Conventional coal-fired power plants generate multiple waste streams including solid waste, wastewater, and flue gas. To minimize waste discharge and the associated environmental impacts, separated treatment technologies for solid, liquid, and gaseous wastes have been applied, but the treatment costs are high, especially when new process such as CO2 emission control is applied. This study demonstrates a new electrolytic carbonation process to synergize the treatment of different waste streams generated by power plants, including fly ash, brine wastewater, and CO2. The acidity generated by electrolysis of brine electrolyte directly liberates calcium from fly ash. The metal ions balance the OH&lt;font size="1"&gt;&lt;span style="line-height:14.166666030883789px"&gt; &lt;/span&gt;&lt;/font&gt;produced at the cathode to form hydroxide, which then fix CO2 into carbonate precipitates. Our findings show that electrolysis could extract metal ions from minerals that dramatically improve carbon capture efficiency. The H2 produced during electrolysis can offset energy consumption and potentially make the process energy neutral or positive. The process can be further integrated with neighboring wastewater treatment facilities, which treats the wastewater generated by the power plant and the millions of wastewater can be ideal sink for carbon capture using the technology. The waste heat generated from power plants can facilitate the reaction rate as well. The wastewater industry consumes 60 terawatt hours of electricity every year and emits 0.7 Gigatonnes of CO2-equivalent emission. Such integration will greatly reduce energy consumption and carbon emission of both industries and save costs, and the generated carbonate and bicarbonate are valuable materials commonly used in wastewater facilities for alkalinity compensation as well as for structural materials or help counter ocean acidification.

Synergizing waste management for power and wastewater facilities via low-energy electrolytic carbonation

251st National Meeting (2016)

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