Supercritical fluid extraction

Our services

  • Process development and scale-up based on ideas of our customers and results from research projects
  • Process design and safety engineering
  • Plant design and engineering
  • Project evaluation, feasibility studies
  • Equipment selection and manufacturing
  • Supervision of erection and commissioning
  • Training of plant operators
  • Product development in our own R&D units and our pilot plant

Apart from customized plants for specific products and applications we supply multifunctional supercritical fluid extraction (SFE) plants. Each plant is usually equipped with 2 separators for fractionated separation. For all plants a co-solvent system can be supplied if required.

Current dense gas applications (CO2)

  • Food industry
    • Coffee, tea, hops, herbs & spices, flavours, antioxidants
    • Extraction of special oils
    • Deoiling of press cakes
    • Cleaning rice
  • Pharmaceutical industry
    • Extraction of herbal medicines
    • Refining of pharmaceuticals
  • Cosmetic industry
    • Active ingredients for cosmeceutical applications
    • Fragrances
  • Other applications
    • Cleaning of cork
    • Impregnation of wood

Possible dense gas applications (CO2)

  • Chemical reactions
    • Polymerization, hydrogenation
    • Catalytic hydrothermal gasification
    • Enzymic reactions
  • Material processing
    • Microencapsulation
    • Coating, dyeing
    • Aerogels
    • Particle formation
    • Impregnation
  • Cleaning
    • Dry cleaning
    • Cleaning of metallic parts
    • Soil reclamation
    • Removal of undesired substances
  • Special applications
    • Membrane-based separation
    • Microwave-inducted SCFE
    • Preparative SCFE
    • Sterilization
    • Thin film extraction

Liquid CO2 from the storage tank is pressurized, heated and transferred to the extractor, where it gets loaded with the extracts according to adjusted conditions. A change of these conditions (pressure, temperature) causes precipitation of the dissolved substances in the separation vessels. The now gaseous CO2 is condensed, intermediately stored and recycled again.

Process principles

  • Gases in fluid condition (above the critical pressure and the critical temperature) dissolve larger quantities of substances than the partial pressure of the substance in the solvent normally permits
  • CO2 is an APOLAR solvent, which results in a high solubility for non polar and low polar substances up to a molecular weight of 250g/molSolubility decreases with increasing polarity
  • Highly polar substances are insolubleThe raw material is exposed to the fluid and soluble substances are transferred into it
  • Separation is achieved by change of parameters (pressure and temperature) or adsorption into, for instance, active coal

Process schema for Supercritical fluid extraction plant

Supercritical fluid extraction

Process schema for Thin-film extraction plant

Thinfilm process

Advantages

  • CO2 is inexpensive, not combustible, not explosive, germicidal, free of bacteria, selective and mobile
  • Heat sensitive materials are gently treated
  • Products and residues are solvent-free
  • Fragrances and aromas remain unchanged
  • An excellent flavour profile can be achieved for oils
  • Pure extracts are produced with few process steps
  • The solvating power can be changed (conditions, or the use of modifiers)
  • Selective extraction and fractionated separation is possible
  • CO2 is recycled within the plant, is physiologically harmless and does not cause environmental problems like some conventional solvents

Disadvantage

  • High capital investment

Easy soluble

  • Esters, alcohols
  • Aldehydes, ketones
  • Volatile oils
  • Aromas
  • Mono- and Sesquiterpenes

Reduced solubility

  • Edible oil from oilseeds
  • Waxes
  • Polyphenols

Unsoluble

  • Sugars
  • Fruit acids
  • Starch
  • Proteins
  • Mineral salt
  • Glycosides