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 CO2. 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.
