Cost and energy requirements of hybrid RO and ED brine concentration systems for salt production
Author(s)Fernandes, Jenifer; McCance, Adriene; Al-Anzi, Bader S.; Nayar, Kishor Govind; McGovern, Ronan Killian; Dominguez, Kyle P.; Lienhard, John H; ... Show more Show less
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A new concept to concentrate seawater up to 200 g/kg for producing vacuum salt using a reverse osmosis (RO) system hybridized with an electrodialysis (ED) system is presented. The RO system operates up to pressures of 120 bar and concentrates seawater up to 120 g/kg with the ED system concentrating RO brine to 200 g/kg. A parametric analysis to minimize the specific cost of brine concentration was conducted. Parameters varied were: the degree of RO-ED hybridization, ED current density, electricity prices and water prices. Optimal hybrid RO-ED designs reduced brine concentration costs by 33–70% over standalone ED systems, with revenue generated from water co-production further subsidizing costs by 1–6%. Optimizing ED current density reduced costs the most. Including a crystallizer, the total reduction in production cost over a standalone ED-crystallizer system was 19–55%, with the production cost for a typical case being $111/tonne-salt. The proposed RO-ED-crystallizer (REC) systems were found to be techno-economically feasible in Cyprus, Japan, Kuwait, Saudi Arabia, and the USA. At a road transportation distance of 735 km, REC based seawater vacuum salt was competitive with conventional vacuum salt. REC systems may open up the potential of small-scale decentralized salt production. Keywords: Reverse osmosis; Electrodialysis; Hybrid; Salt production; Brine concentration; Seawater
DepartmentMassachusetts Institute of Technology. Department of Mechanical Engineering; Sloan School of Management
Nayar, Kishor G. et al. “Cost and Energy Requirements of Hybrid RO and ED Brine Concentration Systems for Salt Production.” Desalination 456 (April 2019): 97–120 © 2018 Elsevier B.V.
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