Optimization of mechanical harvesting of microalgae by centrifugation for biofuels production

This study aims to minimize the energy consumption of the disc-stack centrifuge by optimizing the factors that affect its consumption using response surface methodology. Eight factors with the potential to affect the energy consumption of the centrifuge were identified. A 3(k) factorial Box-Behnken design was used as the design model to investigate the chosen factors using Minitab software. The result indicates that the main three factors that have the largest impact on the energy consumption of the centrifuge are the particle size, the rotational speed, and the outer radius of the centrifuge, respectively. Moreover, the results demonstrate that the energy consumption of the centrifuge can be reduced from 1 kWh/m(3) to 0.1 kWh/m(3) achieving a 90% reduction in total. In order to achieve such a low consumption, the outer radius and the rotational speed of the disc-stack centrifuge should be designed to not exceed 0.175 m and 3000 rpm, respectively.