Techno-economic evaluation of a solar multi‐effect distillation/thermal vapor compression hybrid system for brine treatment and salt recovery

Abstract

Desalination plants, besides freshwater, produce brine (hyper-saline by-product) and high greenhouse gases (GHGs) emissions. To address both issues, this study introduces a solar multi‐effect distillation/thermal vapor compression (SMED-TVC) hybrid system. The aim of the system is to desalinate brine (>70 g/L) and to recover freshwater and solid salt of high purity. Thus, a techno-economic model was developed to evaluate this hybrid process in two cases. Numerous sensitivity analyses have been carried out showing that the freshwater cost and the payback period decrease with an increase in (i) freshwater production capacity (from 10 m3/day to 50 m3/day) and (ii) plant life time (from 20 years to 35 years). In the second case of both freshwater and pure solid salt (NaCl) recovery, the payback period (3.98–4.47 years) is shorter than the equivalent (4.85–5.45 years) of the first case in which only freshwater is recovered. The profit from the treatment can reach up to US$1.22/m3 in the first case, while in the second case it can reach up to US$5.71/m3. The results showed that the proposed hybrid system could be a viable option for sustainable desalination brine management.