A comparative life cycle energy and carbon emission analysis of the solar carbothermal and hydrometallurgy routes for zinc production. (1st November 2018)

• Record Type: Journal Article
• Authors: Yadav, Deepak; Banerjee, Rangan
• Is Part Of: Applied energy. Volume 229(2018)
• Page Start: 577
• Page End: 602
• Publication Date: 2018-11-01
• Subjects: Solar thermochemical processes -- Technology assessment -- Net energy analysis -- Solar energy -- Solar fuels -- Zinc production; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2018.08.001
• Languages: English
• ISSNs: 0306-2619

Abstract

Graphical abstract: Highlights: Life cycle analysis of solar carbothermal and hydrometallurgy systems for zinc. Comparative analysis for the pilot, demonstration and commercial scale plants. Solar carbothermal has higher energy requirement than solar hydrometallurgy. Solar carbothermal with biomass and solar power has lowest carbon footprint. Trade-off between carbon and energy seen. Abstract: This paper provides a framework to assess the viability of the solar carbothermal route for zinc production by comparing the life cycle energy demand and carbon emissions with the photovoltaic (PV), concentrated solar power (CSP) and grid driven hydrometallurgy systems. The data of the pilot-scale demonstration at Weizmann Institute of Science (WIS) is used to propose a hypothetical design of the 300 kW solar thermochemical plant at Jodhpur, India. A conceptual design of the similar scale PV, CSP, and grid hydrometallurgy plants are developed. The effect of upscaling these technologies to the demonstration and commercial levels is assessed. On a commercial scale, the energy demand and carbon footprint of the solar thermochemical process are 2.33–4.36 MJ/kg of zinc and 0.02–0.19 kg CO2 /kg of zinc respectively. The corresponding values for the commercial-scale PV/CSP hydrometallurgy system are 2.15/2.37 MJ/kg and 0.16/0.16 kg/kg respectively. The energy demand of the solar carbothermal process is at least 9% higher than the PV hydrometallurgy system. However, if biomass is the carbon source and electricity for meeting the auxiliary load is obtained from a PV plant, then the carbon footprint of the solar carbothermal process is 82% lower than the PV hydrometallurgy system. In this case, the biomass source has an energy penalty, and hence the energy demand is 58% higher than the PV hydrometallurgy route. From a practical perspective, the use of PV/CSP driven hydrometallurgy system does not require any change in the process of commercial zinc production. Therefore, the commercial-scale adoption of the solar carbothermal route will depend on whether the 82% lower carbon footprint, with the biomass source and PV electricity, compensates for the 58% higher energy demand and complications associated with the high-temperature operation.