A review of integrated cryogenic energy assisted power generation systems and desalination technologies

The last two decades have seen a rapid growth in LNG trade around the world, due to stricter environmental policies and increasing global temperatures. LNG cryogenic energy utilization has attracted a lot of attention over the last few decades, with power generation systems being the most studied application. This review firstly looks at the different optimization techniques available for integrated power generation cycles. The optimization techniques of each cycle include working fluid, parametric and superstructure based optimizations, with different objective functions being prioritized. Combined cycles exhibit higher efficiency than their standalone counterparts, and an advanced exergetic analysis of each component in the combined cycle should be performed, which leads to better multi-objective optimization. Desalination technologies can be intensified using LNG cryogenic energy as the cooling medium. In terms of water production and recovery rates, low pressure single conventional distillation utilizing LNG cryogenic energy is the best option. However, freeze desalination is emerging as a new less energy intensive method, albeit more research is needed for its optimization. At the condenser outlet of the low temperature thermal power cycles, the LNG temperature is still quite low and contains a reasonable amount of cryogenic energy. This energy is most suitable for use in seawater desalination units. This leads to the integration of power cycles with desalination units, and the limited research currently available suggests it is feasible to do so.