Biological

Biological Process Components

Components for biological conversion processes in biogas plants.

Modules:

digester: Main fermenter component implementing ADM1 model for anaerobic digestion,
         supporting single or multiple fermenters in series/parallel, with flexible
         volume, temperature, and retention time configuration.

hydrolysis: Pre-treatment tank for hydrolysis-dominated processes, useful for
           substrates with high lignocellulosic content, can operate at different
           temperatures and retention times than main digester.

separator: Solid-liquid separation component for digestate processing, models
          mechanical (screw press, centrifuge) or gravitational separation with
          configurable separation efficiency and dry matter content.

Example:

    >>> from pyadm1.components.biological import Digester, Hydrolysis, Separator
    >>> from pyadm1.substrates import Feedstock
    >>>
    >>> feedstock = Feedstock(feeding_freq=48)
    >>>
    >>> # Two-stage digestion with hydrolysis pre-treatment
    >>> hydrolysis = Hydrolysis("hydro1", feedstock, V_liq=500, T_ad=318.15)
    >>> digester = Digester("dig1", feedstock, V_liq=2000, T_ad=308.15)
    >>> separator = Separator("sep1", separation_efficiency=0.95)

Classes

• Digester
• Hydrolysis
• Separator

Digester

from pyadm1.components.biological import Digester

Digester component using ADM1 model.

This component wraps the ADM1 implementation and can be connected to other digesters or components in series/parallel.

Attributes:

feedstock (Feedstock): Feedstock object for substrate management.
V_liq (float): Liquid volume in m³.
V_gas (float): Gas volume in m³.
T_ad (float): Operating temperature in K.
adm1 (ADM1): ADM1 model instance.
simulator (Simulator): Simulator for ADM1.
adm1_state (List[float]): Current ADM1 state vector (37 dimensions).
Q_substrates (List[float]): Substrate feed rates in m³/d.

Example:

    >>> feedstock = Feedstock(feeding_freq=48)
    >>> digester = Digester("dig1", feedstock, V_liq=2000, V_gas=300)
    >>> digester.initialize({"adm1_state": initial_state, "Q_substrates": [15, 10, 0, 0, 0, 0, 0, 0, 0, 0]})

Signature:

Digester(
    component_id,
    feedstock,
    V_liq=1977.0,
    V_gas=304.0,
    T_ad=308.15,
    name=None
)

Methods:

add_input()

add_input(component_id)

Add an input connection.

add_output()

add_output(component_id)

Add an output connection.

apply_calibration_parameters()

apply_calibration_parameters(parameters)

Apply calibration parameters to this digester.

Stores parameters for use during simulation. These override the substrate-dependent parameters calculated from feedstock.

Args:

parameters: Parameter values as {param_name: value}.

Example:

    >>> digester.apply_calibration_parameters({
    ...     'k_dis': 0.55,
    ...     'Y_su': 0.105,
    ...     'k_hyd_ch': 11.0
    ... })

clear_calibration_parameters()

clear_calibration_parameters()

Clear all calibration parameters and revert to default substrate-dependent values.

Example:

    >>> digester.clear_calibration_parameters()

get_calibration_parameters()

get_calibration_parameters()

Get currently applied calibration parameters.

Returns:

dict: Current calibration parameters as {param_name: value}.

Example:

    >>> params = digester.get_calibration_parameters()
    >>> print(params)
    {'k_dis': 0.55, 'Y_su': 0.105}

get_state()

get_state()

Get current component state.

initialize()

initialize(initial_state=None)

Initialize digester state.

Args:

initial_state (Optional[Dict[str, Any]]): Initial state with keys:
    - 'adm1_state': ADM1 state vector (37 dims)
    - 'Q_substrates': Substrate feed rates
    If None, uses default initialization.

set_state()

set_state(state)

Set component state.

step()

step(t, dt, inputs)

Perform one simulation time step.

Args:

t (float): Current time in days.
dt (float): Time step in days.
inputs (Dict[str, Any]): Input data with keys:
    - 'Q_substrates': Fresh substrate feed rates [m³/d]
    - 'Q_in': Influent from previous digester [m³/d]
    - 'state_in': ADM1 state from previous digester (if connected)

Returns:

Dict[str, Any]: Output data with keys:
    - 'Q_out': Effluent flow rate [m³/d]
    - 'state_out': ADM1 state vector for next digester
    - 'Q_gas': Biogas production [m³/d]
    - 'Q_ch4': Methane production [m³/d]
    - 'Q_co2': CO2 production [m³/d]
    - 'pH': pH value
    - 'VFA': VFA concentration [g/L]
    - 'TAC': TAC concentration [g CaCO3/L]

to_dict()

to_dict()

Serialize to dictionary.

Returns:

Dict[str, Any]: Component configuration as dictionary.

Attributes:

• feedstock (Feedstock): Feedstock object for substrate management.
• V_liq (float): Liquid volume in m³.
• V_gas (float): Gas volume in m³.
• T_ad (float): Operating temperature in K.
• adm1 (ADM1): ADM1 model instance.
• simulator (Simulator): Simulator for ADM1.
• adm1_state (List[float]): Current ADM1 state vector (37 dimensions).
• Q_substrates (List[float]): Substrate feed rates in m³/d.

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Hydrolysis

from pyadm1.components.biological import Hydrolysis

Hydrolysis tank component (stub for future implementation).

Signature:

Hydrolysis(
    component_id,
    feedstock,
    V_liq=500.0,
    T_ad=318.15,
    name=None
)

Methods:

add_input()

add_input(component_id)

Add an input connection.

add_output()

add_output(component_id)

Add an output connection.

get_state()

get_state()

Get current component state.

initialize()

initialize(initial_state=None)

set_state()

set_state(state)

Set component state.

step()

step(t, dt, inputs)

to_dict()

to_dict()

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Separator

from pyadm1.components.biological import Separator

Separator component (stub for future implementation).

Signature:

Separator(
    component_id,
    separation_efficiency=0.95,
    name=None
)

Methods:

add_input()

add_input(component_id)

Add an input connection.

add_output()

add_output(component_id)

Add an output connection.

get_state()

get_state()

Get current component state.

initialize()

initialize(initial_state=None)

set_state()

set_state(state)

Set component state.

step()

step(t, dt, inputs)

to_dict()

to_dict()

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