Extraction with supercritical fluids in the pharmaceutical, cosmetic and food sectors

In the life science area, processing is increasingly done with fluids in the supercritical aggregate condition.

The advantage of these processes is in the use of solvents that are environmentally friendly and non-damaging to the product, mainly carbon dioxide. The requirements of the pharma & biotech markets are met by working at low temperatures and moderate pressures (gentle handling of the product).

The requirements for the metering and process diaphragm pumps are very specific in these applications.

Solutions for extraction with supercritical fluids

LEWA metering pumps and process diaphragm pumps are very well suited for supercritical processes, since they meet all the relevant requirements.

Advantages of LEWA pumps:

  • Hermetically tight
  • Layout of high pressure pumps and their peripheral equipment for liquid gases (refrigeration equipment)
  • Suitable for thin, non-lubricating fluids
  • High operational reliability
  • Low wear, almost no particle contamination due to minimal movement of pump head parts
  • Easy to clean, food design available
  • Hygienic design possible for pharmaceutical applications (Ra < 0.5 μm electro-polished, ASME BPE)
  • Installation in GMP areas/clean rooms
  • Material conforms to FDA (GRAS: Generally Recognized As Safe)
  • Installation possible in potentially explosive areas
  • Optimum pump head material, for example Hastelloy, available for highly corrosive media
  • Diverse connection geometries
  • Custom valves possible
  • Documentation on qualification/validation
  • Tested for wafer cleaning (Fraunhofer IPA Tested Device®)

It must be noted that carbon dioxide must be in the liquid state to be pumped. This is not practical in the gaseous state due to its compressibility.

Areas of application: Extraction and other supercritical processes with LEWA pumps

LEWA metering pumps and process diaphragm pumps have been successfully used in the following processes:

  • Extraction processes with supercritical CO2 (Supercritical Fluid Extraction SFE), such as decaffeination, degreasing, phytoextraction, as well as the extraction of oil seed, omega fish oil, flavors and spices
  • Supercritical preparative liquid chromatography (Supercritical Fluid Chromatography SFC), as well as separation of optically active substances
  • Supercritical Fluid Reactions SFR
  • Particle formation (e. g., Particles from Gas Saturated Solutions PGSS), such as high-pressure spraying process for pulverizing greases, baked goods, etc.
  • Cleaning processes, e.g., process integrated separation of substances, such as pesticide removal (wool grease, lanolin)
  • Cell breakdown, inactivation (gentle sterilization)
Supercritical fluids, CO2 Applications

Industrial scCO2-Applications

Principle of the PGSS process:

  1. Conditioning and melting two reactants 1 and 2
  2. Feed and compression with LEWA high pressure pumps P1, P2 and P3
  3. Mixing both reactants with supercritical fluid in a static mixer (SM)
  4. Decompression in a spray tower (SP) via a nozzle
  5. Droplet formation
  6. Cooling of droplets and particle formation
  7. Generation of powder in the spray tower with cyclone (ZK)
Extraction of supercritical fluids, Process scheme

Illustration: Principle of the PGSS process

Source: Department of Process Technology, Transport processes, and particle design - technology, University Bochum

 

 

Background for supercritical fluids

A supercritical fluid is a substance whose temperature and pressure are both over their critical point simultaneously (see diagram for CO2).

The critical temperature is the temperature over which the substance can no longer remain liquid, regardless of the pressure level.

Critical pressure is the pressure over which the substance can no longer form gas, regardless of the temperature.

Supercritical fluids have the density and good dissolving properties of fluids, as well as the viscosity, good compressibility, and diffusability of gases.

Due to their good mixing and mass transfer properties, they are classed as a fluid.

Important advantages of supercritical fluids:

  • Safe, cost-effective, environmentally friendly, non-toxic
  • They can replace organic solvents
  • Good influence over slight changes in operating conditions
  • Operating conditions under low temperature and pressure make them attractive for research and development in the pharmaceutical & biotechnology sector.

Selection criteria for the right supercritical fluid:

  • Physical-chemical properties of the desired mixture
  • Task of the solvent in the process in regards to solubility
  • Specific application
  • Safety, especially in regards to flammability, phase behavior under operating conditions
  • Cost of the fluid
  • Cost of the equipment

The most frequently used supercritical fluid is CO2.

Properties of carbon dioxide:

  • Low critical temperature (31.1°C)
  • Moderate critical pressure (73 bar)
  • Non-flammable
  • Non-toxic
  • Mixable with organic solvents
  • Recoverable after processing
  • Diffuses faster than conventional fluid solvents
  • GRAS status
  • Approved by the FDA for use in food and pharmaceuticals
  • Environmentally friendly
  • Cost-effective

Products

LEWA ecoflow diaphragm metering pump

LEWA ecoflow diaphragm metering pump

The ecoflow® diaphragm metering pump from LEWA is a true all-around talent in the field of metering and mixing and can be used in all industries.

LEWA ecoflow sanitary/hygienic

LEWA ecoflow sanitary food pump

The ecoflow® diaphragm metering pump in sanitary/hygienic design is the ideal pump for food and pharmaceutical products.

LEWA ecodos mechanical diaphragm pump

LEWA ecodos mechanical diaphragm pump

The ecodos® mechanical diaphragm metering pump from LEWA is suitable for all pumping and metering tasks in the low-pressure range.

LEWA FC laboratory pump

LEWA micrometering pump FC

The smallest flow rates and precise metering make LEWA micro-metering pumps of the FC series the first choice for laboratory pumps.

LEWA ecoflow process diaphragm pump

LEWA high pressure pump for process engineering

The LEWA ecoflow process diaphragm pump is the top performer among innovative and universal process pumps for high-pressure process technology.

LEWA triplex process pump

LEWA triplex high pressure pump for process engineering

LEWA triplex is the most compact process pump in the world for high-pressure processes in all branches of industry. Contact us, we are happy to help!

HMD Kontro

HMD Kontro centrifugal pump

HMD Kontro sealless permanent magnet driven centrifugal pumps offer exceptional benefits for handling toxic, aggressive, flammable, hazardous and costly fluids.

Customized production units

LEWA metering and mixing system

LEWA develops complete systems for metering, mixing, and filling fluids. Contact us and let us advise you!

Customer-specific metering systems

LEWA metering system

LEWA provides you with custom-designed metering systems according to your specifications. Put your trust in the experience gained from 60 years of metering technology in various industries.

Chemineer Mixing technology

Chemineer agitators

Chemineer agitators cover a wide range of products. From turbine agitators to impellers, these agitators can be used in almost any process that requires liquid or gas agitation.

Contact person

  • Sales Office Hungary
  • LEWA NIKKISO Austria GmbH - Hungarian Representative
  • +36 23 880-975
  • info@lewa.hu

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