Exploring the Use of Static Mixers for Enhanced Flow-Electrode Capacitive Deionization

Water desalination plays a major role in alleviating water scarcity issues, but it faces major barriers due to high energy use, low water utilization, and significant environmental impacts. Flow electrode capacitive deionization (FCDI) is a new ultra-efficient electrochemical water treatment technology capable of desalinating saline streams (e.g., brackish water, seawater) with less than 10% of the feed water rejected as waste. Here we use a structured flow plate design to maximize charge transfer while incurring a negligible pressure drop penalty. Different 3D printed flow plate structures were characterized individually in a flow capacitor arrangement to quantify their relative merits in terms of the tradeoff between conductivity and flow characteristics with carbon slurries containing 5-9 wt% activated carbon and 0-1 wt% carbon black. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Funding was provided by Lawrence Livermore National Laboratory Directed Research and Development (LDRD) Grant 22-DR-011. IM #LLNL-ABS-846456