# -*- coding: utf-8 -*-
# Bioindustrial-Park: BioSTEAM's Premier Biorefinery Models and Results
# Copyright (C) 2021-2024, Yalin Li <mailto.yalin.li@gmail.com>
#
# This module is under the UIUC open-source license. See
# github.com/BioSTEAMDevelopmentGroup/biosteam/blob/master/LICENSE.txt
# for license details.
__all__ = (
'create_high_rate_wastewater_treatment_system',
)
import thermosteam as tmo, biosteam as bst
cost = bst.decorators.cost
CEPCI = bst.design_tools.CEPCI_by_year
from . import (
append_wwt_chemicals, default_insolubles,
InternalCirculationRx, AnMBR, PolishingFilter, BeltThickener, SludgeCentrifuge,
get_combustion_energy, prices, GWP_CFs,
)
_mgd_to_cmh = 157.7255 # auom('gallon').conversion_factor('m3')*1e6/24
_gpm_to_cmh = 0.2271 # auom('gallon').conversion_factor('m3')*60
_Gcal_to_kJ = 4184000 # auom('kcal').conversion_factor('kJ')*1e6 # (also MMkcal/hr)
_kW_to_kJhr = 3600 # auom('kW').conversion_factor('kJ/hr')
Rxn = tmo.reaction.Reaction
ParallelRxn = tmo.reaction.ParallelReaction
__all__ = (
'BiogasUpgrading',
'create_high_rate_wastewater_treatment_system',
'CHP',
'ReverseOsmosis',
'Skipped',
)
[docs]
@cost(basis='Volumetric flow', ID='Reactor', units='m3/hr',
# 2.7 in million gallons per day (MGD)
cost=2450000, S=2.7*_mgd_to_cmh, CE=CEPCI[2012], n=1, BM=1.8)
@cost(basis='Volumetric flow', ID='Evaporator', units='m3/hr',
# 2.7 in million gallons per day (MGD)
kW=1103.636, cost=5000000, S=2.7*_mgd_to_cmh, CE=CEPCI[2012], n=0.6, BM=1.6)
class ReverseOsmosis(bst.Unit):
_N_ins = 1
_N_outs = 2
_units = {'Volumetric flow': 'm3/hr'}
@property
def RO_treated_water(self):
return self.outs[0]
@property
def brine(self):
return self.outs[1]
def _run(self):
influent = self.ins[0]
water, brine = self.outs
self.design_results['Volumetric flow'] = self.F_vol_in
# Based on stream 626 and 627 in ref [1]
water.imass['Water'] = 376324/(376324+4967) * influent.imass['Water']
brine.mol = influent.mol - water.mol
water.T = brine.T = influent.T
[docs]
class Skipped(bst.Unit):
"""
Copy ins[`main_in`] as ins[`main_out`].
Can be also used to calculate the cost of wastewater treatment
by clearing all WWT-related units and streams.
Parameters
----------
main_in : int
Which influent will be copied to `main_out`.
main_out : int
Which effluent will be copied from `main_in`.
wwt_units : Iterable
Collection of units whose costs will be cleared when `clear_wwt` is True.
ins and outs of the units will be emptied if its price isn't 0.
wwt_streams : Iterable
Collection of streams which will be emptied when `clear_wwt` is True.
Usually should at least includes the biogas and sludge stream.
clear_wwt : bool
Whether to clear the costs of and select streams associated with
`wwt_units`.
"""
_ins_size_is_fixed = False
_outs_size_is_fixed = False
cache_dct = {} # to save some computation effort
def _init(self, main_in=0, main_out=0, wwt_units=[], wwt_streams=[],
clear_wwt=False):
self.main_in = main_in
self.main_out = main_out
self.wwt_units = wwt_units
self.wwt_streams = wwt_streams
self.clear_wwt = clear_wwt
def _run(self):
self.outs[self.main_out].copy_like(self.ins[self.main_in])
def _cost(self):
if not self.clear_wwt: return
for u in self.wwt_units:
u.baseline_purchase_costs.clear()
u.installed_costs.clear()
for hu in u.heat_utilities: hu.empty()
u.power_utility(0)
for s in u.ins+u.outs:
if s.price: s.empty()
u._utility_cost = 0.
for s in self.wwt_streams: s.empty()
@property
def utility_cost(self): return 0.
[docs]
class CHP(bst.Unit):
"""
Used to estimate the cost of producing electricity as in [6]_.
Parameters
----------
eff : float
Combined efficiency for combustion and power generation.
unit_CAPEX : float
Capital cost of the CHP per kW of power generated, $/kW.
"""
_ins_size_is_fixed = False
_F_BM_default = {'CHP': 1.}
def _init(self,
eff=0.3375, # average of 40.5%, 27%, 36%, and 31.5% for the four types in ref [1]
unit_CAPEX=1225):
self.eff = eff
self.unit_CAPEX = unit_CAPEX
def _run(self):
mixed, = self.outs
mixed.mix_from(self.ins)
H_net = get_combustion_energy(mixed, 1)
self.H_for_power = H_net * self.eff
def _design(self):
kW = self.H_for_power / 3600 # kJ/hr to kW
self.baseline_purchase_costs['CHP'] = kW*self.unit_CAPEX
self.power_utility(-kW)
[docs]
class BiogasUpgrading(bst.Unit):
"""
Upgrade the biogas to renewable natural gas (RNG).
Note that the second influent is a dummy stream to calculate the upgrading cost.
Parameters
----------
ratio : float
How much of the incoming biogas will be upgraded to RNG.
loss : float
CH4 loss during upgrading.
unit_upgrading_cost : float
Unit cost for upgrading, in $/MMBtu.
unit_upgrading_GWP : float
Unit 100-yr global warming potential (GWP) for biogas upgrading, in kg CO2/MMBtu.
References
----------
Yang et al., Cost and Life-Cycle Greenhouse Gas Implications of
Integrating Biogas Upgrading and Carbon Capture Technologies in Cellulosic Biorefineries.
Environ. Sci. Technol. 2020.
https://doi.org/10.1021/acs.est.0c02816.
IEA. Outlook for Biogas and Biomethane: Prospects for Organic Growth; IEA: Paris, 2020.
https://www.iea.org/reports/outlook-for-biogas-and-biomethane-prospects-for-organic-growth
Rai et al., Comparative Life Cycle Evaluation of the Global Warming Potential (GWP)
Impacts of Renewable Natural Gas Production Pathways. Environ. Sci. Technol. 2022.
https://doi.org/10.1021/acs.est.2c00093.
"""
# Default upgrading cost is calculated by
# 0.18*0.914/35.3147*1055.056
# where $0.18/NM is from ref 1,
# 0.914 ft3/MJ is from U.S. EIA https://www.eia.gov/energyexplained/units-and-calculators/energy-conversion-calculators.php#natgascalc
# 35.3147 ft3/m3 is auom('m3').conversion_factor('ft3')
# 1055.056 MJ/MMBtu is auom('MMBtu').conversion_factor('MJ')
# This cost is close to the general range of $2-4 for a
# 3.5 million m3/yr biogas plant in ref 2.
# Default upgrading GWP is from calculated by
# 8.67/1e3*1055.056
# where 8.67 g CO2/MJ is the average of upgrading GWP (5, 8, 13)
# from Section S5 of ref 3
_N_ins = 2
_N_outs = 2
def _init(self,
ratio=0, loss=0.05,
unit_upgrading_cost=4.92,
unit_upgrading_GWP=9.15):
self.ratio = ratio
self.loss = loss
self.unit_upgrading_cost = unit_upgrading_cost
self.unit_upgrading_GWP = unit_upgrading_GWP
self.RIN_incentive = prices['RIN']
# Credits from the displaced fossil natural gas
self.FNG_price = bst.stream_prices.get('Natural gas', 0) # $/kg
self.FNG_CF = GWP_CFs['CH4']
def _run(self):
biogas, foo = self.ins
RNG, remained = self.outs
RNG.empty()
RNG.phase = remained.phase = 'g'
RNG.imass['CH4'] = biogas.imass['CH4'] * self.ratio
remained.mass = biogas.mass - RNG.mass # assume impurities left in the unused biogas
RNG.mass *= (1 - self.loss) # lost methane not included in the unused biogas
RNG.price = self.FNG_price + self.RIN_incentive
RNG.characterization_factors['GWP'] = self.FNG_CF
foo.copy_like(RNG)
# Upgrading cost/GWP
if not foo.isempty():
foo.price = self.unit_upgrading_cost/1055.056*(foo.HHV/1e3)/foo.F_mass # HHV in kJ/hr
foo.characterization_factors['GWP'] = self.unit_upgrading_GWP/1055.056*(foo.HHV/1e3)/foo.F_mass
# %%
# =============================================================================
# System function
# =============================================================================
@bst.SystemFactory(
ID='wastewater_sys',
outs=[dict(ID='RNG'), # renewable natural gas
dict(ID='biogas'),
dict(ID='sludge'),
dict(ID='RO_treated_water'),
dict(ID='brine')],
fixed_ins_size=False,
fthermo=append_wwt_chemicals,
)
def create_high_rate_wastewater_treatment_system(
ins=None, outs=None, process_ID='6',
flowsheet=None, autopopulate=False,
skip_IC=False, IC_kwargs={},
skip_AnMBR=False, AnMBR_kwargs={},
skip_AeF=False, AeF_kwargs={}
):
"""
Return a system for wastewater treatment (WWT) as described in Li et al. [1]_
The system includes internal circulation (IC), anaerobic membrane bioreactors (AnMBR),
aerobic polishing filter (AeF),
belt thickener and sludge centrifuge, and a reverse osmosis unit.
Users can choose whether to skip IC
(makes sense when influent COD is only on the order of grams per liter),
AnMBR (not recommended unless the COD is very low),
and/or AeF (not recommended if want to achieve low COD in the effluent).
An optional biogas upgrading unit can be included to upgrade the biogas
(from IC and AnMBR) as renewable natural gas (RNG) for sale with incentives,
this is achieved through adjusting `BiogasUpgrading.ratio`.
Parameters
----------
ins :
Wastewater streams (without solids). Defaults to all product streams
at run time that are not sold and cannot generate energy through combustion
(i.e. streams that have no sink, no price, and a LHV less that 1 kJ / g).
outs :
* [0] RNG
* [1] biogas
* [2] sludge
* [3] RO_treated_water
* [4] brine
process_ID : float
Number of the process.
E.g., the default `process_ID` is 6,
then the first mixer of this WWT system will be M601.
flowsheet : Flowsheet, optional
If provided, the WWT system will be added to the given flowsheet.
autopopulate : bool, optional
Whether to automatically add wastewater streams.
skip_IC : bool
Whether to skip the IC unit.
IC_kwargs : dict
kwargs to be passed to the IC unit (refer to the doc of the IC unit for details).
skip_AnMBR : bool
Whether to skip the AnMBR unit.
AnMBR_kwargs : dict
kwargs to be passed to the AnMBR unit (refer to the doc of the AnMBR unit for details).
skip_AeF : bool
Whether to skip the AeF unit.
AeF_kwargs : dict
kwargs to be passed to the AeF unit (refer to the doc of the AeF unit for details).
Examples
--------
Check for PolishingFilter vent accumulation
>>> from biosteam import Stream, create_high_rate_wastewater_treatment_system, settings
>>> from biorefineries import cornstover as cs
>>> settings.set_thermo(cs.create_chemicals())
>>> feed = Stream(
... ID='wastewater',
... Water=2.634e+04,
... Ethanol=0.07225,
... AceticAcid=24.67,
... Furfural=6.206,
... Glycerol=1.784,
... LacticAcid=17.7,
... SuccinicAcid=3.472,
... DAP=1.001,
... AmmoniumSulfate=17.63,
... HMF=2.366,
... Glucose=2.816,
... Xylose=6.953,
... Arabinose=12.78,
... Extract=65.98,
... Ash=83.52,
... Lignin=1.659,
... SolubleLignin=4.202,
... GlucoseOligomer=6.796,
... GalactoseOligomer=0.01718,
... MannoseOligomer=0.009008,
... XyloseOligomer=2.878,
... ArabinoseOligomer=0.3508,
... Z_mobilis=0.6668,
... Protein=2.569,
... Glucan=0.1555,
... Xylan=0.06121,
... Xylitol=4.88,
... Cellobiose=0.9419,
... Arabinan=0.02242,
... Mannan=0.06448,
... Galactan=0.01504,
... Cellulase=25.4,
... units='kmol/hr'
... )
>>> wwt_sys = create_high_rate_wastewater_treatment_system(ins=feed)
>>> wwt_sys.simulate()
>>> wwt_sys.show('cwt100')
System: wastewater_sys
Highest convergence error among components in recycle
stream M603-0 after 6 loops:
- flow rate 1.57e+01 kmol/hr (0.066%)
- temperature 1.19e-03 K (0.00039%)
ins...
[0] wastewater
phase: 'l', T: 298.15 K, P: 101325 Pa
composition (%): Water 94.7
Ethanol 0.000664
AceticAcid 0.296
Furfural 0.119
Glycerol 0.0328
LacticAcid 0.318
SuccinicAcid 0.0818
DAP 0.0264
AmmoniumSulfate 0.465
HMF 0.0595
Glucose 0.101
Xylose 0.208
Arabinose 0.383
Extract 2.37
Ash 0.0167
Lignin 0.0504
SolubleLignin 0.128
GlucoseOligomer 0.22
GalactoseOligomer 0.000556
MannoseOligomer 0.000291
XyloseOligomer 0.0759
ArabinoseOligomer 0.00925
Z_mobilis 0.00328
Protein 0.0117
Glucan 0.00503
Xylan 0.00161
Xylitol 0.148
Cellobiose 0.0643
Arabinan 0.000591
Mannan 0.00209
Galactan 0.000487
Cellulase 0.122
----------------- 5.01e+05 kg/hr
outs...
[0] RNG
phase: 'g', T: 298.15 K, P: 101325 Pa
flow: 0
[1] biogas
phase: 'g', T: 298.15 K, P: 101325 Pa
composition (%): CH4 26.9
H2S 0.0348
CO2 73.1
--- 4.33e+04 kg/hr
[2] sludge
phase: 'l', T: 307.85 K, P: 101325 Pa
composition (%): Water 80
Ethanol 2.49e-05
AceticAcid 0.0111
Furfural 0.00447
Glycerol 0.00123
NH3 0.0448
LacticAcid 0.0117
SuccinicAcid 0.00307
DAP 0.0636
AmmoniumSulfate 1.12
HMF 0.00224
Glucose 0.0038
Xylose 0.00679
Arabinose 0.0144
Extract 0.0872
Ash 0.832
Lignin 2.51
SolubleLignin 0.00469
GlucoseOligomer 0.0081
GalactoseOligomer 2.05e-05
MannoseOligomer 1.07e-05
XyloseOligomer 0.0028
ArabinoseOligomer 0.000341
Z_mobilis 0.163
Protein 0.584
Glucan 0.251
Xylan 0.0805
Xylitol 0.00556
Cellobiose 0.00242
Arabinan 0.0295
Mannan 0.104
Galactan 0.0243
WWTsludge 14
Cellulase 0.00447
----------------- 1e+04 kg/hr
[3] RO_treated_water
phase: 'l', T: 303.15 K, P: 101325 Pa
composition (%): Water 100
----- 4.59e+05 kg/hr
[4] brine
phase: 'l', T: 303.15 K, P: 101325 Pa
composition (%): Water 71.2
Ethanol 2.18e-05
AceticAcid 0.00971
Furfural 0.00391
Glycerol 0.00108
NH3 1.07
LacticAcid 0.0121
SuccinicAcid 0.00269
DAP 1.48
AmmoniumSulfate 26
HMF 0.00195
Glucose 0.00332
Xylose 0.0133
Arabinose 0.0126
Extract 0.09
SolubleLignin 0.00484
GlucoseOligomer 0.00822
GalactoseOligomer 2.08e-05
MannoseOligomer 1.09e-05
XyloseOligomer 0.00284
ArabinoseOligomer 0.000346
Xylitol 0.00486
Cellobiose 0.00211
Cellulase 0.00462
----------------- 8.51e+03 kg/hr
>>> u = wwt_sys.flowsheet.unit
>>> print(round(u.R603.outs[3].F_mol, 2))
50.46
>>> wwt_sys.simulate()
>>> print(round(u.R603.outs[3].F_mol, 2))
50.46
>>> wwt_sys.simulate()
>>> print(round(u.R603.outs[3].F_mol, 2))
50.46
Check if system can finish simulating with a dilute influent stream.
>>> from biosteam import Stream, create_high_rate_wastewater_treatment_system, settings
>>> from biorefineries import cornstover as cs
>>> settings.set_thermo(cs.create_chemicals())
>>> feed = Stream(
... ID='wastewater',
... Water=2.634e+05,
... Ethanol=0.07225,
... AceticAcid=24.67,
... Furfural=6.206,
... Glycerol=1.784,
... LacticAcid=17.7,
... SuccinicAcid=3.472,
... DAP=1.001,
... AmmoniumSulfate=17.63,
... HMF=2.366,
... Glucose=2.816,
... Xylose=6.953,
... Arabinose=12.78,
... Extract=65.98,
... Ash=83.52,
... Lignin=1.659,
... SolubleLignin=4.202,
... GlucoseOligomer=6.796,
... GalactoseOligomer=0.01718,
... MannoseOligomer=0.009008,
... XyloseOligomer=2.878,
... ArabinoseOligomer=0.3508,
... Z_mobilis=0.6668,
... Protein=2.569,
... Glucan=0.1555,
... Xylan=0.06121,
... Xylitol=4.88,
... Cellobiose=0.9419,
... Arabinan=0.02242,
... Mannan=0.06448,
... Galactan=0.01504,
... Cellulase=25.4,
... units='kmol/hr'
... )
>>> wwt_sys = create_high_rate_wastewater_treatment_system(ins=feed)
>>> wwt_sys.simulate()
>>> wwt_sys.show('cwt100')
System: wastewater_sys
Highest convergence error among components in recycle
stream M603-0 after 6 loops:
- flow rate 5.52e+00 kmol/hr (0.027%)
- temperature 4.36e-04 K (0.00014%)
ins...
[0] wastewater
phase: 'l', T: 298.15 K, P: 101325 Pa
composition (%): Water 99.4
Ethanol 6.98e-05
AceticAcid 0.031
Furfural 0.0125
Glycerol 0.00344
LacticAcid 0.0334
SuccinicAcid 0.00859
DAP 0.00277
AmmoniumSulfate 0.0488
HMF 0.00625
Glucose 0.0106
Xylose 0.0219
Arabinose 0.0402
Extract 0.249
Ash 0.00175
Lignin 0.00529
SolubleLignin 0.0134
GlucoseOligomer 0.0231
GalactoseOligomer 5.84e-05
MannoseOligomer 3.06e-05
XyloseOligomer 0.00797
ArabinoseOligomer 0.000971
Z_mobilis 0.000344
Protein 0.00123
Glucan 0.000528
Xylan 0.000169
Xylitol 0.0156
Cellobiose 0.00676
Arabinan 6.21e-05
Mannan 0.000219
Galactan 5.11e-05
Cellulase 0.0128
----------------- 4.77e+06 kg/hr
outs...
[0] RNG
phase: 'g', T: 298.15 K, P: 101325 Pa
flow: 0
[1] biogas
phase: 'g', T: 298.15 K, P: 101325 Pa
composition (%): CH4 26.9
H2S 0.0348
CO2 73.1
--- 4.33e+04 kg/hr
[2] sludge
phase: 'l', T: 307.9 K, P: 101325 Pa
composition (%): Water 79.9
Ethanol 2e-05
AceticAcid 0.00889
Furfural 0.00358
Glycerol 0.000986
NH3 0.0359
LacticAcid 0.00936
SuccinicAcid 0.00246
DAP 0.0511
AmmoniumSulfate 0.9
HMF 0.00179
Glucose 0.00304
Xylose 0.00544
Arabinose 0.0115
Extract 0.0698
Ash 0.838
Lignin 2.53
SolubleLignin 0.00375
GlucoseOligomer 0.00649
GalactoseOligomer 1.64e-05
MannoseOligomer 8.6e-06
XyloseOligomer 0.00224
ArabinoseOligomer 0.000273
Z_mobilis 0.165
Protein 0.589
Glucan 0.253
Xylan 0.0811
Xylitol 0.00445
Cellobiose 0.00193
Arabinan 0.0297
Mannan 0.105
Galactan 0.0245
WWTsludge 14.3
Cellulase 0.00358
----------------- 9.97e+03 kg/hr
[3] RO_treated_water
phase: 'l', T: 303.15 K, P: 101325 Pa
composition (%): Water 100
----- 4.67e+06 kg/hr
[4] brine
phase: 'l', T: 303.15 K, P: 101325 Pa
composition (%): Water 96.1
Ethanol 2.92e-06
AceticAcid 0.0013
Furfural 0.000522
Glycerol 0.000144
NH3 0.144
LacticAcid 0.00161
SuccinicAcid 0.000359
DAP 0.198
AmmoniumSulfate 3.49
HMF 0.000261
Glucose 0.000445
Xylose 0.00178
Arabinose 0.00168
Extract 0.012
SolubleLignin 0.000647
GlucoseOligomer 0.0011
GalactoseOligomer 2.78e-06
MannoseOligomer 1.46e-06
XyloseOligomer 0.000379
ArabinoseOligomer 4.62e-05
Xylitol 0.000651
Cellobiose 0.000282
Cellulase 0.000617
----------------- 6.42e+04 kg/hr
"""
# Setup
if flowsheet: bst.main_flowsheet.set_flowsheet(flowsheet)
RNG, biogas, sludge, RO_treated_water, brine = outs
RO_treated_water.register_alias('recycled_water')
##### Units #####
# Mix waste liquids for treatment
X = str(process_ID)
MX01 = bst.Mixer(f'M{X}01', ins=ins or [])
MX01.autopopulate = False if autopopulate is None else autopopulate
@MX01.add_specification(run=True)
def autopopulate_waste_streams():
if MX01.autopopulate and not MX01.ins:
sys = MX01.system
streams = bst.FreeProductStreams(sys.streams)
MX01.ins.extend(streams.noncombustible_slurries)
for i in sys.facilities:
if isinstance(i, bst.BlowdownMixer): MX01.ins.append(i.outs[0])
RX01_outs = (f'biogas_R{X}01', 'IC_eff', 'IC_sludge')
if skip_IC:
RX01 = Skipped(f'R{X}01', ins=MX01-0, outs=RX01_outs, main_in=0, main_out=1) # outs[0] is the gas phase
else:
RX01 = InternalCirculationRx(f'R{X}01', ins=MX01-0, outs=RX01_outs,
T=35+273.15, **IC_kwargs)
RX02_outs = (f'biogas_R{X}02', f'permeate_R{X}02', f'sludge_R{X}02', f'vent_R{X}02')
if skip_AnMBR:
RX02 = Skipped(f'R{X}02', ins=RX01-1, outs=RX02_outs, main_in=0, main_out=1)
else:
# Just setting the prices, flows will be updated upon simulation
naocl_RX02 = tmo.Stream(f'naocl_R{X}02', NaOCl=0.125, Water=1-0.125, units='kg/hr')
naocl_RX02.price = (naocl_RX02.F_mass/naocl_RX02.F_vol/1000)*prices['naocl'] # $/L to $/kg
citric_RX02 = tmo.Stream(f'citric_R{X}02', CitricAcid=1, units='kg/hr')
citric_RX02.price = (citric_RX02.F_mass/citric_RX02.F_vol/1000)*prices['citric_acid'] # $/L to $/kg
bisulfite_RX02 = tmo.Stream(f'bisulfite_R{X}02', Bisulfite=0.38, Water=1-0.38, units='kg/hr')
bisulfite_RX02.price = (bisulfite_RX02.F_mass/bisulfite_RX02.F_vol/1000)*prices['bisulfite'] # $/L to $/kg
RX02 = AnMBR(f'R{X}02', ins=(RX01-1, '', naocl_RX02, citric_RX02,
bisulfite_RX02, f'air_R{X}02'),
outs=RX02_outs,
reactor_type='CSTR',
membrane_configuration='cross-flow',
membrane_type='multi-tube',
membrane_material='ceramic',
include_aerobic_filter=False,
add_GAC=False,
include_degassing_membrane=True,
# Below include in the TEA
include_pump_building_cost=False,
include_excavation_cost=False, **AnMBR_kwargs)
RX03_outs = (f'biogas_R{X}03', f'treated_R{X}03', f'sludge_R{X}03', f'vent_R{X}03')
if skip_AeF:
RX03 = Skipped(f'R{X}03', ins=(RX02-1, ''), outs=RX03_outs, main_in=0, main_out=1)
else:
RX03 = PolishingFilter(f'R{X}03', ins=(RX02-1, '', f'air_R{X}03'), outs=RX03_outs,
filter_type='aerobic',
include_degassing_membrane=False,
# Below include in the TEA
include_pump_building_cost=False,
include_excavation_cost=False,
**AeF_kwargs)
MX02 = bst.Mixer(f'M{X}02', ins=(RX01-0, RX02-0, RX03-0))
BiogasUpgrading('Upgrading', ins=(MX02-0, 'upgrading_placeholder'), outs=(RNG, biogas))
# Recycled the majority of sludge (96%) to the aerobic filter,
# 96% from the membrane bioreactor in ref [2]
SX01 = bst.Splitter(f'S{X}01', ins=RX03-2, outs=(f'recycled_S{X}01', f'wasted_S{X}01'),
split=0.96)
solubles = [i.ID for i in SX01.chemicals if not i.ID in default_insolubles]
SX02 = BeltThickener(f'S{X}02', ins=(RX01-2, RX02-2, SX01-1),
outs=(f'eff_S{X}02', f'sludge_S{X}02'),
sludge_moisture=0.96, solubles=solubles)
SX03 = SludgeCentrifuge(f'S{X}03', ins=SX02-1,
outs=(f'centrate_S{X}03', sludge),
sludge_moisture=0.8, solubles=solubles,
centrifuge_type='reciprocating_pusher')
# Mix recycles to aerobic digestion
bst.Mixer(f'M{X}03', ins=(SX01-0, SX02-0, SX03-0), outs=1-RX03)
# Reverse osmosis to treat aerobically polished water
ReverseOsmosis(f'S{X}04', ins=RX03-1, outs=(RO_treated_water, brine))
