Development of an Optimal Implementation Model For Seawater Multiple Effect Distillation Technology in Kuwait

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Latest market trends in the seawater desalination industry show that the demand for thermal distillation units is rising more than ever before. Market data show significant shift from multi-stage flash (MSF) toward the multiple effect distillation (MED) technology driven by rising fuel prices and growing concerns over the environment and sustained by technological advances, which have enabled manufacturing of fairly efficient larger MED units. This project is aimed at developing an optimal model to be used as a reference for future implementation of the seawater MED technology in Kuwait. The MED model offered here is for spray falling film horizontal tube heat exchanger type, which is most commonly used in the industry today, with both parallel and forward feed configurations. The approach here is based on establishing basis for interaction between design parameters and efficiency of the MED systems for the operating conditions of Kuwait. The optimal model is meant to represent the interaction that yields a system with the best efficiency and with minimum requirements of the materials of construction and manufacture of the working space and surfaces. Overdesign of heat transfer surface area is a central issue in this development. Other design parameters will include number of effects, heating steam thermodynamic state, temperature difference between the effects, feed water temperature and concentration, and the process configuration in terms of feed water scheme; i.e., parallel or forward feed. The development will involve mathematical modeling combined with comprehensive pilot testing over very wide range of fouling/operating conditions. For this purpose, an MED pilot unit will be designed, constructed and operated to provide means to obtain the needed measurements and operational data. The key deliverables of this project include, in addition to the target model and the MED pilot unit, a case study for implementation on a commercial scale including assessment of economic benefits as well as reference technical specification, which can be used for constructing new commercial MED units.