UniversaBio Fuel

Docker-Generated Additive Screen

Molecule Additive Lab

A 3D discovery lab for candidate hydrogen donors, mineral salts, pretreatment acids, co-solvents, reducing metals, and upgrading catalysts that could improve sewage-sludge HTL biocrude.

12

candidate molecules/materials scored

10

RDKit-parsed candidate structures

Formic acid

top individual candidate

325 C

literature-aligned HTL screen temperature

Interactive Additive Twin

Molecule, salt, and catalyst package screen

Package score61.8
Candidate score54.3
N/O control66/60.7
Residual risk38

Best bench package to test first. Combines an HTL hydrogen donor, mineral/P steering, and upstream nitrogen solubilization, but the combination itself still needs lab validation.

Liquid hydrogen donor

Formic acid CH2O2

Directly studied with municipal sludge HTL as a green liquid hydrogen donor at 325 C and 30 min, with and without heterogeneous catalysts.

Dose, corrosion, gas pressure, carbon efficiency, catalyst compatibility, and whether it lowers N/O enough on site sludge.
Mineral steering salt

Magnesium chloride MgCl2

Reported to reduce N/O in sewage sludge biocrude while steering phosphorus recovery and raising HHV in Mg-assisted HTL.

Chloride corrosion, magnesium dose, metal co-mobilization, phosphorus product purity, and aqueous treatment burden.
Mild pretreatment acid

Citric acid C6H8O7

Mild hydrothermal pretreatment with citric acid is a low-nitrogen biocrude lead because it can solubilize nitrogen before HTL.

Nitrogen removal selectivity, organic carbon loss, acid recycle, metals solubilization, and integration with HTL throughput.

The Docker selection model picks Formic acid + Magnesium chloride + Citric acid as the first bench additive package under hydrogen-donor, nitrogen-control, phosphorus-steering, and residual-risk gates. Pyomo-formulated three-additive selection with hydrogen-donor, nitrogen-control, phosphorus-steering, and residual-risk gates; external H2, downstream catalysts, and aqueous recycle are kept as comparison candidates but excluded from the first bench additive package.

Current additive decision

Test an additive package, not a single molecule claim

The screen ranks formic acid as the strongest individual additive lead because it is directly tied to municipal-sludge HTL hydrogen-donor literature. The best first package is formic acid plus MgCl2 plus citric pretreatment: donor chemistry, phosphorus/mineral steering, and nitrogen control. This is still a bench plan, not a production recipe.

Best bench package to test first

Formic acid + MgCl2 + citric pretreatment

61.8

Combines an HTL hydrogen donor, mineral/P steering, and upstream nitrogen solubilization, but the combination itself still needs lab validation.

H donor
33.3
N/O control
66/60.7
P steering
46.7
Residual risk
38
Downstream upgrading benchmark

Hydrogen + dual-base ZSM-5 + demetallization guard

46.1

Defines the fuel-quality ceiling, but it is not a complete sludge-to-fuel answer unless hydrogen and catalyst life close.

H donor
50
N/O control
64/87
P steering
0
Residual risk
23
Product-slate experiment

Ethanol co-solvent + formic acid + ZSM-5

45.9

Targets lighter oil fractions and deoxygenation while carrying solvent recovery and catalyst coking questions.

H donor
41.3
N/O control
42/65.3
P steering
4
Residual risk
26
Yield-forward but water-risk heavy

Aqueous recycle + KOH + formic acid

38.1

May raise liquid yield, but oxygen/nitrogen and aqueous recycle accumulation can undermine fuel quality.

H donor
32.7
N/O control
34/44
P steering
14
Residual risk
38.7
High-discovery, high-residual-risk watch item

Zero-valent Fe + Ni hydrochar

37.5

Could generate reducing conditions and catalytic activity, but metal residuals and spent catalyst classification dominate the risk.

H donor
48
N/O control
45/56
P steering
36
Residual risk
63

Generated bench package

Pyomo-gated additive selection

62.4

Formic acid

Dose, corrosion, gas pressure, carbon efficiency, catalyst compatibility, and whether it lowers N/O enough on site sludge.

53.4

Magnesium chloride

Chloride corrosion, magnesium dose, metal co-mobilization, phosphorus product purity, and aqueous treatment burden.

47

Citric acid

Nitrogen removal selectivity, organic carbon loss, acid recycle, metals solubilization, and integration with HTL throughput.

Candidate ledger

Each molecule is scored against fuel quality and residual risk

Liquid hydrogen donor62.4

Formic acid CH2O2

Directly studied with municipal sludge HTL as a green liquid hydrogen donor at 325 C and 30 min, with and without heterogeneous catalysts.

H donor
86
N control
50
Metal risk
22
RDKit MW
46.025
External/upgrading reactant56.5

Hydrogen H2

Hydrogen is still the benchmark molecule for HDN/HDO after HTL; it defines how far a sewage biocrude can move toward diesel-range fuel.

H donor
100
N control
82
Metal risk
8
RDKit MW
2.016
Mineral steering salt53.4

Magnesium chloride MgCl2

Reported to reduce N/O in sewage sludge biocrude while steering phosphorus recovery and raising HHV in Mg-assisted HTL.

H donor
2
N control
70
Metal risk
58
RDKit MW
95.211
In-situ reducing metal49.2

Zero-valent iron Fe

Zero-valent metals are being tested as in-situ hydrogen generators for sewage-sludge biocrude quality enhancement under hydrothermal conditions.

H donor
72
N control
46
Metal risk
54
RDKit MW
55.845
Mild pretreatment acid47

Citric acid C6H8O7

Mild hydrothermal pretreatment with citric acid is a low-nitrogen biocrude lead because it can solubilize nitrogen before HTL.

H donor
12
N control
78
Metal risk
34
RDKit MW
192.123
Water-alcohol co-solvent39.5

Ethanol C2H6O

Water-ethanol co-solvent work on fecal sludge and organic solids suggests product-slate steering toward lower-phenolic, naphtha-rich biocrude.

H donor
38
N control
30
Metal risk
18
RDKit MW
46.069
In-situ reducing metal36.7

Zero-valent zinc Zn

Zinc can generate reducing equivalents, but it creates a regulated-metal residual problem for sewage-derived products.

H donor
70
N control
42
Metal risk
82
RDKit MW
65.39
Circular heterogeneous catalyst35.8

Nickel-loaded hydrochar Ni/C

Ni-based hydrochar has been tested as a catalyst for municipal sewage sludge HTL and links catalyst development to residual carbon.

H donor
24
N control
44
Metal risk
72
RDKit MW
58.693
Upgrading catalyst35.7

Dual-base modified ZSM-5 Al2O3/SiO2

2026 municipal sludge biocrude upgrading work reports substantially higher deoxygenation with dual-base modified ZSM-5.

H donor
0
N control
46
Metal risk
38
RDKit MW
material
Alkaline HTL catalyst34.3

Potassium hydroxide KOH

KOH is a common homogeneous catalyst screen for digestate/sludge HTL yield and product distribution.

H donor
0
N control
34
Metal risk
44
RDKit MW
56.105
Iron salt catalyst33.2

Ferrous sulfate FeSO4

Older wet-sludge hydro-liquefaction work reported high conversion and energy recovery with FeSO4 under selected conditions.

H donor
0
N control
28
Metal risk
66
RDKit MW
151.908
Process-water additive loop29.7

HTL aqueous phase recycle mixed organics

Aqueous recycle can increase bio-crude yield, but recent work shows it can worsen oxygen content and leave nitrogen persistent.

H donor
12
N control
18
Metal risk
50
RDKit MW
material
additive-formic-2021

Catalytic hydrothermal liquefaction of municipal sludge assisted by formic acid

Municipal sludge HTL at 325 C and 30 min using formic acid as a green liquid hydrogen donor.

Open source
additive-zvm-2025

Zero-valent metals as hydrogen generators for sewage-sludge biocrude upgrading

Exploratory Fe/Zn in-situ reducing route for quality enhancement under hydrothermal conditions.

Open source
additive-mgcl2-2024

Low-N/O biocrude and nitrogen/phosphorus recovery from sewage sludge HTL with MgCl2

MgCl2-assisted HTL lead for lower N/O biocrude, phosphorus recovery, and higher HHV.

Open source
additive-ethanol-cosolvent-2024

Water-ethanol co-solvent co-HTL for low-phenolic, naphtha-rich biocrude

Adjacent fecal-sludge/organic-solids evidence for solvent-guided product-slate control.

Open source
additive-koh-digestate-2023

Sewage sludge anaerobic digestate HTL with KOH catalyst screening

Temperature, residence time, and KOH catalyst screen for sewage sludge digestate bio-oil.

Open source
additive-feso4-2015

Wet sewage sludge thermochemical hydro-liquefaction with FeSO4 catalyst

Older wet-sludge liquefaction result reporting high conversion and energy recovery with FeSO4 under selected conditions.

Open source
additive-ni-hydrochar-2025

Municipal sewage sludge HTL with Ni-based hydrochar catalyst

2025 municipal sludge HTL catalyst lead connecting hydrochar reuse and nickel catalysis.

Open source
additive-zsm5-2026

Dual-base modified ZSM-5 for municipal sludge hydrothermal biocrude upgrading

2026 upgrading lead reporting improved deoxygenation for municipal sludge hydrothermal biocrude.

Open source
additive-sequential-2021

Sequential hydrothermal processing of sewage sludge for low-nitrogen biocrude

Mild pretreatment route using acid/water steps before HTL to lower nitrogen transfer into biocrude.

Open source
additive-aq-recycle-2025

Aqueous phase recirculation in sewage sludge HTL: yield and quality tradeoffs

Recent evidence that aqueous recirculation can lift bio-crude yield while worsening oxygen content and leaving nitrogen persistent.

Open source
additive-review-2025

Hydrothermal liquefaction of sewage sludge review: production, byproducts, and future perspectives

2025 review quantifying sludge biocrude heteroatom challenges and catalyst classes.

Open source
additive-mild-hdt-2026

Mild hydrotreatment stabilization of nitrogen-rich sewage sludge biocrude

Pilot-scale stabilization context showing oxygen/chlorine/sulfur can move faster than persistent nitrogen.

Open source