Case Studies in Thermal Engineering (May 2023)
Numerical analysis of a solar assisted chemical looping combustion combined power and sea water desalination plant
Abstract
Chemical looping combustion (CLC) with solar integration for power generation is viewed as a technology that would have many economic and environmental benefits. This is because the use of solar systems to provide heating for the CLC process could lead to improved power plant performance and significant reduction of emissions. The performance of energy resources for CLC systems can be further improved via poly-generation. In this study, a novel solar assisted, methane fired CLC power plant with CO2 capture combined with waste heat utilization for sea water desalination is proposed. The plant receives a total thermal energy input of 20 MW. Ni based oxygen carrier is used for the oxygen transfer cycle. The proposed model is developed using Aspen plus software with the consideration of the conservation of mass, momentum and energy. In the study, the effect of using solar energy for the provision of the required heating for the endothermic reaction process in CLC is thoroughly examined by varying the solar share. The results show that an efficiency of 60.56% for the system can be obtained when the solar energy contributes 15–20% of total thermal energy. The system performance is relatively poor for solar share values below 15%. The system performance is further improved (approximately three percentage points) by integrating it with a desalination unit. A parametric study was conducted to ensure that the operating parameters are at their optimum levels. The study also examines the effect of certain key operational parameters for the desalination system such as sea water temperature, sea water salinity and the top brine temperature. The water production is increased with the decrease of top brine temperature and the increase of sea water temperature and salinity.
