冷間通気用ユニット NECTACEL

溶媒ガス蒸気

Process solutions
Since its start-up, CELSIUS builds equipment for the pharmaceutical industries producing active ingredients by chemical synthesis. CELSIUS has developed the NECTACEL process for the extraction of natural molecules using liquefied gases. This process is applicable beyond pharmacy in cosmetics, perfumery, flavourings and food supplement industries.

GREEN CHEMISTRY
Nature contains a wealth of molecules with properties useful for healing, well-being, cosmetics, flavours, scents, nutraceuticals, etc. CELSIUS builds extractors to produce extracts, reagents, essential oils, concretes, absolutes or functional ingredients. Extraction units are designed for a specific matrix and extraction solvent. Possible solvents:

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

EXTRACTION OF NATURAL MOLECULES
Extraction is any process transferring molecules from a solid animal or plant substrate into a liquid phase. Terminology varies by trade (matrix, load, marc, cake, spent solids, etc.). The extraction process generally involves two successive phases:

• An extraction step in which the matrix is mixed with a solvent and the molecule of interest dissolves in the solvent (solvation, maceration, digestion, infusion, leaching, percolation…)
• A separation step to remove the solvent from the extract (evaporation, desolvation, crystallisation, etc.)

SOLVENT SELECTION CRITERIA
Essential criteria for choosing a solvent:

• Solvating power (polarity, ionic character)
• Ability to penetrate cell membranes
• Thermodynamic properties defining operating conditions and technology

Secondary and ethical criteria: solvent selectivity, renewable sources, low energy requirements, operation at temperatures that do not degrade the product.

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

• 1. Hydrodistillation: steam entrains the molecule, used for essential oils; limited to thermostable extracts.
• 2. Cold enfleurage: solid solvent (grease) used for delicate petals; difficult to industrialise.
• 3. Liquid solvent extraction: common liquid solvents (water, alcohols, hexane, toluene); requires solvent evaporation/condensation for separation; attention to residual solvent and recycling.
• 4. Liquefied gases: solvents that are gases at ambient conditions but used liquefied for extraction (advantages: ambient-temperature operation, inert/green solvent options, relatively low pressures vs. supercritical CO2).
• 5. R134a extraction with refrigeration unit: uses refrigerant Carnot cycle with compressor; more mechanical complexity and energy consumption.
• 6. Supercritical CO2 extraction: inert, safe, good solvent in supercritical state; operates at high pressures (practical extraction pressures often 300–500 bar) and used for pilot or dedicated very large units.

LIQUEFIED GAS TECHNIQUE (NECTACEL)
Liquefied gas extraction general schematic: extraction with liquid solvent, transfer to evaporator, solvent evaporates and is condensed in atmospheric condenser, solvent collected and recycled. Key implementation phases:

• Extraction phase: raw material in contact with liquid solvent
• Separation phase: solution transferred to evaporator, solvent evaporated then condensed
• Evaporator and extractor vacuum phase: solvent evaporated to separate and to desorb solvent from solid substrate (drying of spent raw material)

Important thermodynamic selection criteria for liquefied gases: the solvent must be liquid at near-ambient extraction temperature (vapour pressure typically < 10 bar at 35°C) and must have a condensation temperature at atmospheric pressure reachable with conventional refrigeration (practically > -30°C at Patm). Two gas families considered: alkanes and authorised refrigerant HFCs. Compared examples:

Table: comparison of some liquefied gases
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
NECTACEL pressurised extraction is designed to extract polar and non-polar molecules. Advantages vs supercritical CO2: lower investment cost, simpler infrastructure, possible on-site implementation at raw material production site. Liquefied gas extraction advantages include:

• Chemical inertness relative to matrix and extract; safety for exposure
• Extraction and separation at ambient temperature (good for heat-sensitive molecules)
• Small solvent molecules penetrate cell membranes
• Solvation properties extendable with co-solvents
• Extraction and separation at relatively low pressure (< 10 barg) without technological capacity limits

Common liquefied gases used in NECTACEL extractors: BUTANE, HFO1234ze, DME (dimethyl ether). CELSIUS builds extractors with no mechanical pumping parts (no circulation pump nor gas compressor, except vacuum pump for residue drying), low energy needs limited to solvent evaporation/condensation, and with virtually all solvent recycled. The liquefied gas extraction process and system with solvent recycling and without circulation pump are patented by CELSIUS. NECTACEL facilities are assemblies comprising extraction, filtration, solvent evaporation, extract concentration, condensation, storage and solvent recycling equipment; designed and assembled turnkey in CELSIUS workshops, compliant with PED/DESP and ATEX (for butane or DME) and CE. Pilot tests can be performed with pilot extractors (1 L capacity) at CELSIUS testing platforms.

Fields of application
Examples of targeted applications:

• Cannabidiol extraction from hemp
• Artemisinine extraction from Artemisia annua
• Oil extraction from oil cakes

caractéristiques / spécifications techniques

• Process name: NECTACEL (liquefied gas extraction process developed and patented by CELSIUS)
• Typical solvents: n-butane, HFO-1234ze (trans-1,3,3,3-tetrafluoroprop-1-ene), dimethyl ether (DME), supercritical CO2 (alternative process)
• Operation temperature: ambient-temperature extraction possible (advantage for heat-sensitive molecules)
• Operating pressure for liquefied gas extraction: typically < 10 barg; vapour pressure criterion: e.g. butane ~2.3 barg at 35°C, R134a ~7.9 barg at 35°C
• Condensation practical criterion: condensation temperature at Patm must be > -30°C
• Equipment: extractor, evaporator, condenser, solvent storage and recycling; typically no circulation pump or solvent compressor required
• Compliance: designed to meet PED/DESP 2014/68/EU and ATEX 2014/34/EU where applicable; CE marking
• Pilot capacities: pilot extractor 1 L; industrial units demonstrated (example: 200 L capacity unit)
• Extract forms: liquid, powder, suspension or solution in co-solvent; spent matrix dried before reopening extractor
• Applications: pharmaceuticals, cosmetics, flavours, scents, nutraceuticals; specific case studies include cannabidiol, artemisinine, oil extraction