Evaluating the economics of metal recycling from end-of-life lithium ion batteries in South Africa
Date
2020-12
Authors
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Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: Lithium-ion batteries (LIBs) are used in various electronic equipment as well as electric vehicles. With the rapid growth and development in technology usage, it is not surprising that the generation and safe disposal of end-of-life LIBs have become a global problem. Sustainably recycling spent LIBs will address this problem.The study aimed to investigate and compare the techno-economic feasibility of mineral acid based and organic acid based hydrometallurgical processes for metal recovery from end-of-life LIBs within a South African context. This was achieved by developing various hydrometallurgical flow sheets, completing associated mass and energy balances, calculating capital and operating costs, evaluating the profitability and performing a sensitivity analysis to investigate the influence of changing market and operating conditions on the profitability criteria.
A LIB feed capacity of 868 ton per year was selected as basis for mass and energy balances. Six flow sheet alternatives using either hydrochloric or citric acid as leaching reagents were evaluated and compared.ALIB recycling facility using citric acid as leaching reagent and four selective precipitation steps for the recovery of manganese oxide, nickelhydroxide, cobaltoxalate and lithiumphosphate will be the techno-economically most favorable option returning a Net Present Value (NPV)of $ 16.4 million after 20 years.The proposed process has an estimated Capital Expenditure (CAPEX)of $ 22.8million, Operating Expenditure (OPEX)of $ 17.0millionper year and revenue of $25.5millionper year. The Present Value Ratio (PVR)of 1.8 and Discounted Cashflow Rate of Return (DCFROR)of 28.2% confirmed that profitable operation will be possible.However, if the aim of the facility is to produce only two metal products (i.e. a combined metal product that could be used in cathode material regeneration and a lithium product), the use of hydrochloric acid as leaching reagent with two subsequent precipitation steps will be most profitable and result in an NPV of $ 5.7 million.A similar flowsheet using citric acid as lixiviant may also be profitable depending on the chosen precipitant.
The sensitivity analysis indicated that the profitability of the proposed facility is most sensitive to fluctuations in the feed capacity, metal selling prices and the fixed capital investment when all other parameters are kept at base values.Monte Carlo simulations evaluated the sensitivity of the profitability criteria to the random interaction between 17 variables. Depending on the simulation input specifications the probability of profitable operation ranged between 58.45% and 99.52%. It was concluded that citric acid would be a suitable alternative lixiviant for mineral acids in the LIB recycling process.Further research and experimental work should focus on in-depth process development as the current level of process integration and development is only at concept phase.Pilot-plant studies will be the best way to reduce uncertainty in mass and energy balances and to understand the technical challenges that will be faced with large-scale operation. A detailed market analysis to evaluate the current status of LIB recycling in South Africa and correspondence with key stakeholders is recommended.
AFRIKAANSE OPSOMMING: Raadpleeg teks vir opsomming
AFRIKAANSE OPSOMMING: Raadpleeg teks vir opsomming
Description
Thesis (MEng)--Stellenbosch University, 2020.
Keywords
Techno-economic comparison, UCTD, Hydrometallurgy, Lithium-ion batteries, Electric batteries -- Recycling