Abstract
Three types of membrane and module were studied as core technologies in Mega–ton Water System project for realizing mega–scaled seawater desalination plant which is capable of producing 1,000,000 m3 of freshwater per day.Firstly, research for highly efficient spiral reverse osmosis (RO) element focusing on membrane design and element structure was executed. Low pressure polyamide RO membrane was obtained based on structure analyses of the membrane by means of microscopic method and pore size measurement. Regarding to element structure, the numerical simulation method for the whole area of a membrane leaf was developed by using the flow and mass trans-fer characteristics for modeling the spacer–filled channel. Secondly, world’s largest–size hollow fiber type RO element (16 inch diameter)was developed for the first time in the history of hollow fiber membrane business. The prototype element which has more than 4 times higher flow rate than the conventional size element was successfully produced. This element configuration was optimally designed by using simulation model developed to analyze the axial distribution of flow in RO module in consideration for membrane flux. Thirdly, highly efficient UF membrane and module for pretreatment of RO process were studied. Chemical structure of the membrane material was modified to reduce membrane fouling, and pore structure of the membrane was optimized by controlling spinning condition of hollow fiber membrane. The flux of the modified hollow fiber UF membrane has almost doubled compared to that of the conventional UF membranes. Furthermore, the actual large membrane module (12 inch diameter) with the modified membrane was successfully produced.
