Techno-economic evaluation of maximizing minimum liquid discharge from seawater desalination for the fertilizer industry
Year: 2025
Type: article
Abstract: The Middle East and North Africa region faces critical water scarcity and food security challenges that threaten economic development. Fertilizer use supports food self-sufficiency, but its production is highly water intensive. Supplying desalinated water to a decarbonized fertilizer plant offers an environmentally sustainable pathway. This study investigates co-locating a decarbonized fertilizer plant with a seawater desalination facility, optionally implementing minimum liquid discharge (MLD) to generate additional revenue through recovery of magnesium hydroxide and sodium chloride (NaCl). Three configurations were modeled: a conventional seawater reverse osmosis (SWRO)-based plant; and two MLD configurations using high-pressure RO (HPRO), osmotically-assisted RO (OARO), and crystallizers. Financial performance was assessed using a novel discounted and allocated levelized cost (DALC) method, internal rate of return (IRR), and net present value (NPV). In a Moroccan case study, the conventional configuration achieved the lowest DALC and energy consumption (0.70 USD/m 3 water and 3.8 KWh el /m 3 ), with an IRR of 23.9 %. The first MLD configuration had higher costs (0.94 USD/m 3 water , 12.0 KWh el /m 3 ) and a lower IRR (14.5 %), with water recovery limited to 71.4 % due to nonuse of magnesium crystallizer effluent (60.4 % in the conventional setup). Reusing this effluent in the second MLD configuration increased water recovery to 96.7 %, yet higher impurities at the NaCl crystallizer feed reduced the IRR to 9.7 %, which could be improved through financing strategies such as lowering capital costs to endorse the MLD-maximizing option. The findings emphasize advancing impurity removal methods and exploring innovative project financing strategies to enable financially and environmentally sustainable seawater desalination for decarbonized fertilizer production.
Source: Water Resources and Industry
Language: English
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,613
OpenAlex ID: W4416701768