manure separation: bedding and nutrient recovery

GEA Farm Technologies

Andy Lenkaitis, P.E.

Environmental Systems Engineer

Manure Separation: Bedding and Nutrient Recovery

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Nutrient Limitations

• Build-up on close fields

• Nutrient distribution

Proper Lagoon Agitation

Efficiency

• Limited window to apply

• Time to set-up,

application rate, distance

to fields

Manure Application Challenges

Nutrient Management and Separation

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Nutrient Management Process

Nutrient Management and Separation

Transfer Transfer Agitate, Transfer

& Load

Spreading

Primarily Solid

Separation

Secondary Solid

Separation

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Primary Separation

• Bedding production

• Process liquid

Separation Systems

Nutrient Management and Separation

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Cows on Green Bedding

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Primary Separation Capture Rates

• Sacrifice Capture Rates

• Less efficient Separator to make a quality product

• Large variance in nutrient capture rates

Primary Capture

Rates

Dairy TR Dairy GM Dairy CVT

Total Solids 20 43 55

Total Nitrogen 4.2 15 20

Phosphorus 3.5 5 37

Potassium 2.6 10 15

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Green Bedding Material-Equipment

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Secondary Separation

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Secondary Separation

• Nutrient partitioning

• Reduced solids to long term

storage

Following Primary

• Increased capacity of secondary

system

• Reduced volume (10%)

• Process flow rate

• Trash screening

Separation Systems

Nutrient Management and Separation

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Lagoons after Primary Separation

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• Slope Screen System-1.8% to lagoon

Secondary Separation-Slope Screen

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Slope Screen

• 30% Solids Capture Rate

• <10% of all Nutrients

Can run Slower process time

Secondary Separation Systems

Nutrient Management and Separation

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Centrifuge Separation Technology

Solids

Discharge Clarified

Liquid

Discharge

Feed

Drive

Scroll Bowl

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2014 Testing

Centrifuge Separation in Livestock Manure

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Secondary Separation-Centrifuge Results

3800 rpm, 40 gpm DM Dry

Matter

Suspended

Solids

Total

Nitrogen

lb/ton

Total P as

P2O5

lb/ton

Primary Liquid

Infeed Houle

System SW

4.30% 2.59% 4.67 1.42

Centrate SW 2.6% 1.00% 4.07 1.01

Solids Cake SW 34.20% 34.20 10.8 8.2

Capture rate

Centrifuge-

Secondary

Separation, after

2-Stage Primary

45.2% 66.4% 22.6% 34.9%

Flush Reception Pit

GEA WS Centrifuge

Centrate SW Solids Cake SW

GEA FT 2-Stage

Separator w/Roller

Press

Primary

Solids for

Bedding

SW

Primary Liquid Infeed SW

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DM Dry

Matter

Suspended

Solids

Total

Nitrogen

lb/ton

Total P

as P2O5

lb/ton

Primary Liquid

Infeed Houle

System AA

4.40% 2.54% 4.48 1.83

Centrate AA 1.9% 0.89% 4.27 1.01

Solids Cake AA 28.90% 28.90% 12.4 10.6

Capture rate

Centrifuge-

Secondary

Separation, after

digestion

67.0% 71.2% 7.3% 54.2%

Secondary Separation-Centrifuge Results

Digester

GEA WS Centrifuge

Centrate AA Solids Cake AA

GEA FT 2-Stage

Separator w/Roller

Press

Primary

Solids for

Bedding AA

Primary Liquid Infeed AA

Digestate Infeed

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Nutrient Capture

• Up to 25% of Organic Nitrogen,

up to 50% with chemicals

• Up to 50% of Phosphorus,

up to 95% with chemicals

• Variability in results:

• Infeed to system

• Equipment technology

• Equipment Tuning

• Flowrate

• Torque / Differential Speed

• G-Force

Experienced Results

Centrifuge Separation in Livestock Manure

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High solids capture rates (50%+)

• Cleaner liquid for irrigation

• Reduced need to agitate and clean

solids from lagoon

Experienced Results

Centrifuge Separation in Livestock Manure

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30% Dry Matter Solids Cake

• Easy to store or compost

• Can be directly applied to fields

• Transported to fields further away

Experienced Results

Centrifuge Separation in Livestock Manure

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Manure Application

• Centrate Liquid: 90% of volume, 50% nutrients

• Solid Cake: 10% of volume, 50% of nutrients

• Spread liquid close to home at higher rates

• Solid cake transported to further fields

Direct Application Costs

• Manure spreading cost:1.0₵+ per gallon

• Irrigation cost: 0.1₵ per gallon

• 500 cow dairy: 5 Million gallons * 90%

* 0.9 ₵ per gallon = $40,000/year

Milk more cows at home!

Economic Factors

Centrifuge Separation in Livestock Manure

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Indirect Application Benefits

• Lagoon agitation

• Compaction

• Timing of nutrient application

Nutrient Use Efficiency

• More efficient placement of

Phosphorus-less buildup

• $0.43/lb of Phosphate (value

from the market)

• 56 lb/acre =$25/acre

Economic Factors

Centrifuge Separation in Livestock Manure

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• Increased interest in staged separation

• Produce bedding solids

• Staged system for growth of the farm

• Integrated with farm system

• Only create products that can be used

• Bedding

• Nutrient Rich Solids

• Mechanical Processes

• Redundancy and overflow paths

• Significant Potential for Nutrient

Partitioning

• Aid in moving nutrients where needed

Staged Separation Summary

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Thank You!