Albert J. Heber, Associate ProfessorDirector, Purdue Agricultural Air Quality Lab

Agricultural and Biological Engineering

Purdue University

Building EnvironmentResearch & Education

AgAirQuality.com

“A Buoyant Convective Flux Chamber for Measuring Liquid Surface Emissions”

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A.J. Heber, T.T. Lim, J.Q. Ni and K.J. Fakhoury

AgAirQuality.com

Objectives Develop floating emission chamber Evaluate performance

Field Tests

Lab Tests

Air Supply Unit

Blower Adsorbent

Filter

Air Supply Blower

198 m3/h

(117 cfm)

Air Supply Unit

Air Supply Filter

22.4 kg of adsorbent Charcoal Permanganate Zeolite

Top View

Air outlet

Sampling location

Air velocity probe

Stainless steel

divider

Air inlet

Styrofoam boards for buoyancy

Liquid surface area = 0.76 m2

BCFC Inlet

Stainless Steel Lining

“Hairpin” Airflow Path

2.4 m path length

2.2 sec residence

time

1.1 m/sSampling location

Air velocity probe

Air outlet

Side View

Air inlet

End View

Air Inlet

Air Outlet

Divider31 cm

Samplingpoint

Lab Tests

N-butanol at 250-20,250 ppm in 200 L water

Odor emission only.Lagoon effluent: 100, 50 and 25% dilution

H2S, NH3, CO2 and odor emission.

Gas Analyzers Ammonia (0 to 200 ppm)

• Ammonia converted to nitric oxide with a SS converter, 875 C

• Chemiluminescense: PMT detects light emission from reaction of nitric oxide with ozone.

• Sample flow rate = 0.5 Lpm Hydrogen sulfide (0 to 10,000 ppb)

• Hydrogen sulfide converted to sulfur dioxide, SO2

• Pulsed fluorescence: PMT detects UV from decaying SO2 molecules

• Sample flow rate = 1.0 Lpm Carbon dioxide (0 to 5,000 ppm)

• Photoacoustic infrared sensor • Sample flow rate = 1.0 Lpm.

Instrumentation Room

Manifolds

PC

Gas sensors

Odor Threshold Measurement

1 of 8 panelists

Olfactometer

Tedlar bag

Panel leader’s hand

PC

N-Butanol Test Results

Blank: 9 OU Inlet mean: 10.4 OU (8 to 13 OU) Odor emission: 0.5 to 11.2 OU/s-m2

Emission Rate of N-Butanol

Emission Rate = 5.10 Log(C) - 13.05

R2 = 0.82

0

4

8

12

100 1000 10000 100000Concentration of N-butanol in Tank, ppm

Em

issi

on R

ate,

OU

/s-m

2

2027

5163

155

Lagoon Effluent Test Results

Inlet mean: 22 OU Outlet mean: 27 OU Odor emission: 0.8 OU/s-m2 at 100% Hydrogen sulfide too low to measure Inlet ammonia mean: 1.8 ppm Outlet ammonia mean: 2.9 ppm Ammonia emission proportional to

effluent concentration. Ammonia levels below odor threshold

Lagoon Effluent: NH3 Emission

Emission Rate = 4.15x - 18.1

R2 = 0.90

0

100

200

300

400

0 20 40 60 80 100 120Lagoon Effluent Dilution, %

Em

issi

on R

ate,

mg/

hr-

m2

Solids: 0.16%

Field Tests

Swine grow-finish facility Four consecutive days Day 1: Effect of air speed

crustincorner

Anaerobic Treatment Lagoons

2nd Stage Basin

1st Stage Basin

Six Swine Buildings

Deployment

Odor Emission Tests

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3 Lpm

pumpsAir

velocity control

Hammer

Evacuation chamber

Raceway(6 m)

Chamber Inlet and Outlet Samples

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Emission vs. Air Speed

Emission = 1.85 x 0.93

R2 = 0.88

0

1

2

3

4

0.0 0.5 1.0 1.5 2.0

Surface Air Speed, m/s

Measured Predicted

Emission, OU/m2-s

Field Test Results

Inlet mean: 23 OU (12 to 42 OU) Outlet mean: 52 OU Odor emission: 1.5 to 2.1 OU/s-m2

Mean of 1.7 OU/s-m2 corresponded to 1,000 ppm n-butanol.

Advantages

Large air filtration and cleaning unit Inlet air sampling Large liquid surface area Long air path

Disadvantages

Size (van or pickup required) Weight (2-4 people required) Gentle berm slopes required, >3:1 Limited reach (five meters)

Future Research

Reduce size and weight Evaluate and improve internal air profiles Study effect of flow rate on emission

Conclusions

Good comparative measurements of gas and odor emission rates

Conclusions

Low sampling variance

Conclusions

Lower detection limit: 500-1000 ppm n-butanol.

ConclusionsLower limit reached with

properly designed swine lagoon

0.16% solids

“Low odor” lagoon

Conclusions

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Odor emission rate increased for 1000-20,000 ppm n-butanol

Acknowledgements

Purdue University Agricultural Research Program

State of Indiana Value Added Research Program Ramco Sales, Inc.

Questions?

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