Novel lithium production process using desalination wastewater and waste heat from natural gas combined cycle
Hyejeong Lee, Jonghun Lim, Junghwan Kim
Abstract
The rapid growth of lithium-ion battery applications has significantly increased the demand for lithium. Continental brines store approximately 60% of lithium resources, and are commonly used for lithium extraction. However, this process is time-consuming and requires large amounts of Na2CO3 and heat, thus having a low production rate and low economic feasibility. This study presents a novel lithium production process that reduces production time and overcomes high-energy consumption by leveraging waste heat from a natural gas combined cycle (NGCC) and using desalination wastewater as a source. The process model based on validated experimental data consists of four stages: (1) liquid natural gas (LNG) regasification, (2) NGCC power generation, (3) desalination, and (4) recovery of lithium from desalination wastewater. Economic analysis was performed to assess the payback period and demonstrate the feasibility of the proposed method. The results indicate that 108.5 tons/year of Li2CO3 can be produced using the concentrated wastewater generated by the hybrid desalination process. Furthermore, NaOH absorbents can be synthesized using desalination wastewater, capturing approximately 93.0% of CO2 and achieving 48.7% energy savings through waste heat recovery. The proposed process is economically feasible, with a net present value of 2,827 million USD and a payback period of 0.31 years. Therefore, this study provides valuable insight into the efficient and environmentally friendly production of lithium using recovered waste heat and desalination wastewater.