Thermal Technology has developed a process for the production of solar-grade silicon using rice hulls as a raw material. Matt Mede, president and CEO, presented his research at the recent Materials Challenges in Alternative & Renewable Energy Conference.

To meet the growing market need, major producers of high-purity photovoltaic (PV) silicon are expanding production. New technologies are coming on-line with the objective of producing PV-grade silicon at lower costs than the current industry standards.

“An opportunity exists for new and innovative approaches to the production of photovoltaic-grade silicon, especially methods that can demonstrate cost reductions over currently utilized processes,” said Mede. “Advanced carbothermic reduction of SiO2 is a key enabler to the photovoltaic solar industry’s quest for cost reduction.”

Thermal Technology combined the process of carbothermic reduction with biomass pyrolysis technology to convert rice hulls to solar-grade silicon. “Using the combination of pyrolysis and carbothermic reduction, it is possible to make material with sufficient purity for the solar application,” said Mede. “The pyrolysis makes the perfect blend of SiO2 and C suitable for the reduction process, with a morphology that facilitates cleaning to remove tramp elements. “

According to Thermal Technology, this new process has lower production and entry costs than current methodologies. For additional information, e-mail pmede@thermaltechnology.com or visit www.thermaltechnology.com.