Research Projects

These days renewable energy resources have marked their importance as a high potential energy sources that can also act as an alternative to fossil fuels. The attractive characteristics of solar energy i.e. it is a pollution-free energy resource and its conversion into thermal energy shows its utilization in various domestic and industrial applications based on water heating, space heating, crop drying, and can even be extended for water desalination. Desalination of seawater can be a solution for producing fresh water in order to meet the growing water requirements across all levels of society. Out of various desalination techniques, membrane distillation (MD) has a great potential due to its attractive features. The operation of MD lies in low temperature (much lower than boiling point of water, say around 80oC-90oC) and pressure range (significantly lower than that used in reverse osmosis) and hence renewable energy resources can be used. The conventional MD method suffers from severe drawbacks such as large energy consumption, poor thermal efficiency, and a need for centralised infrastructures that hampers its in-field application. In this project, the technique known as photothermal membrane distillation (PMD), which is a variant of the MD technique, will be used to purify saline water in order to obtain fresh, clean, drinking water. Some designs of PMD may directly utilize sunlight as the main energy source for heating the membrane (or one of the water sources). The key component in PMD system is the membrane, and consequently stable freshwater production rate is significantly influenced by the membrane properties. Various nanoparticles shall be incorporated in the membrane, primarily to facilitate the absorption of solar irradiation, and also to optimize the distillate production from the PMD system. Due to direct heating, the system is expected to become very robust as thermal components, and other external devices (which are used in conventional MD) are not required in PMD. The major components of the proposed investigation are: the solar energy-integrated photothermal membrane distillation system. In this investigation the solar irradiation will be directly absorbed by the membrane surface due to the presence of selective nanoparticles on the membrane itself. The experiments will be performed at varying feed-rates, salinity levels, membrane characteristics, and geometrical dimensions of the system in order to ascertain the optimum operation parameters. The key parameters will be the amount of distillate produce by this system for a given area and energy consumption (defined in terms of GOR: gained output ratio). It is expected that such as system will be able to operate in a stand-alone mode, and provide fresh water even at remote locations, and at small-to-medium scales using clean energy sources.