Extraction%20of%20Water%20from%20Air

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Extraction of Water from Air

• Sarah Watson
• Department of Chemical Engineering
• University of Texas at Austin

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Major Concepts

• Water 3 by mass of air 4 by volume
• Absolute humidity
• Relative humidity

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Method 1 Direct Extraction

• Air pumped into a chiller where sensible heat is
  removed
• Air lowered to dew point and water condenses

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Method 2 Desiccant

• Create vapor pressure gradient
• Attract water molecules
• Liquid or Solid

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Method 3 Convection

• Transfer of heat by the circulation or movement
  of the heated parts of a liquid or gas
• Very tall towers are used

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Power Sources
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Efficiency

• Daily capacity (L/day)
• Airflow (m3/s) x 86400s/day x absolute
  humidity (g/m3)X 1/1000 L/g x ?
• ? __amount of water
  extracted per unit time_______
• Total moisture content of air processed per
  unit time

Method Capacity (L/day)
reverse osmosis desalination 284,000-45,000,000
cooled surface atmospheric extraction 5,860,000
solid desiccant extraction 100,000,000
liquid desiccant extraction 1,700,000
convection-based extraction 31,000,000
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QUESTIONS?
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References

• 1. Barlow, M. (2007). Blue Covenant. The New
  Press.
• 2. Ferret, G. (2003, November 2). Water shortages
  threaten Africa Scientists and researchers
  meeting in the Kenyan capital, Nairobi, have
  warned of the growing threat posed by water
  shortages across Africa. . Retrieved November
  16, 2008, from BBC News Web site
  http//news.bbc.co.uk/?1/?hi/?sci/?tech/?3235829.s
  tm
• 3. Festel, D. G. (n.d.). Drinking Water
  Extraction from Air. Retrieved November 19, 2008,
  from Festel Capital Web site http//www.festel.or
  g/?Water_from_Air.pdf
• 4. Kirby, A. (2003, March 5). UN warns of future
  water crisis The worlds water crisis is so
  severe it could take almost 30 years to eradicate
  hunger, the United Nations says.. Retrieved
  November 16, 2008, from http//news.bbc.co.uk/?2/?
  hi/?science/?nature/?2818615.stm
• 5. Kloosterman, K. (2008, November 3). Israeli
  startup EWA squeezes drinking water from thin
  air. Retrieved November 16, 2008, from Israel
  Ministry of Foreign Affairs Web site
  http//www.mfa.gov.il/?MFA/?Israelbeyondpolitics
  /?EWA-squeezes-drinking-water-from-air-3-Nov-2008.
  htm
• 6. Royse, D. (2006, September 29). Air alchemy
  Can humidity solve post hurricane drinking water
  problem? Retrieved November 19, 2008, from
  http//www.usatoday.com/?tech/?news/?techinnovatio
  ns/?2006-09-29-air-water-machines_x.htm
• 7. Scrivani, A., Bardi, U. (n.d.). A study of
  the use of solar concentrating plants for the
  atmospheric water vapour extraction from ambient
  air in the Middle East and Northern Africa
  Electronic version. Desalination, 592-599.
• 8. Wahlgren, R. V. (2000, April). Atmospheric
  Water Vapour Processor Designs for Potable Water
  Production A Review. Pergamon, 1-22.
• Images Google Images