Techno-economic analysis of ion concentration polarization desalination for high salinity desalination applications.

A techno-economic analysis is used to evaluate the economic feasibility of ion concentration polarization (ICP) desalination for seawater desalination and brine management. An empirical optimization model based on a limited set of experimental data, which was obtained from a lab-scale ICP desalination prototype, was established to calculate the required energy and membrane area for a given set of operating parameters. By calculating operating and capital expenses in various feed and product cases, the optimal levelized cost of water is determined over a range of feed salinities, mostly above seawater salinity (35 g/kg).

Sodium Hydroxide Production from Seawater Desalination Brine: Process Design and Energy Efficiency.

The ability to increase pH is a crucial need for desalination pretreatment (especially in reverse osmosis) and for other industries, but processes used to raise pH often incur significant emissions and nonrenewable resource use. Alternatively, waste brine from desalination can be used to create sodium hydroxide, via appropriate concentration and purification pretreatment steps, for input into the chlor-alkali process. In this work, an efficient process train (with variations) is developed and modeled for sodium hydroxide production from seawater desalination brine using membrane chlor-alkali electrolysis.

Wetting phenomena in membrane distillation: Mechanisms, reversal, and prevention.

Membrane distillation (MD) is a rapidly emerging water treatment technology; however, membrane pore wetting is a primary barrier to widespread industrial use of MD. The primary causes of membrane wetting are exceedance of liquid entry pressure and membrane fouling. Developments in membrane design and the use of pretreatment have provided significant advancement toward wetting prevention in membrane distillation, but further progress is needed.

Inorganic fouling mitigation by salinity cycling in batch reverse osmosis.

Enhanced fouling resistance has been observed in recent variants of reverse osmosis (RO) desalination which use time-varying batch or semi-batch processes, such as closed-circuit RO (CCRO) and pulse flow RO (PFRO). However, the mechanisms of batch processes' fouling resistance are not well-understood, and models have not been developed for prediction of their fouling performance. Here, a framework for predicting reverse osmosis fouling is developed by comparing the fluid residence time in batch and continuous (conventional) reverse osmosis systems to the nucleation induction times for crystallization of sparingly soluble salts.

Energy efficiency of batch and semi-batch (CCRO) reverse osmosis desalination.

As reverse osmosis (RO) desalination capacity increases worldwide, the need to reduce its specific energy consumption becomes more urgent. In addition to the incremental changes attainable with improved components such as membranes and pumps, more significant reduction of energy consumption can be achieved through time-varying RO processes including semi-batch processes such as closed-circuit reverse osmosis (CCRO) and fully-batch processes that have not yet been commercialized or modelled in detail. In this study, numerical models of the energy consumption of batch RO (BRO), CCRO, and the standard continuous RO process are detailed.