Cost-based feasibility study and sensitivity analysis of a new draw solution assisted reverse osmosis (DSARO) process for seawater desalination

Abstract

In this study, a newly devised seawater desalination process, namely, the draw solution assisted reverse osmosis (DSARO) process, is proposed. A mathematical model for the DSARO process was developed and energy consumption and economic evaluation models were constructed to assess the feasibility of the DSARO process compared to the conventional reverse osmosis (RO) process. This work presents a characterization of important variables and the research on the effects of these variables. Compared to the conventional RO process, the DSARO process could have a 10% lower specific water production cost. The operating pressures required to reach 40% of overall recovery were approximately 35bar in the 1st RO process, and 30bar in the 2nd RO process. Due to its operating pressure being lower than the conventional RO process, the capital and membrane replacement costs could be reduced. The required conditions in the 1st RO membrane to drive the DSARO process were that the membrane structure parameter must be lower than 0.13mm, and the maximum operating pressure should be higher than 35bar. Even though these conditions are not available commercially at present, they could be attained based on the best available membrane technology in the literature.