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Title: Emerging Technologies for Decarbonizing Silicon Production

Journal Article · · Journal of Sustainable Metallurgy

Abstract Silicon (Si) is an important material for alloying, solar photovoltaics, and electronics. However, current methods of producing silicon require energy consumption of around 11–13 kWh/kg Si and direct carbon emissions are 4.7–5 tons CO 2 per ton Si which conflicts with global efforts to limit climate change. In this work, we discuss several promising methods for reducing or eliminating carbon emissions from the silicon production process. Such methods include using biocarbon, integrating the current process with carbon capture and utilization/storage (CCU/CCS), metallothermic reduction, hydrogen reduction, and molten salt electrolysis. We present the positive aspects and challenges of each approach. Biocarbon coupled with CCU/CCS is the most industrially mature technology and can be carbon–neutral or -negative but is not carbon-free. Hydrogen directly reducing silicon dioxide is not thermodynamically favorable, but it may be viable to use hydrogen in conjunction with other processes to reduce emissions. Metallothermic and electrochemical methods of production are promising and have the potential to create high-purity silicon with no reduction-related carbon emissions but have only been demonstrated at lab scale. Economic viability will likely be the next determining factor for which technologies are more widely researched and implemented. Graphical Abstract

Sponsoring Organization:
USDOE
OSTI ID:
2447866
Journal Information:
Journal of Sustainable Metallurgy, Journal Name: Journal of Sustainable Metallurgy Journal Issue: 4 Vol. 10; ISSN 2199-3823
Publisher:
Springer Science + Business MediaCopyright Statement
Country of Publication:
United States
Language:
English

References (15)

Electrochemical Production of Si without Generation of CO 2 Based on the Use of a Dimensionally Stable Anode in Molten CaCl 2 journal September 2019
Processes for Production of Solar‐Grade Silicon Using Hydrogen Reduction and/or Thermal Decomposition journal February 2014
Trace Elements in the Si Furnace. Part I: Behavior of Impurities in Quartz During Reduction journal January 2013
Carbothermal Reduction of Quartz in Methane–Hydrogen–Argon Gas Mixture journal July 2015
Magnesiothermic Reduction of Natural Quartz journal April 2022
Solar-grade silicon production by metallothermic reduction journal December 2010
Reducing the Carbon Footprint: Primary Production of Aluminum and Silicon with Changing Energy Systems journal August 2021
Silicon powder production by electrochemical reduction of SiO2 in molten LiCl–Li2O journal September 2008
Use of silicon and ferrosilicon industry by-products (silica fume) in cement paste and mortar journal June 2011
Silicon Electrochemistry in Molten Salts journal December 2019
2023 Billion-Ton Report report January 2024
Kinetics of Magnesiothermic Reduction of Natural Quartz journal September 2022
Charcoal as an Alternative Reductant in Ferroalloy Production: A Review journal November 2020
Densification of Biocarbon and Its Effect on CO2 Reactivity journal January 2021
Australia journal February 2023