279402 Algae Dewatering Using an Inclined Gravity Settler

Wednesday, October 31, 2012: 10:35 AM
304 (Convention Center )
Joanne Belovich, Cleveland State University, Cleveland, OH, Zhaowei Wang, Newland Biotech, Cleveland, OH and Jing Hou, Newland Biotech, Inc., Cleveland, OH

One of the main barriers to the cost-effective production of biofuel from microalgae culture is the difficulty of harvesting the algae from dilute cell suspensions.  Because of light limitation, the microalgae concentration in large-scale ponds typically does not exceed 1-2 gdw/L.   A downward flow inclined gravity settler was evaluated for its effectiveness in algae culture dewatering, using two stains of algae, Scenedesmus dimorphus and Chlorella vulgaris.   Experimental results showed that S. dimorphus  can be concentrated up to eight-fold using a single settler stage, with a biomass recovery of 80%.  Separation efficiency was independent of biomass concentration between 1 and 6 gdw/L, suggesting that a two-stage sequential system of settlers may be effective to maximize biomass recovery and concentration.   Efficiency of separation of C. vulgaris was slightly lower than that of S. dimorphus, due to the fact that S. dimorphus cells exist in aggregates of up to eight or more cells and thus settle more easily.  The system demonstrated consistent results and steady state operation for up to three weeks of continuous operation, and is low in energy consumption.   This separation system may be useful as a first stage for removing 95% of the water from large-scale algae cultivation systems.

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See more of this Session: Separation Processes in Biorefineries
See more of this Group/Topical: 2012 International Congress on Energy (ICE)