RDKit-checked fuel, aqueous, gas, ash, corrosion, nutrient, and PFAS markers
Docker-Generated Element Ledger
Element Ledger Lab
A 3D release-gate workspace for seeing where carbon, nitrogen, sulfur, phosphorus, chlorine, metals, water, and PFAS go across oil, aqueous, hydrochar, gas, hydrotreating, residual, and product streams.
element and contaminant ledgers normalized to the same dry-sludge basis
highest current stop-gate ledger before product, water, or residual release claims
selected mass, fuel, aqueous, PFAS, hydrotreating, and residual release gates
mg PFAS-F index / t dry sludge
F ledger: PFAS fluorine
PFAS can be concentrated, transformed, or hidden in residuals unless fluorine closure is measured
Oil15%
Water20%
Char50%
Gas5%
Open10%
- Basis amount
- 250
- Resolved
- 90%
- Confidence
- 61.7
- Fuel relevance
- 96
Pyomo-formulated release-gate selector with deterministic enumeration across mass, carbon, nitrogen, PFAS, product, and residual closure constraints. The selected package covers 9 ledgers and 17 molecular markers.
Markers tied to the selected ledger
PFOS; PFOA; Phosphoric acid; Iron(III) ion; Calcium carbonate
EPA 1633, TOP/suspect screening, total fluorine, oil/aqueous/char/gas fate, and source-control hold rule
- Top marker
- PFOS
- Gate count
- 2
PFAS, chloride, nitrogen, and metals receive stop-gate treatment because oil yield alone cannot prove that the fuel, water return, hydrochar, offgas, and residual routes are safe to release.
The current plan is a validation package, not a commercial-ready recipe: each release gate must close measured molecules and element splits before the pathway can move from bench evidence to pilot fuel production.
Current fuel-readiness decision
The plan is not release-ready until the element ledger closes
The current result is a practical validation plan rather than a finished commercial fuel recipe. Sewage sludge can be converted into an oil-like biocrude through HTL, but the fuel claim only becomes usable after carbon yield, nitrogen removal, chloride/sulfur corrosion, aqueous treatment, PFAS fate, hydrochar release, and upgraded fuel assays pass on the same mass basis.
6 release categories are covered by the selected Docker-generated gate package.
PFAS and fluorine fate ledger carries the largest risk-reduction value because PFAS cannot be inferred from oil yield.
Mean closure confidence is still a bench-program target, not a full-scale operating claim.
Estimated oil-side element mass is reported alongside aqueous, char, gas, and unresolved streams.
Selected release gates
Six gates that must pass together before managers see fuel as ready
PFAS and fluorine fate ledger
Score 99.3; measurement power 98; risk reduction 100; readiness 46. Proof required: EPA 1633, total fluorine, precursor/suspect screen, oil/aqueous/char/gas fate, and source-control hold rule.
Total phase mass closure
Score 98; measurement power 98; risk reduction 92; readiness 82. Proof required: feed, oil, aqueous, hydrochar, gas, solvent, water, and loss terms close on one normalized basis.
Nitrogen oil-water-HDN ledger
Score 95.2; measurement power 96; risk reduction 94; readiness 66. Proof required: oil N, aqueous ammonia, N-heterocycle HRMS, hydrotreating HDN, offgas ammonia, and product nitrogen pass together.
Carbon and COD ledger
Score 91.1; measurement power 94; risk reduction 88; readiness 74. Proof required: oil carbon, aqueous TOC/COD, gas CO2/CH4, hydrochar carbon, and hydrotreating carbon yield agree.
Hydrochar and residual release ledger
Score 89; measurement power 88; risk reduction 94; readiness 54. Proof required: hydrochar mass, P value, metals/PFAS leaching, total fluorine, disposal class, and beneficial-use boundary.
Hydrotreating product release ledger
Score 88.5; measurement power 92; risk reduction 94; readiness 58. Proof required: H2 uptake, HDN/HDO/HDS/HCl removal, catalyst exposure, product SimDist, sulfur, nitrogen, acid number, and stability.
Element ledger
Each element has to be assigned to oil, water, char, gas, or unresolved loss
PFAS fluorine
- Risk
- 96.7
- Oil
- 15%
- Water
- 20%
- Char
- 50%
Chlorine
- Risk
- 91.5
- Oil
- 8%
- Water
- 62%
- Char
- 14%
Nitrogen
- Risk
- 79.5
- Oil
- 18%
- Water
- 62%
- Char
- 12%
Metals and ash
- Risk
- 76.2
- Oil
- 1%
- Water
- 6%
- Char
- 88%
Process water
- Risk
- 74.5
- Oil
- 2%
- Water
- 88%
- Char
- 5%
Sulfur
- Risk
- 69.5
- Oil
- 35%
- Water
- 15%
- Char
- 28%
Oxygen
- Risk
- 61.8
- Oil
- 20%
- Water
- 52%
- Char
- 16%
Phosphorus
- Risk
- 55.1
- Oil
- 2%
- Water
- 10%
- Char
- 82%
Carbon
- Risk
- 51.2
- Oil
- 52%
- Water
- 25%
- Char
- 12%
Gate category ledger
Fuel release, water return, corrosion, residual, and contaminant gates separate the claims
- Gates
- 1
- Score
- 99.3
- Power
- 98
- Readiness
- 46
- Gates
- 1
- Score
- 98
- Power
- 98
- Readiness
- 82
- Gates
- 1
- Score
- 95.2
- Power
- 96
- Readiness
- 66
- Gates
- 1
- Score
- 91.4
- Power
- 90
- Readiness
- 68
- Gates
- 1
- Score
- 91.1
- Power
- 94
- Readiness
- 74
- Gates
- 1
- Score
- 88.5
- Power
- 92
- Readiness
- 58
- Gates
- 2
- Score
- 87.7
- Power
- 88
- Readiness
- 63
- Gates
- 1
- Score
- 86.3
- Power
- 84
- Readiness
- 62
Full gate ledger
Unselected gates stay visible because they become the next proof package
PFAS and fluorine fate ledger
EPA 1633, total fluorine, precursor/suspect screen, oil/aqueous/char/gas fate, and source-control hold rule
- Score
- 99.3
- Markers
- 2
Total phase mass closure
feed, oil, aqueous, hydrochar, gas, solvent, water, and loss terms close on one normalized basis
- Score
- 98
- Markers
- 3
Nitrogen oil-water-HDN ledger
oil N, aqueous ammonia, N-heterocycle HRMS, hydrotreating HDN, offgas ammonia, and product nitrogen pass together
- Score
- 95.2
- Markers
- 4
Aqueous return-load ledger
aqueous COD/TOC, TAN, salts, phenolics, nitrification inhibition, and treatment/valorization route performance
- Score
- 91.4
- Markers
- 5
Carbon and COD ledger
oil carbon, aqueous TOC/COD, gas CO2/CH4, hydrochar carbon, and hydrotreating carbon yield agree
- Score
- 91.1
- Markers
- 5
Hydrochar and residual release ledger
hydrochar mass, P value, metals/PFAS leaching, total fluorine, disposal class, and beneficial-use boundary
- Score
- 89
- Markers
- 5
Hydrotreating product release ledger
H2 uptake, HDN/HDO/HDS/HCl removal, catalyst exposure, product SimDist, sulfur, nitrogen, acid number, and stability
- Score
- 88.5
- Markers
- 5
Phosphorus, ash, and metals ledger
P/metals partition to hydrochar, leaching, reuse/disposal rules, and catalyst-poison risks are quantified
- Score
- 86.3
- Markers
- 4
Sulfur, chloride, and corrosion ledger
sulfur/chloride speciation, hydrotreating offgas, product sulfur, oil chloride, and coupon evidence pass together
- Score
- 86.3
- Markers
- 2
Molecular marker ledger
Molecules used to track the conversion from sewage organics to oil-like fuel
PFOS C8HF17O3S
- Priority
- 74.7
- C
- 28
- N
- 0
- Water
- 54
PFOA C8HF15O2
- Priority
- 73.9
- C
- 30
- N
- 0
- Water
- 58
Pyridine C5H5N
- Priority
- 65.6
- C
- 42
- N
- 88
- Water
- 58
Ammonia H3N
- Priority
- 65.5
- C
- 0
- N
- 96
- Water
- 96
Indole C8H7N
- Priority
- 59.6
- C
- 48
- N
- 82
- Water
- 22
Sodium chloride ClNa
- Priority
- 53.8
- C
- 0
- N
- 0
- Water
- 86
Acetic acid C2H4O2
- Priority
- 53.6
- C
- 68
- N
- 0
- Water
- 90
Phosphoric acid H3O4P
- Priority
- 53.4
- C
- 0
- N
- 0
- Water
- 30
Iron(III) ion Fe+3
- Priority
- 52.3
- C
- 0
- N
- 0
- Water
- 8
Phenol C6H6O
- Priority
- 48.9
- C
- 64
- N
- 0
- Water
- 70
Water H2O
- Priority
- 47.3
- C
- 0
- N
- 0
- Water
- 100
Calcium carbonate CCaO3
- Priority
- 47
- C
- 18
- N
- 0
- Water
- 5
Carbon dioxide CO2
- Priority
- 43.2
- C
- 86
- N
- 0
- Water
- 0
Silica O2Si
- Priority
- 42.7
- C
- 0
- N
- 0
- Water
- 0
Dodecane C12H26
- Priority
- 41.4
- C
- 96
- N
- 0
- Water
- 0
Methane CH4
- Priority
- 40.4
- C
- 78
- N
- 0
- Water
- 16
Oleic acid C18H34O2
- Priority
- 38.8
- C
- 92
- N
- 0
- Water
- 12
Hydrogen sulfide H2S
- Priority
- 38.4
- C
- 0
- N
- 0
- Water
- 12
Toluene C7H8
- Priority
- 38.4
- C
- 84
- N
- 0
- Water
- 5
Hydrogen H2
- Priority
- 35.3
- C
- 0
- N
- 0
- Water
- 0
Highest release priorities
PFAS, ammonia, pyridine, phosphorus, chloride, and hydrogen define the stop-gates
PFOS
sulfonated PFAS marker for fluorine closure and residual/source-control stop gates. Release priority 100; residual signal 92; aqueous signal 54; source IDs ledger-wrf-pfas-2025; ledger-biosolids-pfas-literature-2025.
PFOA
fluorine and PFAS fate marker for source-control, product release, aqueous, and residual routing. Release priority 100; residual signal 88; aqueous signal 58; source IDs ledger-wrf-pfas-2025; ledger-biosolids-pfas-literature-2025.
Pyridine
oil and aqueous N-heterocycle marker that blocks fuel release without HDN proof. Release priority 90; residual signal 0; aqueous signal 58; source IDs ledger-nitrogen-sequential-2022; ledger-water-research-2026.
Ammonia
aqueous nitrogen and WRRF return-load marker. Release priority 92; residual signal 0; aqueous signal 96; source IDs ledger-pnnl-aqueous-monetization-2024; ledger-part-iii-aqueous-2023.
Indole
aromatic nitrogen marker for hydrotreating severity and spent catalyst risk. Release priority 86; residual signal 0; aqueous signal 22; source IDs ledger-nitrogen-sequential-2022; ledger-rti-hydrotreating-2022.
Sodium chloride
chloride marker for corrosion, solvent extraction bias, and hydrotreating equipment risk. Release priority 88; residual signal 34; aqueous signal 86; source IDs ledger-rti-hydrotreating-2022; ledger-water-recycle-2022.
Acetic acid
aqueous COD marker that can hide carbon losses outside the oil phase. Release priority 76; residual signal 0; aqueous signal 90; source IDs ledger-pnnl-aqueous-2017; ledger-pnnl-aqueous-monetization-2024.
Phosphoric acid
phosphorus marker expected to concentrate in hydrochar and residual recovery streams. Release priority 88; residual signal 92; aqueous signal 30; source IDs ledger-part-i-product-distribution-2022; ledger-jclepro-hydrochar-2023.
ledger-part-i-product-distribution-2022
Incorporating HTL into wastewater treatment, Part I: process optimization and product distribution
CEJ source reporting product distribution, energy recovery, elemental distribution, and the key pattern that carbon, nitrogen, and phosphorus mostly distribute to biocrude, aqueous phase, and hydrochar respectively.
Open sourceledger-part-iii-aqueous-2023
Incorporating HTL into wastewater treatment, Part III: aqueous phase characterization and on-site treatment
CEJ aqueous source stating the HTL aqueous phase is a major WWTP integration bottleneck and that HTL concentrates carbon in biocrude, nitrogen in aqueous phase, and phosphorus in hydrochar.
Open sourceledger-jclepro-hydrochar-2023
Incorporating HTL into wastewater treatment, Part II: hydrochar characterization and applications
Hydrochar source covering phosphorus, carbon stability, heavy-metal leachability, slagging/fouling risk, and resource-recovery potential.
Open sourceledger-water-recycle-2022
Aqueous phase recycling in sewage-sludge HTL: energy recovery and pollution mitigation
Water Research source showing aqueous recycle can improve yield while enriching heavy metals in solid residues and changing pollution distribution.
Open sourceledger-pnnl-aqueous-2017
Quantitative characterization of HTL aqueous byproducts from municipal wastes
PNNL source reporting organic acids, nitrogen compounds, alcohols, aldehydes, ketones, and inorganic species in HTL aqueous fractions and noting 20-50% of feed carbon can report to water.
Open sourceledger-pnnl-aqueous-monetization-2024
Aqueous-phase treatment and monetization options for wet-waste HTL
PNNL TEA/LCA source for aqueous carbon and nitrogen treatment burden, COD removal, fuel-gas/fertilizer byproducts, and monetization routes.
Open sourceledger-water-research-2026
Hydrothermal liquefaction of municipal sludge: biocrude production and fuel-quality upgrading
Recent municipal-sludge HTL review framing formation complexity, fuel-quality barriers, nitrogen/oxygen/ash limitations, and upgrading needs.
Open sourceledger-acs-est-water-2026
HTL of sludge for biocrude production and synergistic byproduct utilization in AD
ACS ES&T Water source for HTL product distribution and byproduct utilization through hydrochar and aqueous-phase AD integration.
Open sourceledger-rti-hydrotreating-2022
Hydrotreatment of solvent-extracted biocrude from HTL of municipal sewage sludge
RTI hydrotreating source documenting solvent-dependent biocrude yields, high chloride challenge, catalyst deactivation, equipment corrosion, and product-quality testing.
Open sourceledger-nitrogen-sequential-2022
Sequential extraction and characterization of nitrogen compounds after sewage-sludge HTL
Open nitrogen-forensics source showing aromatic/pyridinic N-compounds in sewage-sludge biocrude fractions.
Open sourceledger-wrf-pfas-2025
WRF project on HTL aqueous integration and PFAS fate
WRF project source for HTL aqueous integration into WRRF digestion processes and PFAS fate assessment.
Open sourceledger-biosolids-pfas-literature-2025
Municipal biosolids PFAS treatment literature review
PFAS literature review source summarizing biosolids treatment, HTL, PFAS fate, and pollutant considerations relevant to source control and residual routing.
Open sourceledger-primary-catalyst-2024
Catalytic HTL of municipal primary sludge and product phase distribution
Open Fuel source reporting primary-sludge HTL product distribution across gas, organic, aqueous, and solid phases under catalyst conditions.
Open sourceledger-sludge-energy-2023
HTL for sludge-to-energy conversion and waste-stream management
Energy source describing biocrude, hydrochar, and HTL aqueous waste streams, phosphorus concentration in hydrochar, and COD/ammonia burden in HTL water.
Open sourceledger-pnnl-site-specific-2024
Site-specific design case study for wet-waste HTL and biocrude upgrading
PNNL design source for site-specific wet-waste HTL, WRRF siting, upgrading, supply-chain GHG comparison, and continuous-flow experimental context.
Open sourceledger-acs-iecr-2024
Characterization of biocrude from HTL of municipal sewage sludge in a 500 mL reactor
Open ACS IECR source reporting sewage-sludge HTL phase yields, biocrude chemistry, water-soluble products, energy recovery, and inorganic partitioning to solids.
Open sourcethe fuel plan is not ready until carbon, nitrogen, sulfur, phosphorus, chlorine, metals, water, and PFAS fate close across feed, oil, aqueous, hydrochar, gas, hydrotreating, residuals, and product assays. Modeling basis: normalized 1000 kg dry sludge entering HTL plus measured process water, hydrotreating gas, and residual streams. Selected package: PFAS and fluorine fate ledger; Total phase mass closure; Nitrogen oil-water-HDN ledger; Carbon and COD ledger; Hydrochar and residual release ledger; Hydrotreating product release ledger.