Optimization of simplified freeze desalination with surface scraped freeze crystallizer for producing irrigation water without seeding

Abstract

Freeze desalination (FD) is a promising desalination technology for overcoming the drawbacks of conventional desalination methods. However, the slow production rate and low productivity of FD have hindered its commercialization. This research presents the challenges confronting current FD processes and proposes a new simplified FD, which employs self-nucleation using the surface scraped freeze crystallizer unit. With the simplified FD process, it was found that optimal conditions are 45 or 50% of the washing water percentage at an operational temperature of −12 °C, and 50% of the washing water percentage at an operational temperature of −16 °C for producing irrigation water (<2000 mg/L in terms of total dissolved solids). Furthermore, we applied the cyclic system, which was the reuse of the mixture of brine and washing waste, on the FD process. The results showed that the use of 45% of the washing water percentage for the 1st cycle raw ice products and 50% for the 2nd cycle at an operational temperature of −12 °C enabled the achievement of >40% in the final productivity. Accordingly, this research introduced the feasibility of the FD process without the use of any additional seeding process.