Abstract
There are several technologies that could help cut greenhouse gas emissions from silicon production, for example increasing the share of biocarbon in the reductant mix. Complete decarbonisation however requires the use of other reducing agents, such as hydrogen, electrolysis or metallothermic reduction. The current article gives an overview of the alternatives to carbothermic reduction; that is to say, the solutions which could remove the need for carbon entirely. The discussion focuses on the possibilities, challenges, and the current technological barriers for these technologies to be applied to produce silicon and silicon alloys. The introduction of new reduction practices would require substantial changes in framework conditions in order to become economically feasible. Most of the alternative processes are more energy demanding than the current carbothermal route so availability of cheap and clean, renewable energy in abundance is an absolute prerequisite for all the new technologies discussed herein
