Reducing CO2 emissions in the copper smelting process by using high-temperature solar heat: Tecno-economic assessment

Abstract

The work explores the idea of using high-temperature solar heat in the copper smelting process; a Hybrid Central Tower system is analyzed to supply the high-temperature air for this process. The methodology was built based on the equilibrium of the smelting reactions; therefore, this analysis only account for the reactions’ energy demand. Two process schemes (process with/without using high-temperature air) and five off-gas scenarios were evaluated. Using Hybrid Central Tower systems with 13 h of Thermal Energy Storage leads to significant reductions in the annual equivalent energy consumption of the reactions (up to 22.61 %) and in the CO2 emissions of the smelting process (up to 61.4 %). The scheme that doesn’t use high-temperature air is the lower-cost option; however, with a 15 % reduction in the capital expenditure and using a discount rate of 5 %, the scheme that uses Hybrid Central Tower systems with 13 h of Thermal Energy Storage shows the similar present value costs. If a carbon price of 25 USD/tCO2e is included, the latter scheme represents the lower-cost option and the most cost-effective solution to avoid CO2 emissions.