This document discusses distillers grains displacement ratios used for corn ethanol life cycle analysis and the limitations and uncertainties involved. It summarizes: 1) The projected increase in distillers grains production from the growing corn ethanol industry and consumption by various animal types both domestically and for exports. 2) The displacement ratios used to estimate what feed ingredients are replaced by distillers grains in different animal diets, though these ratios have uncertainties depending on future market developments and adoption of new technologies. 3) New corn ethanol processing technologies being developed that produce alternative coproducts like de-oiled distillers grains, corn oil, and corn gluten feed, along with estimates of their displacement ratios in

1. Distillers Grains Displacement Ratios for
Corn Ethanol Life Cycle Analysis –
Limitations and Uncertainties
Salil Arora, May Wu, Michael Wang
Salil Arora, May Wu, Michael Wang
Center for Transportation Research
Argonne National Laboratory
Presented at the
CRC Workshop on Life Cycle Analysis of Biofuels
Argonne National Laboratory, October 20‐21, 2009
A N ti lL b t O t b 20 21 2009

2. U.S. Corn Ethanol and Distillers Grains production
By 2015, with 15
Billion gallon of Corn
Ethanol, approximately
Ethanol approximately
37 Million Metric Tons
of Distillers Grains will
be produced
be produced
Source: EIA/DOE Annual Energy Review 2008; RFA, 2009
Source: EIA/DOE Annual Energy Review 2008; RFA 2009
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3. U.S. Distillers Grains consumption – Domestic use
 Beef and Dairy are major consumers, all WDGS consumed by beef and dairy cattle
 Market share of Swine and Poultry animals is increasing, but can only consume DDGS
DDGS/WDGS split (%)
Market
Animal Type Share DDGS WDGS
Beef 40% 58% 42%
Dairy 41% 58% 42%
Swine 13% 100% 0%
Poultry 6% 100% 0%
Total
T t l 100% 66% 34%
Source: RFA, 2009
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4. All of Exported-U.S. Distillers Grains consumed as DDGS
 In 2008, 20% of U.S. distillers grains production was exported
I 2008 20% f U S di till i d ti t d
 Mainly to Mexico, Canada, EU+Turkey, and Southeast Asia
 In near future, export market can absorb 20% or more of the total U.S. Distillers Grains
production
 Distillers Grains exported as DDGS
 Assumed market share by animal type similar to U.S. Domestic consumption
Source: US Grains Council, 2009
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5. U.S. Distillers Grains – Market Size
 U.S. Distillers Grains market size large enough to absorb projected increase in DGS
production by 2015
production by 2015
Feed per GCAU GCAU Market penetration
Animal type (metric tons/unit/yr.) (million units) (1,000 metric tons)
50% 100%
y
Dairy 3.95 10.55
10% 4,331 8,662
DGS Inclusion
20% 8,662 17,324
Beef 2.1 21.22
20% 4,456 8,912
DGS Inclusion
30% 6,684
6 684 13,369
13 369
Swine 2.1 26.24
10% 2,755 5,510
DGS Inclusion
20% 5,510 11,021
Poultry 2.1 30.44
10% 3,196 6,392
DGS Inclusion
15% 4,794 9,589
Total Market Size at current inclusion levels 17,493 34,987
GCAU = Grain Consuming Animal Unit Source: USDA-ERS 2009
 Significant proportion of U.S. Livestock Industry categorized as Concentrated Animal
Si ifi t ti f U S Li t k I d t t i d C t t dA i l
Feeding Operations (CAFOs), thus making it easier to incorporate Distillers Grains:
– 262 Beef‐feedlots handle 60% of US Beef cattle sales
– 40 Swine operations account for 75% of 100 million hogs marketed annually
40 Swine operations account for 75% of 100 million hogs marketed annually
– 36% of Dairy operations have at least 1,000 head
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6. Distillers Grains use by Animal Type – Survey and
Feedback from Animal Science Experts
p
 In our original study we relied on a 2007 NASS‐USDA survey reporting Distillers Grains
use in Beef, Dairy, and Swine
 2007 Texas Tech University surveyed nutritionists consulting Beef cattle feedlots,
2007 Texas Tech University surveyed nutritionists consulting Beef cattle feedlots
survey representative of 69% of total U.S. beef cattle population in 2007
 2009 Univ. Nebraska survey reported distillers grains use in beef feedlot cattle in the
State of Nebraska
State of Nebraska
 For other animal types feedback received from Industry and University feed
nutritionists
Inclusion rate (%)
Beef cattle Dairy Swine Poultry
Survey DDGS WDGS DDGS WDGS DDGS DDGS
NASS-USDA 2007 23% ─ 8% ─ 10% ─
Texas Tech 2007 16.5% 16.5% ─ ─ ─ ─
UNL 2009 ─ 35.5% ─ ─ ─ ─
Industry Nutritionists
dust y ut t o sts *15%
5% *15%
5% 10%
0% 10%
0% 20%
0% 10%
0%
Argonne Study 17% 25% 10% 10% 20% 10%
*For DGS inclusion in SFC diets for Beef Cattle
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7. Feeding of Distillers Grains in Beef Feedlot Cattle &
Corn Processing Methods
g
 2007 Texas Tech survey reported steam‐flaking of corn (SFC) as the most common
processing method in US Beef feedlots
– Dry rolled corn / High moisture corn (DRC/HMC): Midwest
– Steam flaked corn: High Plains, Southwest, other regions
– For current study, we assumed market share of
SFC and DRC/HMC to be 62% and 38%
 Reasons for using SFC:
– Better animal performance compared
Better animal performance compared
to DRC/HMC based diets
– Energy intensive: high Natural gas and Electricity use
 Impact of introducing Distillers grains in Beef feedlot cattle diets
– DRC/HMC + DGS diets have equivalent animal performance compared to SFC + DGS diets
– Energy savings due to switch from SFC to DRC/HMC diets
gy g /
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8. What does Distillers Grains displace in Animal Diets?
 Distillers Grains generally displace equal amounts of corn & SBM, because of high protein
content (~30%, DM basis)
 Beef cattle: mainly replace corn, and small amounts of SBM and urea
– Improved animal performance (weight gain) when fed in combination with DRC/HMC diets
– 75% of the 2009 UNL survey respondents reported improved animal performance, 23.6%‐no
change
– No change in performance when fed in combination with SFC diets
 Dairy cattle: replace equal amounts of corn and SBM
– Improved milk production reported in scientific studies
– NASS‐USDA reported 8% inclusion, no survey data on animal performance available
 Swine: replace equal amounts of corn and SBM
– Animal performance remains unchanged
– NASS‐USDA reported 10% inclusion, recently because of drop in DDGS prices, higher inclusion
between 20‐30%
b 20 30%
 Poultry: replace equal amounts of corn and SBM
– No change is animal performance
 Enteric fermentation credit: due to improved animal performance for Beef cattle fed
DRC/HMC diets and Dairy cattle
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9. Distillers grains Displacement ratios
 Displacement ratio for the entire US DGS production
Di l t ti f th ti US DGS d ti
Displacement ratio kg feed displaced Enteric
per kg DGS (wet basis)** Fermentation Credit
Corn Soybean Urea CO2 savings
Meal (g/mmBtu EtOH)
DGS sold as DDGS
DGS sold as DDGS 0.770
0 770 0.390
0 390 0.021
0 021 ‐1,808
1 808
DGS sold as WDGS 0.925 0.407 0.023 ‐4,576
US DGS production* 0.793 0.398 0.020 ‐2,449
*Includes Domestic Consumption & Exports **Displacement ratio presented as DDGS with 11% moisture
 Uncertainties in determining future displacement ratios
– Whi h i l f d
Which animal feed markets will absorb future increase in DGS production?
k t ill b b f t i i DGS d ti ?
– Beef and Dairy feed markets are saturated at current inclusion levels of 20% and 10%
– Increase in inclusion levels for beef and dairy diets will keep displacement ratios unchanged
– Increase in market share of swine and poultry will decrease displacement ratios but above unity
Increase in market share of swine and poultry will decrease displacement ratios, but above unity
– Increase in Exports market share will decrease overall displacement ratios
9

10. New Corn Ethanol Processing Technologies
 New technologies being adopted by new as well as existing Ethanol plants
– Reduce energy costs
– Improved profitability by producing more valuable co‐products
Improved profitability by producing more valuable co‐products
 Corn oil extraction: corn oil and de‐oiled DGS as co‐products
– Modification to existing dry mills, using centrifuge to extract corn oil from DGS
– DGS generally have fat content of 11%, while de‐oiled DGS have fat content of 2%
 Dry mill corn fractionation: HPDDG, corn oil, and corn gluten feed as co‐products
– Separates corn kernel into endosperm, germ, and bran
Separates corn kernel into endosperm, germ, and bran
– HPDDG has high protein content (35‐44%) and low fat content (3‐6%), used in dairy, swine
and poultry diets
– Corn gluten feed (CGF) has a protein content of 20% used in beef and dairy diets typically
Corn gluten feed (CGF) has a protein content of 20%, used in beef and dairy diets, typically
replaces corn in animal diets
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11. Displacement ratios of coproducts from new
technologies
g
 De‐oiled DDGS
– no data available on inclusion in animal diets
– assumed to have same displacement ratio as DDGS
 Corn oil
– displaces soybean oil
 Corn gluten feed (CGF)
– 1 kg CGF displaces 1 kg of corn in beef and dairy diets
– recommended inclusion levels of 20% in beef diets, animal performance remains unchanged
, p g
 High Protein Dry Distillers Grains (HPDDG)
Displacement ratio kg feed displaced per
– used in dairy, swine and poultry diets kg HPDDG (wet basis)*
– displaces greater amounts of SBM than corn
displaces greater amounts of SBM than corn Corn Soybean Meal
Soybean Meal
– animal performance remains unchanged 0.282 0.735
*Based on HPDDG inclusion in Swine diets,
Widmer et al. 2008, J of Animal Sci.
11

12. Energy Consumption by Technology
EtOH yield
y DGS yield
y Corn Oil HPDDG CGF
Process (gal/bu) (lb/gal EtOH)* (lb/gal) (lb/gal)* (lb/gal)*
Case A. GREET Avg. (80% NG, 20% Coal), DDGS 2.72 5.995
Case B. GREET Avg. (80% NG, 20% Coal), Wet-DGS 2.72 15.244
Case C. GREET Avg. (100% NG), DDGS 2.72 5.995
Case D. Corn oil extraction (100%NG), DDGS 2.73 5.333 0.28
Case E. Corn Fractionation (100% NG) 2.64 0.28 2.6 3.7
Source: GREET 2009, Mueller & C
S 2009 M ll Copenhaver 2009
h *Yield
*Yi ld as wet b i DDGS 11% moisture, W t DGS 65% moisture,
t basis, DDGS: i t Wet-DGS: i t
HPDDG & CGF: 10% moisture. EtOH yield as undenatured gallon
35,000 1.20
Thermal Energy
Electricity
30,000
30 000
1.00
25,000
0.80
kWh/ga EtOH
Btu/gal EtOH
20,000
al
0.60
0 60
15,000
0.40
10,000
0.20
5,000
5 000
0 0.00
Case A Case B Case C Case D Case E
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13. Methods of dealing with Co-products of Biofuels
 Displacement method (System boundary expansion method or Substitution method)
 Allocation methods
– Mass based allocation
Mass based allocation
– Energy content/BTU based allocation
– Market value/Economic revenue based allocation
 Process‐purpose based method
 European Union in its latest directive on renewable energy has selected:
– Energy Allocation method for Individual biofuel manufacturers
– Displacement method in addition to Energy allocation method for policy analysis
 CARB and EPA are using displacement method
 Displacement method is the most conservative LCA approach
Displacement method is the most conservative LCA approach
 Energy Allocation most suitable when majority coproducts are used as fuels, e.g.
Petroleum refineries
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14. Choice of Co-product method has significant effect
on WTW results for Corn Ethanol LCA
1,200,000
PTW
Fossil Energy
WTP Case Use
Btu/mmBtu)
1,000,000 Coproducts
Case 1 Case 2 Case 3 Case 4 Case 5
DM 13%
1
800,000 EA 37%
DM 18%
nergy Use (B
2
EA 37%
600,000
DM 13%
3
EA 37%
400,000
DM 17%
Fossil En
4
EA 37%
200,000 DM 15%
5
EA 39%
0
DM EA DM EA DM EA DM EA DM EA DM = Displacement method
EA = Energy Allocation
Gasoline GREET GREET GREET New EtOH, New EtOH,
Avg. EtOH Avg. EtOH Avg. EtOH Corn oil & Corn
(80% NG, (80% NG, (100% NG), DDGS Fractionation
),
20% Coal), 20% Coal),
), DDGS (
(100% NG) ) (
(100% NG))
DDGS Wet-DGS
14

15. WTW GHG emissions
100,000
100,000
Case 1 Case 2 Case 3 Case 4 Case 5 GHG
Case Emissions
80,000
80,000
Coproducts
HG Emissions (g/mmBtu)
GH Emission (g/mmBtu
DM 17%
60,000
60,000 1
EA 37%
DM 26%
40,000 2
40,000 EA 37%
DM 19%
3
20,000
20,000 EA 37%
DM 20%
4
0
0 EA 36%
PTW DM 18%
5
-20,000 WTP EA 39%
-20,000 WTP
WTW
-40,000
-40,000
-40 000
DM EA DM EA DM EA DM EA DM EA DM = Displacement method
EA = Energy Allocation
Gasoline GREET GREET GREET New EtOH, New EtOH,
Avg. EtOH Avg. EtOH Avg. EtOH Corn oil & Corn
(80% NG, (80% NG, (100% NG), DDGS Fractionation
),
20% Coal), 20% Coal),
), DDGS (
(100% NG) ) (
(100% NG))
DDGS Wet-DGS
15

16. WTW GHG emissions
100,000
80,000
u)
GH Emission (g/mmBtu
60,000
40,000
ns
20,000
HG
0
PTW
-20,000 WTP
WTW
-40,000
DM DM DM DM DM DM = Displacement
method
Gasoline GREET GREET GREET New EtOH, New EtOH,
Avg. EtOH Avg. EtOH Avg. EtOH Corn oil & Corn
(
(80% NG, (
(80% NG, (
(100% NG),
) DDGS Fractionation
20% Coal), 20% Coal), DDGS (100% NG) (100% NG)
DDGS Wet-DGS
16

17. WTW GHG reduction relative to Gasoline
GREET GREET GREET New EtOH
EtOH, New EtOH
EtOH,
Avg. EtOH Avg. EtOH Avg. EtOH Corn oil & Corn
(80% NG, (80% NG, (100% NG), DDGS Fractionation
20% Coal), 20% Coal), DDGS (100% NG) (100% NG)
DDGS Wet-DGS
DM = Displacement method
DM EA DM EA DM EA DM EA DM EA EA = Energy Allocation
gy
0%
-10%
ange
ative GHG Emission Cha
-20%
-26.2%
-30%
30%
-32.4%
-37.4%
-40%
-38.2%
-42.4%
Rela
-43.6%
43 6%
-50% -47.4%
-50.5% -50.7%
-53.4%
-60%
17

18. WTW GHG reduction relative to Gasoline
GREET GREET GREET New EtOH, New EtOH,
Avg. EtOH Avg. EtOH Avg. EtOH Corn oil & Corn
(80% NG, (80% NG, (100% NG), DDGS Fractionation
20% Coal), 20% Coal), DDGS (100% NG) (100% NG)
DDGS Wet-DGS
DM DM DM DM DM DM = Displacement method
Di l t th d
0%
-10%
Relative GHG Emissio Change
-20%
on
-30%
-26.2%
-26 2%
-32.4%
-40%
-38.2% -37.4%
-42.4%
42 4%
G
-50%
-60%
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19. Choice of Co-product methods: Benefits and Issues
 Displacement method
– Most conservative LCA method
– Data intensive: need detailed understanding of the displaced product sector
– Dynamic results: subject to change based on economic and market modifications
– Results developed using this method will need to be revised regularly
 Energy Allocation method
– Easy to use
– Frequent updates not required for mature industry, e.g. Petroleum refineries
– Results not entirely appropriate, when coproducts are used in non‐fuel
applications
19

20. Recommendations and Future Research requirements
 Displacement method
p
Requirements
– Need for regular surveys (annual/biennial) conducted by Independent organization reporting
yield of Corn Ethanol and Coproducts, energy consumption
– Need for regular surveys reporting coproducts use by animal industry type, inclusion levels,
animal performance
– Feedback/Survey of Professional Animal Industry Nutritionists regarding typical animal diets with
or without Coproducts
ith t C d t
Recommendations
– Develop displacement ratio scenarios based on this information; can be used to calculate
Coproduct credit for individual biorefineries
Coproduct credit for individual biorefineries
 Energy Allocation method
Requirements
– Publish heating values of new coproducts (HPDDG Corn germ de‐oiled DDGS)
Publish heating values of new coproducts (HPDDG, Corn germ, de oiled DDGS)
 Reconcile Distillers Grains Displacement Ratios with GTAP/CARB approach
– GTAP/CARB considered 1 kg DGS displace 1 kg Corn
– Should be modified to consider Distillers Grains additional displacement of SBM Urea
Should be modified to consider Distillers Grains additional displacement of SBM, Urea
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21. Acknowledgements
 We thank Zia Haq of DOE’s Office of Biomass Program for his
q g
support of this effort.
21