Integration assessment of the hybrid sulphur cycle with a copper production plant

Abstract

Copper is the third-most widely-used metal worldwide. However, copper processing is an energy-intensive process consuming large quantities of fossil fuels, both as the reducing agent and for energy which contributes significantly to anthropogenic carbon dioxide emissions. The hybrid sulphur cycle combines concentrating solar thermal energy with electrolysis to offer strong potential for low-cost green hydrogen production. A preliminary evaluation is reported of the techno-economic potential of this cycle to displace current fossil-based energy sources in an integrated copper mine and refinery (cradle-to-gate approach) at a remote location in Australia with an excellent solar resource. The effect of ore composition on the integration of the hybrid sulphur cycle and copper processing plant is evaluated using models developed in Aspen Plus. The evaluations show that sizing the hybrid sulphur cycle cycle to meet the oxygen demand of the copper refining process is more technoeconomically viable than sizing the hybrid sulphur cycle to meet the hydrogen required to replace the fossil fuel demand of the copper processing process. Moreover, it has been found that the integration of the hybrid sulphur cycle with the copper process plant has the potential to decrease both the carbon dixoide emissions and the operational expenditure of copper refineries for ores with a sufficiently high sulphide content (~50% mass fraction).