Multi-objective optimization and parametric study of a hybrid waste gasification system integrated with reverse osmosis desalination

Abstract

The increasing population has created two fundamental issues on the islands (in this case, Kish Island): an expansion in waste production and handling and a rise in the need for freshwater for daily consumption. Waste gasification can be used to reduce waste and generate energy. Sea salt water can be converted into drinkable freshwater using energy. This article describes a computational code using a combination of EES (Engineering Equation Solver) and MATLAB software for a hybrid cycle that includes waste gasification and reverse osmosis to generate freshwater and power. Kish Island waste data was carefully collected onsite. An exergy evaluation has been conducted to verify the cycle's irreversibility. Lastly, optimization has been performed to identify the best operation mode. In terms of irreversibility, a gasifier is far more irreversible than any other type of plant equipment. Based on the parametric analysis, salt water and waste flow significantly impact freshwater production. Approximately 20,000 m3/day are consumed on Kish Island each day, so if the entire production power of the steam turbine is used in the reverse osmosis high-pressure pump, 2860 m3/day can be obtained each day (14% of the required amount).