Solar-driven alumina calcination for CO2 mitigation and improved product quality

摘要: We report on the first-of-a-kind experimental demonstration of calcination alumina with concentrated solar thermal (CST) radiation at radiative fluxes up to 2190 suns using a 5 kW novel transport reactor. Aluminium hydroxide was calcined nominal reactor temperatures over range 1160–1550 K yield chemical conversions 95.8% for residence times approximately 3 s. Solar energy conversion efficiencies 20.4% were achieved. The mean pore diameter and specific surface area solar-generated greatest 5.8 nm 132.7 m2 g−1, respectively, which are higher values than typical industrial production. In addition, product is dominated by γ-phase, desirable downstream processing aluminium. This suggests that CST can improve quality existing fossil fuel based processes though combination high heating rate avoided contamination combustion products. Furthermore, solar-driven process has potential avoid discharge combustion-derived CO2 emissions stage conventional Bayer process, typically 165 kg-CO2 per tonne-alumina.