Progress on Developing Value-Added Uses for Distillers Grains: Current and Evolving Opportunities

Kurt A. Rosentrater, Ph.D.Department of Agricultural and Biosystems Engineering

Iowa State University

(515) 294-4019

karosent@iastate.edu1

OVERVIEW

1. Ethyl alcohol

2. Coproducts

3. Ongoing research

4. New opportunities

5. Concluding thoughts

2

ETHYL ALCOHOL

3

Ethyl Alcohol – The Fuel of the Future

Ethanol was extensively used as a motor fuel additive prior to the end of World War II (ca. 1933)

1860 Nicholas Otto (b. 1832, d. 1891), a German inventor, used ethanol to fuel an internal combustion engine

1896 Henry Ford’s (b. 1863, d. 1947) first automobile, the quadricycle, used corn-based ethanol as fuel

1908 Hart-Parr Company (Charles City, IA) manufactured tractors that could use ethanol as a fuel

Henry Ford’s (b. 1863, d. 1947) Model T used corn-based ethanol, gasoline, or a combinations as fuel

1918 World War I caused increased need for fuel, including ethanol; demand for ethanol reached nearly 60 million gal/year

1940 The U.S. Army constructed and operated a fuel ethanol plant in Omaha, NE

4

Ethyl Alcohol – The Fuel of the Future

The first distillation column for the production of fuel ethanol was invented by Dennis and Dave Vander Griend at South Dakota State University in 1978/1979

5

DDGS Historically• Many people have asked what the fuel ethanol industry

is going to do about the growing piles of non-fermented leftovers

– “Grain distillers have developed equipment and an attractive market for their recovered grains” (Boruff, 1947)

– “Distillers are recovering, drying, and marketing their destarched grain stillage as distillers dried grains and dried solubles” (Boruff, 1952)

• This question has been around for quite some time, and it also appears that a viable solution had already been developed as far back as the 1940s

6

DDGS Historically

• In the 1940s / 1950s

– 17 lb (7.7 kg) of distillers feed was produced for every 1 bu (56 lb; 25.4 kg) of grain that was processed into ethanol

• Similar to today

– But over 700 gal (2650 L) of water was required to produce this feed (Boruff, 1947; Boruff, 1952; Boruff et al., 1943)

• vs. < 4 gal. of water today

7

GRAIN ALCOHOL DISTILLERY (ca. 1947)

8

MODERN DRYGRIND PROCESS

9

U.S. ETHANOL GROWTH

0

2000

4000

6000

8000

10000

12000

14000

1600019

80

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

2006

2008

2010

2012

2014

2016

2018

2020

Year

Fuel

Eth

anol

(gal

) x 1

0 6

0

5

10

15

20

25

30

35

40

45

Cop

rodu

cts

(t) x

10

6

Ethanol ProductionRFS Mandated ProductionCoproduct Generation

Growth of U.S. fuel ethanol industry

Feb. 2011: 204 plants, 13,771 Mg/y RFS: 15,000 Mg/y of biofuel by 2015

10

0

2E+16

4E+16

6E+16

8E+16

1E+17

1.2E+17

1950 1960 1970 1980 1990 2000 2010

Year

To

tal U

.S. E

ner

gy

(Btu

)

Consumption - Fossil

Production - Fossil

Nuclear

Renewable

Total Consumption

US EIA, 2011

U.S. ETHANOL GROWTH

11

Renewable8%

Nuclear9%

Crude Oil37%

Natural Gas25%

Coal21%

Hydroelectric, 35%

Wood, 24%

Biofuels, 20%

Wind, 9%

Waste, 6%Geothermal, 5%

Solar, 1%

US EIA, 2011

U.S. ETHANOL GROWTH

Since 1950s, generally 5 to 9 % of total U.S. energy supply has been renewable 12

COPRODUCTS

13

ETHANOL COPRODUCTS

Distillers Wet Grains

Condensed Distillers SolublesDistillers Dried Grains with Solubles

14

COPRODUCT PRICES

15

COPRODUCT PRICES

16

COPRODUCT PRICES

17

COPRODUCT VALUES

18

COPRODUCT VALUES

19

COPRODUCT RESEARCH

• As ethanol industry grows, supply of coproducts will grow

• Balance = key to sustainability

Livestock producers

Ethanol manufacturers

20

ONGOING RESEARCH

21

ONGOING RESEARCH

• Fuel– vs.

• Food– vs.

• Feed– vs.

• Plastics– vs.

• Chemicals– vs.

• Other uses

Goals:• Augment current uses• Develop new market opportunities• Develop/optimize processes and products• Improve sustainability

Context:• Application of physics and chemistry to

biological systems• Manufacturing with biological polymers:

proteins, fibers, lipids

22

ONGOING RESEARCH• Material handling• Pelleting/densification• Aquaculture• Human foods• Plastic composites

23

MATERIAL HANDLING

24

Sieve Opening Size (mm)

2.38 1.68 1.19 0.841

Scale bar = 3.91 mm Scale bar = 2.50 mm

Scale bar = 2.34 mm Scale bar = 0.987 mm

0.595 0.420 0.297 0.210

Scale bar = 0.689 mm Scale bar = 0.52 mm Scale bar = 0.36 mm Scale bar = 0.26 mm

1 2

MATERIAL HANDLING

25

Carbohydrate Protein

2.28

1.68

1.19

Part

icle

Dia

met

er (m

m)

0.84

1

1

Batch 1 Batch 2

1

2

3

4

Pla

nt

5

1

MATERIAL HANDLING

26

AoR (o)

8080

9090

100100

110110

120120

130130

140140

150150

Mas

s F

low

Rat

e (g

/min

)

Mas

s F

low

Rat

e (g

/min

)

z= a + bx + cy

x= AoR (°)y = HR (-)z= MFR (g/min)

R2 = 0.99Error= 2.42

MFR < 100 = Poor Flow100 < MFR < 120 = Fair FlowMFR > 120 = Good Flow

Good flow Fair flow Poor flow

MATERIAL HANDLING

27

z= a + b/x + cy

x= AoR (°)y = HR (-)z= Moisture content (%, db)

R2 = 0.71Error= 4.50

Moisture < 9.9 (Good Flow)9.9 < Moisture < 17.5 (Fair Flow)17.5 > Moisture (Poor Flow)

Good flow Fair flow Poor flow

AoR (o)

00

55

1010

1515

2020

2525

3030

3535

4040

Moi

stur

e C

onte

nt (%

db)

Moi

stur

e C

onte

nt (%

db)

MATERIAL HANDLING

28

y = 2E-11e21.531x

R2 = 0.8368

y = 3.4629x - 3.4854

R2 = 0.8823

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10

PBD/ABD (-)

CC/D

isp

ersi

bil

ity

* d/f

(-)

Plant 4 Plant 3

Plant 5

Plant 1

Plant 2

MATERIAL HANDLING

29

PELLETING/DENSIFICATION

30

PELLETING/DENSIFICATION

Mag.

x

DDGS Mfg

A B

10

60

200

31

0

1000

2000

3000

4000

5000

6000

0 10 20 30 40 50 60 70 80 90 100

Percentage of DDGS Pelleted, p (%)

Tot

al S

lack

Cos

t pe

r C

ar, S

Cca

r ($

/car

)

0

1000

2000

3000

4000

5000

6000

Pel

leti

ng C

ost

per

Car

, Pca

r ($

/car

)

$50/ton DDGS Sales Price, s

$100/ton DDGS Sales Price, s

$150/ton DDGS Sales Price, s

$200/ton DDGS Sales Price, s

15 $/ton pelleting cost, Cop

10 $/ton pelleting cost, Cop

5 $/ton pelleting cost, Cop

a

Resulting slack costs and costs of pelleting for each rail car due to differing DDGS sales prices and annualized pelleting costa) breakeven occurs at points of intersection

PELLETING/DENSIFICATION

32

0

500

1000

1500

40 50 60 70 80

Percentage of DDGS Pelleted, p (%)

Tot

al S

lack

Cos

t per

Car

, SC

car

($/

car)

0

500

1000

1500

Pell

etin

g C

ost p

er C

ar,

Pca

r ($

/car

)

$50/ton DDGS Sales Price, s$100/ton DDGS Sales Price, s$150/ton DDGS Sales Price, s$200/ton DDGS Sales Price, s10 $/ton pelleting cost, Cop15 $/ton pelleting cost, Cop5 $/ton pelleting cost, Cop

b

PELLETING/DENSIFICATION

Resulting slack costs and costs of pelleting for each rail car due to differing DDGS sales prices and annualized pelleting costb) magnification of the intersections clearly shows the proportion of DDGS which needs to be pelleted to achieve breakeven

33

40

4045

4550

5055

5560

606565707075758080

p (

%)

p (

%)

Percent of DDGS pelleted, p (%), required to achieve breakeven increases as both DDGS Sales Price, s ($/ton), and Pelleting Cost, Cop ($/ton), increase

PELLETING/DENSIFICATION

34

35