Developing Inexpensive Design for Converting Biogas to Electricity
Group 22Sung Hoon Bae (BME)Daniel Rim (ChBE)Chris Zachara (ChBE)Advisor: Dr. David OwensOwen Graduate School of Management
Bae, Rim, Zachara http://www.bme.vanderbilt.edu/srdesign/2009/group22/ BME 273: Oral Report #2
Problem Statement
Bangladesh Large population/high poverty rate
Population: 162 Million – 7th
GDP (PPP): $1,500 per capita – 153rd
http://upload.wikimedia.org/wikipedia/en/f/f2/Bangladesh_(orthographic_projection).svghttp://en.wikipedia.org/wiki/File:Flag_of_Bangladesh.svg
Problem Statement
Only 30% electricity distribution (2002) 25% in urban and 10% in rural (2000) 79% of population in rural (1999)
Government efforts 30% to 38% distribution from 2002-2008 Slow progression
Objective
Generate electricity Household scale generator “Reasonable” retail price Sufficient output electricity
LED light
http://www.odec.ca/projects/2007/sidd7g2/Images/appelectricty.gifhttp://image09.webshots.com/9/2/10/75/112721075ZEGbyv_fs.jpghttp://www.ct.gov/opapd/lib/opapd/newsletter-pics/dollar2520squeezed.jpg
Background: Biogas Anaerobic digestion or fermentation Biodegradable materials
Biomass, manure, sewage, and etc. Composition
Methane: 50-70% Carbon dioxide: 30-40% Hydrogen: 5-10% Nitrogen: 1-2%
Application Electricity and heating
Background: Why Biogas?
Clean Fuel 80% less hydrocarbon and 60% less
nitrogen oxides than diesel Negligible concentrated particles or dust
Availability Organic material – virtually unlimited
Animal waste, food waste, and etc. 65% labor force in agriculture in
Bangladesh
Thermoelectrics
Phenomenon: temperature difference creates electric potential or vice versa
Materials: specially doped semiconductors, most commonly made from Bismuth Telluride
Current Uses: portable refrigeration, electronics cooling
Advantages
Less Expensive than Turbine Technology Utilize Low Grade Heat Small Silent Reliable
No moving parts No maintenance
Challenges
TEG Only 10% Energy Efficient Other design aspects will be very
important Significant Heat Gradient Needed
The “cold side” must be cooled Cold side is just cm’s away from heat
source
Light-emitting diode (LED)
120V tungsten incandescent light bulb 60W: 850lm and 14.2lm/W 100W: 1700lm and 17.0lm/W 90% of power emitted as heat
LED Energy efficient Long operating time: up to 50,000hours Current driven: ~20-30mA
Materials: TEG (TEC)
Product Model:CP2,31,06,L1,W4.5 Laird Technology
30mm x 30mm x 4.6mm Qmax = 29.3W (TH=25°C)
Imax = 14.0 A (TH=25°C)
Vmax = 3.5V (TH=25°C)
ΔTmax = 67°C Price = 23.42$ (http://www.mouser.com)
http://lairdtech.thomasnet.com/item/thermoelectric-modules-2/-series-peltier-solid-state-thermoelectric-coolers/pn-4059?&seo=110&bc=100|3001624|3001688|3001251
Materials: LED Product Model:LED5 40-50DG WH
(TheLEDLight.com) Emitted Color: White Luminous Intensity = 6000mcd max at
IA=20mA Beam Angle = 40-50 degrees Continuous forward current = 30mA Forward voltage = 3.0-3.2V Price = 6$/6LEDs
http://www.theledlight.com/5mmwhleds.html
Materials: miscellaneous
Heat sink Wires Resistors Others
Circuit Schematic
R=10Ω
R=10Ω
• Each resistor dissipates ~9mW• Each diode dissipates ~120mW• TEG generates 29.3W
TEG
V ~ 3.5V
Summary of Current Status
Design Brainstorming
Research Materials
High performance Low cost Long durability
Consult Two ME professors
Future Work
Finalize design Start ordering parts by this week (Jan
25-29) Find a place to assemble and test the
prototype
Importance
Provide electricity in rural area with reasonable price for lighting
Prevent wasted resources (biogas) May help with sanitization problem Increase activity time at night Can be distributed to other third world
countries as well
References Department of Economic and Social Affairs Population Division
(2009) (.PDF). World Population Prospects, Table A.1. 2008 revision. United Nations. <http://www.un.org/esa/population/publications/wpp2008/wpp2008_text_tables.pdf>. Retrieved 2009-03-12.
"Bangladesh". <International Monetary Fund. http://www.imf.org/external/pubs/ft/weo/2009/02/weodata/weorept.aspx?sy=2006&ey=2009&scsm=1&ssd=1&sort=country&ds=.&br=1&c=513&s=NGDPD%2CNGDPDPC%2CPPPGDP%2CPPPPC%2CLP&grp=0&a=&pr.x=35&pr.y=9. Retrieved 2009-10-01>.
<http://web.worldbank.org/WBSITE/EXTERNAL/EXTABOUTUS/IDA/0,,contentMDK:21387765~menuPK:3266877~pagePK:51236175~piPK:437394~theSitePK:73154,00.html>.
<http://www.geni.org/globalenergy/library/national_energy_grid/bangladesh/index.shtml>. .
http://www.malmberg.se/module.asp?XModuleId=14085