Beispiel #1
0
def test_kolmogorov_smirnov_d(model):
    # Test made by Yalin.
    import numpy as np
    import biosteam as bst
    from chaospy import distributions as shape

    bst.settings.set_thermo(['H2O', 'Ethanol'], cache=True)

    s1 = bst.Stream('s1', H2O=100)
    M1 = bst.MixTank(ins=s1)
    M2 = bst.MixTank(ins=M1 - 0)
    sys = bst.System('sys', path=(M1, M2))

    model = bst.Model(sys)

    baseline = 1
    distribution = shape.Uniform(lower=0.5, upper=1.5)

    @model.parameter(name='M1 tau',
                     element=M1,
                     kind='coupled',
                     distribution=distribution,
                     units='hr',
                     baseline=baseline)
    def set_M1_tau(i):
        M1.tau = i

    baseline = 1.75
    distribution = shape.Uniform(lower=1, upper=2)

    @model.parameter(name='M2 tau',
                     element=M2,
                     kind='coupled',
                     distribution=distribution,
                     units='hr',
                     baseline=baseline)
    def set_M2_tau(i):
        M2.tau = i

    model.metrics = [
        bst.Metric(name='tau1', getter=lambda: M1.tau, units='hr', element=M1),
        bst.Metric(name='tau2', getter=lambda: M2.tau, units='hr', element=M2),
    ]

    np.random.seed(3221)
    samples = model.sample(100, rule='L')
    model.load_samples(samples)
    model.evaluate()

    D, p = model.kolmogorov_smirnov_d(
        thresholds=[1, 1.5])  # Just make sure it works for now
def system():
    bst.main_flowsheet.clear()
    MockChemical = bst.Chemical('MockChemical', phase='l', search_db=False, default=True)
    bst.settings.set_thermo([MockChemical])
    with bst.System('MockSystem') as system:
        feed = bst.Stream('feed', MockChemical=1e6, units='kg/hr', price=0.150)
        product = bst.Stream('product', price=0.151)
        M1 = bst.MixTank('M1', feed, 's1')
        H1 = bst.HXutility('H1', M1-0, product, T=325, V=0.)
    system.simulate()
    return system
# IDnum_400 = bst.Stream.default_ID_number

# bst.Stream.default_ID_number = 700
T701 = bst.StorageTank('T701', ins=H403 - 0)
T701.line = 'Ethanol storage'
T701.tau = 7 * 24
P701 = bst.Pump('P701', ins=T701 - 0)

# Storage for gasoline
T702 = bst.StorageTank('T702', ins=denaturant)
T702.tau = 7 * 24
P702 = bst.Pump('P702', ins=T702 - 0)

# Mix in denaturant
ethanol = Stream('ethanol', price=price['Ethanol'])
M701 = bst.MixTank('M701', ins=(P702 - 0, P701 - 0), outs=ethanol)
M701.line = 'Mixer'
M701.tau = 0.05

gas_index = denaturant.index('Octane')


def adjust_denaturant():
    denaturant.mol[gas_index] = 0.022 * P701.outs[0].massnet / 114.232


P401.BM = P402.BM = P701.BM = P702.BM = 3.1
T701.BM = T702.BM = 1.7

vent_stream = M304 - 0
stripping_water_over_vent = stripping_water.mol / 21202.490455845436
Beispiel #4
0
def create_system(ID='cornstover_sys'):
    System.maxiter = 400
    System.converge_method = 'Aitken'
    System.molar_tolerance = 0.01

    ### Streams ###
    chemicals = bst.settings.get_chemicals()

    # feed flow
    dry_composition = chemicals.kwarray(
        dict(Glucan=0.3505,
             Xylan=0.1953,
             Lignin=0.1576,
             Ash=0.0493,
             Acetate=0.0181,
             Protein=0.0310,
             Extract=0.1465,
             Arabinan=0.0238,
             Galactan=0.0143,
             Mannan=0.0060,
             Sucrose=0.0077))
    moisture_content = chemicals.kwarray(dict(Water=0.20))
    netflow = 104167.0
    feedflow = netflow * (dry_composition * 0.8 + moisture_content)

    cornstover = Stream('cornstover',
                        feedflow,
                        units='kg/hr',
                        price=price['Feedstock'])
    warm_process_water = Stream('warm_process_water',
                                T=368.15,
                                P=4.7 * 101325,
                                Water=140000,
                                units='kg/hr')
    ammonia_process_water = Stream('ammonia_process_water',
                                   T=368.15,
                                   P=4.7 * 101325,
                                   Water=150310,
                                   units='kg/hr')
    rectifier_bottoms_product = Stream('',
                                       T=100 + 273.15,
                                       P=101325,
                                       Ethanol=18,
                                       Water=36629,
                                       Furfural=72,
                                       HMF=100,
                                       units='kg/hr')
    sulfuric_acid = Stream('sulfuric_acid',
                           P=5.4 * 101325,
                           T=294.15,
                           Water=139,
                           SulfuricAcid=1842,
                           units='kg/hr',
                           price=price['Sulfuric acid'])
    steam = Stream('steam',
                   phase='g',
                   T=268 + 273.15,
                   P=13 * 101325,
                   Water=24534 + 3490,
                   units='kg/hr')
    ammonia = Stream('ammonia',
                     Ammonia=1051,
                     units='kg/hr',
                     phase='l',
                     price=price['Ammonia'])
    cellulase = Stream('cellulase', units='kg/hr', price=price['Enzyme'])

    ### Pretreatment system

    U101 = units.FeedStockHandling('U101', cornstover)
    U101.cost_items['System'].cost = 0
    T201 = units.SulfuricAcidTank('T201', sulfuric_acid)
    M201 = units.SulfuricAcidMixer('M201',
                                   (rectifier_bottoms_product, T201 - 0))
    M202 = bst.Mixer('M202', (M201 - 0, warm_process_water, U101 - 0))
    M203 = units.SteamMixer('M203', (M202 - 0, steam), P=5.5 * 101325)
    R201 = units.PretreatmentReactorSystem('R201', M203 - 0)
    P201 = units.BlowdownDischargePump('P201', R201 - 1)
    T202 = units.OligomerConversionTank('T202', P201 - 0)
    F201 = units.PretreatmentFlash('F201', T202 - 0, P=101325, Q=0)
    M204 = bst.Mixer('M204', (R201 - 0, F201 - 0))
    H201 = units.WasteVaporCondenser('H201', M204 - 0, T=99 + 273.15, V=0)
    M210 = units.AmmoniaMixer('M210', (ammonia, ammonia_process_water))
    M205 = bst.Mixer('M205', (F201 - 1, M210 - 0))
    T203 = units.AmmoniaAdditionTank('T203', M205 - 0)
    P209 = units.HydrolyzatePump('P209', T203 - 0)
    H301 = units.HydrolysateCooler('H301', P209 - 0, T=48 + 273.15)
    M301 = units.EnzymeHydrolysateMixer('M301', (H301 - 0, cellulase))

    def update_pretreatment_process_water():
        warm_process_water.imass[
            'Water'] = 140000.0 * M202.ins[2].F_mass / 104175.33336

    sulfuric_acid_over_feed = sulfuric_acid.mol / cornstover.F_mass

    def update_sulfuric_acid_loading():
        # Also plant air
        F_mass_feed = cornstover.F_mass
        plant_air.mol[0] = 0.8 * F_mass_feed
        sulfuric_acid.mol[:] = sulfuric_acid_over_feed * F_mass_feed

    hydrolyzate = F201.outs[1]
    ammonia_over_hydrolyzate = ammonia.mol / 310026.22446428984

    def update_ammonia_loading():
        ammonia.mol[:] = ammonia_over_hydrolyzate * hydrolyzate.F_mass
        ammonia_process_water.imass[
            'Water'] = ammonia.imass['Ammonia'] * 150310 / 1051

    cooled_hydrolyzate = H301.outs[0]
    enzyme_over_cellulose = 20 / 1000 * 20  # (20 g enzyme / cellulose) / (50 g cellulase / 1 L enzyme)
    water_cellulase_mass = cellulase.imass['Water', 'Cellulase']
    water_cellulase_to_cellulase = np.array([0.95, 0.05])

    def update_cellulase_and_nutrient_loading():
        F_mass_cooled_hydrolyzate = cooled_hydrolyzate.F_mass
        cellulose = cornstover.imass['Glucan']
        # Note: An additional 10% is produced for the media glucose/sophorose mixture
        # Humbird (2011) pg. 37
        water_cellulase_mass[:] = (enzyme_over_cellulose *
                                   water_cellulase_to_cellulase * cellulose *
                                   1.1)
        DAP1.mol[:] = DAP1_over_hydrolyzate * F_mass_cooled_hydrolyzate
        DAP2.mol[:] = DAP2_over_hydrolyzate * F_mass_cooled_hydrolyzate
        CSL1.mol[:] = CSL1_over_hydrolyzate * F_mass_cooled_hydrolyzate
        CSL2.mol[:] = CSL2_over_hydrolyzate * F_mass_cooled_hydrolyzate

    pretreatment_sys = System('pretreatment_sys',
                              path=(U101, T201, M201,
                                    update_pretreatment_process_water, M202,
                                    M203, R201, P201, T202, F201, M204, H201,
                                    M210, M205, T203, P209, T203, H301, M301))

    ### Fermentation system ###

    DAP1 = Stream('DAP1', DAP=26, units='kg/hr', price=price['DAP'])
    DAP2 = Stream('DAP2', DAP=116, units='kg/hr', price=price['DAP'])
    DAP_storage = units.DAPTank('DAP_storage', Stream('DAP_fresh'), outs='DAP')

    S301 = bst.ReversedSplitter('S301', DAP_storage - 0, outs=(DAP1, DAP2))
    CSL1 = Stream('CSL1', CSL=211, units='kg/hr', price=price['CSL'])
    CSL2 = Stream('CSL2', CSL=948, units='kg/hr', price=price['CSL'])
    CSL_storage = units.CSLTank('CSL_storage', Stream('CSL_fresh'), outs='CSL')

    S302 = bst.ReversedSplitter('S302', CSL_storage - 0, outs=(CSL1, CSL2))
    denaturant = Stream('denaturant',
                        Octane=230.69,
                        units='kg/hr',
                        price=price['Denaturant'])
    stripping_water = Stream('stripping_water', Water=26836, units='kg/hr')
    DAP1_over_hydrolyzate = DAP1.mol / 451077.22446428984
    DAP2_over_hydrolyzate = DAP2.mol / 451077.22446428984
    CSL1_over_hydrolyzate = CSL1.mol / 451077.22446428984
    CSL2_over_hydrolyzate = CSL2.mol / 451077.22446428984

    M302 = bst.Mixer('M302', (M301 - 0, None))
    R301 = units.SaccharificationAndCoFermentation('R301',
                                                   (M302 - 0, CSL2, DAP2))
    M303 = bst.Mixer('M303', (R301 - 2, CSL1, DAP1))
    R302 = units.SeedTrain('R302', M303 - 0)
    T301 = units.SeedHoldTank('T301', R302 - 1)
    T301 - 0 - 1 - M302

    fermentation_sys = System('fermentation_sys',
                              path=(update_cellulase_and_nutrient_loading,
                                    M302, R301, M303, R302, T301),
                              recycle=M302 - 0)

    ### Ethanol purification ###

    M304 = bst.Mixer('M304', (R302 - 0, R301 - 0))
    T302 = units.BeerTank('T302')

    M401 = bst.Mixer('M401', (R301 - 1, None))
    M401 - 0 - T302

    D401 = bst.VentScrubber('D401', (stripping_water, M304 - 0),
                            gas=('CO2', 'NH3', 'O2'))
    D401 - 1 - 1 - M401

    # Heat up before beer column
    # Exchange heat with stillage
    H401 = bst.HXprocess('H401', (T302 - 0, None),
                         phase0='l',
                         phase1='l',
                         U=1.28)

    Ethanol_MW = chemicals.Ethanol.MW
    Water_MW = chemicals.Water.MW

    def Ethanol_molfrac(e):
        """Return ethanol mol fraction in a ethanol water mixture"""
        return e / Ethanol_MW / (e / Ethanol_MW + (1 - e) / Water_MW)

    # Beer column
    xbot = Ethanol_molfrac(0.00001)
    ytop = Ethanol_molfrac(0.50)
    D402 = bst.BinaryDistillation('D402',
                                  H401 - 0,
                                  k=1.25,
                                  Rmin=0.3,
                                  P=101325,
                                  y_top=ytop,
                                  x_bot=xbot,
                                  LHK=('Ethanol', 'Water'))
    D402.tray_material = 'Stainless steel 304'
    D402.vessel_material = 'Stainless steel 304'
    D402.boiler.U = 1.85
    P401 = bst.Pump('P401', D402 - 1)
    P401 - 0 - 1 - H401

    # Mix ethanol Recycle (Set-up)
    M402 = bst.Mixer('M402', (D402 - 0, None))

    ytop = Ethanol_molfrac(0.915)
    D403 = bst.BinaryDistillation('D403',
                                  M402 - 0,
                                  Rmin=0.3,
                                  P=101325,
                                  y_top=ytop,
                                  x_bot=xbot,
                                  k=1.25,
                                  LHK=('Ethanol', 'Water'))
    D403.tray_material = 'Stainless steel 304'
    D403.vessel_material = 'Stainless steel 304'
    D403.is_divided = True
    D403.boiler.U = 1.85
    P402 = bst.Pump('P402', D403 - 1)

    P402 - 0 - 0 - M201

    # Superheat vapor for mol sieve
    H402 = bst.HXutility('H402', D403 - 0, T=115 + 273.15, V=1)

    # Molecular sieve
    U401 = bst.MolecularSieve('U401',
                              H402 - 0,
                              split=(2165.14 / 13356.04, 1280.06 / 1383.85),
                              order=('Ethanol', 'Water'))

    U401 - 0 - 1 - M402

    ethanol_recycle_sys = System('ethanol_recycle_sys',
                                 path=(M402, D403, H402, U401),
                                 recycle=M402 - 0)

    # Condense ethanol product
    H403 = bst.HXutility('H403', U401 - 1, V=0, T=350.)

    T701 = bst.StorageTank('T701',
                           H403 - 0,
                           tau=7 * 24,
                           vessel_type='Floating roof',
                           vessel_material='Carbon steel')
    P701 = bst.Pump('P701', T701 - 0)

    # Storage for gasoline
    T702 = bst.StorageTank('T702',
                           denaturant,
                           tau=7 * 24,
                           vessel_type='Floating roof',
                           vessel_material='Carbon steel')
    P702 = bst.Pump('P702', T702 - 0)

    # Mix in denaturant
    ethanol = Stream('ethanol', price=price['Ethanol'])
    M701 = bst.MixTank('M701', (P702 - 0, P701 - 0), outs=ethanol)
    M701.line = 'Mixer'
    M701.tau = 0.05

    def adjust_denaturant():
        denaturant.imol['Octane'] = 0.022 * P701.outs[0].F_mass / 114.232

    P401.BM = P402.BM = P701.BM = P702.BM = 3.1
    T701.BM = T702.BM = 1.7

    vent_stream = M304 - 0
    stripping_water_over_vent = stripping_water.mol / 21202.490455845436

    def update_stripping_water():
        stripping_water.mol[:] = stripping_water_over_vent * vent_stream.F_mass

    puresys = System('purification',
                     path=(M304, update_stripping_water, D401, M401, T302,
                           H401, D402, H401, P401, H401, ethanol_recycle_sys,
                           P402, H403, T701, P701, adjust_denaturant, T702,
                           P702, M701))

    ### Lignin Separation
    recycled_water = tmo.Stream(Water=1,
                                T=47 + 273.15,
                                P=3.9 * 101325,
                                units='kg/hr')

    splits = [('Glucose', 19, 502), ('Xylose', 40, 1022),
              ('OtherSugars', 81, 2175), ('SugarOligomers', 60, 1552),
              ('OrganicSolubleSolids', 612, 15808),
              ('InorganicSolubleSolids', 97, 2513), ('Furfurals', 19, 513),
              ('OtherOrganics', 52, 1348), ('Glucan', 1230, 25),
              ('Xylan', 415, 8), ('OtherStructuralCarbohydrates', 94, 2),
              ('Lignin', 12226, 250), ('Protein', 3376, 69),
              ('CellMass', 925, 19), ('OtherInsolubleSolids', 4489, 92)]

    S401 = units.PressureFilter('S401', ('', recycled_water),
                                moisture_content=0.35,
                                split=find_split(*zip(*splits)))
    H401 - 1 - 0 - S401

    ### Waste water treatment ###

    combustion = chemicals.get_combustion_reactions()

    def growth(reactant):
        f = chemicals.WWTsludge.MW / getattr(chemicals, reactant).MW
        return rxn.Reaction(f"{f}{reactant} -> WWTsludge", reactant, 1.)

    organic_groups = [
        'OtherSugars', 'SugarOligomers', 'OrganicSolubleSolids', 'Furfurals',
        'OtherOrganics', 'Protein', 'CellMass'
    ]
    organics = list(
        sum([chemical_groups[i] for i in organic_groups],
            ('Ethanol', 'AceticAcid', 'Xylose', 'Glucose')))
    organics.remove('WWTsludge')

    P_sludge = 0.05 / 0.91 / chemicals.WWTsludge.MW
    MW = np.array([chemicals.CH4.MW, chemicals.CO2.MW])
    mass = np.array([0.51, 0.49]) * MW
    mass /= mass.sum()
    mass *= 0.86 / (0.91)
    P_ch4, P_co2 = mass / MW

    def anaerobic_rxn(reactant):
        MW = getattr(chemicals, reactant).MW
        return rxn.Reaction(
            f"{1/MW}{reactant} -> {P_ch4}CH4 + {P_co2}CO2 + {P_sludge}WWTsludge",
            reactant, 0.91)

    # TODO: Revise this with Jeremy
    anaerobic_digestion = rxn.ParallelReaction(
        [anaerobic_rxn(i) for i in organics] +
        [rxn.Reaction("H2SO4 -> H2S + 2O2", 'H2SO4', 1.)])

    # Note, nitogenous species included here, but most of it removed in R601 digester
    # TODO: Add ammonium to reaction, make sure it can be a liquid, possibly add Henry's constant
    aerobic_digestion = rxn.ParallelReaction([
        i * 0.74 + 0.22 * growth(i.reactant) for i in combustion
        if (i.reactant in organics)
    ])
    aerobic_digestion.X[:] = 0.96

    splits = [('Ethanol', 1, 15), ('Water', 27158, 356069), ('Glucose', 3, 42),
              ('Xylose', 7, 85), ('OtherSugars', 13, 175),
              ('SugarOligomers', 10, 130), ('OrganicSolubleSolids', 182, 2387),
              ('InorganicSolubleSolids', 8, 110), ('Ammonia', 48, 633),
              ('AceticAcid', 0, 5), ('Furfurals', 5, 70),
              ('OtherOrganics', 9, 113), ('Cellulose', 19, 6), ('Xylan', 6, 2),
              ('OtherStructuralCarbohydrates', 1, 0), ('Lignin', 186, 64),
              ('Protein', 51, 18), ('CellMass', 813, 280),
              ('OtherInsolubleSolids', 68, 23)]

    well_water = Stream('well_water', Water=1, T=15 + 273.15)
    M601 = bst.Mixer('M601', (S401 - 1, '', ''))
    H201 - 0 - 1 - M601

    WWTC = units.WasteWaterSystemCost('WWTC', M601 - 0)
    R601 = units.AnaerobicDigestion('R601', (WWTC - 0, well_water),
                                    reactions=anaerobic_digestion,
                                    sludge_split=find_split(*zip(*splits)))

    air = Stream('air_lagoon', O2=51061, N2=168162, phase='g', units='kg/hr')
    caustic = Stream('WWT_caustic',
                     Water=2252,
                     NaOH=2252,
                     units='kg/hr',
                     price=price['Caustic'] * 0.5)
    # polymer = Stream('WWT polymer') # Empty in humbird report :-/

    M602 = bst.Mixer('M602', (R601 - 1, None))

    caustic_over_waste = caustic.mol / 2544300.6261793654
    air_over_waste = air.mol / 2544300.6261793654
    waste = M602 - 0

    def update_aerobic_input_streams():
        F_mass_waste = waste.F_mass
        caustic.mol[:] = F_mass_waste * caustic_over_waste
        air.mol[:] = F_mass_waste * air_over_waste

    R602 = units.AerobicDigestion('R602', (waste, air, caustic),
                                  outs=('evaporated_water', ''),
                                  reactions=aerobic_digestion)

    splits = [('Ethanol', 0, 1), ('Water', 381300, 2241169), ('Glucose', 0, 2),
              ('Xylose', 1, 3), ('OtherSugars', 1, 7),
              ('SugarOligomers', 1, 6), ('OrganicSolubleSolids', 79, 466),
              ('InorganicSolubleSolids', 4828, 28378), ('Ammonia', 3, 16),
              ('Furfurals', 0, 3), ('OtherOrganics', 1, 7),
              ('CarbonDioxide', 6, 38), ('O2', 3, 17), ('N2', 5, 32),
              ('Cellulose', 0, 194), ('Xylan', 0, 65),
              ('OtherStructuralCarbohydrates', 0, 15), ('Lignin', 0, 1925),
              ('Protein', 0, 90), ('CellMass', 0, 19778),
              ('OtherInsolubleSolids', 0, 707)]

    S601 = bst.Splitter('S601', R602 - 1, split=find_split(*zip(*splits)))

    S602 = bst.Splitter('S602', S601 - 1, split=0.96)

    M603 = bst.Mixer('M603', (S602 - 0, None))
    M603 - 0 - 1 - M602

    M604 = bst.Mixer('M604', (R601 - 2, S602 - 1))

    centrifuge_species = ('Water', 'Glucose', 'Xylose', 'OtherSugars',
                          'SugarOligomers', 'OrganicSolubleSolids',
                          'InorganicSolubleSolids', 'Ammonia', 'Furfurals',
                          'OtherOrganics', 'CO2', 'COxSOxNOxH2S', 'Cellulose',
                          'Xylan', 'OtherStructuralCarbohydrates', 'Lignin',
                          'Protein', 'CellMass', 'OtherInsolubleSolids')
    S623_flow = np.array(
        [7708, 0, 0, 1, 1, 13, 75, 3, 0, 1, 1, 2, 25, 8, 2, 250, 52, 1523, 92])
    S616_flow = np.array([
        109098, 3, 6, 13, 9, 187, 1068, 46, 5, 8, 14, 31, 1, 0, 0, 13, 3, 80, 5
    ])

    S603 = bst.Splitter('S603',
                        M604 - 0,
                        outs=('', 'sludge'),
                        split=find_split(centrifuge_species, S616_flow,
                                         S623_flow))
    S603 - 0 - 1 - M603

    S604 = bst.Splitter('S604',
                        S601 - 0,
                        outs=('treated_water', 'waste_brine'),
                        split={'Water': 0.987})

    aerobic_digestion_sys = System('aerobic_digestion_sys',
                                   path=(M602, update_aerobic_input_streams,
                                         R602, S601, S602, M604, S603, M603),
                                   recycle=M602 - 0)

    ### Facilities

    M501 = bst.Mixer('M501', (S603 - 1, S401 - 0))
    BT = bst.facilities.BoilerTurbogenerator(
        'BT',
        ins=(M501 - 0, R601 - 0, 'boiler_makeup_water', 'natural_gas', 'lime',
             'boilerchems'),
        turbogenerator_efficiency=0.85)

    CWP = bst.facilities.ChilledWaterPackage('CWP')
    CT = bst.facilities.CoolingTower('CT')
    CT.outs[1].T = 273.15 + 28

    process_water_streams = (caustic, stripping_water, warm_process_water,
                             steam, BT - 1, CT - 1)

    makeup_water = Stream('makeup_water', price=price['Makeup water'])

    PWC = bst.facilities.ProcessWaterCenter('PWC', (S604 - 0, makeup_water),
                                            (), None, (BT - 1, CT - 1),
                                            process_water_streams)
    blowdown_mixer = bst.BlowdownMixer('blowdown_mixer', (BT - 1, CT - 1),
                                       2**M601)

    CIP = Stream('CIP', Water=126, units='kg/hr')
    CIP_package = units.CIPpackage('CIP_package', CIP)
    plant_air = Stream('plant_air', N2=83333, units='kg/hr')
    ADP = bst.facilities.AirDistributionPackage('ADP', plant_air)
    fire_water = Stream('fire_water', Water=8343, units='kg/hr')
    FT = units.FireWaterTank('FT', fire_water)

    ### Complete system

    cornstover_sys = System(ID,
                            path=(pretreatment_sys, fermentation_sys, puresys,
                                  S401, M601, WWTC, R601,
                                  aerobic_digestion_sys, S604),
                            facilities=(M501, CWP, BT, CT, PWC, ADP,
                                        CIP_package, S301, S302, DAP_storage,
                                        CSL_storage, FT, blowdown_mixer),
                            facility_recycle=blowdown_mixer - 0)

    return cornstover_sys