Green Process Engineering Group

Research members:

Luca Fiori, Group Leader, Associate Professor –ING-IND/24
Roberta Ferrentino, Post Doc
Giulia Ischia, Ph.D student
Donato Scrinzi, Ph.D student
Ghanya Al-naqeb, visiting professor
Dominik Wust, Ph.D student  
Mostafa Ahmed Sattar, Ph.D student

Research and activities of our team are focused on the development of new technologies in Waste to Energy and Waste to Chemicals sectors.

Our competences in process, chemical and industrial engineering make our research activities focused on real life cases. The aim is valorising biomasses, such as agro-industrial residues and organic wastes, through experimental tests and process modelling simulations. By combining them, we are capable to simulate chemical-physical phenomena at lab- and industrial-scale level. Among all the technologies available for biomass thermochemical conversion (e.g. gasification, dry pyrolisis, combustion), we particularly deal with hydrothermal processes: supercritical water gasification and, especially, hydrothermal carbonization.

We have also high-level expertise in the food engineering sector. In this field, our research principally concerns the extraction of nutraceuticals (omega-3, antioxidants, food oils) contained in food residues by using supercritical CO2 or alternatively, classical chemical solvents or mechanical pressure.

HydroThermal Carbonization

HydroThermal Carbonization (HTC) is a thermochemical process for organic waste conversion into valuable products. During HTC, the organic matter in aqueous suspension is transformed in a short time (1-3 h) at moderate temperatures (180-250 °C) and pressures (10-50 bar) in a solid carbonaceous material, named hydrochar.


The hydrochar has different applications as:

  • Sustainable biofuel with a high heating value (25-30 MJ/kg). It can be used in form of pellets in domestic stoves or in district heating boilers;
  • Soil improver;
  • Precursor for activated carbon;
  • Precursor of catalyst;
  • Carbonaceous material for fuel cells electrodes.

Treated biomass

The HTC process is suitable for high moisture residues (>50 wt. %):

  • Organic fraction of municipal solid waste (OFMSW);
  • Agro-industrial residues (e.g. vine and oil processing by-products, manure, orange pomace…);
  • Pruning residues;
  • Sewage sludge;
  • Digestate (from anaerobic plant).

Advantages of HTC

  • It is a CO2 neutral process;
  • It is adaptable to a small scale industry context;
  • It could be implemented easily in existing plants (composting and anaerobic digestion plants);
  • The biomass can be used as it is, without pre-drying;
  • It is a simple and fast technology.

Supercritical CO2 Extraction

Concerning the food engineering field, we use supercritical CO2 (SC-CO2) as a solvent for extraction of biochemical products for food, pharmaceutical and cosmetic sectors.

Substrates utilized

  • Grape marc;
  • Seeds;
  • Agro-industrial waste;
  • Fish processing by-products;
  • Medicinal herbs.

Extracted bio-based substances

  • Natural antioxidants (e.g. polyphenols);
  • Grape seeds oil;
  • Omega-3 enriched oil;
  • Caffeine (in case of decaffeinated coffee).

Advantages of SC-CO2

  • CO2 is not toxic
  • CO2 is not flammable;
  • CO2 is ecologically sustainable;
  • For the highest quality of extracts obtained with respect the other extraction technologies, SC-CO2 extraction is used especially for high added-value extracts.

Moreover, we are specialized also in SC-CO2 fractionation. We apply this technique for obtaining omega-3 enriched concentrates starting from fish oil.

Laboratory equipment

Our lab is equipped with:

  • Lab scale HTC reactor (Working volume: 50 mL; design pressure: 140 bar; design temperature: 300 °C; material: AISI316).

  • Bench scale HTC reactor (Working volume: 2.5 L; design pressure: 140 bar; design temperature: 300 °C; material: AISI316). The reactor is monitored and controlled by software developed in LABView programming language. 

  • Calorimeter for HHV measurement.
  • Elemental analyzer for elemental composition (C, H, O, N, S) determination.
  • Supercritical CO2 extractor (Working volume: 500 mL; design pressure: 600 bar), equipped to work also with organic co-solvent (e.g. ethanol).

  • Soxhlet extractor, used with organic solvent (ethanol, hexane…).
  • Mechanical extractor;
  • Vacuum rotary evaporator;
  • Ovens, thermos-balance, grinders, vibrating screen.