Algae Biofuels - Colorado State University

Report
Sustainable Bioenergy Development Center - Bioenergy at CSU Seminar
October 16, 2012
Fuel Properties and Pollutant Emissions
from Algal Biodiesel, Algal Renewable
Diesel and Algal HTL Fuels
Anthony J. Marchese
Associate Prof. and Associate Dept. Head
Department of Mechanical Engineering
Colorado State University
http://www.engr.colostate.edu/~marchese
Acknowledgments
Advanced Biofuels Combustion and Characterization Laboratory
Graduate Students:
Caleb Elwell
Timothy Vaughn
Torben Grumstrup
David Martinez
Esteban Hincapie
Kristen Naber
Marc Baumgardner
Jessica Tryner
Andrew Hockett
Harrison Bucy, ‘11
Kelly Fagerstone, ’11
Bethany Fisher, ‘10
Esteban
Andrew
Harrison
Bethany
Anthony
Kelly
Kristen
Dave
Marc
Jessica
Torben
David
Tim
Review Algal Biofuels Conversion Technologies
Overview
• Motivation for Algal Biofuels
• The Algal Biofuel Value Chain Revisited
• Algal Methyl Ester Biodiesel Properties
• Algal Synthetic Paraffinic Diesel/Jet Fuel Properties
• Algal Hydrothermal Liquefaction Oil Properties
• Conclusions
Review Algal Biofuels Conversion Technologies
Overview
• Motivation for Algal Biofuels
• The Algal Biofuel Value Chain Revisited
• Algal Methyl Ester Biodiesel Properties
• Algal Synthetic Paraffinic Diesel/Jet Fuel Properties
• Algal Hydrothermal Liquefaction Oil Properties
• Conclusions
Peak Oil
Are we there yet?
The End of the Oil Age?
Peak Oil
Anomalous Age of Easy Oil is Nearing its End
Peak Oil
Anomalous Age of Easy Oil is Nearing its End
Campbell, C. J. (2012). The Anomalous Age of Easy Energy. Energy, Transport and the Environment, Springer.
The Master Equation
Fossil Fuel Depletion (A Matter of WHEN…not IF)
FFC/GDP is fundamentally
constrained by the 2nd Law of
Thermodynamics!
Non-Conventional Liquid Fossil Fuels
Substantial Resources Still Exist for GTL or CTL
Enhanced oil
recovery
Potential Liquid Hydrocarbon Production (Gbbl)
Non-Conventional Liquid Fossil Fuels
Do We Really Want to Release All of That Carbon?
Keeling Curve, CO2 at Mauna Loa
U.S. Advanced Biofuels Mandate
21 billion gal/year by 2022
• The United States typically consumes 300 Billion gallons per year of
liquid fuels:
• 130 Billion gal/year gasoline, 70 Billion gal/year diesel, 24 Billion
gal/year jet fuel
• The 2007 Energy Independence and Security Act (EISA) mandates
the production of 36 billion gallons per year of biofuels by 2022
• Corn ethanol is capped at 15 billion gallons per year.
• 21 billion gallons per year must qualify as advanced biofuels.
• Can Algal Biofuels help meet the advanced biofuels mandate?
The Case for Algae
21 billion gallons per year of “advanced biofuels” ≈ 10% of U.S. liquid onroad fuel usage ≈ how much cultivation area?
21 billion gallons per year of
soy biodiesel (≈ Alaska)
21 billion gallons per year of
algae biodiesel (≈ Connecticut)
Review Algal Biofuels Conversion Technologies
Overview
• Motivation for Algal Biofuels
• The Algal Biofuel Value Chain Revisited
• Algal Methyl Ester Biodiesel Properties
• Algal Synthetic Paraffinic Diesel/Jet Fuel Properties
• Algal Hydrothermal Liquefaction Oil Properties
• Conclusions
Review Algal Biofuels Conversion Technologies
Overview
• Motivation for Algal Biofuels
• The Algal Biofuel Value Chain Revisited
• Algal Methyl Ester Biodiesel Properties
• Algal Synthetic Paraffinic Diesel/Jet Fuel Properties
• Algal Hydrothermal Liquefaction Oil Properties
• Conclusions
The Algal Biofuels Value Chain
The “Conventional” Route
Biology
Cultivation
Harvesting,
Drying?
Nutrient
Recycle
Co-products
Lipid to Fuel
Conversion
Lipid Extraction
The Algal Biofuels Value Chain
Conversion of Whole Algal Biomass To Biofuels via HTL
Biology
Cultivation
Harvesting
Nutrient
Recycle
Upgrading to
Drop-In Fuels
Conversion to
Biocrude
Whole Wet
Algal Biomass
Review Algal Biofuels Conversion Technologies
Overview
• Motivation for Algal Biofuels
• The Algal Biofuel Value Chain Revisited
• Algal Methyl Ester Biodiesel Properties
• Algal Synthetic Paraffinic Diesel/Jet Fuel Properties
• Algal Hydrothermal Liquefaction Oil Properties
• Conclusions
Review Algal Biofuels Conversion Technologies
Overview
• Motivation for Algal Biofuels
• The Algal Biofuel Value Chain Revisited
• Algal Methyl Ester Biodiesel Properties
• Algal Synthetic Paraffinic Diesel/Jet Fuel Properties
• Algal Hydrothermal Liquefaction Oil Properties
• Conclusions
Conversion of Algal Lipids into Liquid Fuels
Algal Paraffinic Renewable Diesel vs. Algal Biodiesel
Algal Renewable Diesel
• Straight and branched alkanes:
Algal Biodiesel
• Alkyl esters produced via transesterification of TAG’s:
• Processing requirements and fuel
properties are relatively agnostic to fatty
acid composition of TAG’s
• Fuel properties are directly related to
fatty acid composition of TAG’s.
• Processing is susceptible to
contaminants (P, S, Ca, Mg, K, etc.)
• Processing susceptible to contaminants
(P, S, Ca, Mg, K, etc.) and FFA’s
• Final products compatible with existing
refinery and distribution infrastructure
• Only suitable for diesel engines
• Properties can be tailored for gasoline,
diesel, or jet fuel (ASTM D7566-11)
• Large scale processing facilities are
favored ( >100 million gal/year)
• Currently feedstock limited
• Small to moderate scale processing
facilities ( < 100 million gal/year)
• Current U.S. production capacity (3
billion gal/year) is under utilized.
• Currently feedstock limited
Conversion of Algal Lipids to Fuels
Algal Methyl Ester Biodiesel
Fatty acid profiles of some extracted algal lipids differ from that of
conventional biodiesel feedstocks.
8:0 10:0 12:0 14:0 16:0 16:1 18:0 18:1 18:2 18:3 20:1 20:4 20:5 22:6
Soy
11
4
24
53
8
Jatropha
11
17
13
47
0
18
9
3
7
2
1
39
5
46
3
30
39
1
8
1
1
3
11
2
15
16
2
10
4
3
6
21
3
23
14
3
1
14
5
7
5
14
Coconut
Palm
Nannochloropsis
salina
Nannochloropsis
oculata
Isoschrysis galbana
8
6
47
5
9
For algal FAME, the fatty acid profile has implications in terms of oxidative
stability, cold temperature properties, ignition quality and engine
emissions.
Bucy, H., Baumgardner, M. and Marchese, A. J. (2012). Chemical and Physical Properties of Algal Methyl Ester Biodiesel
Containing Varying Levels of Methyl Eicosapentaenoate and Methyl Docosahexaenoate. Algal Research 1 pp. 57–69.
Oxidative Stability of Algal Methyl Esters
Effect of EPA and DHA
• In natural oils, multiple olefinic unsaturation occurs in a methyleneinterrupted configuration. The bis-allylic C-H bonds are susceptible to
hydrogen abstraction, followed by oxygen addition, and peroxide formation
●
+O2
O-O
O-O-H
●
• Fuels containing long chain unsaturated methyl esters such as EPA (C20:5)
and DHA (C22:6) have poor oxidative stability.
Oxidative Stability of FAME
Bis-Allylic Position Equivalents (BAPE) (Knothe and Dunn, 2003)
• Oxidative stability of FAME has been shown to correlate with the total
number of bis-allylic sites in the FAME blend.
• To capture this effect, Knothe and Dunn (2003) have defined Bis-Allylic
Position Equivalents (BAPE) parameter, which is a weighted average of
the total number of bis-allylic sites in the FAME mixture:
n
BAPE 
 bp
i
Ai
i 1
bis-allylic sites
• For the present work, model algal methyl ester compounds were
formulated to match the BAPE value of real algal methyl esters subject to
varying levels of EPA/DHA removal.
Oxidative Stability Tests
Metrohm 743 RANCIMAT Test
Instrument
Method
Followed
Metrohm
EN 14112
743Rancimat
Standard
Specification
D6751
EN 14214
Measuring vessel
Conductivity
measuring
cell
Reaction vessel
Heating block
Sample
Measuring solution
3 hours
minimum
6 hours
minimum
Test Parameters
10 L/h
air flow
110°C
3 gram
sample
Oxidative Stability Tests
Metrohm 743 RANCIMAT Test
Instrument
Method
Followed
Metrohm
EN 14112
743Rancimat
Standard
Specification
D6751
EN 14214
Measuring vessel
Conductivity
measuring
cell
Reaction vessel
Heating block
Sample
Measuring solution
3 hours
minimum
6 hours
minimum
Test Parameters
10 L/h
air flow
110°C
3 gram
sample
Oxidative Stability Test Results
Model Compounds and Real Algal Methyl Esters Correlate with BAPE
M e th yl L a u ra te -F is h M e th yl E s te r B le n d s
25
N a n n o S p F o rm u la tio n s
N a n n o O c u la ta F o rm u la tio n s
Is o G a lb a n a F o rm u la tio n s
S o y M e th yl E s te r
In d u ctio n P e rio d (h r)
20
C a n o la M e th yl E s te r
C o rn M e th yl E s te r
E ld o ra d o A lg a l M e th yl E s te r
S o lix A lg a l M e th yl E s te r
15
In ve n tu re A lg a l M e th yl E s te r
3 H o u r A S T M L im it
6 H o u r E N L im it
10
5
0
0
50
100
150
BAPE
200
250
Oxidative Stability
Effect of EPA/DHA Removal from Nannochloropsis oculata
14
Nannochloropsis oculata Formulations
3 Hour ASTM Limit
6 Hour EN Limit
Induction Period (hr)
12
10
Curve Fit: y=1.0373exp(0.0232x) R2=0.9343
8
6
4
2
0
0
20
40
60
80
100
Percent Removal of EPA and DHA
Bucy, H., Baumgardner, M. and Marchese, A. J. (2012). Chemical and Physical Properties of Algal Methyl Ester Biodiesel
Containing Varying Levels of Methyl Eicosapentaenoate and Methyl Docosahexaenoate. Algal Research 1 pp. 57–69.
Oxidative Stability Test Results
Effect of TBHQ Oxidative Stability Additive
The effect of adding an oxidative stability additive (Vitablend Bioprotect
350) is shown here. Active ingredient: tert-Butylhydroquinone (TBHQ))
No Additive
0.1% Additive = 0.03% TBHQ
0.15% Additive = 0.045% TBHQ
0.2% Additive = 0.06% TBHQ
0.33% Additive = 0.1% TBHQ
3 Hour ASTM Limit
6 Hour EN Limit
25
Induction Time (hr)
20
15
10
5
0
20
40
60
80
Modeled % EPA + DHA Removed
100
Ignition Quality Tests
Derived Cetane Number Tests with Waukesha FIT System
Cetane Number is a measure of the propensity for a liquid fuel to autoignite under diesel engine conditions. For biodiesel a minimum Cetane
Number of 47 is required.
Instrument
Method Standard
Specification
Waukesha
FIT
D7170
47 minimum
D6751
ASTM D7170 Method
Measures ignition delay of 25
injections into a fixed volume
combustor
DCN = 171/ID
# of
Injections
25
injections
Test Parameters
Injection
Fuel
Coolant
Period
Temperature Temperature
5.00+/35+/-2°C
30+/-0.5°C
0.25 ms
Cetane Number
Effect of EPA/DHA Removal from Nannochloropsis oculata
• Nannochloropsis and Isochrysis galbana based algal methyl esters were
shown to have lower than acceptable Cetane Number.
• As EPA and DHA are removed, Cetane Number increases.
50
Derived Cetane Number
48
Nannochloropsis sp.
Nannochloropsis oculata
Isochrysis galbana
46
44
42
40
38
36
34
0
20
40
60
80
100
120
Percent Removal of EPA and DHA
Bucy, H., Baumgardner, M. and Marchese, A. J. (2012). Chemical and Physical Properties of Algal Methyl Ester Biodiesel
Containing Varying Levels of Methyl Eicosapentaenoate and Methyl Docosahexaenoate. Algal Research 1 pp. 57–69.
Cloud Point and Cold Filter Plugging Point
• Removal of C20:5 and C22:6 from algal methyl esters also results in an
increase in the percentage of fully saturated methyl esters C16:0 and
C18:0, resulting in increased cloud point and cold filter plugging point.
4
o
C lo u d P o in t [ C ]
0
-4
-8
N a n n o o cu la ta fo rm u la tio n s
N a n n o sp fo rm u la tio n s
Iso g a lb a n a fo rm u la tio n s
-1 2
-1 6
20
22
24
26
% C 1 6 :0 + C 1 8 :0
28
30
Cloud Point and Cold Filter Plugging Point
• Removal of C20:5 and C22:6 from algal methyl esters also results in an
increase in the percentage of fully saturated methyl esters C16:0 and
C18:0, resulting in increased cloud point and cold filter plugging point.
-4
o
C o ld F ilte r P lu g P o in t [ C ]
0
-8
N a n n o o cu la ta fo rm u la tio n s
N a n n o sp fo rm u la tio n s
Iso g a lb a n a fo rm u la tio n s
-1 2
-1 6
20
22
24
26
% C 1 6 :0 + C 1 8 :0
28
30
Speed of Sound and Bulk Modulus
• Increased bulk modulus of FAME (in comparison to petroleum diesel)
results in advanced injection timing and increased NOx.
• Speed of sound (a) and bulk modulus (a2r) of the liquid FAME
formulations also correlated well with BAPE.
1360
1640
N a n n o ch lo ro p sis o cu la ta
N a n n o ch lo ro p sis sp
Iso ch rysis g a lb a n a
1600
B u lk M o d u lu s (M P a )
S p e e d o f S o u n d (m /s)
1620
N a n n o ch lo ro p sis o cu la ta
N a n n o ch lo ro p sis sp
Iso ch rysis g a lb a n a
1350
1340
1330
1580
1560
1540
1520
1320
1500
1310
1480
40
60
80
BAPE
100
120
40
60
80
BAPE
100
120
Emissions Testing (Fisher et al., 2010)
Characterization of PM and NOx from Algae Based Methyl Esters
Objective: Characterize PM size distribution
/composition and gaseous pollutants from
algae-based methyl esters.
Approach: Engine tests were performed on
a 52 HP John Deere 4024T diesel engine at
rated speed at 50% and 75% of maximum
load.
Fuels: Fuels tested include ULSD, soy
methyl ester, canola methyl ester, and two
model algal methyl ester compounds:
• Nannochloropsis oculata and Isochrysis
galbana methyl ester compounds.
• B20 and B100 blends of each methyl
ester were tested.
• Nine fuel blends tested in total
Hydrocarbon and CO Emissions
Emissions of CO and THC for the algal methyl esters were similar to
that of the soy and canola methyl esters, which were similar to that
reported in the literature.
Total Hydrocarbons
Carbon Monoxide
1.8
0.5
0.4
0.3
0.2
B20 Blends
B20 Blends
B100 Blends
B100 Blends
0.1
Brake Specific CO (g/bkWh)
Brake Specific THC (g/bkWh)
1.6
1.4
1.2
1.0
0.8
0.6
B20 Blends
0.4
B20 Blends
B100 Blends
B100 Blends
0.2
0.0
0.0
50% Load
ULSD
Soy
50% Load
75% Load
Canola
Algae 1
Algae 2
ULSD
Soy
75% Load
Canola
Algae 1
Algae 2
NOx Emissions from Diesel Engines
Nannochloropsis Methyl Ester Model Compounds
Emissions of NOx were shown to decrease for the algal methyl esters in
comparison to the ULSD, in contrast to the soy and canola methyl esters
which resulted in NOx increases at the higher engine load.
5.0
Brake Specific NOx (g/kWh)
4.8
4.6
4.4
10% decrease
4.2
4.0
3.8
3.6
2% decrease
B20 Blends
B20 Blends
3.4
B100 Blends
3.2
B100 Blends
3.0
50% Load
ULSD
Soy
75% Load
Canola
Algae 1
Algae 2
Fisher, B. C., Marchese, A. J., Volckens, J., Lee, T. and Collett, J. (2010). Measurement of Gaseous and Particulate
Emissions from Algae-Based Fatty Acid Methyl Esters. SAE Int. J. Fuels Lubr. 3, pp.
PM Mass Emissions
• PM mass emissions decreased substantially for all of the B100 methyl esters
in comparison to ULSD at the high engine loading condition.
• At the lower engine loading condition, Algae 1 B100 had increased PM
emissions in comparison to ULSD.
Brake Specific Mass (g/kWh)
0.12
0.10
0.08
0.06
0.04
B20 Blends
B20 Blends
B100 Blends
0.02
B100 Blends
0.00
50% Load
ULSD
Soy
75% Load
Canola
Algae 1
Algae 2
PM Size Distribution
B100 Fuels
• All of the B100 methyl esters resulted in a decrease in the mean mobility
diameter.
• The PM size distribution from several of the methyl esters including
Algae 1 B100 exhibited a nucleation mode peak centered between 10
and 20 nm.
50% Load
75% Load
1.2e+6
2.5e+6
ULSD
Soy B100
Canola B100
Algae 1 B100
Algae 2 B100
1.0e+6
dN/dln(dp)/cm3
dN/dln(dp)/cm3
2.0e+6
ULSD
Soy B100
Canola B100
Algae 1 B100
Algae 2 B100
1.5e+6
1.0e+6
5.0e+5
8.0e+5
6.0e+5
4.0e+5
2.0e+5
0.0
0.0
10
20
30
40 50
100
Mobility Diameter (nm)
200
300
10
20
30
40 50
100
Mobility Diameter (nm)
200
300 400
Elemental and Organic Carbon
• The PM from all of the methyl esters contained substantially higher
quantities of volatile organic carbon in comparison to ULSD,
particularly at the lower engine loading condition.
• Algae 1 B100 had the highest ratio of OC:EC of all the fuels tested at
both engine loading conditions.
75% Load
50% Load
0.08
0.14
Elemental Carbon
Organic Carbon
0.06
0.04
0.02
0.00
Brake Specific Carbon (g/bkWh)
Brake Specific Carbon (g/bkWh)
0.10
Elemental Carbon
Organic Carbon
0.12
0.10
0.08
0.06
0.04
0.02
0.00
20
20
00
00
20
20
00
00
SD
UL oy B ola B e 1 B e 2 B oy B1 la B1 1 B1 2 B1
S an
a
a
S ano gae gae
C
Alg Alg
C
Al
Al
UL
SD B20 B20 B20 B20 B100 B100 B100 B100
y
a
1
2
So anol gae gae Soy nola ae 1 ae 2
l
l
C
A
A
Ca Alg Alg
Review Algal Biofuels Conversion Technologies
Overview
• Motivation for Algal Biofuels
• The Algal Biofuel Value Chain Revisited
• Algal Methyl Ester Biodiesel Properties
• Algal Synthetic Paraffinic Diesel/Jet Fuel Properties
• Algal Hydrothermal Liquefaction Oil Properties
• Conclusions
Review Algal Biofuels Conversion Technologies
Overview
• Motivation for Algal Biofuels
• The Algal Biofuel Value Chain Revisited
• Algal Methyl Ester Biodiesel Properties
• Algal Synthetic Paraffinic Diesel/Jet Fuel Properties
• Algal Hydrothermal Liquefaction Oil Properties
• Conclusions
Conversion of Algal Lipids into Liquid Fuels
Algal Renewable Diesel/Jet Fuel
Renewable Jet Fuel from Algal Oil is Approved for Use
ASTM D7566-11
• In July 2011, ASTM passed specifications that allow use of renewable jet
fuels produced from vegetable, algal oil and animal fat feedstocks.
• ASTM D7566-11 allows a 50 per cent blending of fuels derived from
hydroprocessed esters and fatty acids (HEFA) with conventional
petroleum-based jet fuel.
• ASTM D7655-11 is currently only valid for HEFA processes.
Conversion of Algal Lipids into Liquid Fuels
Algal Renewable Diesel/Jet Fuel
Conversion of Algal Lipids into Liquid Fuels
Algal Renewable Diesel/Jet Fuel
Conversion of Algal Lipids into Liquid Fuels
Algal Renewable Diesel/Jet Fuel
Conversion of Algal Lipids into Liquid Fuels
Algal Renewable Diesel/Jet Fuel
Conversion of Algal Lipids into Liquid Fuels
Algal Renewable Diesel/Jet Fuel
Review Algal Biofuels Conversion Technologies
Overview
• Motivation for Algal Biofuels
• The Algal Biofuel Value Chain Revisited
• Algal Methyl Ester Biodiesel Properties
• Algal Synthetic Paraffinic Diesel/Jet Fuel Properties
• Algal Hydrothermal Liquefaction Oil Properties
• Conclusions
Review Algal Biofuels Conversion Technologies
Overview
• Motivation for Algal Biofuels
• The Algal Biofuel Value Chain Revisited
• Algal Methyl Ester Biodiesel Properties
• Algal Synthetic Paraffinic Diesel/Jet Fuel Properties
• Algal Hydrothermal Liquefaction Oil Properties
• Conclusions
Conversion of Whole Algal Biomass into Fuels
Hydrothermal Liquefaction (HTL)
• Hydrothermal liquefaction uses water at sufficient temperature and pressure
to convert a wet biomass feedstock directly into a liquid bio-crude oil.
• By processing the feedstock wet, the need for drying is eliminated.
• Process temperatures are lower compared to dry pyrolysis.
• Current process conditions for the continuous flow system at PNNL are just
below the supercritical point of water (350⁰C, 3000 psi).
Simplified Process Diagram
Elliott, D. and Oyler, J. (2012). Hydrothermal processing: Efficient production of highquality fuels from algae. 2nd International Conference on Algal Biomass, Biofuels and
Bioproducts, San Diego, CA, June 2012.
Bench Scale
Reactor at PNNL
Conversion of Whole Algal Biomass into Fuels
Hydrothermal Liquefaction (HTL)
• Hydrothermal liquefaction uses water at sufficient temperature and pressure
to convert a wet biomass feedstock directly into a liquid bio-crude oil.
• By processing the feedstock wet, the need for drying is eliminated.
• Process temperatures are lower compared to dry pyrolysis.
• Current process conditions for the continuous flow system at PNNL are just
below the supercritical point of water (350⁰C, 3000 psi).
Feedstock: Wet
Nannochloropsis
salina Paste
HTL Bio-Oil
Hydrotreated
HTL Bio-Oil
Fractionated cuts:
naphtha, diesel, bottoms
Conversion of Whole Algal Biomass into Fuels
Hydrothermal Liquefaction
PNNL Process: Continuous Flow HTL of Whole Algal Biomass
Conversion of Whole Algal Biomass into Fuels
Hydrothermal Liquefaction
PNNL Results: HTL of Whole Algal Biomass
•
Nannochloropsis salina from Solix BioSystems
•
Sample was frozen after harvest—no processing or lipid extraction
•
Wet algae paste, approximately 21% solids.
Parameter
Data
Lipid content of whole algae
33%
Bio-oil from HTL as % algae mass
58%
Bio-oil from HTL as % algae AFDW
64%
% of algae carbon in HTL oil
69%
Elliott, D. and Oyler, J. (2012). Hydrothermal processing: Efficient production of
high-quality fuels from algae. 2nd International Conference on Algal Biomass,
Biofuels and Bioproducts, San Diego, CA, June 2012.
Conversion of Whole Algal Biomass into Fuels
Hydrothermal Liquefaction
Schaub, et al. (2012). Lipid Feedstocks, Produced Ester Fuel and Hydrothermal Liquefaction Products of
Nannochloropsis salina: Detailed Compositional Analysis by Ultrahigh Resolution FT-ICR Mass Spectrometry 2nd
International Conference on Algal Biomass, Biofuels and Bioproducts, San Diego, CA, June 2012.
Conversion of Whole Algal Biomass into Fuels
Upgrading of Hydrothermal Liquefaction Bio-Oil
Conversion and upgrading of HTL bio-oils
• Hydrotreating for O, S and N removal
• Hydrocracking/isomerization to finished fuel
• Produces renewable (non-oxygenated) fuel
Conversion of Whole Algal Biomass into Fuels
Upgrading of Hydrothermal Liquefaction Bio-Oil
HTL Bio-Oil
Hydrotreated HTL
Bio-Oil
Fractionated cuts: naphtha,
diesel, bottoms
Review Algal Biofuels Conversion Technologies
Overview
• Motivation for Algal Biofuels
• The Algal Biofuel Value Chain Revisited
• Algal Methyl Ester Biodiesel Properties
• Algal Synthetic Paraffinic Diesel/Jet Fuel Properties
• Algal Hydrothermal Liquefaction Oil Properties
• Conclusions
Review Algal Biofuels Conversion Technologies
Overview
• Motivation for Algal Biofuels
• The Algal Biofuel Value Chain Revisited
• Algal Methyl Ester Biodiesel Properties
• Algal Synthetic Paraffinic Diesel/Jet Fuel Properties
• Algal Hydrothermal Liquefaction Oil Properties
• Conclusions
Conclusions
Phototropic microalgae is a potentially scalable liquid biofuel
o
The “ambitious” U.S. biofuels goal is 36 billion gal/year by 2022.
o
300 billion gal/year will be needed in future generations.
Conventional Lipid to Liquid Fuel Conversion Technologies
o
Fractionation necessary (and perhaps desirable) for some algal methyl
esters.
o
Hydrotreated renewable alkanes (diesel, jet) are ready for scale up.
o
Preprocessing of crude lipid extracts must be considered. Not all
extracts are alike and they differ from vegetable oil.
Direct Conversion of Whole Algal Biomass to Liquid Fuels
o
Hydrothermal liquefaction looks promising. Can be considered a highyield, feedstock agnostic, wet extraction process.
o
Upgrading to drop-in fuels for jet or diesel via hydrotreating is possible.
o
New certification process would be necessary for HTL jet fuel.
Questions?

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