# -*- coding: utf-8 -*-
# BioSTEAM: The Biorefinery Simulation and Techno-Economic Analysis Modules
# Copyright (C) 2020-2023, Yoel Cortes-Pena <yoelcortes@gmail.com>
#
# This module is under the UIUC open-source license. See
# github.com/BioSTEAMDevelopmentGroup/biosteam/blob/master/LICENSE.txt
# for license details.
"""
This module contains unit operations for drying solids.
.. contents:: :local:
.. autoclass:: biosteam.units.drying.DrumDryer
References
----------
.. [1] Kwiatkowski, J. R.; McAloon, A. J.; Taylor, F.; Johnston, D. B.
Modeling the Process and Costs of Fuel Ethanol Production by the Corn
Dry-Grind Process. Industrial Crops and Products 2006, 23 (3), 288–296.
https://doi.org/10.1016/j.indcrop.2005.08.004.
"""
import flexsolve as flx
import numpy as np
from thermosteam import separations as sep
from .design_tools import (
CEPCI_by_year,
cylinder_diameter_from_volume,
cylinder_area,
)
from .decorators import cost
from .._unit import Unit
from math import exp, log
from thermosteam import separations
from warnings import warn
from ..exceptions import DesignWarning
__all__ = ('SprayDryer', 'DrumDryer', 'ThermalOxidizer')
@cost('Evaporation rate', CE=567, units='lb/hr', # lb=30, ub=3000,
BM=2.06, f=lambda W: exp(8.5133 + 0.9847*(logW:=log(W)) - 0.0561 * logW * logW)
)
class SprayDryer(Unit):
_units = {'Evaporation rate': 'lb/hr'}
_N_ins = 1
_N_outs = 2
def _init(self, moisture_content=0.90):
self.moisture_content = moisture_content
def _run(self):
feed = self.ins[0]
water, solids = self.outs
solids.copy_like(feed)
water.copy_flow(solids, 'Water', remove=True)
separations.adjust_moisture_content(solids, water, self.moisture_content)
water.phase = 'g'
def _design(self):
water, solids = self.outs
self.design_results['Evaporation rate'] = water.get_total_flow('lb/hr')
# TODO: The drum dryer is carbon steel. Add material factors later
[docs]
@cost('Peripheral drum area', CE=CEPCI_by_year[2007], ub=7854.0, BM=2.06,
S=1235.35, units='m2', n=0.6, cost=0.52 * 2268000., kW=938.866)
class DrumDryer(Unit):
"""
Create a drum dryer that dries solids by passing hot air
(heated by burning natural gas).
Parameters
----------
ins :
* [0] Wet solids.
* [1] Dry gas.
* [2] Natural gas.
outs :
* [0] Dried solids
* [1] Hot gas
* [2] Emissions
split : dict[str, float]
Component splits to hot gas (stream [1]).
RH : float, optional
Relative humidity of hot gas as a fraction. Defaults to 0.80.
H : float, optional
Specific evaporation rate [kg/hr/m3]. Defaults to 20.
length_to_diameter : float, optional
Note that the drum is horizontal. Defaults to 25.
T : float, optional
Operating temperature [K]. Defaults to 343.15.
moisture_content : float
Moisture content of solids [wt / wt]. Defaults to 0.10.
Notes
-----
The flow rate for gas in the inlet is calculated to meet the `RH` specification
(i.e. relative humidity of hot gas depending on moisture_ID evaporated). The flow
rate of inlet natural gas is also altered to meet the heat demand.
The default parameter values are based on heuristics for drying
dried distillers grains with solubles (DDGS).
Examples
--------
>>> import biosteam as bst
>>> from biorefineries import corn as c
>>> bst.settings.set_thermo(c.create_chemicals())
>>> feed = bst.Stream('feed', phase='l', T=352.33, P=101325,
... Water=0.6749, Ethanol=5.041e-06, Ash=0.01978, Yeast=0.008452,
... CaO=0.0001446, TriOlein=0.02702, H2SO4=0.001205, Fiber=0.1508,
... SolubleProtein=0.04805, InsolubleProtein=0.06967,
... total_flow=32720, units='kg/hr',
... )
>>> dryer = bst.DrumDryer('D610',
... (feed, 'dryer_air', 'natural_gas'),
... ('dryed_solids', 'hot_air', 'emissions'),
... moisture_content=0.10, split=dict(Ethanol=1.0)
... )
>>> dryer.simulate()
>>> dryer.show('cwt100')
DrumDryer: D610
ins...
[0] feed
phase: 'l', T: 352.33 K, P: 101325 Pa
flow (%): Water 67.5
Ethanol 0.000504
Ash 1.98
Yeast 0.845
CaO 0.0145
TriOlein 2.7
H2SO4 0.12
Fiber 15.1
SolubleProtein 4.8
InsolubleProtein 6.97
---------------- 3.27e+04 kg/hr
[1] dryer_air
phase: 'g', T: 298.15 K, P: 1.01325e+06 Pa
flow (%): O2 23.3
N2 76.7
-- 1.33e+06 kg/hr
[2] natural_gas
phase: 'g', T: 298.15 K, P: 101325 Pa
flow: 2.45e+03 kg/hr CH4
outs...
[0] dryed_solids
phase: 'l', T: 343.15 K, P: 101325 Pa
flow (%): Water 10
Ash 5.48
Yeast 2.34
CaO 0.04
TriOlein 7.48
H2SO4 0.334
Fiber 41.7
SolubleProtein 13.3
InsolubleProtein 19.3
---------------- 1.18e+04 kg/hr
[1] hot_air
phase: 'g', T: 343.15 K, P: 1.01325e+06 Pa
flow (%): Water 1.55
Ethanol 1.23e-05
O2 22.9
N2 75.5
------- 1.35e+06 kg/hr
[2] emissions
phase: 'g', T: 373.15 K, P: 101325 Pa
flow (%): Water 45
CO2 55
----- 1.22e+04 kg/hr
>>> dryer.results()
Drum dryer Units D610
Electricity Power kW 845
Cost USD/hr 66
Natural gas (inlet) Flow kg/hr 2.45e+03
Cost USD/hr 534
Design Evaporation kg/hr 2.09e+04
Volume 1.05e+03
Diameter m 3.76
Length 94
Peripheral drum area m2 1.11e+03
Purchase cost Drum dryer USD 1.2e+06
Total purchase cost USD 1.2e+06
Installed equipment cost USD 2.46e+06
Utility cost USD/hr 600
"""
# auxiliary_unit_names = ('heat_exchanger',)
_units = {'Evaporation': 'kg/hr',
'Peripheral drum area': 'm2',
'Diameter': 'm'}
_N_ins = 3
_N_outs = 3
@property
def isplit(self):
"""[ChemicalIndexer] Componentwise split of feed to 0th outlet stream."""
return self._isplit
@property
def split(self):
"""[Array] Componentwise split of feed to 0th outlet stream."""
return self._isplit.data
@property
def natural_gas(self):
"""[Stream] Natural gas to satisfy steam and electricity requirements."""
return self.ins[2]
def _init(self, split, RH=0.80, H=20., length_to_diameter=25, T=343.15, P=10*101325,
moisture_content=0.15, utility_agent='Natural gas', gas_composition=None,
moisture_ID=None):
self._isplit = self.chemicals.isplit(split)
self.define_utility('Natural gas', self.natural_gas)
self.P = P
self.T = T
self.RH = RH
self.H = H
self.gas_composition = [('N2', 0.79), ('O2', 0.21)] if gas_composition is None else gas_composition
self.length_to_diameter = length_to_diameter
self.moisture_content = moisture_content
self.utility_agent = utility_agent
self.moisture_ID = 'Water' if moisture_ID is None else moisture_ID
@property
def utility_agent(self):
return self._utility_agent
@utility_agent.setter
def utility_agent(self, utility_agent):
if utility_agent not in ('Natural gas', 'Steam'):
raise ValueError(f"utility agent must be either 'Steam' or 'Natural gas'; not '{utility_agent}'")
self._utility_agent = utility_agent
def _get_moisture_vapor_pressure(self, T):
chemical = self.thermo.chemicals[self.moisture_ID]
return chemical.Psat(T)
def _convert_air_mol_to_mass(self, n_air, gas_composition):
mol_weight_air = 0.
for chem, x in gas_composition:
chem_mol_weight = self.thermo.chemicals[chem].MW
mol_weight_air += x / chem_mol_weight
return n_air / mol_weight_air
def _run(self):
wet_solids, dry_gas, natural_gas = self.ins
dry_solids, hot_air, emissions = self.outs
wet_solids.split_to(hot_air, dry_solids, self.split)
sep.adjust_moisture_content(dry_solids, hot_air, self.moisture_content, self.moisture_ID)
hot_air.P = dry_gas.P = self.P
emissions.phase = dry_gas.phase = natural_gas.phase = hot_air.phase = 'g'
design_results = self.design_results
design_results['Evaporation'] = hot_air.F_mass
# Calculate n_moisture_ID and n_evap_compounds
n_moisture = hot_air.imol[self.moisture_ID]
# Calculate y_moisture_ID
Psat = self._get_moisture_vapor_pressure(self.T)
P = self.P
if Psat > P:
warn(
f'saturated pressure of {self.moisture_ID} ({int(Psat)} Pa) '
f'is greater than operating pressure ({int(P)} Pa)',
category=DesignWarning,
)
Psat = P
y_moisture = self.RH * Psat / P
# Calculate total gas flow (molar basis)
n_other = n_moisture * (1 - y_moisture) / y_moisture
dry_gas.reset_flow(**dict(self.gas_composition), total_flow=n_other) # In kmol / hr
hot_air.mol += dry_gas.mol
dry_solids.T = hot_air.T = self.T
emissions.T = self.T + 30.
natural_gas.empty()
emissions.empty()
if self.utility_agent == 'Natural gas':
LHV = self.chemicals.CH4.LHV
def f(CH4):
CO2 = CH4
H2O = 2. * CH4
natural_gas.imol['CH4'] = CH4
emissions.imol['CO2', 'H2O'] = [CO2, H2O]
duty = (dry_solids.H + hot_air.H + emissions.H) - (wet_solids.H + dry_gas.H + natural_gas.H)
CH4 = duty / LHV
return CH4
flx.wegstein(f, 0., 1e-3)
def _design(self):
length_to_diameter = self.length_to_diameter
design_results = self.design_results
design_results['Volume'] = volume = design_results['Evaporation'] / self.H
design_results['Diameter'] = diameter = cylinder_diameter_from_volume(volume, length_to_diameter)
design_results['Length'] = length = diameter * length_to_diameter
design_results['Peripheral drum area'] = cylinder_area(diameter, length)
if self.utility_agent == 'Steam':
self.add_heat_utility(self.H_out - self.H_in, self.T)
class ThermalOxidizer(Unit):
"""
Create a ThermalOxidizer that burns any remaining combustibles.
Parameters
----------
ins :
[0] Feed gas
[1] Air
[2] Natural gas
outs :
Emissions.
tau : float, optional
Residence time [hr]. Defaults to 0.00014 (0.5 seconds).
duty_per_kg : float, optional
Duty per kg of feed. Defaults to 105858 kJ / kg.
V_wf : float, optional
Fraction of working volume. Defaults to 0.95.
Notes
-----
Adiabatic operation is assumed. Simulation and cost is based on [1]_.
"""
_N_ins = 3
_N_outs = 1
max_volume = 20. # m3
_F_BM_default = {'Vessels': 2.06} # Assume same as dryer
@property
def natural_gas(self):
"""[Stream] Natural gas to satisfy steam and electricity requirements."""
return self.ins[2]
def _init(self, tau=0.00014, duty_per_kg=61.):
self.define_utility('Natural gas', self.natural_gas)
self.tau = tau
self.duty_per_kg = duty_per_kg
def _run(self):
feed, air, ng = self.ins
ng.imol['CH4'] = self.duty_per_kg * feed.F_mass / self.chemicals.CH4.LHV
ng.phase = 'g'
air.phase = 'g'
emissions, = self.outs
ng.P = air.P = emissions.P = feed.P
emissions.phase = 'g'
ng_burned = ng.copy()
combustion_rxns = self.chemicals.get_combustion_reactions()
# Enough oxygen must be present in air to burn natural gas
combustion_rxns.force_reaction(ng_burned)
O2 = max(-ng_burned.imol['O2'], 0.)
air.imol['N2', 'O2'] = [0.79/0.21 * O2, O2]
# Enough oxygen must be present in air to burn feed as well
emissions.mix_from(self.ins)
dummy_emissions = emissions.copy()
combustion_rxns.force_reaction(dummy_emissions)
O2 = max(-dummy_emissions.imol['O2'], 0.) # Missing oxygen
air.imol['N2', 'O2'] += [0.79/0.21 * O2, O2]
emissions.mix_from(self.ins)
# Account for temperature raise
combustion_rxns.adiabatic_reaction(emissions)
def _design(self):
design_results = self.design_results
volume = self.tau * self.ins[0].F_vol
V_max = self.max_volume
design_results['Number of vessels'] = N = np.ceil(volume / V_max)
design_results['Vessel volume'] = volume / N
design_results['Total volume'] = volume
def _cost(self):
design_results = self.design_results
N = design_results['Number of vessels']
vessel_volume = design_results['Vessel volume']
C = self.baseline_purchase_costs
C['Vessels'] = N * 918300. * (vessel_volume / 13.18)**0.6
