Environmental Impacts of Bio-derived Silicon: Uncertainty in the Benefit of Industrial Transition

Millions of tonnes of silicon are produced each year as part of a global supply chain supporting the manufacture of steel, automobiles, electronics and silicones. However, the supply chain does have its challenges – particularly the high energy intensity of silicon purification methods, and the lack of global supply chain diversity. Consequently, this study investigates the benefit of producing high purity silicon metals (>98 wt% Si) from agricultural biomass wastes from an environmental perspective using Life Cycle Assessment methodology. Taking rice husk as a case study, findings show a reduction in carbon emissions is achievable for co-recovery of silicon with bio-energy. The robustness of these findings is also addressed through uncertainty modelling, which provides further confidence in the major findings. Future agricultural sources of biomass-derived silicon have also been projected for staple crops including corn, sugarcane and wheat.