Docker-Generated Response Surface

Optimization Lab

A 3D bench-design workspace for optimizing sewage-sludge HTL temperature, residence time, solids loading, catalyst family, and aqueous-phase recirculation before the next physical campaign.

864

response-surface candidates generated in Docker

8

bench runs selected for the first optimization portfolio

Ni-hydrochar catalyst

top modeled catalyst family in the balanced objective

43.6%

modeled yield for the top balanced run; best yield ceiling is 49.11%

Interactive Response Surface

Search temperature, residence, solids, catalyst, and aqueous-recycle choices together

Objective score61.1
Biocrude yield43.6%
Fuel quality100
Aqueous risk65.6
Frontier run

Ni-hydrochar catalyst at 350 C, 60 min, 15 wt% solids, 1x AP recycle

Fuel quality condition with 60.9% modeled energy recovery, 36.51 MJ/kg HHV,4.78% oil nitrogen, and 38.2 g H2/kg oil estimated upgrading burden.

Oil C
74.58%
Oil O
9.32%
Aqueous COD
79.2 g/L
NH3
4.83 g/L

Aqueous recycle is treated as a real tradeoff: the literature-backed branch can lift yield from 32.1% toward 40.2%, but the model also penalizes lower oil carbon, higher oxygen, COD, ammonia, and biological-return risk.

The Docker selector picked 8 runs from 864 modeled candidates. Portfolio average yield is 42.78%, average quality index is 92.1, and average aqueous risk is 71.9. Pyomo-formulated eight-run design-of-experiments portfolio with baseline, catalyst, recirculation, yield-ceiling, continuous-stress, and lower-temperature-quality gates; selected by deterministic category enumeration.

The current top run is Ni-hydrochar catalyst at 350 C, 60 min, 15 wt% solids, 1x AP recycle. It is a bench priority, not a recipe, until real product separation, hydrotreating, catalyst carryover, aqueous treatment, and LCA data are measured.

RDKit marker molecules keep the response surface tied to lipid, protein, carbohydrate, aqueous COD, oil nitrogen, oxygenate, fuel proxy, and oxidant chemistry.

Current optimization decision

Run a measured portfolio around Ni-hydrochar, aqueous recycle, and a no-catalyst control

The response surface ranks Ni-hydrochar at 350 C, 60 min, 15 wt% solids, and one aqueous-phase recycle as the strongest balanced run. The selected portfolio deliberately includes a baseline, a 3x and 6x recycle tradeoff, acid hydrochar, CuSO4 reference chemistry, a 20 wt% solids stress condition, and a lower-temperature quality check so the team can learn why the optimum works instead of only testing the single best-looking condition.

Composition anchor48% DAF yield

Published optimized sludge-composition work is carried as a high-performance benchmark with 69% energy recovery.

Recycle anchor32.1% to 40.2%

AP recycle can raise yield, but the same branch is penalized for carbon dilution, oxygen increase, COD, ammonia, and return-load risk.

Surrogate anchorR2 0.89

ML-aided TEA/LCA is treated as a planning aid; measured data still controls product, economics, and climate claims.

Selected bench portfolio

Eight-run portfolio to find the next real optimum

baseline control

No catalyst baseline

350 C, 60 min, 15 wt% solids, 0x AP recycle. Yield 36.32%, quality 100, aqueous risk 52.7.

balanced Ni-hydrochar

Ni-hydrochar catalyst

350 C, 60 min, 15 wt% solids, 1x AP recycle. Yield 43.6%, quality 100, aqueous risk 65.6.

middle recirculation

Ni-hydrochar catalyst

350 C, 60 min, 15 wt% solids, 3x AP recycle. Yield 46.78%, quality 84.9, aqueous risk 90.3.

yield ceiling

Ni-hydrochar catalyst

350 C, 40 min, 15 wt% solids, 6x AP recycle. Yield 48.45%, quality 52, aqueous risk 100.

acid hydrochar

Acid-activated hydrochar

350 C, 60 min, 15 wt% solids, 1x AP recycle. Yield 41.32%, quality 100, aqueous risk 65.

CuSO4 reference

CuSO4 reference catalyst

350 C, 60 min, 15 wt% solids, 1x AP recycle. Yield 42.09%, quality 100, aqueous risk 66.7.

continuous solids stress

Ni-hydrochar catalyst

350 C, 60 min, 20 wt% solids, 1x AP recycle. Yield 42.46%, quality 100, aqueous risk 71.

lower-temperature quality

Ni-hydrochar catalyst

325 C, 60 min, 15 wt% solids, 1x AP recycle. Yield 41.23%, quality 100, aqueous risk 64.2.

Response-surface averages

Temperature and aqueous recycle change yield and quality together

300 C / 0x
Yield
23.6%
Quality
100
Energy
47.7%
Water risk
51
300 C / 1x
Yield
25.76%
Quality
99.4
Energy
47.6%
Water risk
63.2
300 C / 3x
Yield
29.09%
Quality
80.6
Energy
46.5%
Water risk
88
300 C / 6x
Yield
31.65%
Quality
47.8
Energy
43.2%
Water risk
100
325 C / 0x
Yield
34.14%
Quality
100
Energy
55.4%
Water risk
52
325 C / 1x
Yield
36.43%
Quality
99.6
Energy
55.3%
Water risk
64.3
325 C / 3x
Yield
39.6%
Quality
82
Energy
54.2%
Water risk
89
325 C / 6x
Yield
42.22%
Quality
49.3
Energy
50.9%
Water risk
100
350 C / 0x
Yield
36.56%
Quality
100
Energy
57.1%
Water risk
53.1
350 C / 1x
Yield
38.71%
Quality
99.7
Energy
57%
Water risk
65.5
350 C / 3x
Yield
42.09%
Quality
81.9
Energy
55.9%
Water risk
90.2
350 C / 6x
Yield
44.7%
Quality
49.3
Energy
52.7%
Water risk
100
360 C / 0x
Yield
35.28%
Quality
100
Energy
56%
Water risk
53.4
360 C / 1x
Yield
37.42%
Quality
99.5
Energy
55.8%
Water risk
65.9
360 C / 3x
Yield
40.76%
Quality
80.7
Energy
54.8%
Water risk
90.6
360 C / 6x
Yield
43.4%
Quality
47.9
Energy
51.5%
Water risk
100

Catalyst ledger

Catalysts are ranked as bench candidates, not deployment decisions

Recycled hydrochar catalyst

Ni-hydrochar catalyst

Best score
61.1
Best yield
49.11%
Mean quality
83.6
Water risk
76.4
Recycled hydrochar catalyst

Acid-activated hydrochar

Best score
57.5
Best yield
47.75%
Mean quality
83.2
Water risk
76.8
Soluble metal salt

CuSO4 reference catalyst

Best score
57.1
Best yield
48.32%
Mean quality
82.5
Water risk
77.5
Recycled hydrochar catalyst

KOH-activated hydrochar

Best score
56.5
Best yield
46.79%
Mean quality
83.9
Water risk
76.5
Soluble metal salt

FeSO4 low-cost salt

Best score
55.6
Best yield
46.73%
Mean quality
81.9
Water risk
76.6
Control

No catalyst baseline

Best score
53.9
Best yield
43.84%
Mean quality
79
Water risk
76

Molecular anchors

Representative chemistry behind the optimization surface

mild pretreatment marker

Citric acid C6H8O7

Weight
73.6
MW
192.123
C atoms
6
Hetero
7
carbohydrate oxygen proxy

Glucose C6H12O6

Weight
66.6
MW
180.156
C atoms
6
Hetero
6
lipid oil-yield proxy

Oleic acid C18H34O2

Weight
51.8
MW
282.468
C atoms
18
Hetero
2
protein nitrogen proxy

Glycine C2H5NO2

Weight
49.7
MW
75.067
C atoms
2
Hetero
3
oil nitrogen marker

Pyridine C5H5N

Weight
39
MW
79.102
C atoms
5
Hetero
1
aqueous pretreatment marker

Ozone O3

Weight
39
MW
47.997
C atoms
0
Hetero
3
aqueous COD marker

Acetic acid C2H4O2

Weight
34.2
MW
60.052
C atoms
2
Hetero
2
aqueous nitrogen marker

Ammonia H3N

Weight
33.5
MW
17.031
C atoms
0
Hetero
1
carbon-balance marker

Carbon dioxide CO2

Weight
33.1
MW
44.009
C atoms
1
Hetero
2
aromatic oxygen marker

Phenol C6H6O

Weight
31.6
MW
94.113
C atoms
6
Hetero
1
finished-fuel proxy

Dodecane C12H26

Weight
31.2
MW
170.34
C atoms
12
Hetero
0
upgrading reagent

Hydrogen H2

Weight
18
MW
2.016
C atoms
0
Hetero
0
opt-sludge-composition-2025

Municipal sludge composition and HTL performance optimization

Supports treating feedstock composition, biocrude elemental quality, HHV, and energy recovery as linked optimization outputs.

Open source
opt-cuso4-optimization-2025

Municipal sludge HTL optimization with CuSO4 catalyst

Supports metal-salt catalyst and response-surface style optimization around operating conditions.

Open source
opt-ni-hydrochar-2025

Ni-hydrochar catalytic sludge HTL

Supports recycled hydrochar catalyst screening at roughly 350 C, 60 min, and 5 wt% loading as a high-value bench branch.

Open source
opt-aqueous-recirculation-2026

Aqueous phase recirculation in sewage-sludge HTL

Supports explicitly modeling recirculation as a yield/quality tradeoff rather than assuming recycled aqueous phase is free upside.

Open source
opt-ml-tea-lca-2025

Machine-learning-aided LCA and TEA for sludge HTL

Supports using surrogate models as planning tools while preserving measured TEA/LCA validation gates.

Open source
opt-continuous-pfr-2025

Continuous plug-flow sludge HTL modeling and optimization

Supports carrying batch optimization into continuous residence-time, heat-transfer, and operability questions.

Open source
opt-ozone-aqueous-2025

Ozonation and anaerobic digestion of HTL aqueous phase

Supports testing aqueous-phase pretreatment near an optimum ozone dose before returning water to biological treatment.

Open source
opt-aqueous-cotreatment-2025

Co-treatment of HTL wastewater in activated-sludge systems

Supports measuring biological compatibility, settling, and effluent quality when HTL water is blended into WRRF treatment.

Open source

optimization output is a bench-experiment plan, not a proven recipe, until every selected condition has measured oil, gas, char, aqueous, upgrading, TEA, and LCA data