intrinsic characteristics of modified ddgs and effective handling strategies nc -213 meeting,...
TRANSCRIPT
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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!