Biomass as Energy Resource
John Jechura – jjechura@mines.edu
Updated: January 4, 2015
Energy Markets Are Interconnected
https://publicaffairs.llnl.gov/news/energy/energy.html
2
Combustion
• Conversion efficiency ‐ 20‐25% to power
• Mineral management
• Emissions NOx, SOx, CO, particulate
• Mature technology
3
Petroleum Production
"Fossil fuels are a one‐time gift that lifted us up from subsistence agriculture and eventually should lead us to a future based on renewable resources." Hubbert's Peak: The Impending World Oil Shortage
by Kenneth S. Deffeyes 4
Biomass Pros & Cons
Pros:
Cons:
• Domestic benefits
• Lower energy density
 Reduced trade deficit
• Solids difficult to handle
 Create jobs
• High water content
 Strengthen rural economies
 Local raw materials
• Renewable resources
• Carbon cycle to reduce build up of greenhouse gases
• Technology improvements should continue to reduce costs
• Competing uses as high value food stuff
• Symbiotic relationship — producers & users
• Commercial Issues
 Biomass feedstock, availability, & cost
 Suitable sites
 Production technologies
 Qualified owner‐operator
 Project financing
5
Clean Air Act & Amendments
• Series of Clean Air Acts
 Air Pollution Control Act of 1955
 Clean Air Act of 1963
 Air Quality Act of 1967
 Clean Air Act Extension of 1970
 Clean Air Act Amendments in 1977 & 1990
• 1977 Clean Air Act amendments set requirements for "substantially similar gasoline"  Oxygenates added to make motor fuels burn more cleanly & reduce tailpipe pollution (particularly CO)
 Required that oxygenates be approved by the U.S. EPA  MTBE & ethanol primary choices
• California Phase 3 gasoline regulation approved by California Air Resources Board in December 1999 prohibits gasoline with MTBE after December 31, 2002
 Water quality issues
6
2007 Renewable Fuel Standard
Energy Independence & Security Act of 2007
Year
Renewable Fuel
Standard
Advanced
Biofuels
Cellulosic
Biofuel
RFS - AB
Mgal/yr
Mgal/yr
Mgal/yr
Mgal/yr
2006
4,000
4,000
2007
4,700
4,700
2008
9,000
9,000
2009
11,100
600
2010
12,950
950
40,000
35,000
30,000
10,500
100
12,000
25,000
Millions
2011
13,950
1,350
250
12,600
2012
15,200
2,000
500
13,200 G allons
2013
16,550
2,750
1,000
13,800
2014
18,150
3,750
1,750
14,400
2015
20,500
5,500
3,000
15,000
5,000
2016
22,250
7,250
4,250
15,000
0
2017
24,000
9,000
5,500
15,000
2018
26,000
11,000
7,000
15,000
2019
28,000
13,000
8,500
15,000
2020
30,000
15,000
10,500
15,000
2021
33,000
18,000
13,500
15,000
Administered by the Environmental Protection Agency
2022
36,000
21,000
16,000
15,000
http://epa.gov/otaq/renewablefuels/index.htm
Annual 20,000
15,000
10,000
Advanced Biofuels
Corn Stach Derived Ethanol (Max)
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022
7
EPA Clarifications & Adjustments
• RFS‐2 Advanced Biofuels amounts have had to be adjusted since 2010
 Significantly less development of cellulosic biofuels than had been anticipated in 2007
• Adjustments have been required each year
 Have needed to drastically reduce Cellulosic Biofuel
 Increases allowed biodiesel  Have started to expand the types of allowable advanced biofuel
 Proposed 2014 amounts are lower than Standard – takes into account “blend wall” & actual fuel sales
Ref: http://epa.gov/otaq/fuels/renewablefuels/regulations.htm
8
Cellulosic Biofuels Projects?
Last EIA update: February 26, 2013
Ref: http://www.eia.gov/todayinenergy/detail.cfm?id=10131
9
Typical Elemental Analyses:
Fossil Fuels, Biomass, & Biofuels
10
1st Generation Biofuels
• Ethanol
 Typically derived from fermentation of sugars & starches
• US: Corn starch
• Brazil: Sugar cane juice
• Biodiesel
 FAME – Fatty Acid Methyl Ester
 From fats and oils
• US: Soybean oil
• Europe: Rapeseed oil 11
Edible Constituents of Biomass
•Starch: 70%–75% (corn)
• Readily available and hydrolysable
• Basis for existing U.S. “biorefineries”
•Oil: 4%–7% (corn), 18%–20% (soybeans)
• Readily separable from biomass feedstock
• Basis for oleochemicals and biodiesel
•Protein: 20%–25% (corn), 80% (soybean meal)
• Key component of food
• Chemical product applications 12
Ethanol From Corn Starch
• Two primary processing options
 Wet mills
• Expensive to build – not common
• Sophisticated operations
• Multiple products
o
Fuel, food, & fiber
 Dry mills
• Most common – fairly simple operations
o
Processing options making more sophisticated
• Limited products – primarily ethanol & DDG/DDGS
o
More sophisticated operations may add germ, fermentation co‐products, … 13
Ethanol from Corn vs. Sugar Cane
Starch
Saccharification &
Fermentation
Dilute
Ethanol
Distillation,
Rectification, &
Dehydration
Whole Stillage
Liquifaction
Centrifugation
Thin
Stillage
Evaporation
Recyclable
Water
Syrup
Wet DDG
Fermentation
Juice
Juice
Ex traction
Bagasse
(Fiber)
Dilute
Ethanol
Distillation,
Rectification, &
Dehydration
Dried
Bagasse
Power
Evaporation
Recyclable
Water
Drying
Power
14
Worldwide Ethanol Capacity
Annual World Ethanol Production by Country
(Millions of Gallons, All ethanol Grades)
4,491
5,019
6,472
1,004
1,017
486
502
India
462
449
502
53
66
Europe
858
929
1,030
570
734
Thailand
74
79
93
79
90
Canada
61
61
153
211
238
Australia
Others
Total
33
33
39
26
26
794
1,104
1,309
158
208
10,770
12,150
13,489
13,102
17,335
9,000
8,000
7,000
6,000
Million Gallons (All
Ethanol Grades)
Source: F.O. Licht
http://www.ethanolrfa.org/industry/statistics/#E
5/28/2009
5,000
4,000
3,000
2,000
1,000
2008
0
2006
2004
Others
4,227
964
Australia
3,989
China
Canada
Brazil
Thailand
2008
9,000
Europe
2007
6,499
India
2006
4,855
China
2005
4,264
Brazil
2004
3,535
U.S.
Country
U.S.
15
Current US Ethanol Capacity
Historic U.S. fuel Ethanol Production
Year
Millions of
Gallons
1980
175
1981
215
8000
1982
350
7000
1983
375
1984
430
1985
610
1986
710
1987
830
1988
845
1989
870
1990
900
1991
950
1992
1,100
1993
1,200
1994
1,350
1995
1,400
1996
1,100
1997
1,300
1998
1,400
1999
1,470
2000
1,630
2001
1,770
2002
2,130
2003
2,800
2004
3,400
2005
3,904
2006
4,855
2007
6,500
2008
9,000
9000
6000
Millions of Gallons
5000
4000
3000
2000
1000
0
1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008
http://www.ethanolrfa.org/industry/statistics/#A
7/21/2008
16
Criticisms of Ethanol
• Food vs fuel
 Divert land from growing food to growing fuel
• Just a farmer subsidy
• Ethanol not compatible with gasoline infrastructure
 RBOB – special blend stock to allow for RVP increase at E10 levels
 Picks up water
• Cannot be transported in petroleum pipelines – use water slugs between batches
• Takes more energy to make that you get back
 Based on “wells to wheels” Life Cycle Assessment
 LCA normally compare energy out vs. fossil energy in
 Highly dependent upon feedstock, farming practice, processing, … • Takes too much water to make
 Highly dependent upon feedstock, farming/irrigation practice, processing, …
17
U.S. Corn Yield & Amount to Ethanol
180
160
U.S. Corn Yield [bu/acre]
140
120
100
80
60
40
20
0
1840
1860
1880
1900
1920
1940
1960
1980
2000
2020
Year
http://quickstats.nass.usda.gov/results/AFBDFE1E‐1AFC‐35DE‐8A93‐
7FB72F0DA089?pivot=short_desc
http://ethanol.typepad.com/my_weblog/2011/01/response‐to‐the‐wsj‐
ethanol‐is‐not‐reducing‐the‐amount‐of‐corn‐for‐food.html#tp
18
Corn Ethanol Energy Balance
40,000
30,000
Lorenz and Morris
Net Energy Value (Btu/gallon)
20,000
Marland and Turhollow
10,000
Shapouri et al.
Agri. Canada
Shapouri et al.
Kim and
Wang
Wang et al.
Dale
Graboski
0
-10,000
Ho
Keeney and DeLuca
-20,000
-30,000
Pimentel
Pimentel
-40,000
1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
Source: M. Wang (2003)
19
A Response to Five Ethanol Criticisms
• Ethanol requires more energy to make than it yields?
 ANL research has shown corn ethanol delivers positive
energy balance of 8.8 MJ/L (32,000 Btu/gal). • Corn production efficiency has increased dramatically –
160 bu/acre today vs. 95 bu/acre in 1980
• Ethanol production more energy‐efficient in modern dry mills vs. older wet mills
• Ethanol yield per bushel also increased about 50% since 1980
• Ethanol production reduces our food supply?
 Only 1% of corn grown in U.S. eaten by humans. Rest is No. 2 yellow field corn, indigestible to humans; used in animal feed, food supplements and ethanol.
 Bushel of corn used for ethanol produces 1.5 lbs corn oil, 17.5 lbs high‐protein DDGS, 2.6 lbs corn meal, & 31.5 lbs
starch.
• Starch used for sweeteners or produce 2.8 gal ethanol. • DDGS displaces whole corn & some soybeans used in animal feed.
• Ethanol requires too much water to produce?
 Amount of water used to make ethanol has declined dramatically. Requirements today are about 3.5 gallons water/gallon ethanol.
• Little more than it takes to process a gallon of gasoline.  Much of the criticism about ethanol’s water requirements stem from irrigation of feedstock crops in drier climates. However, most ethanol is produced crops grown in the Midwest without irrigation.
• Cars get lower gas mileage with ethanol?
 True on a mile per gal basis. E85 about 25% lower mpg than gasoline.
 However, depending on cost of ethanol could have a lower dollars per mile.
 Higher octane of ethanol could lead to modified engines (compression ratios & valve timings) that are optimized for ethanol use.
• Ethanol crops and production emit more greenhouse gases than gasoline?
 Blending ethanol with gasoline dramatically reduces CO tailpipe emissions & tailpipe emissions of VOCs that form ozone.
 LCA of ethanol found “at present and in the near future, using corn ethanol reduces greenhouse gas emission by more than 20%, relative to those of petroleum gasoline.” Blog by Forrest Jehlik, Argonne National Laboratory
http://www.wired.com/autopia/2011/06/five‐ethanol‐myths‐busted‐2/
20
Response to 6 Biofuel “Myths”
• 40% of the US corn crop is used to make biofuel
 13% of the US corn crop is used to make, specifically, fuel ethanol
 Per‐acre crop yields have grown significantly in recent years – taken over the long term, the US has not had to increase its corn acreage to make fuel ethanol. There’s less land used to grow grain in the US today than 100 years ago
• “Now that the United States is using 40 percent of its crop to make biofuel, it is not surprising that tortilla prices have doubled in Guatemala.”
 Two types of corn grown ‐‐ #2 yellow corn (animal feed & biorefineries) & white corn (food)
 Very little white corn grown in US. Acres dedicated to white corn in the US have not decreased since passage of the RFS.
• The world is going to climate hell and there’s nothing anyone can do about it, except starve. If you don’t die of thirst, first.
 Drought resistant strains of crops being developed by multiple companies; Ceres given as example
• Biofuels cause higher carbon emissions, instead of lowering them
 According to EPA, corn ethanol reduces greenhouse gas emissions by 20% compared to the use of fossil fuels, including contributions for direct & indirect land‐use change
• Biofuels have lower fuel economy
 Ethanol has 70% energy density compared to gasoline but higher octane rating.
 Cost per mile driven is the important factor
• Biofuels use more energy in their production than they provide as a transport fuel.
 Depending on study, energy return for corn ethanol is 1.3 to 1, sugarcane ethanol (primarily from Brazil) is 8:1, biodiesel is 2.5:1, & cellulosic biofuels range from 2:1 to 36:1
 Dependent on process improvements, …
Blog by Jim Lane, Biofuels Digest
http://www.biofuelsdigest.com/bdigest/2013/01/09/the‐biggest‐biofuels‐myths‐demythtefied/
21
Conversion of FOG (Fats, Oils & Greases)
• Biodiesel
Fats, Oils,
& Grease
Nat Gas
Water
Catalytic
Reforming &
Synthesis
Methanol
Mild Conditions
Liquid Phase
Base Catalyzed
FAME
(Biodiesel)
Glycerin
Ox ygen
• Hydrogenation
22
Biodiesel – Fats & Oils
Picture of molecule from:
“Hydrotreating in the production of green diesel”
R. Egeberg, N. Michaelsen, L. Skyum, & P. Zeuthen
Journal of Petroleum Technology, 2nd Quarter 2010 23
Biodiesel Production
Ref: http://www.endress.com/eh/home.nsf/#page/~biodiesel‐process
24
Biodiesel Production Example
Oleic Fatty Acid (18:1)
Oil
Methanol
CH3OH
C3H5‐(OOC‐C17H33)3
Formula
Molar Mass
wt% C
wt% H
wt% O
3
Density (g/cm )
Stoichiometric Coefficient
Mass
Volume
Mass Ratio
Volume Ratio
Glycerin
C3H5(OH)3
FAME
CH3‐OOC‐C17H33
885.4
77%
12%
11%
32.0
37%
13%
50%
92.1
39%
9%
52%
296.5
77%
12%
11%
0.92
1
885.4
962.4
1.00
1.00
0.80
3
96.1
120.2
0.11
0.12
1.26
1
92.1
73.1
0.10
0.08
0.90
3
889.5
988.3
1.00
1.03
Soybean oil cost (March 2014 contract) = $837.54 per tonne = $0.3799 per lb = $2.917 per gal @ 0.92 kg/L Methanol cost (December 2013) = $632 per tonne = $0.2867 per lb = $1.900 per gal @ 332.6 gal/tonne
“Hydrotreating in the production of green diesel”
R. Egeberg, N. Michaelsen, L. Skyum, & P. Zeuthen
Journal of Petroleum Technology, 2nd Quarter 2010 25
2nd Generation & Advanced Biofuels
• Cellulosic/Lignocellulosic Ethanol
 Biochemical pathway
• Utilize sugars from cellulose & hemicellulose
 Thermochemical pathway
• Utilize all carbon, including lignin
• Butanol
 More closely compatible to petroleum derived gasoline
 From fermentation (BP/DuPont)
 Gasification & catalytic synthesis
• Green/Renewable Diesel/Gasoline
 Hydrocarbon just like petroleum‐
derived products
 Multiple sources & processing paths
• Hydroprocessed fats & oils
o
Both diesel & gasoline
o
Could be integrated into existing refineries
• End product from gasification & FT synthesis
o
Excellent diesel
o
Poor gasoline – requires isomerization
26
US Biomass Resource Base
High Yield Increase
Urban Wood Residue
Pulping Liquors
Wood Residues
Fuel Wood
Fuel Treatments (Other Forestland)
Fuel Treatments (Timberland)
Other Removal Residue
Logging Residue
Soybeans
Grains to biofuels
Manures
Perennial (Energy) Crops
Corn Stover
Wheat Straw
Small grain residues
Soybean residues
CRP Biomass
Other crop residues
Other residues
0
50
100
150
200
250
300
350
400
Million Tons Annually
Perlack, R.D.; Wright, L.L.; Turhollow, A.F.; Graham, R.L.; Stokes, B.J.; Erbach, D.C. Biomass as Feedstock for a Bioenergy and Bioproducts Industry: the Technical Feasibility of a Billion‐Ton Annual Supply. A joint U.S. Department of Energy and U.S. Department of Agriculture report. DOE/GO‐
102995‐2135 & ORNL/TM‐2005/66. April 2005. 27
US Biomass Resource Base
High Yield Growth
With Energy Crops
High Yield Growth
Without Energy
Crops
Forest Resources Total
Grains & Manure Sub-Total
Existing &
Unexploited
Resources
Ag Residues (non Energy Crops)
Perennial (Energy) Crops
0
100
200
300
400
500
Million Tons Annually
Perlack, R.D.; Wright, L.L.; Turhollow, A.F.; Graham, R.L.; Stokes, B.J.; Erbach, D.C. Biomass as Feedstock for a Bioenergy and Bioproducts Industry: the Technical Feasibility of a Billion‐Ton Annual Supply. A joint U.S. Department of Energy and U.S. Department of Agriculture report. DOE/GO‐
102995‐2135 & ORNL/TM‐2005/66. April 2005. 28
Significance of the 1.3 Billion Ton Biomass Scenario
NREL analysis, July 2005, documented in:
J.L. Jechura, Ethanol Potential from Billion Ton Biomass Resource, NREL Technical Memo, May 22, 2006.
29
Non‐Edible Constituents of Biomass
•
Lignin: 15%–25%
• Complex aromatic structure
H3CO
HO
H3CO
O
OCH3
O
O
• Very high energy content
OH
OCH3OCH3
• Resists biochemical conversion
O
OH
O
•
Hemicellulose: 23%–32%
• Xylose is the second most abundant sugar in the biosphere
OCH3
•
OCH3
OH
Cellulose: 38%–50%
HO
OH
H3CO
OCH3
• Most abundant form of carbon in biosphere
OH
OH O
HO
O HO
O
OH
OH O
OH O
O
HO
HO
OH
O
O
OH
O
OH
HO
OH O
HO
O
O
O
O
O
OH
O HO
O
OH
O
OH
HO
OH O
OH
O HO
OH
OH
O
O
OH
OH O
O HO
OH
OH
O
OH
O
HO
O HO
OH O
HO
O
OH
OH O
OH
OH
O
OH
O
O HO
OH
OH
O
OH O
O HO
OH
OH O
O HO
O
OH
OH
O HO
OH
HO
HO
OH
OH
O
O HO
OH
O
O
OH
HO
O HO
O
OH
O
OH
HO
O
• Polymer of glucose, good biochemical feedstock
OH
OH
O
O
OH
OH
OH
OH
O
HO
O
O
O
O HO
OH O
O
HO
O
OH
HO
O
OH
OH
OH
OCH3OCH3
• Polymer of 5‐ and 6‐carbon sugars, marginal biochemical feed
O
OH
O
HO
OH
H3CO
OCH3
OH
O
OCH3
OH
HO
O
HO
O
OCH3
O
OH
OH
O
OH
OH O
HO
HO
O HO
OH
O
OH
HO
OH O
OH
O
O
OH
OH O
O HO
OH
O HO
OH
O
OH
OH
O
OH
OH O
HO
O HO
OH
O
OH
OH O
OH
30
Biofuels Technology “Square Dance”
Liquid Phase
Fermentation
Gas Phase
Amyris
LanzaTech
Solazyme
Coskata
Gevo
INEOS Bio
Traditional Ethanol
Virent
KiOR
Traditional Biodiesel
Enerkem
Envergent
Catalytic Conversion
Anellotech
Dynamotive
ClearFuels/Rentech
SilvaGas/Rentech
Combinations
ZeaChem: Hydrolysis, Fermentation, & Catalytic Conversion
Saphire Energy: Algae lipids to biodiesel & residual biomass to
power
http://biofuelsdigest.com/bdigest/2011/04/18/the‐biofuels‐technology‐square‐dance/
31
Biochemical Conversion Process
Feedstock Handling
Pretreatment
Corn Stover
S/L Separation
Steam &
Acid
Recycle
CO2
Liquor
Lime
Enzyme
Ethanol
Gypsum
Dewatering
Wastewater
Treatment
Steam
Distillation &
Ethanol Purification
Lignin
Residue
Saccharification
&
Fermentation
Conditioning
Burner/Boiler
Turbogenerator
Lignocellulosic Biomass to Ethanol Process Design and Economics NREL/TP‐510‐32438 June, 2002 http://www.nrel.gov/docs/fy02osti/32438.pdf
Steam
Electricity
32
Thermochemical Conversions
• Pyrolysis
 Thermal conversion (destruction) of organics in the absence of oxygen  In the biomass community, this commonly refers to lower temperature thermal processes producing liquids as the primary product
 Possibility of chemical and food byproducts
• Gasification
 Thermal conversion of organic materials at elevated temperature and reducing conditions to produce primarily permanent gases, with char, water, & condensibles as minor products
 Primary categories are partial oxidation and indirect heating
33
Syngas Products
• Hydrogen
• Methanol and its derivatives (NH3, DME, MTBE formaldehyde, acetic acid, MTG, MOGD, TIGAS)
• Olefins
• Oxosynthesis
i-C4
Ethanol
MTO
MTG
Olefins
Gasoline
se
Aldehydes
Alcohols
U
ect
h
sis
(K2O, Al2O3, CaO)
H2
,R
NH3
e
th
yn
H2O
WGS
Purify
Methanol
Di r
Co
ThO2 or ZrO 2
Acetic Acid
zeolites
Cu/ZnO
Syngas
CO + H2
Isosynthesis
N2 over Fe/FeO
Ag
)
os
u3
) 4 (B
Ox
CO ) 3P 3) 3
o( O Ph
HC Co(C O)(P
H (C
Rh
• Isosynthesis
Formaldehyde
hom
Co ologa
tion
3
d
l 2O
pe
/A
do
nO
l i3
/Z 3
ka
r 2O Cu l 2O
Al
/C ; A
O nO O/
Zn /Z Co
Cu uO/
C oS 2
M
• Mixed alcohols
Fischer-Tropsch
ca
CH rbon
y
3O
H latio
Co
+C n
,R
O
h,
Ni
Mixed
Alcohols
Fe, Co, Ru
• Ethanol
MTBE
isobutylene
acidic ion exchange
• Fischer Tropsch Liquids
Olefins
Gasoline
Al2O3
Waxes
Diesel
DME
M100
M85
DMFC
34
Thermochemical Conversion
Gasifier
Flue Gas
Reformer
Biomass
Scrubber
Dryer
Compressor
Solids
(Waste) Air
Sludge
(Waste)
Steam
Water to recycle
Steam
Acid Gas Cleanup
Air
Alcohol Separation
CO2
Sulfur
Alcohol
Synthesis
Ethanol
Compressor
Mixed
Alcohols
Methanol & Water
Personal communication Ryan Davis, National Renewable Energy Laboratory. November 2009. 35
Hydrodeoxygenation of Organic Oils
• Organic oils can be hydrotreated to form “green” diesel
 Fully compatible with petroleum derived diesel
 Excellent cetane number because of the straight chain nature
• Challenges for catalyst design
 Oxygen relatively easy to remove, but large oxygen content
 Prefer to deoxygenate to CO2 to maximize fuel usage of H2
“Hydrotreating in the production of green diesel”
R. Egeberg, N. Michaelsen, L. Skyum, & P. Zeuthen
Journal of Petroleum Technology, 2nd Quarter 2010 36
Green Diesel Production Examples
Formula
Molar Mass
%C
%H
%O
Density (g/cm3)
Stoichiometric Coefficient
Mass
Volume (Liquid)
Mass Ratio
Volume Ratio
scf/bbl
Formula
Molar Mass
%C
%H
%O
Density (g/cm3)
Stoichiometric Coefficient
Mass
Volume (Liquid)
Mass Ratio
Volume Ratio
scf/bbl
Oil
C3H5‐(OOC‐C17H33)3
885.4
77%
12%
11%
0.92
1
885.4
962.4
1.00
1.00
Oil
C3H5‐(OOC‐C17H33)3
885.4
0%
0%
0%
0.92
1
885.4
962.4
1.00
1.00
Oleic Fatty Acid (18:1)
Hydrogen
Water
H2
H2 O
2.0
18.0
0%
0%
100%
11%
0%
89%
1.00
15
6
30.2
108.1
108.1
0.03
0.12
0.11
2,071
Oleic Fatty Acid (18:1)
Hydrogen
Carbon Dioxide
H2
CO2
2.0
44.0
0%
0%
0%
0%
0%
0%
6
12.1
3
132.0
0.01
0.15
Propane
C3H8
44.1
82%
18%
0%
0.51
1
44.1
86.5
0.05
0.09
Octadecane
C18H38
254.5
85%
15%
0%
0.78
3
763.5
978.8
0.86
1.02
Propane
C3H8
44.1
0%
0%
0%
0.51
1
44.1
86.5
0.05
0.09
Heptadecane
C17H36
240.5
0%
0%
0%
0.78
3
721.4
924.9
0.81
0.96
828
37
Expectations for Hydrotreating Fats & Oils
• Configuration
 Expect to have similar configuration & materials of construction as hydrodesulfurization
• Product considerations
 Remove the produced CO2/CO/H2O  Fractionation required to remove light ends
 Different catalyst than hydrodesulfurization
• Will get additional light ends from autothermal cracking
 Lower severity expected?
• Propane & other light gases to LPG
• Oxygen easier to remove
• Fewer complex molecular structures
• But experience shows higher reactor temperatures
 Additional processing of feed?
• Hydrogen requirements
• Naphtha should go to Isomerization
 Distillate • Extremely high cetane number
• May have cloud point issues
• High portion of the boiling point fraction  5X or more than hydrodesulfurization
38
Other conversions analogous to petroleum refining
• KiOR process uses a fluidized bed catalytic cracking unit to convert biomass into petroleum‐
like gasoline, diesel, & residual fuel oil
 Demonstration plant in Columbus, MS
• 500 bone dry ton/day wood chips
• 15 bpd liquid products – 13 MMgal/yr
 Next commercial facility to be in Natchez, MS –
1,500 bone dry ton/day feedstock
http://www.kior.com
Image: http://www.kior.com/content/?s=11&t=Technology
39
Algae • Better solar collector than land‐
based biomass
- Higher solar utilization
• Lower land use requirements
- Can use brackish water
- Limitation is getting carbon to the organism
• Co‐locate with power plants – use CO2 in flue gas
• Near‐term processing steps
 Cultivation
• Open ponds
o
• Photo bioreactors – flat panel, tubular, column
o
• Biofuels potential
- Kill the algae & harvest its natural oils
• Biodiesel or biocrude feedstock
- Biocatalyst to secrete desired product
• Like yeast for fermentation
Low cost but high potential for contamination
Higher cost but more controlled conditions
 Harvesting
• High water content of algae
 Oil extraction
• Intercellular rather than intracellular
o
Usually chemical extraction
• Hydrogen production possible
40
General Cultivation & Processing of Algae
“Algal Feedstock‐Based Biofuels: Separating Myth from Reality”
A. Darzins, NREL Power Lunch Lecture Series
February 18, 2009 41
Algal Oil Extraction
“Algal Feedstock‐Based Biofuels: Separating Myth from Reality”
A. Darzins, NREL Power Lunch Lecture Series
February 18, 2009 42
Desirable Features of Growing Algal Oil
“Algal Feedstock‐Based Biofuels: Separating Myth from Reality”
A. Darzins, NREL Power Lunch Lecture Series
February 18, 2009 43
Potential Oil Yields
“Algal Feedstock‐Based Biofuels: Separating Myth from Reality”
A. Darzins, NREL Power Lunch Lecture Series
February 18, 2009 44
Resource Requirements
“Algal Feedstock‐Based Biofuels: Separating Myth from Reality”
A. Darzins, NREL Power Lunch Lecture Series
February 18, 2009 45
Illustration by Oak Ridge National Lab
46