Energy minimization of a tilted panel filtration system for microalgae filtration: performance modeling and optimization

Abstract

To realise the enormous potential of biofuel feedstock for commercial purposes, the energy for harvesting microalgae biomass must be significantly lowered. A recently developed tilted panel filtration system offers ease of unit operation and energy saving, but it still can be further optimized to lower its energy consumption. This paper investigates and optimizes the concurrent effects of tilting angle (θ), specific aeration demand (SADm) and switching frequency (Sf) in a tilted panel system on microalgae filtration permeability using developed empirical equations. Experiment was designed to create random sets of operational parameters, and the experimental data were plotted with response surface methodology to develop permeability model. Analysis of variance verifies that the model is excellent fit with high correlational value (p-value < 0.0001). After developing and solving the energy consumption model, the optimum parameters that offer a minimum energy (of 0.238 kWh m−3) were at θ = 45°, Sf = 12 h−1 and SADm = 0.115 m3 m−2 h−1. The most sensitive parameter was SADm, followed by Sf and θ. Overall results suggest that the tilted panel filtration system incorporating reverse panel switching offers a significant energy reduction for any microfiltration process, especially after system optimization.