnology
100% Efficient
Biomass Energy Economics
Typical biomass Cost
(US$ per ton)
Cost of Electricity compared to feedstock prices,
with various conditions, incentives, or subsidies
Typical Cost of Energy from Conventional Co-firing Combustion
Acknowledgement: Graph provided by Antares Group Inc
PTC – proposed production tax credit
Incentive, e.g., Green Pricing Premium
Fuel Prices
$0.00$0.50$1.00$1.50$2.00$2.50$3.00$3.50$4.00$4.50
Biodeisel BGFT Corn Ethanol Petroleum
$/ga
l gas
equ
ival
ent Retail Prices
Production Prices
Biomass Cofiring Best Uses Resource
0.4
0.5
0.6
0.7
0.8
0.9
1
Effic
ienc
y/C
oal E
ffici
ency
Cofired Units(demonstation and optimized)
Dedicated Unit Increasing Size
10 MWe 60 MWe
Transporation Fuel Impact
2-4% of US oil supply could be offset from forest process industry residues.
Fuel Properties2.0
1.5
1.0
0.5
0.0
H:C
Mol
ar R
atio
1.00.80.60.40.20.0
O:C Molar Ratio
SemianthraciteBituminous Coal
Subbituminous CoalLignite
Anthracite
Cellulose
Average BiomassWood
Grass
Lignin anthracite semianthracite bituminous coal subbituminous coal lignite peat biomass black liquor
average values
Peat
Black Liquor
Typical Fuel Properties
Elemental Compositions Differ
Black Thunder Pittsburgh #8
Imperial Wheat Straw Red Oak Wood Chips
C
H
N
S
Cl
Ash
O (diff)
COAL:
BIOMASS:
Pittsburgh #8
7.8% Ash
Imperial Wheat Straw
15.4% Ash
Red Oak
1.3% Ash
Black Thunder
7.2% Ash
SiO2
Al2O3
TiO2
Fe2O3
CaO
MgO
Na2O
P2O5
K2O
SO3
Cl
COAL:
BIOMASS:
Ash Compositions Differ
Commercial Fuel Mix Varies
Woodland Fuel Mix, Spring-Summer 1993
0%
20%
40%
60%
80%
100%
23-A
pr
30-A
pr
7-M
ay
14-M
ay
21-M
ay
28-M
ay
4-Ju
n
11-J
un
18-J
un
25-J
un
2-Ju
l
9-Ju
l
16-J
ul
23-J
ul
30-J
ul
6-A
ug
13-A
ug
20-A
ug
27-A
ug
EucalyptusAlmondCoffeeMich CalPit MixPitsSawdustShellsPruningsPine DustWhite PineWEYCOUWW
No Unusual NOx Synergies
0
200
400
600
800
1000
0 200 400 600 800 1000
15% SW G33% SW G66% SW G58% W C 20% W C
Mea
sure
d N
O X (p
pmv,
dry
)
P red icted N OX (ppm v, dry)
Alfalfa Generates NH3
0 .4
0 .3
0 .2
0 .1
0 .0
Sign
al (a
rbitr
ary)
1 1 2 51 1 2 01 1 1 51 1 1 01 1 0 51 1 0 0
W ave num b e r (cm -1)
C alib ratio n @ 1 0 0 0 p p m NH3 A lfalfa C alib ratio n @ 2 5 0 p p m NH3 Natural G as
NOx Behavior Complex (No Surprises)
200
150
100
50
0
Axia
l dist
ance
(cm
)
-20 0 20Radial distance (cm)
500
450
450
450 450
450
400
400
400
400
400 400
400
350 350 350
350
350
350
3
50
350
300
300
250 2
00
200
150
150
100 100
50
50
200
150
100
50
0
Axia
l dist
ance
(cm
)
-20 0 20Radial distance (cm)
450 450
450
400 400
400
400
400
400
400 400 400
400
400
350
350
300 250 250 200 200
150 150 100
100 50 50
200
150
100
50
0
-30 -20 -10 0 10 20 30
600
6
00
600 600
550
550 550
550 500
500
450
450
400
400
400 350
350
350
300
300
250 250
200
150
100 100 100 50 50
Straw (φ = 0.6) Coal (φ = 0.9) 70:30 Straw:Coal (φ = 0.9
NO
NH3
Stoichiometry and Temperature Impacts
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0.9 1.0 1.1 1.2
Nominal Reburn Zone Equivalence Ratio
Nor
mal
ized
NO
x (bo
th d
ry a
t 3%
O2)
900 C, 250 ppm
1200 C, 500 ppm
900 C, 500 ppm
1200 C, 250 ppm
Alfalfa
Cofiring Deposition
Deposition Rates Vary Widely• Cofiring biomass can
lead to either decrease or increase in deposition rates.
• Cofiring decreases deposition relative to neat fuels.
0.01
0.1
1
10
100
Dep
ositi
on R
ate
(gm
dep
osit/
kg fu
el)
Woo
d
Sw
itchg
rass
Str
aw
Whe
at S
traw
Pitt
sbu
rgh
#8
Eas
tern
Ken
tuck
y
Commercial Stoker
Slag Screen
SecondarySuperheater
PrimarySuperheater
BoilerGenerator Bank
Stokers
Overfire Air
Grate
Stoker
Fuel Bin
1
2 3
4
5
Deposits Dissimilar to Fuel
SiO2 Al2O3 TiO2 Fe2O3 CaO MgO Na2O K2O P2O5 SO30
10
20
30
40
50
60
Mas
s P
erce
nt [-
]
Fuel
Ceiling/Corner Deposit
Composition Maps Support Corrosion Hypothesis
Cl S Fe
100% Imperial Wheat Straw
85% E. Kentucky 15% Wheat Straw
Fuel Properties Predict Corrosion
Increasing Time
Oxygen Isosurfaces
Striations in T-fired Units
Vapor deposition
Vapor deposition flux [g/m2/h]
Strength
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
40.00
45.00
1 3 7 28 56 91 365
Day
Com
pres
sion
(MPa
)
Cement
Class C
Class F
SW1
SW2
Wood
Wood C
Wood F
Compression test
RGB Camera Performance
0
5
10
15
20
25
30
0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Wavelength (micron)
Spec
tral
Res
pons
ivity
[(D
N)/(
nJ/c
m^2
)]
Red
Green (R)
Green (B)
Blue
Optical Signal Validation
800
900
1000
1100
1200
1300
1400
1500
1600
800 900 1000 1100 1200 1300 1400 1500
T exp, K
T ca
lcul
ated
, K
Optical Signal Validation
800
900
1000
1100
1200
1300
1400
1500
800 900 1000 1100 1200 1300 1400 1500
Blackbody Temperature, K
Cal
cula
ted
Tem
pera
ture
, K
CalculatedtemperatureBlackbodytemperature
Surface Temperature & Emissivity
Devolatilization
Char burning (0.26 s later)
Measurable range (1000-1800 K), -40 ~ 80 K uncertainty
Combustion History: Switchgrass
0
0.2
0.4
0.6
0.8
1
0 0.5 1 1.5 2 2.5 3 3.5 4
Vol
ume
(mm
3 )
Time (s)
Char Oxidation
Devolatilization
Heat &Dry
Initial nominal diameter = 3 mm
Typical Mass/Temperature Data
0 10 20 30 40200
400
600
800
1000
1200
1400
0.0
0.2
0.4
0.6
0.8
1.0
Mas
s Lo
ss
T Center T SurfaceTe
mpe
ratu
re, K
Time, s
Mass Loss
Isothermal Approximation
0 2 4 6 8 10 12200
400
600
800
1000
1200
1400
-0.1
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
Tem
pera
ture
, 'K
Time, s
E F
0 10 20 30 40 50200
400
600
800
1000
1200
1400
-0.1
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
3/8" poplar in N2
Mas
s Lo
ss
Tem
pera
ture
, 'K
Time, s
Shape Impacts
0 5 10 15 20 25 30 35 40-0.1
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0M
ass
Loss
, 1-m
/m0
Residence Time, s
in N2
d = 11 mm. Plate (exp.) Plate (model) Cylinder (model) Cylinder (exp.) Near-sphere (exp.) Near-sphere (model)
Impacts on Conversion Time
-2 0 2 4 6 8 10 12 14 16 18
1.0
1.2
1.4
1.6
1.8
2.0
2.2 Near-sphere/Plate, exp Cylinder/Plate, exp Plate/Plate Near-sphere/Plate, model Cylinder/Plate, model
Con
vers
ion
Tim
e R
atio
Equivalent Diameter, mm
AR=5.0, in N2
Impacts on Conversion Time
0 2 4 6 8 10 12 14 16 18 200.5
1.0
1.5
2.0
2.5
3.0
Con
vers
ion
Tim
e R
atio
Equivalent Diamter, mm
near-spherical/plate - exp. cylinder/plate - exp. plate/plate near-spherical/plate - model cylinder/plate-model plate/plate
AR=8, in N2
Impacts on Temperature
-5 0 5 10 15 20 25 30 35 40 45 50 55200
300
400
500
600
700
800
9001000
1100
1200
1300
1400
Tem
pera
ture
, K
Time, s
Center (TC) Surface (TC) Surface (Camera 1) Surface (Camera 2) Surface (Camera 3) Center (model) Surface (model)
d=11mm in N2
Tw=1373 KTg=1050 K
In Situ Experimental Data
Chlorine Controls Aerosol Amount
Chenevert
0.001
0.01
0.1
1
10
0.1 1 10aerodynamic diameter, µm
d(M
/Mo)
/dln
(d)
0.12% Cl, 0.17% Alkali 0.16% Cl, 0.25% Alkali0.01% Cl, 0.09% Alkali 0.01% Cl, 0.48 % Alkali
High-chlorine Aerosol Composition
Si 13% Al
4%Ca5%
Na17%
K14%
Cl45%
S 2%
Chenevert
Low-chlorine Aerosol Composition
Si45%
Al12%
Mg3%
Ca20%
Na6%
K9%
S 5%
Chenevert
Basic Compounds Poison CatalystsCatalyst Activity vs. Na Poison Amount
0.000.100.200.300.400.500.600.700.800.901.00
0 0.5 1 1.5 2 2.5 3
Poison Ratio (Na:V)
Act
ivity
(k/k
0)
BYU wetBYU dryChen et al.
1.0
0.9
0.8
0.7
0.6
0.5
0.4
NO
Con
vers
ion
340320300280260240
Temperature (OC)
M1 Catalyst Fresh Fresh Fit Exposed 2063 hr Exposed 2063 hr Fit Exposed 3800 hr Exposed 3800 hr Fit
20
18
16
14
12
10
8
6K
, cm
3 /g*s
590580570560550540530520Temp, K
Light sulfatedA = 27045 +/- 7580Ea = 34556 +/- 1270
FreshA = 17736 +/- 21500Ea = 34640 +/- 5720
24-hour sulfatedA = 28527 +/- 18400Ea = 34737 +/- 2920
24-hour sulfated fit 24-hour sulfated CI_24HSK Lightly sulfated fit lightly sulfated CI lightly sulfated Fresh fit fresh CI_KF
Ultimate Best Practices Attributes
• Use of residues• Integration in existing industry• Production of fungible product• Broad opportunity• Focus on objective (climate change,
sustainable energy, energy security, etc.)
Bottom-line Conclusions
• Any solution to the global climate change problem involves all of the following:• All practical renewable energy options• Storage and capture• Substantial increase in nuclear power• Substantial change in lifestyle in
developed world
Australia is the Key
Acknowledgements
• 12 Graduate Students and 163 Undergraduate students at BYU
• DOE, EPRI, Eltra, and many industrial collaborators
• Faculty and staff collegues