FERMENTABLE SUGARS
FOR BIOFUELS
Donal F. Day
Audubon Sugar Institute
UNO Sept. 2014
Target: regionally appropriate biomass feedstocks
The deep south states can to produce
50% of the biofuels in the future
because they have the most
available land with adequate water
and sun.
Questions to be Answered
Agricultural
Are these crops suitable for production
in underutilized agricultural areas
(Cold tolerance)?
Industrial
Are the products (syrups) suitable for
use by industrial partners?
Financial-Environmental
What is the financial baseline for
producing biofuels from these crops
and what are the environmental costs
associated with the production?
CROP CHOICES (POTENTIAL YIELDS)
Energycane
Sweet Sorghum
Wet
ton/acre
40.5
Wet
ton/acre
24.3
lbs simple
Sugar/acre
123.6
lbs simple
Sugar/acre
184.1
lbs complex
Sugar/acre
362.3
lbs complex
Sugar/acre
186.4
Total lbs
Sugar/acre
19,679
Total lbs
Sugar/acre
9,003
TASKS
Approaches
Feedstock Development
Sustainable Production
Logistics and processing
Conversion and Refining
Crops with staggered harvests that will
grow across desired range (and not
compete with food crops)
Low input, sustainable production
Harvest, transport, effective range
Conversion to sugars (syrups) suitable
for jet fuel production
Economics, Markets and Distribution
Establishment, market, selling costs
Education
Training of potential workers for new
industry
Extension
Bringing stakeholders on-board
Developing Process
Sustainable Production
Feedstock development
Sustainability
Harvest
analyze
Deliver
Technology development
Sugar
Cane
Gasoline
ZSM-5
Biomass
APR
Kerosene
Jet Fuel
Condensation
Corn
Starch
Hydrotreating
Diesel
Conversion to Fuel
Value to Consumer
Intermediate Product
Process
Economic feasibility
Process
Indeterminate
Technology development
Biomass
*
Primary processing plants supplying centralized biorefineries
Storable syrups as feedstocks
Primary plants drawing on local acreage
*
Staggered Harvest, Complementary Crops, producing
both fermentable sugars and biomass.
Sweet Sorghum
July - September
Energycane
October -March
Bagasse, syrup,
woodchips,
molasses, etc.
April - June
SUSTAINABLE PRODUCTION
EXPERIMENTAL SITES
Sites were established in Louisiana in
different soil types and climatic
zones for growing energycane and
sweet sorghum.
FEEDSTOCK DEVELOPMENT
Energy cane- seven molecular markers have been
found, four for leaf greenness and three for
regrowth damage. Genetic variability was
created by cross hybridization between a set of
distinct species
Cross pollination between sugarcane and
miscanthus, F1 in field tests across Louisiana
Cold tolerance testing of Energy cane in North
Louisiana location
Low input testing in North Louisiana
One semi-commercial variety released
sugarcane
Energycane
St. Gabriel (early June 2013)
Breeding for Cold Tolerance
Molecular markers developed for cold
tolerance
Energycane grows faster
Than commercial varieties
ENERGYCANE – YEAR 3 (N. LOUISIANA
June 2014
SWEET SORGHUM
Annual crop
Contains, a sugar containing juice,
starch containing seed heads and
fiber
90-120 day crop cycle, can be grown
across target region
Gross structure similar to sugarcane
Can be widely grown across Southern
US
SWEET SORGHUM PRODUCTION FOLLOWING LEGUME
INCORPORATION IN THE SOIL (LOW INPUT TESTING)
HARVESTING
Sweet Sorghum
Weight loss- 6-7% over 72 hr. period
on harvesting
3 trials, one acre lots (about 18
rows) 8 inch billets, 3 different fan
speeds evaluated
Energy cane
7-9% weight loss over a 72 hr.
period. Same design.
Harvesting in October
TOTAL FOSSIL ENERGY USE (LCA)
Brazilian sugar cane
Biofuel Feedstock
Production Feasibility Index
Crop
Energy cane
Corn
Cotton
Sorghum
Rice
Soybeans
Sugarcane
Market Price
Crop Yield
Variable Cost
$75/ton
10 dry ton/A
$500/A
$5.00/bu.
$0.80/lb.
$8.00/bu.
$16.00/cwt.
$14.00/bu.
$0.23/lb.
160 bu./A
1,200 lb./A
90 bu./A
70 cwt./A
45 bu./A
7,500 lbs./A
$530/A
$600/A
$310/A
$660/A
$340/A
$530/A
Energy Cane Production
Feasibility Scale
5 (75% - 100%)
4 (50% - 74%)
3 (25% - 49%)
2 (1% - 24%)
1 (no change)
Feedstock Breakeven Economic Analysis
PROCESSING- DEMONSTRATE SCALABILITY
PRODUCE PRODUCTS FOR INDUSTRIAL TESTING
Flexible Pilot Plant: Education, Extension and Training Facility
Plant operational- initial process run July 2013
PILOT PLANT
MILLING
Sweet Sorghum
Three runs of 5 ton
lots. For two runs the
whole plant was
harvested, for one the
seed heads and leaves
were removed.
Feed rate low. It was
not possible to mill the
clean billets because
of choking (not enough
fiber).
Energy Cane
Feed rate dependent
on variety.
Leaf removal
necessary to
improve
efficiency.
Increased power
requirement due
to high fiber
content.
POWER REQUIREMENTS- MILLING (CROP DEPENDENT)
Sweet sorghum and energycane fall at different ends for
fiber.
Sugarcane
Energy Cane
Sweet Sorghum
Eiland and Clarke, 2008 ASSCT, Panama City, Florida
COMPOSITION SORGHUM SYRUP
27.1 % Water
72.9 %
Dissolved
Solids
0.1 % S
0.1 % P
0.25 % N
3.5 % Potassium
46 % Sucrose
1.1 % Chloride
13.2 % Glucose
11.2 % Fructose
8.4 % Ash
0.7 % Nitrate
0.4 % Calcium
0.3 % Sulfate
0.2 % Sodium
0.2 % Magnesium
0.1 % Phosphate
0.1 % Ammonium
FUELS PRODUCTION -VIRENT ENERGY SYSTEMS
Sugar
Cane
Gasoline
ZSM-5
Biomass
APR
Kerosene
Jet Fuel
Condensation
Corn
Starch
Hydrotreating
Diesel
COMPOSITION SORGHUM SYRUP
27.1 % Water
72.9 %
Dissolved
Solids
0.1 % S
0.1 % P
0.25 % N
Removal of potassium and chloride
requires advanced separation
46 % Sucrose
techniques
such as
3.5 % Potassium
• Ion exchange
• Electrodialysis
13.2 % Glucose
• Nanofiltration
1.1 % Chloride
11.2 % Fructose
8.4 % Ash
0.7 % Nitrate
0.4 % Calcium
0.3 % Sulfate
0.2 % Sodium
0.2 % Magnesium
0.1 % Phosphate
0.1 % Ammonium
LIGNOCELLULOSIC UTILIZATION
CO-GENERATION
Model developed in SUGARSTM
 Extraction by diffusion
 Diluted acid pretreatment for lignocellulosic conversion
Annual production of fermentable sugars, excess bagasse, electric power and
syrup
Scenario 1
Excess bagasse used for electric power generation
Feedstock
Energy cane
Sweet
Sorghum
Facility total
Primary
Excess
Power
sugars, million bagasse, million export,
kg
t
million kWh
99.8
600.8
268
Scenario 2
Excess bagasse used for lignocellulosic sugars
production
99.8
Excess
bagasse,
million t
330.2
Lignocellulosi
c sugars,
million kg
85.8
Syrup,
K-m3
Primary sugars,
million kg
50.5
Syrup,
K-m3
94.1
49.6
164.2
119.9
24.9
49.6
147.4
38.9
44.5
149.4
765.0
387.9
75.4
149.4
477.6
124.7
138.6
LIGNOCELLULOSIC LOGISTICS AND
Fragmentation patterns on milling
PRE-PROCESSING
(the lower the fiber the less fragmentation)
Storage Pile storage best for short-term biomass
storage
Particle size effects pretreatment rates
SURPLUS SUGARS PER DAY
(10,000 T/D)
Power Bagasse can be fluidized for steam
drying, increasing energy value.
Fiber Composition: 40% Cellulose (C6-Glucose) & 25% Hemicellulose (C5-Xylose)
Grinding Rate : 10,000 tons/day , Bagasse Production : 3000 tons/day
SUGARS FROM LIGNOCELLULOSE
 Unlike starch (corn),
lignocellulose is made of tightly
bonded sugars (cellulose,
hemicellulose) and lignin
 The primary technical problem
 is economic access to the
carbohydrates in this matrix.
IDEALIZED PROCESS
Sugar
Cane
Pretreatment
Gasoline
ZSM-5
Biomass
APR
Syrup
Kerosene
Jet Fuel
Condensation
Corn
Starch
Hydrotreating
Diesel
PRETREATMENT TECHNOLOGIES
Treatment
Temperature
oC
Pressure
(atm)
Time
(min)
acid
190-200
3-15
2-30
water
160-190
6-14
10-30
ammonia
150-170
9-17
30-60
lime
70-130
1-6
60-360
oxidizers
20-100
1
3-60
As yet there is no low cost ideal pretreatment
Pretreated
Post -hydrolysis
Pretreatment
Dilute Ammonia (DA) Pretreatment
Sugarcane bagasse
A
Energy cane bagasse
C
E
B
D
F
Sorghum bagasse
Untreated
Treated
SEM Images of Untreated and Treated Sugarcane, Energy Cane and Sorghum
Bagasse
Salvi, D., Aita, G., et al. 2010. "Dilute ammonia pretreatment of sorghum and its effectiveness on enzyme hydrolysis and ethanol fermentation." Applied Biochemistry and Biotechnology, 161 (1-8): 67-74.
Aita, G., Salvi, D., Walker, M. 2011. "Enzyme hydrolysis and ethanol fermentation of dilute ammonia pretreated energy cane." Bioresource Technology, 102 (6): 4444-4448.
ENZYMATIC SUGAR PRODUCTION
Start
6 hours
3 hours
sugar yield - 70-90% of cellulose in biomass
converted to fermentable sugars
40 hrs
IMMOBILIZED CELL COLUMNS
Laboratory
Small Scale-up
BUTANOL PRODUCTION COMPARISON
Batch Fermentation with 4%
glucose
Continuous Culture (0.6 ml/min)
with 4% glucose
0.42% butanol
0.61% butanol
0.60% solvents
0.99% solvents
Anoxic conditions needed
Anoxic conditions maintained
1.5 L media used (5 days)
4.32 L media used (5 days)
3 L reaction vessel
400 ml reaction vessel
0.6 g solvents/L/day
21.384 g solvents/L/day
Research financed by Optinol LLC
(GLUCOSE TO BUTANOL)
Scale-up
Simplified Plant Design
tentative
Product Concentration
ACONITIC ACID IS AN ABUNDANT
ORGANIC ACID IN SUGARCANE,
ENERGYCANE AND SWEET SORGHUM.
Aconitic acid ~1% on Brix solids
Found in molasses at 3-5%
Used as flavor ingredient and adjuvant (up to 300 ppm)
Similar to citric acid
“Green Plastic”
Aconitic acid
36
Biodegradable
photolithotrophic
plastics from
sugarcane materials
POLYESTER FROM ORGANIC ACID.
Trans-Aconitic Acid
Formulation
The trans-aconitic acid is
darker in color and
contributes to the
polymer color.
Cis-Aconitic Acid
Formulation
The cis-aconitic acid is
darker in color and
contributes to the
polymer color.
Citric Acid
Formulation
The citric acid is a white
crystalline powder
forming a clear polymer
with some bubbles.
THANK YOU
Always thinking outside the box
This work supported by a USDA AFRI-Cap grant (Award No. 2011-69005-30515)