Vacuum membrane distillation of liquid desiccants Utilizing Hollow Fiber Membranes
Srivatsa Bettahalli, N.M.
Fedoroff, Nina V.
Nunes, Suzana Pereira
KAUST DepartmentBiological and Environmental Sciences and Engineering (BESE) Division
Environmental Science and Engineering Program
Water Desalination and Reuse Research Center (WDRC)
Advanced Membranes and Porous Materials Research Center
Physical Sciences and Engineering (PSE) Division
Emeritus Distinguished Professor of Biosciences, KAUST, Thuwal, 23955-6900, Saudi Arabia
MetadataShow full item record
AbstractThis paper documents the testing of a vacuum membrane distillation system intended for use with liquid desiccants. Liquid desiccants offer the possibility for low-energy, ambient temperature dehumidification. Effective desalination and purification of diluted desiccants outputs two important products: a concentrated desiccant for reuse in dehumidification and fresh water. In this study, vacuum membrane distillation was used in the laboratory to purify diluted liquid desiccants. Calcium chloride and magnesium chloride were the desiccants selected for testing. Desiccant solutions were pumped through the lumens of poly(vinylidene fluoride) (PVDF) hollow fiber membranes at varying feed inlet temperatures, solution velocity rates and vacuum set points during membrane distillation. An average flux of 8 kg m-2 h-1 was obtained using 30 wt% magnesium chloride solution at a temperature of 50 °C while applying vacuum to achieve 25 mbar absolute pressure on the air side of the membrane. The results are promising for the development of a full-scale vacuum membrane distillation process for desiccant solution regeneration and fresh water recovery. In addition, the recovered condensate was of sufficient quality for use in agricultural irrigation or drinking water.
CitationLefers R, Srivatsa Bettahalli NM, Fedoroff N, Nunes SP, Leiknes T (2018) Vacuum membrane distillation of liquid desiccants Utilizing Hollow Fiber Membranes. Separation and Purification Technology. Available: http://dx.doi.org/10.1016/j.seppur.2018.01.042.
SponsorsThe research reported in this publication was sponsored by King Abdullah University of Science and Technology (KAUST). The authors thank colleagues from the Nanostructured Polymeric Membrane (NPM) group, as well as the Water Desalination and Reuse Center (WDRC), and KAUST’s Core Labs for their help on equipment and analysis.