V-Hydronovum
ESEN

Hydrothermal liquefaction (HTL) for wet organic waste

We turn sewage sludge, digestates and other wet waste into biocrude, with no need to dry it first.

V-Hydronovum · Five Bioenergy Group
See how it works Products
Vertical HTL reactor: natural turbulence, no mechanical stirring
  • up to 80%moisture in the feed
  • 275–374 °Cprocess temperature
  • 100–250 barsubcritical water
  • >95%energy recovery

How an HTL plant works

Follow the waste on its way through the plant: it goes in as wet sludge and comes out separated into four products. Click on each stage or piece of equipment to see what happens.

Swipe to see the whole plant

Animated diagram of a hydrothermal liquefaction plant The waste passes through the reception and grinding tank, the feed pump, the heat-recovery exchanger and the vertical reactor. The hot product flows back through the exchanger to preheat the incoming feed and reaches the centrifuge, which separates it into process gas, biocrude, aqueous phase and biochar. Reception filter and mill Pumping pressurised Heat recovery concentric tubes HTL reactor vertical · 275–374 °C Centrifuge Process gas Biocrude Aqueous phase with N and P Biochar
  • Wet waste
  • Hot product preheating the feed
  • Cooled product to separation

Reception and pre-treatment

The sewage sludge or digestate arrives at the reception tank and goes through a turbo-filter and a mill. There is no need to dry it first.

Up to 80% moisture

HTL: direct conversion of wet biomass

The waste is heated with water at high pressure. Under these conditions the organic matter is transformed into biocrude, biochar, aqueous phase and gas.

Process conditions

Temperature
275–374 °C (moderate)
Pressure
100–250 bar (subcritical water)
Feed
up to 80% moisture
Residence time
10–60 minutes

  • No prior drying

    Removes the main energy penalty.

  • More bio-oil

    35–50% compared with 20–30% in pyrolysis.

  • >95% energy recovery

    Practically energy-neutral operation.

  • Nutrient recovery

    N and P in the aqueous phase.

Ideal for wet organics and digestates: no energy-intensive drying

Process products

The plant for sewage sludge and digestates has biocrude, process gas and aqueous phase as its main products.

Biocrude

Fuel or a product for sale.

Process gas

Gaseous fraction generated during the reaction.

Aqueous phase

Contains recoverable nitrogen and phosphorus.

Biochar

Used in compost and to enhance anaerobic digestion.

Product distribution (wt%)

Bio-oil28–34%
Biochar46–56%
Aqueous15–20%
Gas5–10%

Laboratory results. Conditions: 350 °C | 20 min | 15–20% solids | subcritical pressure.

> 0.95Energy recovery ratio

Almost energy-neutral operation.

+16–25%Biogas increase with biochar

At a dose of 7.5 g/L in anaerobic digestion.

HTL results by feedstock

Bio-oil yield obtained in a 600 mL laboratory reactor.

FeedstockChartwt%
Used cooking oil (UCO)
80.6
Finished leather
73.4
100 % PE
51.2
Cosmetic sludge
47.0
Sewage sludge
44.8
Diapers
38.2
FS Bioselval
34.3

Optimal HTL conditions: 325 °C · 30 min · S/L 0.20. In-house laboratory-scale tests.

8 years of innovation (2017–2025)

From laboratory research to the design of the pre-industrial plant.

  1. 2017–2019

    Foundation

    Initial R&D with a range of feedstocks.

  2. 2020–2022

    Optimisation

    Fine-tuning of the process parameters.

  3. 2023–2024

    Scale-up

    Design and engineering of the pre-industrial plant.

  4. 2025

    Patent and launch

    IP protection and launch of V-Hydronovum.

Patent P202530312

“Hydrothermal carbonisation, liquefaction and gasification plant”. Filed on 14 April 2025. Multi-process HTC · HTL · HTG design on a single platform.

"La Conselleria de Innovación, Industria, Comercio y Turismo ha concedido a V-HYDRONOVUM, S.L. una subvención de 189.735,30€ en la convocatoria de ayudas para apoyar las inversiones para la reindustrialización realizadas por las pymes de diversos sectores industriales de la Comunitat Valenciana. INPYME 2026. El proyecto consiste en la adquisición e instalación de una planta industrial de Licuefacción Hidrotermal (HTL) de baja capacidad para el tratamiento de lodos de EDAR y digestatos orgánicos, con producción de biocrudo, gas de proceso y fase acuosa como productos principales. INPYME/2026/873"