Global Sensitivity Analysis To Characterize Operational Limits and Prioritize Performance Goals of Capacitive Deionization Technologies

Abstract

Capacitive deionization (CDI) technologies couple electronic and ionic charge storage, enabling improved thermodynamic efficiency of brackish desalination by recovering energy released during discharge. However, insight into CDI has been limited by discrete experimental observations at low desalination depths (Δc, typically reducing influent salinity by 10 mM or less). In this study, the performance and sensitivity of three common CDI configurations [standard CDI, membrane CDI (MCDI), and flowable electrode CDI (FCDI)] were evaluated across the operational and material design landscape by varying eight common input parameters (electrode thickness, influent concentration, current density, electrode flow rate, specific capacitance, contact resistance, porosity, and fixed charge). All combinations of designs were evaluated for two influent concentrations with a calibrated and validated one-dimensional (1-D) porous electrode model. Sensitivity analyses were carried out via Monte Carlo and Morris methods, focusing on six performance metrics. Across all performance metrics, high sensitivity was observed to input parameters which impact cycle length (current, resistance, and capacitance). Simulations demonstrated the importance of maintaining both charge and round-trip efficiencies, which limit the performance of CDI and FCDI, respectively. Accounting for energy recovery, only MCDI was capable of operating at thermodynamic efficiencies similar to reverse osmosis.

State‐level material flow analysis suggests the need to reconsider current monitoring practice and mitigation policies for poly‐ and perfluoroalkyl substances in carpet

“…The global sensitivity analysis combines Latin-Hypercube (LH) sampling (McKay et al, 1979) and One-factor-At-a-Time (OAT) sensitivity (Morris, 1991) as outlined in a previous study (Hand et al, 2019;van Griensven et al, 2006). The LH-OAT analysis is done for each emission model for in-use and landfill emissions (F2 and F5 in Figure 1 and Table 1).…”

Parameter Sensitivity and Inversion Analysis for a Concrete Face Rockfill Dam Based on CS‐BPNN

“…e modified Morris method is a qualitative global screening method to identify the parameters with significant impact on the outputs of various models, whose feasibility has been validated in previous researches [10][11][12]. e key procedure of this method is to determine the input sample of parameters with rational variations in certain threshold range and calculate the sensitivity indexes of dependent variables to parametric changes.…”

“…erefore, it is necessary to conduct sensitivity analysis before parametric inversion to eliminate insensitive parameter and promote computational efficiency. e modified Morris method [10][11][12] is adopted to identify the parameters of high sensitivity for parametric inversion of the coupled E-ν and Burgers model. e coupled E-ν and Burgers model contains numerous parameters with complex relationship, whose inversion analysis is a typical nonlinear problem [13][14][15][16][17][18].…”

Low voltage operation of a silver/silver chloride battery with high desalination capacity in seawater

“…9 CDI can achieve a high charge efficiency, that is, most of the invested charge is used for the ion immobilization (desalination) and not lost to redox-reactions that do not contribute towards the actual desalination process. 10,11 Using nanoporous carbon and aqueous saline media, one can typically achieve desalination capacities of 10-25 mg g À1 (mg NaCl per g of the electrode) [12][13][14][15][16] at cell voltages of about 1 V for low molar concentrations. State-of-the-art nanoporous carbon materials for CDI electrodes include biomass-derived carbon (ref.…”