Electrodialysis Costing Method
Costing Method Parameters
The following parameters are constructed for the unit on the FlowsheetCostingBlock (e.g., m.fs.costing.electrodialysis) when applying the cost_electrodialysis costing method in the watertap_costing_package:
Description |
Symbol |
Parameter Name |
Default Value |
Units |
|---|---|---|---|---|
Membrane unit cost |
\(C_{mem}\) |
|
160 |
\(\text{USD}_{2018}\text{/m}^2\) |
Membrane replacement factor (fraction of membrane replaced/year) |
\(f_{mem,\, replace}\) |
|
0.2 |
\(\text{yr}^{-1}\) |
Electrode unit cost |
\(C_{elec}\) |
|
2100 |
\(\text{USD}_{2018}\text{/m}^2\) |
Electrode replacement factor (fraction of electrode replaced/year) |
\(f_{elec,\, replace}\) |
|
0.2 |
\(\text{yr}^{-1}\) |
Rectifier cost coefficient, a |
\(a_{rectifier}\) |
|
508.6 |
\(\text{dimensionless}\) |
Rectifier cost coefficient, b |
\(b_{rectifier}\) |
|
2810 |
\(\text{dimensionless}\) |
AC to DC conversion efficiency |
\(\eta_{AC-DC}\) |
|
0.9 |
\(\text{dimensionless}\) |
Costing Method Variables
The following variables are constructed on the unit block (e.g., m.fs.unit.costing) when applying the cost_electrodialysis costing method in the watertap_costing_package:
Description |
Symbol |
Variable Name |
Index |
Units |
|---|---|---|---|---|
Cell pair number in a stack |
\(n_{pair}\) |
|
None |
\(\text{dimensionless}\) |
Cell width |
\(w\) |
|
None |
\(\text{m}\) |
Cell length |
\(l\) |
|
None |
\(\text{m}\) |
Power |
\(P\) |
|
[t] |
\(\text{kW}\) |
Capital Cost Calculations
Capital cost is dependent upon the cell pair number, cell width, and cell length, as shown in the equations below.
If the system has a rectifier (has_rectifier=True):
\[ \begin{align}\begin{aligned}C_{rectifier} = b_{rectifier} + (a_{rectifier} * P / \eta_{AC-DC})\\C_{cap,tot} = (C_{mem} * 2 * n_{pair} * w * l) + (C_{elec} * 2 * w * l) + C_{rectifier}\end{aligned}\end{align} \]
Otherwise:
\[C_{cap,tot} = (C_{mem} * 2 * n_{pair} * w * l) + (C_{elec} * 2 * w * l)\]
Operating Cost Calculations
Electricity \(C_{elec}\) is a variable operating cost based on the energy intensity \(E\) of the unit process (power for electrodialysis), electricity price \(P\), electricity flow \(Q\), and the plant utilization factor \(f_{util}\). If a rectifier is included, the energy intensity is the power required for the rectifier. The annual electricity costs are calculated as:
\[C_{op, tot} = C_{elec} = E Q f_{util} P\]