Added bipolar membrane unit model and costing #1500

johnson12742 · 2024-10-02T00:31:41Z

Fixes/Resolves:

(replace this with the issue # fixed or resolved, if no issue exists then a brief statement of what this PR does)

Summary/Motivation:

Adding the bipolar membrane unit model capability

Changes proposed in this PR:

Bipolar Electrodialysis 0-D unit model with a test. Heavily borrows from Electrodialysis 0-D.
Documentation for the Bipolar Electrodialysis 0-D unit model
Costing package for Bipolar Electrodialysis unit model. This is a slightly modified version of the electrodialysis costing. With bipolar there is a negative cost component (value addition)

Legal Acknowledgement

By contributing to this software project, I agree to the following terms and conditions for my contribution:

I agree my contributions are submitted under the license terms described in the LICENSE.txt file at the top level of this directory.
I represent I am authorized to make the contributions and grant the license. If my employer has rights to intellectual property that includes these contributions, I represent that I have received permission to make contributions and grant the required license on behalf of that employer.

adam-a-a · 2024-10-03T20:33:58Z

docs/technical_reference/unit_models/Biploar_electrodialysis_0D.rst

+    Figure 1. Schematic representation of a bipolar electrodialysis unit
+
+
+One bipolar membrane along with the **Acidate** and **Basate** channels can thus be treated as a modelling unit that can


Are acidate and basate typical terminology for BPMD?

They are not. I needed a name for the acid & base channel.
I went off diluted/ concentrated channel which are called diluate/concentrate (in ED documentation). Extrapolating from this I chose acidate/basate.

If anybody has better suggestion I am happy to use it.

In theory they are an acid concentrate and base concentrate (increasing in concentration), where the brine is a brine diluate (deceasing in concentration) based on the donation of ions toward the objective of the system, correct?

Yes, they do increase concentration. But I think there is a subtle difference. BPMED increase concentration via production of new acid/base (through water splitting) and not by just transporting ions across the membranes. I feel like that deserved a distinction in nomenclature. Thoughts?

I'd go with either acid and base or acidic and basic.

@adam-a-a That's reasonable. I have changed the names to Acidic & Basic

adam-a-a

Here are some initial comments until I finish my pass

adam-a-a · 2024-10-10T18:39:11Z

docs/technical_reference/unit_models/index.rst

@@ -6,6 +6,7 @@ Unit Models

   anaerobic_digester
   aeration_tank
+   Biploar_electrodialysis_0D


Suggested change

Biploar_electrodialysis_0D

bipolar_electrodialysis_0D

adam-a-a · 2024-10-10T18:42:51Z

docs/technical_reference/unit_models/Biploar_electrodialysis_0D.rst

@@ -0,0 +1,340 @@
+Bipolar Electrodialysis (0D)


This is great! While we're here, you should also add an rst file to describe costing, e.g.,: https://watertap.readthedocs.io/en/latest/technical_reference/costing/detailed_unit_model_costing.html

That's a good idea. However, I made some changes to the unit model costing and would like some feedback (before committing it to the docs).
While doing analysis I realised that a big component (negative cost/value addition) of the bipolar costing might be best done on the flowsheet level. So, I have removed it (in the most recent version).

As it stands the BPMED costing is very similar to the ED costing. The difference being the variable name for number of membranes. (cell_pair_num vs cell_num). Is there a way to inherit the ED costing?

Also, just for future reference I plan to add the bpmed + ED unit model (a configuration that is commonly used and something that I have been using for analysis). This would require minor alteration to the costing. It would be nice to know the capabilities/limits of the inheritance. Since that would inform whether I need a costing just for bipolar membrane.
I am happy to elaborate more on this issue.

adam-a-a · 2024-10-10T18:44:01Z

docs/technical_reference/unit_models/Biploar_electrodialysis_0D.rst

@@ -0,0 +1,340 @@
+Bipolar Electrodialysis (0D)
+============================


Looks like you updated the terminology to acidic and basic channels. One other place where this should be updated is in the png diagram.

Thanks for pointing that out. Somehow I missed that.

adam-a-a · 2024-10-10T18:46:52Z

docs/technical_reference/unit_models/Biploar_electrodialysis_0D.rst

+ion and water transport across the membrane along with water splitting. Modelled transfer mechanisms include
+electrical migration, diffusion of ions, osmosis, electroosmosis, and water splitting. The following are the key
+assumptions made:


This sounds great. A question that comes to mind is -- what notable mechanisms does the model not account for at this time (but technically could be based on latest literature)? I suggest creating an issue to track any such mechanisms so that we chart a path for future enhancement, whether that be by you or another developer later on.

@adam-a-a This is a good question. I actually faced the other problem. It was challenging finding the appropriate steady state equations for bipolar membrane (there are many equations/features for dynamic bipolar modelling but that's a can of worms for another day).
Even now there are some features (like the boundary layer details) that have not been added to the unit model because I can't find appropriate equations.

adam-a-a · 2024-10-10T18:47:08Z

docs/technical_reference/unit_models/Biploar_electrodialysis_0D.rst

+
+* The **acidic** and **basic** side channels have identical geometry.
+* For each channel, component fluxes are uniform in the bulk solutions (the 0-dimensional assumption)  and are set as the average of inlet and outlet of each channel.
+* Steady state: all variables are independent on time.


Suggested change

* Steady state: all variables are independent on time.

* Steady state: all variables are independent of time.

adam-a-a · 2024-10-10T18:52:04Z

docs/technical_reference/unit_models/Biploar_electrodialysis_0D.rst

+* **acidic** channel
+* **basic** side channel


Is one called acidic and the other called basic or basic_side? I'd remove "side" if not used in the attribute name to avoid confusion.

adam-a-a · 2024-10-10T18:56:21Z

docs/technical_reference/unit_models/Biploar_electrodialysis_0D.rst

+
+   "Time", ":math:`t`", "[t] ([0])\ :sup:`1`"
+   "Phase", ":math:`p`", "['Liq']"
+   "Component", ":math:`j`", "['H\ :sub:`2` \O', 'Na\ :sup:`+`', 'Cl\ :sup:`-`', 'H\ :sup:`+`', 'OH\ :sup:`-`']"


It is not yet clear whether this unit works with MCAS, the NaCl prop package, both, and/or other property models. Can you elaborate?

How do I check this? I took what the ED folks have been using and ran with it. So, theoretically whatever is applicable for the prop packages in the ED unit model should be applicable here (with the caveat that users should also supply H_+ and OH_- ).

adam-a-a · 2024-10-10T18:58:03Z

docs/technical_reference/unit_models/Biploar_electrodialysis_0D.rst

+to fully solve the model. The exact degrees of freedom depend on the mode of operation. For the simplest case where no water
+splitting occurs and the bipolar membrane acts like a simple electrodialysis memrbane these are:


Suggested change

to fully solve the model. The exact degrees of freedom depend on the mode of operation. For the simplest case where no water

splitting occurs and the bipolar membrane acts like a simple electrodialysis memrbane these are:

to fully solve the model. The exact degrees of freedom depend on the mode of operation. For the simplest case, where no water

splitting occurs and the bipolar membrane acts like a simple electrodialysis membrane, these are:

adam-a-a · 2024-10-10T19:02:18Z

docs/technical_reference/unit_models/Biploar_electrodialysis_0D.rst

+   ion_dict = {
+        "solute_list": ["Na_+", "Cl_-", "H_+", "OH_-"],
+        "mw_data": {
+            "H2O": 18e-3,


Suggested change

"H2O": 18e-3,

"H2O": 18e-3,

Note, you no longer need to supply MW for water anymore.

adam-a-a · 2024-10-10T19:04:15Z

docs/technical_reference/unit_models/Biploar_electrodialysis_0D.rst

+        },
+    }
+
+This model, by default, uses H\ :sub:`2`\ O  as the solvent of the feed solution.


I probably should wait until I get to the code, but what happens when the user omits H_+ and OH_- from the solute_list? Would the unit model raise the appropriate exception? If so, and I may have missed it, you should add a note here stating that H2 and OH must be provided.

Yes, the user needs to supply H_+ and OH_- . I have now added a note saying that it must be added.

…rrect error in water flux. Updated unit model and test (changes are minor)

…rrect error in water flux. Updated unit model and test (changes are minor) v1.1

…rrect error in water flux. Updated unit model and test (changes are minor) v1.2

lbibl · 2024-10-31T12:54:03Z

docs/technical_reference/unit_models/bipolar_electrodialysis_0D.rst

+
+   "Component mass balance", ":math:`N_{j, in}^{acidic \: or\:  basic}-N_{j, out}^{acidic\: or\:  basic}+J_j^{acidic\: or\:  basic} bl=0`", ":math:`j \in \left['H_2 O', '{Na^+} ', '{Cl^-} '\right]`"
+   "mass transfer flux, basic, solute", ":math:`J_j^{C} = -t_j^{bpem}\frac{\xi i_{lim}}{ z_j F}`", ":math:`j \in \left['{Na_+} ', '{Cl^-} '\right]`"
+   "mass transfer flux, acidic, Water ions", ":math:`J_j^{C} = \frac{i - i_{lim}}{ z_j F}`", ":math:`j \in \left['{H^+} '\right]`"


I would annotate "Water ions" or replace them with "proton" and "hydroxide".

lbibl · 2024-10-31T12:57:23Z

docs/technical_reference/unit_models/bipolar_electrodialysis_0D.rst

+:math:`mol\, m^{-3}` and are taken to be constants. :math:`f(E)` is the second Wien effect driven enhanacidicent of the
+dissociation rate under applied electric field. It requires as input temperature and relative permittivity (:math:`\epsilon_r`).
+To close the model :math:`\lambda = E_{crit} \epsilon_0 \epsilon_r / (F \sigma)`
+


I recommend tabulating these equations along others for easier following. It could be even better to tabulate them side by side with the catalysis-modeled scenario. I also recommend referencing them more precisely, i.e., annotating which eq is from which literature.

@lbibl This is a very good suggestion. I have rewritten the doc file to tabulate the equations (and correct some errors).

lbibl · 2024-10-31T12:59:09Z

docs/technical_reference/unit_models/bipolar_electrodialysis_0D.rst

+
+Bipolar electrodialysis, an electrochemical separation technology, has primarily been used to generate acids and bases
+from waste salts produced in water purification. By providing in-situ access to valuable raw materials bipolar membranes can
+significantly reduce the total cost of the operation.  This cell stack is shown in Figure 1 with **basic** and **acidic** channels, that produce base and acid


This sentence somewhat puzzles me without specifying what is the "raw material" and what operation.

lbibl · 2024-10-31T13:02:37Z

docs/technical_reference/unit_models/bipolar_electrodialysis_0D.rst

+.. csv-table:: **Table 2.** List of Degree of Freedom (DOF)
+   :header: "Description", "Symbol", "Variable Name", "Index", "Units", "DOF Number \ :sup:`1`"
+
+   "Temperature, inlet_acidic", ":math:`T^acidic`", "temperature", "None", ":math:`K`", 1


Please check the rst formatting in the printout throughout. For instance, it should probably be T^{acidic}, etc.

lbibl · 2024-10-31T13:04:47Z

docs/technical_reference/unit_models/bipolar_electrodialysis_0D.rst

+
+   "mass transfer flux, acidic/basic, Water ions", ":math:`J_j^{C} = J_{diss}`", ":math:`j \in \left['{H^+, OH^-} '\right]`"
+   "mass transfer flux, acidic H\ :sub:`2`\ O", ":math:`J_j^{C} = t_w^{bpem} \left(\frac{i}{F}\right)+\left(L^{bpem} \right)\left(p_{osm}^CEM-p_{osm}^AEM \right)\left(\frac{\rho_w}{M_w}\right) -  J_{diss}`", ":math:`j \in \left['H_2 O'\right]`"
+   "mass transfer flux, basic, H\ :sub:`2`\ O", ":math:`J_j^{C} = -t_w^{bpem} \left(\frac{i}{F}\right)-\left(L^{bpem} \right)\left(p_{osm}^CEM-p_{osm}^AEM \right)\left(\frac{\rho_w}{M_w}\right) -  J_{diss}`", ":math:`j \in \left['H_2 O'\right]`"


Check formatting throughout.

…anup to remove unused performance metrics

…anup to remove unused performance metrics v1.1

lbibl · 2024-11-07T20:30:34Z

watertap/unit_models/tests/test_biploar_electrodialysis_0D.py

+                expt_current_density[indx], rel=rel_tol
+            )
+
+


I think the purpose of such tests is to ensure the model is numerically stable over time, i.e., it reproduces key solutions over time. For such a purpose, you may wanna set a constant and small tol to assert the equality to a value that is close within acceptable errors by your estimate to the value you are citing from literatures.

This is advisable for all value assertions throughout.

…inst experimental data

…embrane

lbibl · 2024-11-10T14:27:54Z

docs/technical_reference/unit_models/bipolar_electrodialysis_0D.rst

+   "Electrode areal resistance", ":math:`r_{el}`", "electrodes_resistance", "[t]", ":math:`\Omega m^2`", 1
+   "Cell number", ":math:`n`", "cell_num", "None", "dimensionless", 1
+   "Current utilization coefficient", ":math:`\xi`", "current_utilization", "None", "dimensionless", 1
+   "Shadow factor", ":math:`\xi`", "shadow_factor", "None", "dimensionless", 1


\xi is doubly used.

lbibl · 2024-11-10T14:29:53Z

docs/technical_reference/unit_models/bipolar_electrodialysis_0D.rst

+
+All equations are coded as "constraints" (Pyomo). Isothermal and isobaric conditions apply.
+
+The model used here is derived from works by Wilhelm et al. (2002) and Ionescu, Viorel (2023).It has been validated using the bipolar membrane information available online: Fumatech, Technical Data Sheet for


is "Ionescu, Viorel (2023)" missing in the end references? I would make sure a reader can easily find the references for all used theories/equations.

lbibl · 2024-11-14T15:32:43Z

docs/_static/unit_models/BPEDdiagram.png

On the figure and its surrounding text: I suspect you are only showing a segment of a more complete picture- should there be regular aem on the left side and cem on the right side? So that'll give another two channels into which NaCl is fed? The current picture indicates the charge isn't balanced . It's likely you are not modeling a cell involving a NaCl solution feed- in either case, the current picture and the text aren't clear about what is being simulated. You may refer to Fig 2 in "X. Tongwen / Resources, ConserTation and Recycling 37 (2002) 1–22" - I suppose you are modeling of one of the two scenarios in this figure.

This is an important point/distinction. The bipolar membrane by itself cannot support production of acids and bases. It needs AEM and CEM in parallel. I have now made it explicitly clear in the documentation that these features are not in this unit model.
I do have this unit mode (that has BPEM + ED). It needs to be cleaned up before I push it (and all the results I have shown in meetings use the BPEM + ED unit model).

My reasoning to push a standalone bipolar membrane unit model is if someone in the future needs just the bipolar part. I am open to counter arguments.

I am not commenting on which basic unit should be modeled, but I am unclear about the focus of the current version due to several issues:

You stated that this model allows "direct comparisons with works by Mareev et al. (2020) and Melnikov (2022)," which primarily develop Nernst-Planck (N-P) models for simulating potential profiles across bipolar membranes (BPM). However, this version does not establish such a simulation, and the basis for direct comparison is unclear. The test file also references data from a third work-work-Wilhelm et al. (2002)- and the cited data is used as the model input rather than output verification.

The inclusion or absence of adjacent AEM or CEM layers next to the BPM significantly impacts the model. Melnikov (2022) does not consider such adjacent layers, leading to salt ion transport characteristics (e.g., K⁺ moving in the same direction as OH⁻) that differ from scenarios with adjacent AEM/CEM layers, where counter-ion transport would be supplemented from the other side facing the BPM. Mareev et al. (2020), as well as your diagram, suggest the presence of adjacent layers, as salt counter-ions are supplemented from the opposite side of the BPM. Also, clarifying the charge identity of the BPM layers could be very helpful.

Questions about mass balance for all components remain unanswered and are essential for understanding the model. If the goal is not solving N-P PDEs to establish electric field profiles but rather to account for mass transfer and balances, clear definitions of reaction terms are crucial.

Overall, I recommend clarifying the electrochemical cell scheme and explicitly defining the scope of the model. Additionally, validation against literature data in the test file would strengthen the results.

lbibl · 2024-11-14T15:37:37Z

docs/technical_reference/unit_models/bipolar_electrodialysis_0D.rst

+   "mass transfer flux, acidic, proton", ":math:`J_j^{C} = \frac{i - i_{lim}}{F}`", ":math:`j \in \left['{H^+} '\right]`"
+   "mass transfer flux, acidic, hydroxide", ":math:`J_j^{C} = 0`", ":math:`j \in \left['{OH^-} '\right]`"
+   "mass transfer flux, basic, proton", ":math:`J_j^{C} = 0`", ":math:`j \in \left['{H^+} '\right]`"
+   "mass transfer flux, basic,  hydroxide", ":math:`J_j^{C} = \frac{i - i_{lim}}{F}`", ":math:`j \in \left['{OH^-} '\right]`"


If there is a flux of H+ and OH- , why are they not reflected in the mass balance eq? I also think you should show a reaction term, a critical feature of an electrolysis cell, in the overall mass balance . The namely "mass transfer" terms for H+ and OH- are essentially reaction terms by your equations, although their mass was transferred...

lbibl · 2024-11-14T15:46:12Z

docs/technical_reference/unit_models/bipolar_electrodialysis_0D.rst

+   "Salt concentration, acidic side ", ":math:`C_{acidic}`", "salt_conc_acidic", "[bpem]",":math:`mol m^{-3}`"
+   "Membrane Fixed charge ", ":math:`\sigma`", "membrane_fixed_charge", "[bpem]",":math:`mol m^{-3}`"
+   "Dissociation rate constant, zero electric field ", ":math:`k_2(0)`", "kd_zero", "[bpem]",":math:`s^{-1}`"
+   "Recombination rate constant ", ":math:`k_r`", "k_r", "[bpem]",":math:`L^1 mol^{-1} s^{-1}`"


In the code it's called kr instead of k_r

lbibl · 2024-11-14T15:53:00Z

docs/technical_reference/unit_models/bipolar_electrodialysis_0D.rst

+   "Depletion length", ":math:`\lambda = E_{crit} \epsilon_0 \epsilon_r / (F \sigma)`", "``limiting_potential_method_bpem =LimitingpotentialMethod.Empirical``"
+   "Water splitting rate at electric field :math:`E` ", ":math:`R_{H^+/OH^-} (E) = [k_2(0)f(E)C_{H_2O}-k_r C_{H^+}C_{OH^-} ]`", "``limiting_potential_method_bpem =LimitingpotentialMethod.InitialValue``"
+   "Critical electric field", ":math:`R_{H^+/OH^-}(E = E_{crit})F/\lambda= 0.1 i_{lim}`", "``limiting_potential_method_bpem =LimitingpotentialMethod.Empirical``"
+


I am seeing that all constraints in Table 4 can be set as expressions as they would all fall in the null space in the ultimate matrix for the linear solver - however, nothing problematic has been observed so far that would absolutely prevent them from being set as constraints.

johnson12742 added 5 commits October 1, 2024 20:18

Added bipolar membrane unit model and costing

2e5e903

Minor corrections based on autocheck

1b65114

Minor corrections based on autocheck v1.1

3e85b9f

Minor corrections based on autocheck v1.2

1e3471d

Minor corrections based on autocheck v1.3

ecb5db1

johnson12742 marked this pull request as ready for review October 3, 2024 00:59

Minor corrections based on autocheck v1.4

ff6a753

lbianchi-lbl added the Priority:Normal Normal Priority Issue or PR label Oct 3, 2024

johnson12742 requested review from lbibl and hunterbarber October 3, 2024 20:28

adam-a-a reviewed Oct 3, 2024

View reviewed changes

Name change: Acidate/Basate to Acidic/Basic

a833442

adam-a-a reviewed Oct 24, 2024

View reviewed changes

johnson12742 added 4 commits October 30, 2024 18:58

Updates to (mainly) documentation based on first set of reviews. + Co…

2c2ca6d

…rrect error in water flux. Updated unit model and test (changes are minor)

Updates to (mainly) documentation based on first set of reviews. + Co…

ecaeaa0

…rrect error in water flux. Updated unit model and test (changes are minor) v1.1

Updates to (mainly) documentation based on first set of reviews. + Co…

895599a

…rrect error in water flux. Updated unit model and test (changes are minor) v1.2

Updates to (mainly) documentation based on first set of reviews. + Co…

a56bb73

…rrect error in water flux. Updated unit model and test (changes are minor) v1.2

lbibl reviewed Oct 31, 2024

View reviewed changes

lbianchi-lbl assigned johnson12742 Oct 31, 2024

johnson12742 added 2 commits November 2, 2024 00:05

Updates to (mainly) documentation based on second set of reviews. Cle…

981da41

…anup to remove unused performance metrics

Updates to (mainly) documentation based on second set of reviews. Cle…

c09399b

…anup to remove unused performance metrics v1.1

lbianchi-lbl mentioned this pull request Nov 5, 2024

pandas ImportError when running idaes get-extensions #1514

Closed

Merge branch 'main' into biploar_membrane

8b043e3

lbibl reviewed Nov 7, 2024

View reviewed changes

johnson12742 added 2 commits November 8, 2024 19:15

Change pytest to check for numerical accuracy instead of directly aga…

d0b0449

…inst experimental data

Merge remote-tracking branch 'origin/biploar_membrane' into biploar_m…

5b60c59

…embrane

lbibl reviewed Nov 10, 2024

View reviewed changes

johnson12742 added 2 commits November 12, 2024 15:22

fix typos

7bed754

fix typos

0e7c3ae

johnson12742 requested review from lbibl and adam-a-a November 12, 2024 23:54

lbibl reviewed Nov 14, 2024

View reviewed changes

Corrections to the documentation

e4ad509

		Figure 1. Schematic representation of a bipolar electrodialysis unit


		One bipolar membrane along with the Acidate and Basate channels can thus be treated as a modelling unit that can

		@@ -0,0 +1,340 @@
		Bipolar Electrodialysis (0D)
		============================

	* Steady state: all variables are independent on time.
	* Steady state: all variables are independent of time.

		to fully solve the model. The exact degrees of freedom depend on the mode of operation. For the simplest case where no water
		splitting occurs and the bipolar membrane acts like a simple electrodialysis memrbane these are:


		All equations are coded as "constraints" (Pyomo). Isothermal and isobaric conditions apply.

		The model used here is derived from works by Wilhelm et al. (2002) and Ionescu, Viorel (2023).It has been validated using the bipolar membrane information available online: Fumatech, Technical Data Sheet for

Added bipolar membrane unit model and costing #1500

Are you sure you want to change the base?

Added bipolar membrane unit model and costing #1500

Conversation

johnson12742 commented Oct 2, 2024 • edited Loading

Fixes/Resolves:

Summary/Motivation:

Changes proposed in this PR:

Legal Acknowledgement

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

johnson12742 Oct 10, 2024 • edited Loading

Choose a reason for hiding this comment

adam-a-a left a comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

adam-a-a Oct 10, 2024 • edited Loading

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

lbibl Nov 14, 2024 • edited Loading

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

johnson12742 commented Oct 2, 2024 •

edited

Loading

johnson12742 Oct 10, 2024 •

edited

Loading

adam-a-a Oct 10, 2024 •

edited

Loading

lbibl Nov 14, 2024 •

edited

Loading