Supercritical water oxidation (SCWO)

[1]:
import PFAS_SAT_ProcessModels as pspd
import numpy as np
import matplotlib.pyplot as plt
from IPython.display import Image
import pandas as pd
pd.set_option('display.max_colwidth', 0)

Model document

SCWO systems use supercritical water (i.e., water above 373.946 C and 22.064 MPa) to facilitate the oxidation of PFAS or other hazardous substances in aqueous streams. SCWO systems are already in operation in Japan and Korea to manage PCBs and halogenated wastes, and the Chematur Engineering facility in the UK uses SCWO to recover metals from catalysts. Research into the use the SCWO for PFAS destruction is ongoing, and there are several different systems being developed. SCWO produces steam, water, and slurry outputs. The mineralized fluoride remains in the slurry. The destruction of PFAS is modeled using a destruction and removal efficiency (DRE). Any PFAS that is not destroyed or removed remains in the water. There may also be small amounts of PFAS volatilized in the steam and remaining in the slurry. The process model estimates the fraction of incoming water that goes to each stream, and the PFAS remaining in each.

Drawing

Assumptions and Limitations:

  1. It assumes that the destruction and removal efficiency remains constant for each PFAS.

  2. By default, the model assumes that all the remaining PFAS is in the water stream. However, this is a user input, and the user can send PFAS to the steam or slurry streams as well.

Input Parameters for SCWO model

[2]:
SCWO = pspd.SCWO()
SCWO.InputData.Data[['Category','Dictonary_Name','Parameter Name', 'Parameter Description', 'amount', 'unit','Reference']]
[2]:
Category Dictonary_Name Parameter Name Parameter Description amount unit Reference
0 Total destruction and removal efficiency DRE PFOA DRE of PFOA 0.99260 fraction
1 Total destruction and removal efficiency DRE PFOS DRE of PFOS 0.99997 fraction
2 Total destruction and removal efficiency DRE PFBA DRE of PFBA 0.95043 fraction
3 Total destruction and removal efficiency DRE PFPeA DRE of PFPeA 0.94257 fraction
4 Total destruction and removal efficiency DRE PFHxA DRE of PFHxA 0.99843 fraction
5 Total destruction and removal efficiency DRE PFHpA DRE of PFHpA 0.96303 fraction
6 Total destruction and removal efficiency DRE PFNA DRE of PFNA 0.99260 fraction
7 Total destruction and removal efficiency DRE PFDA DRE of PFDA 0.99970 fraction
8 Total destruction and removal efficiency DRE PFBS DRE of PFBS 0.99950 fraction
9 Total destruction and removal efficiency DRE PFHxS DRE of PFHxS 0.99993 fraction
10 SCWO parameters SCWO frac_water_to_steam Fraction of incoming water to steam 0.01000 fraction
11 SCWO parameters SCWO frac_water_to_slurry Fraction of incoming water to slurry 0.10000 fraction
12 SCWO parameters SCWO frac_PFAS_to_steam Fraction of destroyed and removed that remains in steam 0.00000 fraction
13 SCWO parameters SCWO frac_PFAS_to_slurry Fraction of destroyed and removed that remains in slurry 0.00000 fraction

Incoming Contaminated Water to SCWO

[3]:
IncominWaste = pspd.IncomFlow()
IncominWaste.set_flow('ContaminatedWater', 1000)
IncominWaste.calc()
ContaminatedWater = IncominWaste.Inc_flow
ContaminatedWater.report()
[3]:
Parameter Unit Amount
0 Mass flow kg 1000
1 Solids flow kg 5.0
2 Moisture flow kg 995.0
3 Volume flow L 1000.0
4 Carbon flow kg 2.5
5 PFOA μg 100000.0
6 PFOS μg 100000.0
7 PFBA μg 100000.0
8 PFPeA μg 100000.0
9 PFHxA μg 100000.0
10 PFHpA μg 100000.0
11 PFNA μg 100000.0
12 PFDA μg 100000.0
13 PFBS μg 100000.0
14 PFHxS μg 100000.0

PFAS balance in SCWO

[4]:
SCWO.calc(Inc_flow=ContaminatedWater)
SCWO.report(normalized=True)
[4]:
Effluent Slurry Steam Destroyed
PFOA 0.74 0.0 0.0 99.26
PFOS 0.00 0.0 0.0 100.00
PFBA 4.96 0.0 0.0 95.04
PFPeA 5.74 0.0 0.0 94.26
PFHxA 0.16 0.0 0.0 99.84
PFHpA 3.70 0.0 0.0 96.30
PFNA 0.74 0.0 0.0 99.26
PFDA 0.03 0.0 0.0 99.97
PFBS 0.05 0.0 0.0 99.95
PFHxS 0.01 0.0 0.0 99.99
[5]:
SCWO.plot_sankey()
../_images/Notebooks_SCWO_9_0.png
[6]:
SCWO.plot_sankey_report(margin=.5)
../_images/Notebooks_SCWO_10_0.png