Renewable Energy from Waste A Review of Case Studies
Michael P. O’NeilApplied Technologies, Inc.
2009 AIEC Waste To Energy WorkshopSpringfield, IllinoisOctober 20, 2009
Two Case Studies
• Case 1: AD/CHP application in La Crosse, Wisconsin– Substrate: brewery wastewater– AD system: two UASBs– CHP: Jenbacher engine generator, 633 kW
• Case 2: AD/CHP application in Waterloo, Wisconsin– Substrate: dairy farm manure/whey– AD system: two CSTRs– CHP: Jenbacher engine generator, 633 kW
LaCrosse, Wisconsin
Case Study 1: A Partnership Between a Brewery and a Hospital
City Brewing Company
• State-of-the-art contract brewing facility– Produces and packages various beers and beverages– Brewing capacity: 7 million barrels annually – Packaging capacity: 50 million cases annually
• Wastewater treatment– Up-flow anaerobic
sludge blanket reactors– Effluent to local POTW– Biogas to flares
Gundersen Lutheran
• Serves 19 counties in western Wisconsin, northeastern Iowa, and southeastern Minnesota
• Offers broad range of medical care with over 50 facilities
• Renewable energy goal– “…offset 100% of its energy needs by creating
renewable energy and by improving energy efficiency by the year 2014.”
The Partnership
• Gundersen Lutheran has a goal to offset 100% of its energy use with renewable energy by 2014
• City Brewing Company was generating and flaring 100% of its biogas
Wastewater Characteristics
Substrate: Brewery wastewater
Average daily volume 868,000 gal/day
COD concentration 4,900 mg/L
TSS concentration 590 mg/L
Seasonal variation (peak) May-September
Biogas Characteristics
Estimated biogas flow rate (avg) 0 - 600 scfm
Predicted annual volume 89 million ft3
Methane content 60 - 82%
Estimated H2 S concentration 0.5 – 2.5 %
Estimated siloxane concentration 0 - 3.0 ppmv
Estimated energy value 600 – 650 BTU/scf
Wastewater and Biogas Characteristics
Major ChallengesHigh H2 S
ParameterTest - 1
(11/6/07)Test - 2
(4/21/08)Test - 3
(4/29/08)Test - 4(5/6/08)
Test - 5(5/14/08)
Methane (%) N/A 81 72 75.5 71.6
Carbon Dioxide (%) N/A 17.1 25.1 21.1 26.3
Sulfur Species (ppmv) 2,622 3,660 18,706 13,595 9,984
Silicon (ppmv) 1.04 0.44 2.41 N/A N/A
Results of Initial Biogas Testing Results(Test Samples: grab; Biogas: RH: 100%, Temp: 35oC, Flow: 0 - 600 scfm)
Correlation Between H2 S in Biogas and Sulfur Species in Wastewater
H2S
0
200
400
600
800
1,000
1,200
1,400
1,600
1,800
2,000
6/16
18:
59
6/17
0:5
9
6/17
6:5
9
6/17
12:
59
6/17
18:
59
6/18
0:5
9
6/18
6:5
9
6/18
12:
59
6/18
18:
59
6/19
0:5
9
6/19
6:5
9
6/19
12:
59
6/19
18:
59
6/20
0:5
9
6/20
6:5
9
6/20
12:
59
6/20
18:
59
6/21
0:5
9
6/21
6:5
9
6/21
12:
59
6/21
18:
59
6/22
0:5
9
6/22
6:5
9
6/22
12:
59
6/22
18:
59
6/23
0:5
9
6/23
6:5
9
6/23
12:
59
6/23
18:
59
Time
Sul
fur S
peci
es -
WW
(mg/
L)
0.0
0.3
0.6
0.9
1.2
1.5
1.8
2.1
2.4
2.7
3.0
Hyd
roge
n S
ulfid
e - G
as (%
)
WW Inf - Sulfate WW Inf - Sulf ide WW Inf - Sulf ite H2S
Gas Processing
H2 S Removal
Equali- zation Tank
Rapid Mix Tank
East
Anaerobic
UASB
West
Anaerobic
UASB
Heat Exchanger
Gas Processing
H2 S Polishing
Gas Processing
Moisture Removal
Chemical Conditioning
Filter Press Solids
Removal
City of La Crosse
Wastewater Treatment
Plant
City Brewing
Company Processing
Plant
Combined Heat and
Power Generator
Transformer
Solid Waste
Fertilizer Supplement
Solid Waste
Landfill Disposal
Flares
Wastewater
Screens
Solids
HeatPower
Biogas
Wastewater
Treatment Solution
Site Plan
Pre-Construction Site Location
Waterloo, Wisconsin
Crave Brothers Dairy
Crave Brothers Cheese Plant
Case Study 2: Dairy Farm and Cheese Plant Go Green
Crave Brothers Dairy Farm
• Started by two of the four Crave brothers with 70 cows in 1978; the other two brothers joined later
• Today– 1,100 Holstein milking cows– 900 young stock– 1,800 acres of corn, soybeans, and alfalfa used to
feed the cows• Each cow produces approximately 28,000 pounds
of milk annually (3,300 gallons)
Farmstead Cheese Factory
• Originally built in 2001(6,000 square feet), and later expanded to 20,000 square feet
• Milk from the dairy is piped directly across the road to the cheese factory
• Cheese factory produces a variety of craft and specialty cheeses
Wastewater Characteristics
Substrate: Manure 50,000 gpd
Substrate: Whey 5,000 gpd
Substrate: Off-site wastes (3-4 substrates: generally FOG)
5,000 gpd (varies) (10% by volume)
Average Total Volume to Digesters 55,000 - 60,000 gpd
TS 14,000 mg/L
VS 50% of TS
Biogas Characteristics
Estimated biogas flow rate (avg) 0 - 600 scfm
Predicted annual volume 75 million ft3
Methane content 56 - 62%
Estimated H2 S concentration 0.45 – 0.53 %
Estimated siloxane concentration 0 ppmv
Estimated energy value 560 – 620 BTU/scf
Wastewater and Biogas Characteristics
Transformer Grid
Process and Control Unit
Cheese Plant
Milking Parlor
ADSystem
(2)
BiogasConditioning
System
CogenerationSystem
MilkingCowBarn
Young Cow Barn
BeddingSolids
Crop Fields
EffluentHolding
Pond
FOG
WheyTank
ManurePit
Manure / wheyPit
Cheese To
Market
Major Challenges
• Foaming– Solved problem by better operational control
of substrate loading• Plugged pipes
– Solved problem by installing gradual turning radius on elbows and optimizing the pipe size
Pre-Construction Site Location
City Brewing Company Crave Brothers Dairy Farm
Utility: Alliant Energy Utility: We Energies, Inc.
AD System AD System
Substrates Brewery wastewater Substrates Manure, whey, and
off-site FOG
Digester type (2) UASBs Digester type (2) CSTRs
Cogeneration Engine Cogeneration Engine
Manufacturer Jenbacher Manufacturer Jenbacher
Size 880 HP Size 880 HP
Rated output 633 kW Rated output 633 kW
Heat output* 2.6 MMBTUH Heat output 2.5 MMBTUH
Fuel consumption* 8,719 scfhr Fuel consumption 12,402 scfhr
Turndown* 4,829 scfhr Turndown 6,869 scfhr
Summary Comparison
Some Lessons Learned
• Select one organization and one person to be “in charge” throughout the project
• You as owners and/or stakeholders have a responsibility to be a part of project planning and execution
• Plan for the possibility of the unforeseen• Always do a feasibility study first
Thanks!
Any questions?
Contact
Mike O’NeilApplied Technologies, Inc.
16815 West Wisconsin AvenueBrookfield, WI 53005