1. Co-treating flue gas desulfurized effluent and produced water enables novel waste management and recovery of critical minerals.
- Author
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Ahmed, Mohammad Hafez, Buzby, Karen, Finklea, Harry, Hodges, Cole, Amos, Morgan, Seats, Payton, White, Nathan, Rutnik, Charlotte, Siefert, Nicholas, and Lin, Lian-Shin
- Subjects
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FLUE gases , *WASTE management , *WASTE recycling , *OIL field brines , *CALCITE , *MINERALS , *REVERSE osmosis , *WATER softening - Abstract
This study reports a novel approach of resource recovery from co-managing two geographically co-located and chemically complementary wastewaters using a pilot-scale treatment process. Designed to treat flue gas desulfurized (FGD) effluent from combustion powerplants and produced water (PW) from energy industries, the process consists of soda-ash softening, nanofiltration (NF), and reverse osmosis (RO). Recovered products are barite, calcite, and low-salinity water. Using field-collected waters, the results show that softening at pH ≈ 8.5 produces calcite (yield: ~ 30 kg/m3 treated water), a chemical used as SO₂ (g) scrubbers. NF treatment under an applied pressure of ~ 3.5 MPa yields a permeate stream laden with monovalent ions (water recovery ~ 60 %) and a concentrate stream with a sulfate concentration ~ 1.8 times of the feedwater concentration. Mixing the NF concentrate and PW at a volumetric ratio of 1.0 precipitates a high-density barite material (4.1 g/cm3, yield: ~ 7.5 kg/m3 mixture) – a critical mineral commonly used as a weighting agent in drilling. The RO treatment recovers >64 % water as the permeate, which can be readily used as cooling make-up water at the powerplants. The RO concentrate stream can be further processed in a thermal evaporative system for additional water recovery and brine production. [Display omitted] • FGD effluent and PW have complimentary chemistries for critical mineral recovery. • FGD and PW co-treatment recovered barite, calcite, and low-salinity water. • Successful pilot-scale operation demonstrated feasibility of the co-treatment approach. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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