FERMENTABLE SUGARS FOR BIOFUELS

Donal F. Day

Audubon Sugar Institute

UNO Sept. 2014

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?

Target: regionally appropriate biomass feedstocks

CROP CHOICES (POTENTIAL YIELDS)

Wet ton/acre

40.5

lbs simpleSugar/acre

123.6

lbs complexSugar/acre

362.3

Total lbsSugar/acre

19,679

Wet ton/acre

24.3

lbs simpleSugar/acre

184.1

lbs complexSugar/acre

186.4

Total lbsSugar/acre

9,003

Energycane Sweet Sorghum

TASKS

Feedstock Development

Sustainable Production

Logistics and processing

Conversion and Refining

Economics, Markets and Distribution

Education

Extension

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

Establishment, market, selling costs

Training of potential workers for new industry

Bringing stakeholders on-board

Approaches

APR

ZSM-5

Gasoline

Diesel

KeroseneJet Fuel

Condensation Hydrotreating

Biomass

SugarCane

CornStarch

Sustainable Production Harvest Deliver

ProcessIntermediate ProductConversion to Fuel

Biomass

ProcessIndeterminate

analyzeFeedstock developmentSustainability

Technology development

Technology development

Economic feasibilityValue to Consumer

Developing Process

Primary processing plants supplying centralized biorefineries

Storable syrups as feedstocksPrimary plants drawing on local acreage

*Industrial Model

Sweet Sorghum July - September

Energycane October -March

Bagasse, syrup,woodchips,molasses, etc.

April - June

Staggered Harvest, Complementary Crops, producing both fermentable sugars and biomass.

*Agricultural Model

SUSTAINABLE PRODUCTIONEXPERIMENTAL 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

Breeding for Cold Tolerance

Molecular markers developed for cold

tolerance

St. Gabriel (early June 2013)

Energycane grows fasterThan commercial varieties

Energycane

sugarcane

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)

HARVESTINGSweet Sorghum Energy cane

Weight loss- 6-7% over 72 hr. period on harvesting3 trials, one acre lots (about 18 rows) 8 inch billets, 3 different fan speeds evaluated

7-9% weight loss over a 72 hr. period. Same design.Harvesting in October

TOTAL FOSSIL ENERGY USE (LCA)

Brazilian sugar cane

4 (50% - 74%)

3 (25% - 49%)

2 (1% - 24%)

Biofuel FeedstockProduction Feasibility

Index

5 (75% - 100%)

1 (no change)

Energy Cane ProductionFeasibility Scale

Crop Market Price Crop Yield Variable Cost

Energy cane

CornCottonSorghumRiceSoybeansSugarcane

$75/ton

$5.00/bu.$0.80/lb.

$8.00/bu.$16.00/cwt.$14.00/bu.

$0.23/lb.

10 dry ton/A

160 bu./A1,200 lb./A

90 bu./A70 cwt./A45 bu./A

7,500 lbs./A

$500/A

$530/A$600/A$310/A$660/A$340/A$530/A

Feedstock Breakeven Economic Analysis

PROCESSING- DEMONSTRATE SCALABILITYPRODUCE PRODUCTS FOR INDUSTRIAL TESTING

Plant operational- initial process run July 2013

Flexible Pilot Plant: Education, Extension and Training Facility

PILOT PLANT

MILLING

Sweet Sorghum Energy Cane

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).

Feed rate dependent on variety.

Leaf removal necessary to improve efficiency.

Increased power requirement due to high fiber content.

Sweet sorghum and energycane fall at different ends for fiber.

POWER REQUIREMENTS- MILLING (CROP DEPENDENT)

Eiland and Clarke, 2008 ASSCT, Panama City, Florida

Sweet Sorghum

Energy Cane

Sugarcane

COMPOSITION SORGHUM SYRUP

27.1 % Water

72.9 % Dissolved Solids

8.4 % Ash

13.2 % Glucose

11.2 % Fructose

46 % Sucrose

0.1 % S0.1 % P0.25 % N

3.5 % Potassium

1.1 % Chloride

0.4 % Calcium0.3 % Sulfate0.2 % Sodium0.2 % Magnesium

0.7 % Nitrate

0.1 % Ammonium0.1 % Phosphate

FUELS PRODUCTION -VIRENT ENERGY SYSTEMS

APR

ZSM-5

Gasoline

Diesel

KeroseneJet Fuel

Condensation Hydrotreating

Biomass

SugarCane

CornStarch

COMPOSITION SORGHUM SYRUP

27.1 % Water

72.9 % Dissolved Solids

8.4 % Ash

13.2 % Glucose

11.2 % Fructose

46 % Sucrose

0.1 % S0.1 % P0.25 % N

3.5 % Potassium

1.1 % Chloride

0.4 % Calcium0.3 % Sulfate0.2 % Sodium0.2 % Magnesium

0.7 % Nitrate

0.1 % Ammonium0.1 % Phosphate

Removal of potassium and chloride requires advanced separation techniques such as

• Ion exchange• Electrodialysis• Nanofiltration

LIGNOCELLULOSIC UTILIZATION

CO-GENERATION

Scenario 1Excess bagasse used for electric power

generation

Scenario 2Excess bagasse used for lignocellulosic

sugars production

FeedstockPrimary sugars,

million kg

Excess bagasse, million t

Power export, million kWh

Syrup, K-m3

Primary sugars,

million kg

Excess bagasse, million t

Lignocellulosic sugars,

million kg

Syrup, K-

m3

Energy cane

99.8 600.8 268 50.5 99.8 330.2 85.8 94.1

Sweet Sorghum

49.6 164.2 119.9 24.9 49.6 147.4 38.9 44.5

Facility total

149.4 765.0 387.9 75.4 149.4 477.6 124.7 138.6

Annual production of fermentable sugars, excess bagasse, electric power and syrup

Model developed in SUGARSTM

Extraction by diffusion Diluted acid pretreatment for lignocellulosic

conversion

LIGNOCELLULOSIC LOGISTICS AND PRE-PROCESSING

Storage Pile storage best for short-term biomass storage

Fragmentation patterns on milling

(the lower the fiber the less fragmentation)

Particle size effects pretreatment rates

SURPLUS SUGARS PER DAY (10,000 T/D)

Fiber Composition: 40% Cellulose (C6-Glucose) & 25% Hemicellulose (C5-Xylose)Grinding Rate : 10,000 tons/day , Bagasse Production : 3000 tons/day

Power Bagasse can be fluidized for steam drying, increasing energy value.

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

Pretreatment

APR

ZSM-5

Gasoline

Diesel

KeroseneJet Fuel

Condensation Hydrotreating

Biomass

SugarCane

CornStarch

Syrup

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

PretreatmentDilute Ammonia (DA) Pretreatment

SEM Images of Untreated and Treated Sugarcane, Energy Cane and Sorghum Bagasse

Aita, G., Salvi, D., Walker, M. 2011. "Enzyme hydrolysis and ethanol fermentation of dilute ammonia pretreated energy cane." Bioresource Technology, 102 (6): 4444-4448.

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.

Sugarcane bagasse

Energy cane bagasse

Sorghum bagasse

Untreated

Treated

A

B

C

D

E

F

ENZYMATIC SUGAR PRODUCTION

Start

3 hours

6 hours

40 hrs

sugar yield - 70-90% of cellulose in biomass converted to fermentable

sugars

OTHER P

RODUCTS

BU

T AN

OL ;

AC

ON

I TI C

AC

I D B

I OP

L AS

TI C

S

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

Simplified Plant Designtentative

(GLUCOSE TO BUTANOL)

Product ConcentrationScale-up

36

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

O

OH

O

O

O

O OH

OO

Aconitic acid“Green Plastic”

BIO-PLASTICS MATRICES FROM ACONITIC ACID

Biodegradablephotolithotrophicplastics from sugarcane materials

POLYESTER FROM ORGANIC ACID.

Trans-Aconitic Acid Formulation

Citric Acid

Formulation

The trans-aconitic acid is darker in color and contributes to the polymer color.

The citric acid is a white crystalline powder forming a clear polymer with some bubbles.

Cis-Aconitic Acid

Formulation

The cis-aconitic acid is darker in color and contributes to the polymer color.

THANK YOU

Always thinking outside the box

This work supported by a USDA AFRI-Cap grant (Award No. 2011-69005-30515)