Small-Scale Solar-Biopower Generation For
Rural Central America
Project support from:
US Department of State, Western Hemisphere Affairs
Energy & Climate Partnership of the Americas (ECPA)
Dana Kirk, Ph.D., P.E.
Michigan State University
Biosystems and Agricultural Engineering
kirkdana@anr.msu.edu
Project Partners
Core Project Team
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PI – Ajit Srivastava, MSU BAE
Co PI – Wei Liao, MSU BAE
Co PI – Dawn Reinhold, MSU BAE
Educational coordinator – Luke Reese, MSU BAE
Project manager – Dana Kirk, MSU BAE
Francisco Aguilar – UCR AE
Daniel Baudrit – UCR AE
Alberto Miranda – UCR AE
Lorena Lorio – UCR Micro
Lidieth Uribe – UCR Micro
Project Objectives
1. Optimize local thermophilic anaerobic microbial
consortia
2. Implement a solar-biopower generation system
3. Evaluate the technical and economic
performance
4. Establish an outreach program in Central
America
Facts of solar energy
Central America
 Advantages
 Theoretical: 1.76 x 105 TW
striking Earth, Practical: 600 TW
 It is the cleanest energy source
on the Earth.
 Solar energy reaching the earth
is abundant.
 Disadvantages
 Sun does not shine
consistently.
 Solar energy is a diffuse
source.
 It is difficult to collect, covert,
and store solar energy.
From: http://www.global-greenhouse-warming.com/solar.html
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Facts of Biogas Energy from Wastes
 Disadvantages
 Advantages
 A biological process
 Low efficiency of organic
 Reducing greenhouse gas
emission
 Enhancing nutrient
management
Completely Stirred Tank
Reactor (CSTR)
matter degradation
 Difficulty of power
generation for small-medium
operations
Anaerobic Sequence Batch
Reactor (ASBR)
Plug-flow digester
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Agricultural residues available in Costa Rica
Residues
Total amount (metric ton dry
matter per year)
2006
Cattle manure
1,530,000
Swine manure
95,000
Banana residues
Coffee residues
Sugarcane bagasse
Pineapple residues
158,000
(pulp) 251,000
(husk) 25,000
1,290,000
6,351,000
Current treatment practices
Projection 2012
1,679,900 Only 20% of producers treat wastes, dried
and composted
110,000 0.68% for production of energy and rest in
agriculture, fertilizer (45.5%) food
animal (53.1%) or other uses (0.7%).
132,000 Not used as energy source,100% discarded
or composted organic
(pulp) 262,000 Pulp is used for composting, and husk is used
(husk) 26,300 for combustion
1,518,200 95.3% dried and used as combustion, 4.7% non
energetic
8,452,000 Combusted and soil improvement
 More than 600 MW electricity per year could be potentially generated
from this amount of waste streams through anaerobic digestion
technology.
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Solar-biopower concept
Integrating wastes utilization with solar and biological
technologies will create a novel self-sustainable clean
energy generations system for small-medium scale
operations
Bioenergy
Animal Manure
Other Organic
Wastes
Solar
Energy
Anaerobic
Digestion
Posttreatment
Fertilizers
Reduced GHG
Clean Water
Solar-biopower concept
Benefits of system integration
 Overcome the disadvantages of individual technologies
 Unsteady energy flow for solar power generation
 Low efficiency of mesophilic anaerobic digestion on degradation
of organic matter
 Higher energy requirement of thermophilic aerobic digestion
 Provide sufficient and stable energy for small-medium
sized rural community
 Solar energy utilization
 Improved efficiency of anaerobic digestion on degradation of
organic matter
 Biogas energy as chemical storage – steady energy flow
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Mass balance
Predicted mass balance for the integrated solar-bio system on 1,000 kg of
mixed sludge and food wastes
Boiler
Biogas production from
anaerobic treatment
Bioenergy
Amount: 684 MJ/day
Methane: 18,000 L/day
Mixture of feedstocks:
Thermophilic CSTR
Total amount: 1,000 kg/day
Total solid: 10%
COD: 90 g/kg
Reaction temp.: 50°C
Retention time: 15 days
COD reduction: 50%
Total solid reduction:40%
Generator
Liquid effluent
Amount: 595 kg/day
Total solid: 10 g/kg effluent
COD: 45 g/kg effluent
To wetland
Solid residue accumulated
from the CSTR
Amount: 360 kg/day wet solid
Dry matter: 15%
 Generating 66 kWh electricity per day
 Producing 5 gasoline gallon equivalent (GGE) renewable fuel per day
a.
b.
The calculation of mass balance was based on the expected results that will be achieved by this project.
A kg COD destroyed produces 350 L methane gas.
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Solar-biopower system
Power unit
Solar unit
Bioreactor
Post-treatment
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Construction site
Solar Bio-Reactor Site
Fabio Baudrit Experiment Station
Major system components
 16 – 2 m2 flat-plate solar collector with support
 22 m3 anaerobic digester
 50 m3 gas bag
 2 – 10 kW electric generators
 4 – 144 m2 wetland/sand filter cells
Solar Bio-Reactor
Sand Filter / Wetland
Solar thermal system
Solar collectors,
hot water tank (white),
& hot water storage (green)
Anaerobic digester
Poly tank anaerobic digester
Official ribbon (digester in background clad in
tin)
Field engineering
Feedstock & digestate handling
Digestate solid-liquid separator
Feedstock grinder, auger & mix tank
(pump not shown)
Biogas storage
Gas bag, foam interceptor, & scrubber
Biogas sampling
Full gas bag, May 2, 2013
Sand filter & wetlands
Sand filter 1
Vertical wetland (sand filter 2)
Surface wetland 1
Surface wetland 2
Solar-biopower system performance
 Feedstock:
 Beef manure (950+ kg/d)
 Food waste
 Chicken litter (20 kg/d)
 Temperature:
 Currently 45oC±2oC
 Target 50oC±1oC
 Biogas production: ≈20 m3/d
 Biogas quality: 60+% CH4
 Volatile solids destruction: 39% to 44%
Water reclamation
Organic
waste
Original waste
stream
May 2013
Anaerobic
digester
The effluent
from solarbioreactor
Sand filter
No. 1
Sand filter
No. 2
The water
from the 1st
cell of posttreatment
Reclaimed
water
The water
from the 2nd
cell of posttreatment
Outcomes to date
 Pilot system
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Biogas production at 70% of goal
Biogas quality and solids destruction have achieved goals
Install biogas flow meter
Connect electrical generators to the experiment station power
Begin sand filter/wetland research
 Bioenergy support lab at UCR – capable of carrying
out BMP’s and other analysis
 Utilization of local manufacturing – coffee equipment &
solar panels
 Study abroad “Ecological Engineering in the Tropics”
completed in December of 2012
Next steps
 Finalize microbial consortia papers
 Continue to operate pilot system until Sept. 2014
 Operate portable unit at second location – wastewater
or food processor
 Complete economic and policy evaluation
 2013 study abroad planned for December
 Expand bioenergy capabilities to address commercial
needs
Other announcements
 August 13, 2013 – MSU Waste to Resource Field Day
 Highlights:
 South Campus Anaerobic Digester (500 kW from 130 cows)
 Research digester, compost facility, student organic farm,
recycling center, power plant, ADREC
 For more information go to :http://events.anr.msu.edu/adrec/
 October 15 to 17 – Anaerobic Digester Operator
Training (East Lansing, MI)
 Highlights
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System commissioning
Maintaining biological health
Safety
Operational troubleshooting
 For information contact kirkdana@anr.msu.edu
Questions?
Dana M Kirk, Ph.D., P.E.
Biosystems and Agricultural Engineering
Anaerobic Digestion Research and Education Center
E: kirkdana@anr.msu.edu
P: 517.432.6530