FAQs

Even before testing supercritical fluid extraction on their products or raw materials, prospects frequently ask questions about costs and safety.

Q:  Is supercritical fluid extraction (SFE) expensive compared to other extraction methods?

A:  Today, commodity items such as coffee, hops, and spices are processed by SFE and are economically competitive with traditional organic solvent extraction.  Supercritical fluid extraction of nutraceuticals such as saw palmetto, antioxidants, and omega-3 concentrates can, in many instances, be even less expensive than traditional solvent extraction processes due to the elimination of solvent recovery steps.

Q:  Is SFE complex?

A:  Customarily SFE is simpler than traditional extraction processes: simplified clean-up and recovery of the SCF solvent, single-step extraction yielding often highly concentrated actives due to high selectivity of CO₂, and elimination of solvent residues in the product.

Q:  Is high pressure operation hazardous?

A:  With proper standard operating procedures and abiding by ASME standards, working at high pressure is a safe operation.  Supercritical CO₂ plants have been in operation in the US, Europe, and Asia since the late 1970s.  Additionally, CO₂ is non-toxic and non-flammable, unlike many organic solvents.

Q:  Will CO₂ emissions from SFE processes contribute to global warming?

A:  Industrial scale SFE does not generate any CO_2.  The CO₂ used for SFE is sourced from existing processes such as fermentation, and, thus, does not add emissions.

Q:  Is SFE equipment expensive?

A:  As in any commercial operation, equipment costs depend on many factors such as plant size and throughput, operating conditions, feed characteristics, markets, and selling price.  Case-by-case economic evaluations point out the commercial viability of products produced by SFE.

Q:  Will the SFE be too harsh on my material?

A:  Extractions can be carried out at much lower temperatures as compared to other separation or purification methods, such as molecular distillation and wiped film evaporation.  CO₂ extraction is often the preferred method for sensitive raw materials products. 

The Top Ten Effective Applications of Supercritical Fluids

Phasex Corporation has developed a series of Top Ten Lists that provide interesting information and insight about supercritical fluids; this one is about Applications and we continue to Discover What's Possible.

1. Medical Polymers - Residual monomers/by products are extracted near ambient temperature avoiding polymer degradation.
2. Nutraceuticals (phytosterols, carotenoids, specialty oils) - Concentrated active fractions are produced with simple sequential pressure reduction eliminating multiple solvent/distillation steps.
3. Implantable Tissue Scaffolds - Lubricants and surfactants are extracted without degradation of fiber networks.
4. Titanium and Ceramic Implants - Machining oils and lubricants are removed from porous surfaces without the use of detergents.
5. Reactive/heat labile compounds - Extraction of residual raw materials and by-products is accomplished near ambient temperature, eliminating possible reactions during high vacuum, high temperature wiped film evaporation.
6. Omega-3 Oils (EPA, DHA, GLA) - Extraction from yeast, fungal, botanical substrates using CO2 eliminates regulatory, technical, and purity issues present with hexane/heptane solvent processes.
7. Pharma and Agricultural Compounds - Nanoparticles are formed free of grinding media and surfactants.
8. Biofuels - Solvent-free extraction of products from sustainable sources.
9. High Performance Surfactants and Lubricants - Extraction of impurities and fractionation can tailor product properties and improve performance.
10. Advanced Materials - Deposition of coatings onto surfaces and impregnation of APIs into porous substrates are accomplished with no diffusional limitations.

                            

The Top Ten Benefits of Supercritical CO2 Extraction

Phasex Corporation has developed a Top Ten List providing interesting information and insight about supercritical fluid extraction services.

1. Single step extraction is tailored to achieve highly concentrated products.
2. Extracts and spent biomass are free of solvent residues.
3. Mild operating temperature ensures product stability and quality.
4. Supercritical CO2 is universally accepted as a "friendly" and fully recyclable solvent.
5. Product recovery is accomplished via a simple pressure reduction.
6. Hazardous solvent wastes are eliminated.
7. Compounds in a complex mixture can be selectively separated using the pressure dependent dissolving power of supercritical fluids.
8. Supercritical fluids can penetrate and extract from micro-porous substrates because of gas-like diffusion properties and the absence of surface tension limitations.
9. Lower operating costs are often realized because compression energy is more efficient than distillation energy.
10. Large scale supercritical fluid extraction of low price, commodity items such as coffee, tea, and saw palmetto indicates that supercritical CO2 processing can compete economically with traditional extraction and separation processes.