Supercritical Fluid Applications: Industrial Developments and Economic Issues

Abstract

:This lecture intends to give a brief overview of the status of Supercritical Fluid industrial applications and to draw some prospective trends. Based on the know-how gathered by SEPAREX along these 20 last years of work on many supercritical fluids applications and manufacture of more than 80 plants at pilot scale or industrial scale, economic evaluations and comments about design, maintenance and operation of supercritical fluid plants will be presented. Present status of industrial applications :During the last two decades, except for processes used in the petroleum industry -that are not in the scope of this lecture -industrial applications have been mostly developed for natural products extraction/fractionation, both for food and pharmaceutical products (Hundreds of references are available in literature ; I advice the reader to begin by [1][2][3][4][5][6][7]) . At present time, these applications are still continuing to slowly spread worldwide with a wide potential of capacity increase as high quality products are more and more required and environment/health problems are more and more taken into account.• Extraction (SFE) from solid materials is the most developed application, mainly for food products (coffee, tea,…), food ingredients (hops and aromas, colorants, vitamin-rich extracts, specific lipids, …) and nutraceuticals/ phytopharmaceuticals. Residual organic solvent or other impurities, like pesticides, are also removed from final active compounds or food ingredients/nutraceuticals (like ginseng) at large scale [1][2][3][4][5][6][7]. I estimate the number of industrial-scale SFE units now under operation on natural products about 100 (or slightly over) with a growth of about 10% per year.Some "niches" applications concern high-added value products, like delipidation of bones for allografts preparation, or specialty polymer stripping.• Fractionation (SFF) of liquid mixtures are designed to take profit of the very high selectivity of supercritical fluids with attractive costs related to continuous operation ; nevertheless, few industrial units are now used for aromas production from fermented and distilled beverages, fractionation of polyunsaturated fatty acids and polar lipids, polymer fractionation (specialty lubricants, pharmaceuticals,…), recovery of active compounds from fermentation broths, pollution abatement on aqueous streams,….• Preparative Scale Supercritical Fluid Chromatography (PSFC) is operated for ultimate fractionation of very similar compounds, especially for lipids like polyunsaturated fatty acids in a few large-scale units.•

Supercritical Carbon Dioxide Drying of Methanol−Zinc Borate Mixtures

“…Supercritical fluids have been used in areas ranging from natural products extraction, materials cleaning, chemical reactions, nanoparticle preparation and drying. 11,12 The production of nanosized metal borates was studied using supercritical ethanol drying and supercritical CO 2 drying. 13,14 Supercritical CO 2 drying has been utilized in many applications owing to the fact that carbon dioxide is inexpensive, environmentally benign, not flammable, nontoxic and can be regenerated easily by a cycle system.…”

Supercritical CO₂ Extraction of Rice Bran Oil –the Technology, Manufacture, and Applications

“…Another disadvantage of SC-CO 2 extraction technology is the requirement for high pressures to maintain the solvent in supercritical state. This results in higher capital costs for plants and operating costs 31 . Typically, SC-CO 2 extraction technology is used where there are significant advantages e.g., recovery of high value functional compounds, when conventional extractions are inappropriate, and need treatments of toxic wastes .…”

Supercritical CO2 extraction pilot plant design - towards IoT integration

“…Perrut [20] in his work gave cost estimation for the various types of applications, based on his experience of equipment supplier and SFE plant operators. He had reported that all prices for such unit (represented by a dimensionless price index PI on a logarithmic scale) are near to a straight line with a slope of 0,24 versus the log of product of total volume V T by the design flow rate Q (Eq.…”

“…Perrut [20] shows also that capital amortization sharply decreases when capacity increases, what is a strong incentive to use large capacity multi-products units in "time-sharing" rather than operating small capacity units dedicated to only one product, when possible! In this work we present the data we have gathered from our own experience of building laboratory SFE plant.…”