Thermoeconomic model and feasibility study of geothermal power cycle with Lithium extraction
Geothermal brine obtained while exploiting a geothermal resource for power generation applications consists of various minerals in different concentrations. Increased demand for lithium, mainly for the electric vehicle industry, has increased the economic viability of extracting the mineral from geothermal brine. Lithium is a critical mineral for the green technology revolution due to its importance in battery manufacturing. Many countries supporting their climate change policies have mandated the purchase of electric vehicles, which is causing the price to rise dramatically in recent years. The economic viability of exploiting the different resources globally due to the varying chemical composition of the geothermal brine and the concentration of minerals. This thesis project has developed a combined thermoeconomic model for extracting lithium and power from geothermal brines. The model estimates the overall unit cost of extracting lithium and electricity from geothermal resources. two power cycles for generating geothermal power with Li-Al Double Hydroxide Chloride (LDH) Sorbent combined with forward osmosis as a direct lithium extraction (DLE) method. This DLE method was chosen because it has previously been used in Argentinian salar brines and in a small pilot scale in the Upper Rhine Graben at Rittershoffen Geothermal Plant in similar conditions to the case study area. Each component in the power generation cycle and in the DLE method was evaluated in the creation of this model. The case study resource data was also added to determine the economic viability of the Eich-Hamm Geothermal project. The lithium content of the Eich-Hamm project was not sampled, so an average of lithium contents from other geothermal plants in the northern Upper Rhine Graben nearby was used. This study aims to create a model that can be marketed to investors and developers is they are questioning whether their Lithium and Geothermal combined resource could potentially be economical to develop. A case study using a lithium enriched geothermal prospect is modelled and a feasibility study was created. The analysis considers the economy of scale for an industrial system and is based on laboratory-scale experimental data and stoichiometry. For the LiOH and Li2CO3 production paths, this lithium extraction addon unit could achieve a payback period of 26 years depending on lithium price stability and equipment costs, net present values of -$315 million, and internal rates of return of -9%. The economic performance shows that further research should be done and that LDH sorption combined with forward osmosis has great promise to enable increased manufacturing of battery lithium compounds.
Orkuvísindi, Meistaraprófsritgerðir, Jarðhiti, Litín, Raforkuframleiðsla, Sustainable energy, Geothermal resources, Lithium, Electric power production
Networked Digital Library of Theses and Dissertations