Co2 Capture for the Silicon Process-Effects of Flue Gas Recirculation

Flue gas recirculation has been proposed as a potential process improvement for the silicon and ferrosilicon process. In this paper, flue gas flows and concentration from a 100 MW silicon production operation has been calculated for 0, 25, 50, 62.5 and 75 % flue gas recirculation. Using these flue gas flows as inputs in a carbon capture model shows that specific reboiler duty can be reduced from 3,55 GJ/mtCO2 to 2,85 GJ/mtCO2 by implementing 75 % flue gas recirculation. Cost estimation of the absorber, heat exchanger and blowers indicate a potential 13,3 M$ (62 %) cost reduction between 0 and 75 % FGR.