How can I add custom adsorbent information to the IDAES model?

[Thanapat18]

Dear everyone,
I am currently conducting research on TSA CO2 capture, and I have realized that I need to modify the adsorbent information in the IDAES model. I am using a metal oxide adsorbent, which is not provided in the default IDAES library. Could someone please guide me on how to input custom adsorbent properties or modify the model to incorporate my adsorbent? Any advice or references would be greatly appreciated.

Thank you in advance!

[dallan-keylogic]

You'll want to look at the FixedBedTSA0D model, located here.

In order to add another adsorbent, add an option to the Enum here, then search the file for config.adsorbent. For each of the three existing adsorbents, there are methods that build parameters, variables, and equations, so you'll want to add appropriate functions for your adsorbent and put if statements in order to call them.

I haven't personally worked on this model, so the amount of help I can offer is limited. @Daison2102 would be a better person to answer questions.

[Thanapat18]

Dear,

I am very new to coding and to using the IDAES framework, so please excuse any naive questions. I have developed a new code segment for incorporating CeO₂ as an adsorbent into a fixed-bed TSA CO₂ capture model. I have extended the Adsorbent enum and defined a method to add CeO₂ parameters. Below is the code I developed:

# 1. Extend the Adsorbent enum
from enum import Enum
from pyomo.environ import units

class Adsorbent(Enum):
    zeolite_13x = 1
    mmen_mg_mof_74 = 2
    polystyrene_amine = 3
    CeO2 = 4  # New adsorbent: Cerium Oxide

# 2. Define the method for CeO2 parameters in the TSA model class
def _add_parameters_CeO2(self):
    """
    Method to add adsorbent-related parameters for CeO2.
    """
    # Physical properties
    self.bed_voidage = Param(
        initialize=0.3634,
        units=units.dimensionless,
        doc="Bed voidage (interparticle porosity) for CeO2",
    )
    self.particle_voidage = Param(
        initialize=0.86,
        units=units.dimensionless,
        doc="Particle voidage (intraparticle porosity) for CeO2",
    )
    self.heat_transfer_coeff = Param(
        initialize=20.0,
        units=units.J/units.s/units.m**2/units.K,  # W/m².K
        doc="Global bed-wall heat transfer coefficient for CeO2",
    )
    # Convert heat capacity from J/(mol*K) to J/(kg*K)
    cp_mass_val = 72.15 / 0.172114  # CeO2 molecular weight approx. 0.172114 kg/mol → ~419.2 J/(kg*K)
    self.cp_mass_sol = Param(
        initialize=cp_mass_val,
        units=units.J/units.kg/units.K,
        doc="Heat capacity of CeO2 adsorbent",
    )
    self.dens_mass_sol = Param(
        initialize=7220,
        units=units.kg/units.m**3,
        doc="Density of CeO2 adsorbent",
    )
    self.particle_dia = Param(
        initialize=0.00075,
        units=units.m,
        doc="Particle diameter for CeO2 (assumed similar to other adsorbents)",
    )

    # Adsorption (Isotherm) parameters
    # Heat of adsorption (J/mol)
    self.dh_ads = Param(
        self.isotherm_components,
        initialize={"CO2": -35000, "N2": -15000},
        units=units.J/units.mol,
        doc="Heat of adsorption for CeO2",
    )
    self.temperature_ref = Param(
        initialize=298.15,
        units=units.K,
        doc="Reference temperature for CeO2 isotherm",
    )
    self.saturation_capacity_ref = Param(
        self.isotherm_components,
        initialize={"CO2": 0.132, "N2": 1e-10},  # For N2, uptake is negligible
        units=units.mol/units.kg,
        doc="Saturation capacity at reference temperature for CeO2",
    )
    # Placeholders for missing parameters (to be refined by fitting experimental data)
    self.saturation_capacity_exponential_factor = Param(
        self.isotherm_components,
        initialize={"CO2": 0.0, "N2": 0.0},
        units=units.dimensionless,
        doc="Saturation capacity exponential factor (placeholder)",
    )
    self.affinity_parameter_preexponential_factor = Param(
        self.isotherm_components,
        initialize={"CO2": 1e-4, "N2": 1e-6},
        units=units.bar**-1,
        doc="Affinity parameter pre-exponential factor (placeholder)",
    )
    self.affinity_parameter_characteristic_energy = Param(
        self.isotherm_components,
        initialize={"CO2": 30.0, "N2": 10.0},
        units=units.kJ/units.mol,
        doc="Affinity parameter characteristic energy (placeholder)",
    )
    self.heterogeneity_parameter_ref = Param(
        self.isotherm_components,
        initialize={"CO2": 1.0, "N2": 1.0},
        units=units.dimensionless,
        doc="Heterogeneity parameter at reference temperature (placeholder)",
    )
    self.heterogeneity_parameter_alpha = Param(
        self.isotherm_components,
        initialize={"CO2": 0.0, "N2": 0.0},
        units=units.dimensionless,
        doc="Heterogeneity parameter temperature dependence (placeholder)",
    )

# 3. In your build() method, include a branch for CeO2
def build(self):
    # ... (other build code)
    if self.config.adsorbent == Adsorbent.zeolite_13x:
        self._add_parameters_zeolite_13x()
    elif self.config.adsorbent == Adsorbent.mmen_mg_mof_74:
        self._add_parameters_mmen_Mg_MOF_74()
    elif self.config.adsorbent == Adsorbent.polystyrene_amine:
        self._add_parameters_polystyrene_amine()
    elif self.config.adsorbent == Adsorbent.CeO2:
        self._add_parameters_CeO2()
    # ... (rest of build code)

I have a few questions regarding the integration:

1. Jupyter Notebook Environment:
   I am running IDAES in a Jupyter Notebook. Could you please advise on the best approach to update or correct my code revisions within the IDAES environment? Do I need to restart the kernel or use a specific workflow to update the model code?

2. Assumed “Similar” Properties:
   For properties like the particle diameter, I assumed a value (0.00075 m) based on the range used for other adsorbents in my model. Is this a reasonable approach, or are there additional considerations I should be aware of when making these “similar” assumptions?

Thank you very much for your help. I look forward to your guidance!

Best regards,

[dallan-keylogic]

It looks like you provided only a function to create parameters. You also need to provide a function to generate the loading from those parameters here.

Every time you change the files in the IDAES repo, you need to reset the kernel. (If you haven't installed IDAES in editable mode, as described in the advanced user installation, you need to do so in order for Python to see any of your changes.)
I don't know much about TSA modeling, maybe @Daison2102 could give a better answer. Particle diameter should be available from the adsorbent manufacturer, though.

[Daison2102]

You are missing a method for the isotherm model, which is generally a function of partial pressure or concentration and temperature. After creating it, you need to add it into the loading method in the if statement.

Regarding the particle diameter, it depends on the type of adsorbent you are working with. For zeolites and MOFs, it is typically on the order of 10⁻³ m.