Title: A one-dimensional model for water desalination by flow-through electrode capacitive deionization,
Abstract: Capacitive deionization (CDI) is a fast-emerging water desalination
technology in which a small cell voltage of ~1 V across porous carbon
electrodes removes salt from feedwaters via electrosorption. In flow-through
electrode (FTE) CDI cell architecture, feedwater is pumped through macropores
or laser perforated channels in porous electrodes, enabling highly compact
cells with parallel flow and electric field, as well as rapid salt removal. We
here present a one-dimensional model describing water desalination by FTE CDI,
and a comparison to data from a custom-built experimental cell. The model
employs simple cell boundary conditions derived via scaling arguments. We show
good model-to-data fits with reasonable values for fitting parameters such as
the Stern layer capacitance, micropore volume, and attraction energy. Thus, we
demonstrate that from an engineering modeling perspective, an FTE CDI cell may
be described with simpler one-dimensional models, unlike more typical
flow-between electrodes architecture where 2D models are required.