For this project, two experimental raceway reactors, situated at the Estación Experimental “Las Palmerillas” owned by the Fundación CAJAMAR (Almería, Spain), will be used. Each raceway has a total surface area of 100 m2 and is formed of two 50 m channels, each 1 m wide and connected by U-shaped bends (see Fig. 1). The raceway is operated at a constant depth of 0.2 m to give the best overall hydraulic performance in terms of power consumption, providing a total reactor volume of 20 m3. Mixing was provided by a 1.2 m diameter paddlewheel with 8 blades made of marine plywood and driven by an electric motor (W12 35 kW, 1500 rpm, Ebarba, Barcelona, Spain) with gear reduction (WEB Ibérica S.A., Barcelona, Spain). The paddlewheel speed is controlled with a frequency inverter (CFW 08 WEB Ibérica, S.A., Barcelona, Spain). Carbonation is done via a 1 m deep, 0.65 m wide sump which spanned the full width of the channel (1 m), and is located 1.8 m downstream of the paddlewheel. Flue gas is injected through three plate membrane diffusers at the bottom of the sump (AFD 270, EcoTec, Spain). The raceway and sump are made of white fiberglass of 3 mm thickness.




(a) sche (top and side view)


(b) real raceway photobioreactors

Figure 1. Raceway photobioreactors located a the Estación Expermental, Las Palmerillas (Almería)