Unidade de extração a frio NECTACEL

de solventede gásde vapor

Process solutions
Since its start-up, CELSIUS has built equipment for the pharmaceutical industries producing active ingredients by chemical synthesis. CELSIUS also develops processes for the extraction of natural molecules for industries beyond pharmacy (cosmetics, perfumery, flavourings, food supplements). For this industry CELSIUS has developed the NECTACEL process for the extraction of natural molecules using liquefied gases.

GREEN CHEMISTRY
CELSIUS presents NECTACEL extraction processes and equipment that leverage plant chemistry principles and aim at safety, optimised resource management, energy savings and environmental protection.

• Extraction solvents considered: Steam
• Water
• Alcohol
• Hexane, Toluene, etc.
• Green solvents
• Liquid gases

EXTRACTION OF NATURAL MOLECULES
By extraction of natural molecules is meant any process used to transfer molecules from a solid animal or plant substrate to a liquid phase. Depending on the trade, raw material is referred to as matrix, load, solid, plant, bagasse, etc. Once consumed by extraction, residues remain (cake, spent solids, marc, insolubles…).

The process involves two successive phases:

• An extraction step: matrix is intimately mixed with a solvent; the molecule of interest dissolves in the solvent (terms used: solvation, maceration, digestion, decoction, infusion, leaching, elution, trituration, percolation, etc.).
• A separation step: solvent is removed from the extract (evaporation, boiling, desolvation, crystallisation) and the residual extract may be liquid, solid or suspension.

SOLVENT SELECTION CRITERIA
The essential criteria for selecting a solvent are:

• The solvating power of the desired molecule (polarity/ionic character).
• Solvent’s ability to cross cell membranes (molecule size).
• Thermodynamic properties defining operating conditions and required technologies.

Secondary and ethical criteria include solvent selectivity, the use of renewable/green or recycled solvents, low energy requirement and operating temperatures that do not degrade the product.

EXTRACTION PROCESSES
Extraction processes differ depending on solvent state (gaseous, solid, liquid, supercritical). Main processes described:

• Hydrodistillation: steam entrains volatile molecules (used for essential oils), limited to extracts tolerating vapour temperature.
• Cold enfleurage: solid solvent method (e.g., flower petals on grease); difficult to industrialise.
• Liquid solvent extraction: common solvents include water, alcohols, hexane, toluene. Solvent/solute separation requires evaporation/pressure reduction and recycling considerations.
• Liquefied gases: solvents that are gases at ambient conditions but used in liquid state for extraction. Advantages: operation at ambient temperature (preserve heat-sensitive molecules), inert/green solvents possible, relatively low pressure compared to supercritical CO2 and often no mechanical pumping required.
• R134a extraction with refrigeration unit: uses refrigerant properties and a gas compressor (higher mechanical complexity and energy consumption).
• Supercritical CO2: inert, safe and effective in supercritical state but requires high pressures (in practice 300–500 bar for extraction) and higher equipment investment; suited to pilot or dedicated large-scale units.

LIQUEFIED GASES: GENERAL SCHEME AND ADVANTAGES
Typical scheme: liquid solvent extraction → evaporation → condensation → solvent recycling. Advantages include ambient-temperature extraction, inert solvents, small solvent molecules penetrating cell membranes, and relatively low operating pressures enabling onsite units with lower investment vs supercritical CO2.

Table: Liquid gas properties
Liquid gas | Butane C4H10 | R134a (1,1,1,2-tetrafluoroethane C2F4H2)
Boiling point at Patm | -0.5°C | -26°C
Vapour pressure at 35°C | 2.3 barg | 7.9 barg

NECTACEL PRESSURISED PROCESS
The NECTACEL pressurised extraction process developed by CELSIUS is intended to allow extraction of polar or non-polar plant/animal molecules. Key points and advantages:

• Designed for solvent-based extraction using liquefied gases (examples: BUTANE, HFO1234ze, DME dimethyl ether).
• No mechanical pumping parts in extractors (no circulation pump nor gas compressor) except a vacuum pump for final drying of residues.
• Limited energy needs essentially for solvent evaporation and condensation.
• Virtually all solvent is recycled; process and system patented by CELSIUS.
• Facilities can be multi-purpose or dedicated, laboratory or industrial scale, and are assembled turnkey in CELSIUS workshops; compliance cited with DESP 2014/68/EU and ATEX 2014/34/EU (in the case of butane or DME).

IMPLEMENTATION & APPLICATIONS
Celsius can perform qualitative tests on pilot extractors (e.g., 1 litre pilot units). NECTACEL installations may deliver extracts as liquid, powder, suspension or solution in a co-solvent. Applications include pharmaceuticals, cosmetics, flavours, scents, nutraceuticals; specific application examples highlighted on the page are cannabidiol extraction from hemp, artemisinine extraction from Artemisia annua and oil extraction from oil cakes.

Notes
The process emphasises safety, optimized resource management, energy saving and environmental protection. Thermodynamic selection criteria for solvents include working vapour pressure (practical limit: vapour pressure should not exceed ~10 bar at 35°C) and condensation temperature achievable with conventional refrigeration (practical limit: condensation temperature higher than -30°C at atmospheric pressure).

Caractéristiques / spécifications techniques

• Commercial process name: NECTACEL
• Manufacturer / provider: Celsius Process (CELSIUS)
• Solvent families usable: liquefied alkanes (butane), HFC/HFO refrigerants (e.g., R134a, HFO1234ze), dimethyl ether (DME), also conventional liquids (water, alcohols, hexane, toluene) and supercritical CO2 for specific cases.
• Extraction temperature: ambient temperature operation possible (advantage for heat-sensitive molecules).
• Practical vapour pressure criterion: typically <= 10 bar at 35°C for extractor liquid phase.
• Condensation temperature criterion: condensation temp at atm should be > -30°C for conventional refrigeration.
• Evaporation/condensation performed isobarically and isothermally in NECTACEL cycle; no solvent compressor or pump required for recycling.
• Typical equipment features: extractor, filtration, solvent evaporation, extract concentration, condenser, storage and solvent recycling; assembled turnkey.
• Regulatory / safety compliance mentioned: DESP 2014/68/EU and ATEX 2014/34/EU (when applicable).
• Pilot/test capacities referenced: 1 L pilot extractors and larger industrial units (examples cited up to 200 L).
• Industrial advantages vs alternatives: lower investment and infrastructure than supercritical CO2; ability to install units near raw material production sites.