RDKit-checked markers across amino acids, acids, donors, solvents, aqueous burden, metals, and lipid retention
Docker-Generated Pretreatment Screen
Pretreatment Chemistry Lab
A molecule-backed route screen for low-nitrogen hydrothermal pretreatment, zero-valent donor chemistry, solvent extraction, co-solvent HTL, DES hydrochar support, and aqueous-recycle controls before sewage sludge is promoted into a fuel pathway.
pretreatment and donor routes scored for N extraction, oil quality, donor power, recovery, aqueous burden, and corrosion
top modeled route because lipid recovery and lower nitrogen burden are useful only if solvent recovery closes
selected routes spanning low-N hydrolysis, baseline wash, donors, solvents, and recycle-risk control
recycle control
Aqueous-recycle control window
Use as a warning branch: yield can rise while oil oxygen and N-heterocycles make quality worse.
Track cycle-by-cycle yield, oil O/N, N-heterocycle accumulation, salts, toxicity, and recycle purge needs.
- Conditions
- 350 C / 30 min
- Donor
- 0
- Recovery
- 90
- Corrosion
- 48
Pyomo-formulated pretreatment selector with deterministic enumeration, category coverage, low-N, donor, and low-corrosion baseline constraints. Current package covers 6 categories and 14 molecular markers.
Route marker molecules
Pyridine; Ammonia; Phenol; Water
Pretreatment chemistry has to remove protein nitrogen or improve oil quality without turning the aqueous phase, corrosion, solvent recovery, or residual routing into a larger problem.
- Top marker
- Sulfuric acid
- Experiment
- Aqueous-recycle accumulation limit
The selected package keeps a water-only wash beside acids, donors, solvents, and recycle controls so every chemical gain is compared against a lower-risk baseline.
Current pretreatment decision
Pretreatment is useful only if it lowers downstream burden
Low-nitrogen hydrolysis, zero-valent metal donors, DME extraction, ethanol co-solvent HTL, and aqueous recycle can all improve one metric. The selected package keeps them tied to aqueous COD/TN, corrosion, solvent recovery, reagent fate, metals partitioning, and oil N/O before any route is allowed to simplify the fuel plan.
6 categories are covered by the selected Pyomo route package.
Sulfuric acid leads the marker priority because strong N extraction also carries high corrosion and sulfate burden.
Nitrogen extraction is valuable only if lipid retention and aqueous treatment still close.
Fe/Zn and formic donor branches remain experimental until metal partitioning and gas/oil response are measured.
Selected pretreatment package
Six branches to test before choosing upstream chemistry
Aqueous-recycle control window
Score 24.6; N extraction 36; oil quality 22; aqueous penalty 96; corrosion 48. Track cycle-by-cycle yield, oil O/N, N-heterocycle accumulation, salts, toxicity, and recycle purge needs.
Ethanol-water co-solvent HTL
Score 38.8; N extraction 28; oil quality 56; aqueous penalty 50; corrosion 18. Close solvent recovery, pressure safety, oil N/O, aqueous COD, residual solvent, and economics.
Fe/Zn zero-valent donor upgrade
Score 36; N extraction 20; oil quality 68; aqueous penalty 54; corrosion 34. Measure H2 generation, Fe/Zn partitioning, oil O/N shift, gas make, solids metal loading, and aqueous toxicity.
Liquid DME lipid extraction pretreatment
Score 47.8; N extraction 44; oil quality 72; aqueous penalty 32; corrosion 12. Measure solvent loss, solvent safety, dewatering gain, protein residual route, oil N, and whole-site energy.
Citric-acid low-nitrogen pretreatment
Score 44.8; N extraction 84; oil quality 74; aqueous penalty 68; corrosion 42. Measure TN and TOC in liquor, lipid retention in solids, biocrude N/O, acid recovery, corrosion, and aqueous treatment load.
Water-only hydrothermal wash
Score 42.3; N extraction 58; oil quality 42; aqueous penalty 46; corrosion 10. Measure soluble TN, lipid retention, solids dewaterability, aqueous COD, and HTL oil quality shift.
Selected experiment package
Experiments convert molecule ideas into measured pretreatment gates
Water, citric, and sulfuric low-N pretreatment panel
Run matched 150 C hydrothermal pretreatments and close TN/TOC in liquor, lipids in solids, corrosion, sulfate/citrate, and HTL oil N/O.
Decides whether acid pretreatment meaningfully lowers downstream HDN burden.
Aqueous-recycle accumulation limit
Run cycle-by-cycle oil yield, O/N, N-heterocycle, COD, salts, toxicity, and purge threshold measurements.
Sets a recycle ceiling so yield gain does not degrade oil quality and plant biology.
Fe/Zn and formic donor screen
Compare donor conversion, H2 generation, gas make, oil O/N, metal partition, TAN, and corrosion.
Tests if in-situ hydrogen can improve oil quality before imported H2 hydrotreating.
DME and ethanol solvent-recovery panel
Measure lipid recovery, oil N/O, solvent loss, pressure safety, COD, residual solvent, and whole-site energy.
Prevents solvent-enhanced yield from hiding recovery and safety penalties.
Route ledger
Every route is scored against benefits and the burdens it creates upstream
Liquid DME lipid extraction pretreatment
- Score
- 47.8
- N
- 44
- Quality
- 72
- Aq
- 32
Citric-acid low-nitrogen pretreatment
- Score
- 44.8
- N
- 84
- Quality
- 74
- Aq
- 68
Water-only hydrothermal wash
- Score
- 42.3
- N
- 58
- Quality
- 42
- Aq
- 46
Ethanol-water co-solvent HTL
- Score
- 38.8
- N
- 28
- Quality
- 56
- Aq
- 50
Fe/Zn zero-valent donor upgrade
- Score
- 36
- N
- 20
- Quality
- 68
- Aq
- 54
Sulfuric-acid low-nitrogen pretreatment
- Score
- 33.7
- N
- 90
- Quality
- 76
- Aq
- 86
Formic-acid donor pretreatment
- Score
- 33.7
- N
- 24
- Quality
- 62
- Aq
- 62
Aqueous-recycle control window
- Score
- 24.6
- N
- 36
- Quality
- 22
- Aq
- 96
Arginine/butyric DES hydrochar branch
- Score
- 15.9
- N
- 30
- Quality
- 28
- Aq
- 70
Category ledger
Solvents, donors, acids, baselines, and recycle controls are compared on the same burden scale
- Routes
- 1
- Score
- 47.8
- N
- 44
- Aq
- 32
- Routes
- 1
- Score
- 42.3
- N
- 58
- Aq
- 46
- Routes
- 2
- Score
- 39.2
- N
- 87
- Aq
- 77
- Routes
- 1
- Score
- 38.8
- N
- 28
- Aq
- 50
- Routes
- 2
- Score
- 34.9
- N
- 22
- Aq
- 58
- Routes
- 1
- Score
- 24.6
- N
- 36
- Aq
- 96
- Routes
- 1
- Score
- 15.9
- N
- 30
- Aq
- 70
Molecular marker ledger
Molecules used to evaluate sewage pretreatment before oil conversion
Sulfuric acid H2O4S
- Priority
- 63.1
- N
- 88
- Donor
- 0
- Aq
- 92
Citric acid C6H8O7
- Priority
- 55.2
- N
- 80
- Donor
- 8
- Aq
- 78
Formic acid CH2O2
- Priority
- 49.7
- N
- 28
- Donor
- 92
- Aq
- 64
Ammonia H3N
- Priority
- 47.9
- N
- 92
- Donor
- 0
- Aq
- 98
Glycine C2H5NO2
- Priority
- 47.7
- N
- 94
- Donor
- 0
- Aq
- 84
Pyridine C5H5N
- Priority
- 45.5
- N
- 90
- Donor
- 0
- Aq
- 96
Alanine C3H7NO2
- Priority
- 45
- N
- 88
- Donor
- 0
- Aq
- 80
Arginine C6H14N4O2
- Priority
- 43.8
- N
- 74
- Donor
- 18
- Aq
- 74
Zero-valent iron Fe
- Priority
- 43.5
- N
- 26
- Donor
- 88
- Aq
- 48
Zero-valent zinc Zn
- Priority
- 43
- N
- 24
- Donor
- 94
- Aq
- 52
Ethanol C2H6O
- Priority
- 36.9
- N
- 20
- Donor
- 26
- Aq
- 44
Dimethyl ether C2H6O
- Priority
- 36.5
- N
- 36
- Donor
- 0
- Aq
- 30
Water H2O
- Priority
- 33.5
- N
- 8
- Donor
- 0
- Aq
- 96
Butyric acid C4H8O2
- Priority
- 33.1
- N
- 24
- Donor
- 10
- Aq
- 60
Oleic acid C18H34O2
- Priority
- 28.9
- N
- 0
- Donor
- 16
- Aq
- 12
Hydrogen H2
- Priority
- 26.2
- N
- 16
- Donor
- 100
- Aq
- 6
Phenol C6H6O
- Priority
- 24.6
- N
- 0
- Donor
- 0
- Aq
- 76
Highest marker priorities
Strong acids, soluble nitrogen, pyridines, donors, and lipid markers decide the first pretreatment package
Sulfuric acid
strong acid nitrogen extraction reagent with corrosion/sulfate burden. Nitrogen signal 88; lipid signal 46; recovery signal 22; source IDs pretreat-sequential-low-n-2021.
Citric acid
milder acid for nitrogen solubilization and mineral chelation. Nitrogen signal 80; lipid signal 52; recovery signal 42; source IDs pretreat-sequential-low-n-2021.
Formic acid
in-situ hydrogen donor and oxygen-control candidate. Nitrogen signal 28; lipid signal 20; recovery signal 36; source IDs pretreat-water-research-2026-review.
Ammonia
TN removal and return-load marker. Nitrogen signal 92; lipid signal 0; recovery signal 34; source IDs pretreat-aqueous-recycle-2026; pretreat-htl-ad-2025.
Glycine
protein nitrogen extraction and Maillard precursor marker. Nitrogen signal 94; lipid signal 10; recovery signal 40; source IDs pretreat-sequential-low-n-2021; pretreat-rser-2025-review.
Pyridine
N-heterocycle accumulation and biology/catalyst burden marker. Nitrogen signal 90; lipid signal 4; recovery signal 28; source IDs pretreat-aqueous-recycle-2026.
Alanine
protein hydrolysis and soluble nitrogen marker. Nitrogen signal 88; lipid signal 12; recovery signal 38; source IDs pretreat-sequential-low-n-2021.
Arginine
hydrochar functionalization and nitrogen-doped residual marker. Nitrogen signal 74; lipid signal 12; recovery signal 36; source IDs pretreat-des-htc-2026.
Full experiment ledger
Unselected routes stay visible as deferred branches, not discarded assumptions
Water, citric, and sulfuric low-N pretreatment panel
Urgency 113.8; route score 40.3. Decides whether acid pretreatment meaningfully lowers downstream HDN burden.
Aqueous-recycle accumulation limit
Urgency 107.7; route score 24.6. Sets a recycle ceiling so yield gain does not degrade oil quality and plant biology.
Fe/Zn and formic donor screen
Urgency 106.5; route score 34.9. Tests if in-situ hydrogen can improve oil quality before imported H2 hydrotreating.
DME and ethanol solvent-recovery panel
Urgency 100.7; route score 43.3. Prevents solvent-enhanced yield from hiding recovery and safety penalties.
DES hydrochar support and residual assay
Urgency 66.7; route score 15.9. Determines whether DES belongs in residual/catalyst support work or should stay deferred.
pretreat-sequential-low-n-2021
Sequential hydrothermal processing of sewage sludge to produce low nitrogen biocrude
Hydrothermal pretreatment with water, sulfuric acid, or citric acid solubilized nitrogen-containing compounds while retaining crude lipids before HTL.
Open sourcepretreat-zvm-2025
Quality enhancement of sewage-sludge biocrude using zero-valent metals as hydrogen generators
2025 exploratory work using Fe and Zn as hydrothermal hydrogen generators for sewage-sludge-derived biocrude upgrading.
Open sourcepretreat-des-htc-2026
Deep eutectic solvent-assisted hydrothermal carbonization of sewage sludge
2026 DES-assisted HTC record reporting higher hydrochar carbon content and improved H/C and O/C ratios with arginine plus butyric acid.
Open sourcepretreat-rser-2025-review
Hydrothermal liquefaction of sewage sludge: biocrude oil, byproducts, and future perspectives
Open-access review reporting pretreatment classes, co-solvent and catalyst yield effects, and persistent heteroatom limits.
Open sourcepretreat-water-research-2026-review
Hydrothermal liquefaction of municipal sludge: biocrude production and fuel quality upgrading
2026 review linking pretreatment, catalytic HTL, fractionation, cracking, hydrotreating, and pilot integration gaps.
Open sourcepretreat-aqueous-recycle-2026
Balancing yield and quality: effects of aqueous phase recirculation in sewage sludge HTL
Six-cycle aqueous recirculation study showing yield increase but lower biocrude quality and accumulating N-heterocycles.
Open sourcepretreat-rti-solvent-2022
Hydrotreatment of solvent-extracted biocrude from HTL of municipal sewage sludge
Solvent extraction study showing strong differences in recovered biocrude yield, chloride burden, nitrogen-containing compounds, and hydrotreated oil quality.
Open sourcepretreat-dme-2022
HTC coupling with liquid dimethyl ether extraction pretreatment for low-nitrogen biocrude
Liquid DME extraction pretreatment source for hydrochar performance improvement and low-nitrogen biocrude production.
Open sourcepretreat-htl-ad-2025
Processing high-solid sludge through HTL to boost anaerobic fermentation and bioresource yield
2025 high-solid sludge HTL work connecting pressure/temperature to COD/TN removal, suspended solids reduction, and biogas response.
Open sourcea pretreatment route should not enter the fuel plan until nitrogen extraction, lipid retention, oil-yield response, aqueous burden, reagent recovery, corrosion, and residual fate are measured together. Modeling basis: pretreatment and donor-chemistry screen before municipal sludge HTL. Selected package: Aqueous-recycle control window; Ethanol-water co-solvent HTL; Fe/Zn zero-valent donor upgrade; Liquid DME lipid extraction pretreatment; Citric-acid low-nitrogen pretreatment; Water-only hydrothermal wash.