Intrinsic Characteristics of Modified DDGS and Effective Handling Strategies NC -213 Meeting, February 18-19 th Kansas city, 2015 1.

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Intrinsic Characteristics of Modified DDGS and Effective Handling

Strategies

NC -213 Meeting, February 18-19th Kansas city, 2015

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InvestigatorsK-State

Kaliramesh SiliveruGraduate Research Assistant

Kingsly AmbroseAssistant Professor

Rumela BhadraPostdoctoral Research Associate

USDA-ARS

Mark CasadaResearch Agricultural Engineer

NDSU

Kristin WhitneyResearch Specialist

Senay SimsekAssociate Professor

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• Introduction• Objectives• Materials and Methods• Results• Future Work

Outline

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Distillers Dried Grains with Solubles (DDGS)

28-35% protein, 30-32% fiber & 8-12% fat (comes from CDS*/syrup), vital amino acids, phosphorous

Dry grinding process

Corn Ground Cooked Liquefaction

Alpha amylase

Fermentation

Yeast & Glucoamylase

CO2

DistillationSeparatedDistiller’s Grains (DDG)

Ethanol

Thin stillageCondensed

Solubles (CDS)

DDG + S (DDGS)

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DDGS and Ethanol Production

• 35.5 million MT (2013)

• 9.7 million MT exported

• 210 Bioethanol Plants

• Operating Capacities of

14,877.5 MG/year ethanol

Source: Colorado Geological Survey website, updated March 2011

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Modified DDGS (M-DDGS)

• Low oil ( 4- 5% fat) DDGS

• Increased profits in oil extraction

• Around 105 dry grind ethanol plant extracted oil (USGC, 2012) (50% of plants)

• Price of crude oil is $0.45/lb

• Oil extraction investment ~ $3 million, recovery period – 3 to 4 months

Ref: Shurson, J. and B. Kerr. Reduced oil DDGS – It’s not the fat, It’s the fiber. Nutriquest DDGS Symposium. Des Moines, IA, March 21, 2012.

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Thin stillage

Crude Corn Oil

Extraction Method 1

Whole stillage

Extraction Method 2

CDS

Corn Oil

Feed

Back- end Extraction Flow Diagram

About 30% corn oil is removed from Method 1 and 60% oil is removed from Method 2

Ref: Shurson, J. and B. Kerr. Reduced oil DDGS – It’s not the fat, It’s the fiber. Nutriquest DDGS Symposium. Des Moines, IA, March 21, 2012.

Modified DDGS (M-DDGS)

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Flowability Problems in M-DDGS

• Caking of DDGS in rail cars; segregation during discharge

• Economic loss: Cost to break the ‘cakes’ and unload cars

• Safety Issues

• App. $9000 in repairs (semi-annually)• Avoiding loading hot DDGS can delay

onset of caking (Kingsly and Ileleji, 2011)

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• Develop heat transfer model for cooling of M-DDGS pile

• Validate the developed model experimentally in a lab scale

Objectives

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Governing equation: Energy balance

• Left hand side

• 1st term - energy stored at a specified period of time

• 2nd term - energy transfer due to convection

• Right hand side

• 1st term - energy transfer due to conduction (Fourier law of heat conduction)

• 2nd term - energy liberated due to evaporation for a specific period of time.

Materials and Methods

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Inclusion: Momentum transfer due to convection

• Left hand side

• Pressured drop across the length

• Right hand side

• 1st term – viscous loss coefficient

• 2nd term – inertial loss coefficient

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SIMULATION

Solved by: Finite volume method in ANSYS FLUENT

Simulations were carried out for summer (24.77 °C) and winter (6 °C).

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Boundary Conditions

Initial condition: T = T0 = 373.15 K (at t = 0)

Energy equation:

Momentum equation:

side walls (contact with atmosphere) = interior (to allow porous media)

bottom wall (contact with concrete slab) = interface

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VALIDATION• Low oil DDGS was heated in hot air

oven. (@ M.C 9.07% to M.C 0.89%).

• Pile dimensions: 0.20 m diameter; 0.1 m height considering angle of repose 45°

• J- type thermocouples, FLUKE data logger

• Summer (24.77 °C) and Winter (6 °C)

• Measure of accuracy of prediction

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Results

Predicted and actual temperature profiles of low oil DDGS pile when cooled to 297.92 K (24.77 °C) .

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Predicted and actual temperature profiles of low oil DDGS pile when cooled to 279.15 K (6 °C) .

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Predicted Temperature Profiles for a larger pile

(A) when cooled to 297.92 (24.77 °C) (B) when cooled to 279.15 K (6 °C) .

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Standard error of prediction (K) for the developed model

LocationWhen cooled to

297.92 K

When cooled to

279.15 K

Bottom side A 0.56 1.00

Bottom mid 0.72 1.31

Bottom side B 0.55 1.32

Center side A 1.43 2.58

Center mid 2.46 2.31

Center side B 1.47 2.35

Top mid 1.32 2.73

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Conclusions

• A 3-dimensional heat transfer model based on finite volume method was developed to predict cooling pattern of M-DDGS pile.

• The developed model predicted temperatures with acceptable accuracy.

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• The model will be validated with the field data which will be collected in an industry in summer and winter seasons.

• Hopper flow analysis of M-DDGS is currently being carried out.

Future Work

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Acknowledgements

• The Andersons Research Grant Program• POET Nutrition• Dr. Josephine Boac- Grain Science and

Industry, K-State

Thank You!