RENEWABLE ENERGY-DRIVEN ION RECOVERY FROM BRINE AND SEAWATER FOR VARIOUS APPLICATIONS

Abstract

This study explores the potential of renewable energy-driven ion recovery systems from brine and seawater for various applications, offering sustainable solutions to soil salinity, water scarcity, food security, and energy efficiency issues. The study investigates various aspects of ion recovery using electrodialysis and other renewable energy sources. Initially, an integrated system is developed that recovers ions, generates electricity, produces freshwater, and fertilizes hydroponic crops, achieving an overall energy efficiency of 16.1% and exergy efficiency of 13.4%. Secondly, a multigeneration system is designed and analyzed for seawater desalination and ion recovery, demonstrating an overall energy efficiency of 39.80% and exergy efficiency of 41.40%. This thesis also experimentally investigates hydrogen gas generation in an electrodialysis system, achieving a maximum hydrogen production rate of 118.8 mg H2/ h·kg Na2SO4 solution, with maximum energy and exergy efficiencies of 25.29% and 28.78%, respectively. Moreover, an electro-membrane process for recovering lithium and boron from aqueous solutions while producing hydrogen was experimentally tested, with a maximum ion removal efficiency of 90% and hydrogen gas production rate of 13.54 mmol/h, requiring a net energy consumption of 13.53 kWh/m3 of synthetic wastewater. Finally, an experimental unit consisting of Monovalent Selective Membrane-Electrodialysis for beneficial ion recovery from seawater was studied, achieving around 80% ion recovery and producing hydrogen gas at the rate of 0.31 mmol/h. Overall, this thesis proposes innovative and efficient systems for ion recovery and highlights the feasibility of utilizing renewable energy sources for different applications. The results indicate that these systems effectively recover essential hydroponic farming nutrients, desalinate seawater, and sustainably and efficiently produce hydrogen gas. In summary, this approach holds great potential for promoting sustainable agriculture and enhancing access to safe and clean water while contributing to a low-carbon economy.

Date of Award	2023
Original language	American English
Awarding Institution	HBKU College of Science and Engineering