Sythhesis and Optimization of Hybrid Membrane Desalination Networks with Value Extraction

Membrane desalination technology has become a valuable advanced water treatment process to purify difficult water sources for potable use. Reverse Osmosis (RO) and Nanofiltration (NF) processes are commonly used desalination technologies. Studies of hybrid RO-NF membrane desalination systems have shown promising benefits of lower power usage, higher overall obtainability, and better water quality. Under the proposed title, a systematic network synthesis approach is to be developed to evaluate the performance of a hybrid membrane desalination plant consisting of NF and RO processes in order to achieve an optimal design network for a given water capacity with ideal operating conditions. This work is done using a superstructure optimization, while taking into account desired process conditions and constraints that are associated with the hybrid RO-NF system. The superstructure captures all the structural and operational options that enable the extraction of a global optimal design, giving a better visualization of the hybrid design network. The optimization problem is formulated while accounting for all the design decisions that are supported by superstructure representation, based on numbers and types of units, flow rates, and pressures.An economic objective function is utilized so as to provide an efficient and desirable configuration capturing all the significant capital and operating costs, such as intake, pre and post treatment, along with the revenue from the value extraction. Optimized designs for hybrid RO-NF desalination plant were illustrated using a case study of sea water desalination with around 35 parts per thousand (ppt) of salinity. The solutions show increased the overall recovery with the addition of an NF membrane into the design