(152aq) An Improved Closed-Circuit RO (CCRO) System: Design and Cyclic Simulation

A volume-varying stirred tank with a free-piston are placed in front of DuPont's Closed-Circuit RO (CCRO) system to achieve improved energetics. Valves are used to direct fluid flow and piston motion to enable cyclic operations consisting of CC filtration and flushing steps. Similar to CCRO, overall system recovery in the proposed system is controlled by the CC/flushing time ratio, and uninterrupted permeate production is possible if the flushing is done at high pressures. Spatiotemporal system-level models are developed and formulated as a set of coupled partial differential equations (PDEs) and ordinary differential equations (ODEs). Detailed numerical simulations and parametric studies are carried out to explore the flow and mass transfer characteristics and to compare its performance at the cyclic steady-state (CSS) with the original CCRO and the conventional steady-state RO.

References:

[1] Li, M. An Improved Closed-Circuit RO (CCRO) System: Design and Cyclic Simulation, Desalination, 554, 116519, 2023.

[2] Li, M. Cyclic Simulation and Energy Assessment of Closed-Circuit RO (CCRO) of Brackish Water, Desalination, 545, 116149, 2023.