Desalination using solar energy: Towards sustainability

This paper describes the theoretical rationale for a new low temperature phase-change desalination process, and six examples of applications to illustrate how this process can be engineered for sustainable desalination. In this process, brackish water is evaporated at near-ambient temperatures under near-vacuum pressures created by the barometric head without any mechanical energy input. Thermodynamic advantages and benefits of low temperature phase-change desalination are discussed and results from simulation studies and a prototype test system are presented. Three of the examples illustrate how the proposed process can be driven by solar energy: a) utilizing direct solar energy; b) inclusion of an external reflector; c) utilizing photovoltaic energy during non-sunlight hours. The other examples illustrate how the proposed process can be driven by waste heat: i) waste heat rejected by an absorption refrigeration unit driven by grid power; ii) waste heat rejected by an absorption refrigeration unit driven by solar collectors; and iii) waste heat rejected by an absorption refrigeration unit supported by a photovoltaic array. Merits of utilizing solar energy and process waste heat in reducing energy consumption and greenhouse gas emissions are discussed in detail.

[1]  Raphael Semiat,et al.  Energy issues in desalination processes. , 2008, Environmental science & technology.

[2]  Nagamany Nirmalakhandan,et al.  Renewable and sustainable approaches for desalination , 2010 .

[3]  Soteris A. Kalogirou,et al.  Survey of solar desalination systems and system selection , 1997 .

[4]  Abdulghani A. Al-Farayedhi,et al.  Second-law-based thermoeconomic optimization of a sensible heat thermal energy storage system , 1993 .

[5]  D. Yogi Goswami,et al.  Experimental study of an innovative solar water desalination system utilizing a passive vacuum technique , 2003 .

[6]  Jie Liu,et al.  Integration of thermal energy and seawater desalination , 2010 .

[7]  Nagamany Nirmalakhandan,et al.  Desalination at low temperatures and low pressures , 2009 .

[8]  Zeinab S. Abdel-Rehim,et al.  Experimental and theoretical study of a solar desalination system located in Cairo, Egypt , 2007 .

[9]  Soteris A. Kalogirou,et al.  Seawater desalination using renewable energy sources , 2005 .

[10]  N. Duić,et al.  Two energy system analysis models: A comparison of methodologies and results , 2007 .

[11]  Nagamany Nirmalakhandan,et al.  Low temperature process to recover impaired waters , 2010 .

[12]  Gholamreza Zahedi,et al.  Greener energy: Issues and challenges for Pakistan--Biomass energy prospective , 2011 .

[13]  Nagamany Nirmalakhandan,et al.  Low temperature desalination using solar collectors augmented by thermal energy storage , 2012 .

[14]  G. A. Bemporad,et al.  Basic hydrodynamic aspects of a solar energy based desalination process , 1995 .

[15]  Nagamany Nirmalakhandan,et al.  Desalination Using Low-Grade Heat Sources , 2007 .

[16]  F. Lokiec,et al.  Low-temperature distillation processes in single- and dual-purpose plants☆ , 2001 .

[17]  Nagamany Nirmalakhandan,et al.  Combined desalination and solar-assisted air-conditioning system , 2008 .

[18]  W. Beckman,et al.  Solar Engineering of Thermal Processes , 1985 .

[19]  A. E. Kabeel,et al.  Performance of solar still with a concave wick evaporation surface , 2009 .