Background
Design
Future Work
Acknowledgements
References
Team: Nicolas Sitts, Max Gorman, Joe Squire Sponsor: Dr. David Hackleman
School of Chemical, Biological, and Environmental Engineering
Solar Powered Steam Generator Solar Powered Steam Generator
Objective •Design and construct a solar steam generator capable of at least 1 kW steam output.
•Propose “scaled up” designs for 100 & 500 BHP (1 & 5 MW) solar boiler for use in peppermint oil extraction.
•The most common extraction process used by the Oregon mint industry uses steam distillation.
•Current methods of producing the steam are to use diesel or coal fired boilers with high emissions and fuel consumption.
Welty J.R., et. Al. (2008). Fundamentals of Momentum, Heat, and Mass Transfer. Hoboken, NJ. John Wiley & Sons, Inc.
W. Stine, et. al. (1985). Solar Energy Fundamentals and Design. New York, NY. John Wiley & Sons, Inc.
Sanford, S., Mint Oil Energy Consumption, Energy Use Efficiency and Distillation Processes: A Review of Essential Oil Extraction Technologies. University of Wisconsin-Madison, 2011.
Gregory. (2012) Supporting Report: "Carbon Footprint Analysis for Mint Farming". Mirc Report
U.S. Energy Information Administration. (2012). Gasoline and Diesel Fuel Update. Retrieved from <http://www.eia.gov/petroleum/gasdiesel/>
EarthSky. (2012) <Earthsky.org> EarthSky Communications, Inc.
• Andy Brickman • Dr. Philip Harding • Larry Winiarski • Dr. Alex Yokochi
Energy Balance
Geometric Loss 13% Reflective/
Absorbtive Loss 10%
Convective Loss 20%
Radiative Loss 5%
Useful Energy
52%
Incident Energy Distribution
Io Insolation Aa Collector Aperture ρ Reflectivity η Geometric Efficiency α Receiver Absorptivity σ Stefan-Boltzmann Constant ε Receiver Emissivity Tp, Ta, Tsky Temperatures of pipe, ambience, and sky
• Parabolic trough solar concentrator: o 4’x8’ aperture. o 1” copper pipe coated with a selective
surface paint. o Reflective metalized polyester
• Generates steam at 15 psig within 4 minutes.
• 140 oC maximum temperature achieved.
• 52% Estimated efficiency.
• Steam passes through mint. • Mint Oil diffuses into steam. • The steam-oil mixture is condensed. • Oil separates from water in a holding vessel.
Scale Up Parameters
• Modify prototype for continuous flow. • Investigate direct steam generation
versus heat transfer fluid. • Develop an automated tracking system.
100 BPH System
Aperture Area [ft2] 21,500
Estimated Land Use [acres] 1.5
Fuel Displacement [gal/h] 43
CO2 Emissions Displaced [lb/h] 963
