New Seawater Desalination Technology
Doctor Kim Yu-chang’s research team at the Korea Institute of Machinery & Materials (KIMM) developed a new forward osmosis (FO) reverse osmosis (RO) hybrid desalination technology that can significantly reduce energy consumption.
“If early-stage existing seawater desalination devices are to obtain fresh water through seawater evaporation, reverse osmosis processes in which fresh water is separated by means of greater pressure than osmosis pressure are more prevalent nowadays,” the doctor explained, adding, “The FO-RO hybrid process, with much improved energy efficiency, is a type of third-generation technology optimized for small and mid-sized plants.”
According to the results of the pilot tests conducted at Korea Maritime and Ocean University, the new process can save 15% to 20% more energy than a reverse osmosis process, consuming 4 kWh to 10 kWh to produce one ton of fresh water while removing up to 99% of the trace toxic substances. In addition, it requires less maintenance costs, because the separation membrane is less subject to contamination. In a reverse osmosis process, the membrane has to be replaced every two years.
“With the aid of the hybrid process, the fresh water production cost can be decreased from 1,200 won or 1,300 won to less than 1,000 won [US$0.94] per ton,” said the doctor, continuing, “Our development at this time is the second one of its kind in the world, following the pilot-scale system designed, produced, and run by the UK’s Modern Water, but renders better results than the first one.”
He went on to say, “In fact, FO desalination technology has been around for a long while in a theoretical form, but commercial development has not been easy due to difficulties relating to re-separation and the performance of the separation membrane.” He also mentioned that the FO-RO hybrid process can also be utilized for the enrichment treatment of sewage and super high-salinity wastewater.
The research team is working on the expanded application of the pilot plant to commercial plants. It is planning to set up a demonstration plant in 2015 and then beef up its sale in the Middle East. The 10,000-ton-or-less seawater desalination plant market is estimated to be 11 trillion won (US$10.4 billion) a year worldwide, accounting for approximately 40% of the entire desalination plant industry.