Next Generation Technology Swine Waste-to-Energy Project
AgSTAR National Conference June 11, 2013
By: William G. “Gus” Simmons, Jr., P.E. Presented by: Marvin Cavanaugh,
Cavanaugh & Associates, P.A.
Renewable Energy Generation and GHG Emission Reductions via Innovative Waste Management
North Carolina Swine Energy Potential 2
Asheville
Triad Raleigh/RTP
Charlotte Wilmington
Data provided by Duke University Carbon Offsets Initiative
Why is NC Looking at Alternative Energy / Fuels from Ag Waste? • NC Ranks 2nd in the US in pigs produced, with 15%; 2nd to Iowa • NC Ranks 2nd in the US for turkeys produced with 13% after MN • NC Ranks 10th in US for residential electricity consumption, per capita
Commercial-Scale Demonstration Project: Loyd Ray Farms Swine Waste-to-Energy Project Converts waste from 9,000 pigs into electricity Improved Environmental Management
Raw
Was
te
Mixed Digester B
ioga
s
Liqu
ids
How it Works
Existing Storage Lagoon
How it Works: ~65% CH4
What it looks like… After Construction
Photos by: Marc Deshusses, Duke University, 2011
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What it looks like… Steady State
Covered Anaerobic Digester 7
Aeration System 8
Electricity Production Rate - 2012
0
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7012
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Pow
er (k
W)
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Compressor cooler failure, controls
Manual Operation Only – Gas Skid
Replacement
Gas Conditioning System & Microturbine
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Microturbine Specifications: •65 kilowatt Generative Capacity •First Scheduled Service @ 8,000 Hrs •Only one moving part @ >90,000 RPM •Air bearings – no lubricant or coolant required
11 A COUPLE OF FIRSTS:
• First Swine Waste-to-Energy project in the State of North Carolina to place RECs on the NC Utilities Commission REC Tracking System • First Transfer of RECs from a NC Swine Farm to Duke Energy • First ‘Innovative Swine Waste Treatment System’ permitted that utilizes digester
Costs and Benefits Costs Capital: $1.7M O&M: $80,000/year
Funding sources NCACSP LCP CCPI/EQIP Sale of RECs to Utility Sale of Carbon Offsets
(voluntary market)
Note: No capital or operating costs passed on to farm owner! Farm owner receives excess electricity!!!
Benefits Cash flow for farm owner Improved animal health Other ecosystem services (N,
P control) Variability in nitrogen output
for fertilizer Reduced sludge management
cost Improved air quality on-site Reduction of odors off site More choice in cropping plan Sustaining NC Agriculture Reduced GHG Emissions
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Challenges & Lessons Learned: Gas Skid Challenges – Gas skid has suffered from multiple outages, which prevents REC generation, gas skid control issues Abundance of Gas – Very conservative on gas production expectations – Electrical Load Balancing – Environmental system operating at full capacity requires more electricity (demand) than the microturbine produces.
CAR Protocol Requirements – Adding additional gas flow meters, thermocouples on flare, etc.
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Next Steps… In April 2013, Duke University released ENERGY GENERATION FROM SWINE
WASTE: A SPATIAL-ECONOMIC OPTIMIZATION STUDY (OptimaBiogas Study) The analysis determined that the swine WTE portion of the REPS could be met with
as few as 127 farms located in Sampson and Duplin Counties, assuming the use of highly efficient mixed anaerobic digesters to produce biogas (the fuel generated from swine waste) at each farm. Researchers evaluated four scenarios for producing electricity from swine waste-
derived biogas, including: 1. On-farm electricity production, using on-farm digesters and on-farm generators; 2. On-farm digesters and biogas collection for direct injection into the existing natural gas pipeline; 3. Transport of biogas from individual farms to a centralized location for electricity production; and 4. Transport of biogas from individual farms to a centralized location for purification, pressurization and injection into the existing natural gas pipeline (and assumed combustion in a highly efficient combined cycle natural gas plant).
Special Thanks
Mr. Loyd Bryant, Loyd Ray Farms LNH Farms
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