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Super critical fluid extraction

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Super critical fluid extraction

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The process of separation of one component from the other using super
critical fluid as solvent is termed as super critical fluid extraction(SCFE)
The technique of supercritical fluid extraction utilizes the
dissolution power of supercritical fluids, i.e. fluids above their
critical temperature and pressure.

The process of separation of one component from the other using super
critical fluid as solvent is termed as super critical fluid extraction(SCFE)
The technique of supercritical fluid extraction utilizes the
dissolution power of supercritical fluids, i.e. fluids above their
critical temperature and pressure.

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Super critical fluid extraction

  1. 1. SUPERCRITICAL FLUID EXTRACTION PRACHI GHADGE BFT-17034
  2. 2. SUPERCRITICAL FLUIDS?  At a certain temperature and pressure condition, liquid and vapour phases of a substance become indistinguishable. Known as CRITICAL CONDITION  Substances above critical point- "SUPERCRITICAL FLUIDS" (SCF)
  3. 3. INTRODUCTION • Supercritical fluids (SCFs) are increasingly replacing the organic solvents that are used in industrial purification and recrystallization operations because of regulatory and environmental pressures on hydrocarbon and ozone-depleting emissions. • A supercritical fluid (SCF) is defined as “non-compressible and high density fluid”. • With increasing scrutiny of solvent residues in pharmaceuticals and medical products the use of SCFs is rapidly proliferating in all industrial sectors. • Used supercritical fluids. (Carbon dioxide and water are the most common)
  4. 4. SUPERCRITICAL FLUID In the supercritical domain, the SCF increases in density as the pressure is raised whilst other physical properties, including diffusivity, change but remain gas- like.
  5. 5. SUPERCRITICAL FLUID EXTRACTION (SFE) • Supercritical Fluid Extraction (SFE) is the process of separating one component (the extractant) from another (the matrix) using supercritical fluids as the extracting solvent. • Extraction is usually from a solid matrix, but can also be from liquids. • The technique of supercritical fluid extraction utilizes the dissolution power of supercritical fluids, i.e. fluids above their critical temperature and pressure.
  6. 6. SUPERCRITICAL FLUID EXTRACTION (SFE)  Carbon dioxide (CO2) is the most used supercritical fluid, sometimes modified by co-solvents such as ethanol or methanol.  Other current and potential uses include the removal of undesirable substances such as pesticide residues, removal of bacteriostatic agents from fermentation broths, the recovery of organic solvent from aqueous solution, cell disintegration, destruction and treatment of industrial wastes and liposome preparation.
  7. 7. Why CO2 is used most often in SFE? • Separation of the carbon dioxide from the extract is simple and nearly instantaneous. • Unlike liquid solvents, the dissolving power of supercritical carbon dioxide can be easily adjusted by slight changes in the temperature and pressure, making it possible to extract particular compounds of interest. • Additional advantages of carbon dioxide are that it is inexpensive, available in high purity; FDA approved, and is generally regarded as a safe compound (GRAS).
  8. 8. WORKING OF SUPER CRITICAL FLUID EXTRACTION NAME-GRISHMA.MEHTA ROLL NO.-BFT-18012
  9. 9.  Triple point-The temperature and pressure at which solid liquid and gas phases of pure substances  Critical point- The end point of the phase equilibrim curve between liquid and gas;beyond this point,they are indistinguishable and form supercritical fluid.  Supercritical fluids- • quickly spread dissolve substance and make space for more. • They are unaffected by surface tension. • They can also get to parts where the liquids cant
  10. 10.  Extrcation and isolation of natural products by conventionally means creates copious amount of waste organic solvent  The industrial solvent are hazardous to human health  So there is a need for more environmentally vaible solution that has recently paved the way for green chemistry  Strict regulations in terms of usage of industrial solvents has led to increase in the demand of super critical fluid extraction technology(SCFE) Safe Inexpensive Non toxic Environmental friendly Non flammable Less energy requirements SCFE
  11. 11. WHAT IS SCFE? The process of separation of one component from the other using super critical fluid as solvent is termed as super critical fluid extraction(SCFE)
  12. 12. It displays property intermidiate to those of liquid and gaseous state also known as compressable liquid or dense gases. High solvent power is due to their liquid like density excellent transport properties owing to the gas like viscosity and diffusivity together with zero surface tension PROPERTIES OF SCF
  13. 13. STATIC DYNAMIC COMBINATION Modes of extraction
  14. 14. Circulation of SCF IN LOOP containing the extraction vessel for a certain period followed by it release through the restrictor to the trapping vessel STATIC DYNAMIC Conduction of static extraction for some time followed by dynamic extraction COMBINATI ON Continous flow of SCF through the sample in the extraction vessel and out of the restrictor to the trapping vessel
  15. 15. Simple model of SFE
  16. 16. Figure shows the stages during extraction from a spherical particle where at the start of the extraction the level of extractant is equal across the whole sphere As extraction commences, material is initially extracted from the edge of the sphere, and the concentration in the center is unchanged As the extraction progresses, the concentration in the center of the sphere drops as the extractant diffuses towards the edge of the sphere a b c
  17. 17.  The relative rates of diffusion and dissolution are illustrated by two extreme cases in Figure.  Figure a shows a case where dissolution is fast relative to diffusion.  The material is carried away from the edge faster than it can diffuse from the center, so the concentration at the edge drops to zero.  The material is carried away as fast as it arrives at the surface, and the extraction is completely diffusion limited. Here the rate of extraction can be increased by increasing diffusion rate, for example raising the temperature, but not by increasing the flow rate of the solvent.  Figure b shows a case where solubility is low relative to diffusion. The extractant is able to diffuse to the edge faster than it can be carried away by the solvent, and the concentration profile is flat.  In this case, the extraction rate can be increased by increasing the rate of dissolution, for example by increasing flow rate of the solvent.
  18. 18. The extraction curve of % recovery against time can be used to elucidate the type of extraction occurring. Figure (a) shows a typical diffusion controlled curve. The extraction is initially rapid, until the concentration at the surface drops to zero, and the rate then becomes much slower. The % extracted eventually approaches 100%. Figure (b) shows a curve for a solubility limited extraction. The extraction rate is almost constant, and only flattens off towards the end of the extraction. Figure (c) shows a curve where there are significant matrix effects, where there is some sort of reversible interaction with the matrix, such as desorption from an active site. The recovery flattens off, and if the 100% value is not known, then it is hard to tell that extraction is less than complete.
  19. 19. Feed introduction in the extraction vessel Before pressurization,the system is allowed to reach the present operating temperature Cooling of SCF(CO2) in the chiller to ensure liquid feed to the pump Discharge of chilled CO2 into the pressure vessel and adjustment of the pressure to the desired level 1 2 3 4 OPERATING PROCEDURE FOR SCFE
  20. 20. Simultaneous discharge of co-solvent through pump at pre- determined flowrate Conduction of extraction through static /dynamic/combination mode pf extraction Isolation of dissolved solute by precipitation;release recovery of SCF 5 6 7 OPERATING PROCEDURE FOR SCFE
  21. 21. References • https://www.che.iitb.ac.in/online/page/overview-scf-research-iitb • https://www.youtube.com/watch?v=icfpml9hKP8 • https://www.chemistryviews.org/details/ezine/4393381/50th_Anniv ersary_Supercritical_Fluid_Extraction.html • https://www.youtube.com/watch?v=UxAjlmaUNzs • https://www.youtube.com/watch?v=LQfVJ0MvqEo&t=121s
  22. 22. Application of SCFE in Food Industry Shamika Gavali BFT18010
  23. 23. SCFE has wide application in natural products and food industry such as • Decaffeination of coffee and tea • Spice Extraction(oil and oleoresin) • Deodorization of oils and fats • Flavors, fragrances, aromas and perfumes • Decholesterolization of egg yolk and dairy cream • Antioxidants from plants • Food colors from botanicals • Natural pesticides
  24. 24. SCFE Technology can be used for Extraction, purification and separation of: • Edible oils and fats • Hop extraction • Natural dyes: Annatto, Hibiscus • Vitamins(tocopherols, vit E, etc) • Carotenoids • Sterols • Essential fatty acids(EPA, DHA, DPA) • Bioactive compounds (pyrethrum, caffeine, theobromine, cholesterol, capsaicin, etc) • Mono and di glycerides • Aroma compounds • Citrus oils
  25. 25. Decaffeination of coffee and tea using SCFE technology plant • Coffee is wetted with water. • Wetting tends to dissolve and deorb caffeine from the solid material • The operating conditions are- pressure:300bar Temperature: 40oC • Green beans are loaded into vessel and SCF CO2is introduced in vessel. • Extract is transferred to separator which oper- ates at low pressure and separtes it into two Phases- Aquous caffeine and CO2 • The CO2 is recycled • Caffeine can be recovered by adsorption on an Activated carbon column.
  26. 26. Decaffeination Effect SCFE Process parameters on yield
  27. 27. Decaffeination Effect SCFE process parameters on recovery
  28. 28. Etraction of natural Food Antioxidants • SFE has been widely studied by several authors to obtain highly active rosemary antioxidant extracts. • Topal et al. (2008) demonstrated that the antioxidant activity of supercritical extracts of different Turkish plants (rosemary among them) were higher than those obtained by steam distillation. • Better results in terms of antioxidant activity were also achieved when compared to liquid solvent sonication.
  29. 29. Low Cholesterol Whole milk powder and cream powder • SC CO2 and ethanol(co solvent) modified SC CO2 were employed to extract Cholesterol from whole milk powder and cream powder. • About 55.8% and 46% of cholesterol removal from WMP could be achieved by using SC CO2 alone and Ethanol modified SC CO2. • Addition of Ethanol led to enhanced extraction rate. • About 39% Cholesterol could be removed from cream powder using SC CO2 alone.
  30. 30. Process flowchart for preparation of Low cholesterol milk powder using SCFE Technology
  31. 31. Application of SCFE for quality control in fat analysis • Conventional methods of fat analysis for baking, milk and chocolate products are time and labour intensive and require large amount of hazardous organic solvents. • Supercritical fluid extraction using CO2 as a solvent is an alternative method for extraction of fat content from these products.
  32. 32. ` Optimization of SFE Bft-18011 Snehal Gite
  33. 33. Supercritical fluid extraction • For all experiments, the extraction vessel (15 mL is first packed with 6.5 g of glass beads, followed by 125 mg of plant material. The remaining void of the vessel is filled with 1 g of anhydrous Na2SO4. • The SFE extractions are carried out using a combination of 2-min static period to allow the extraction vessel to reach its extraction pressure and a dynamic extraction step of 23 min. • The extract is trapped by bubbling the CO2 through 25 mL of methanol. The flow-rate of supercritical fluid in the dynamic extraction step is fixed to 2 mL min−1 with the help of a heated variable restrictor. • A high-pressure pump is connected to the restrictor in order to obviate its plugging by non-meltable residue. Methanol was selected as solvent and its flow rate was −1 fixed to 0.3 mL min for the determinations, the SFE /FT-IR interface was held at 30◦C. Results and discussion Infrared spectra of the extraction of tagitinin C from T. diver-sifolia leaves in SCCO2 over time.
  34. 34. Supercritical fluid extraction • well-defined absorbance spectra were obtained between 3400– 2800 and 1900–950 cm Consequently, information on vibrational modes of functional groups of components such as CH stretching vibrations (3200–2800 cm−1) and C O stretching vibrations (1800–1650 cm−1 ) were gathered. • In addition, the presence of the OH bending vibration of water contained in the leaves and extracted by SCCO2 was also observed at −11608 cm
  35. 35. SFE optimisation through experimental design approach • The traditional optimisation procedure varying one variable at a time does not guarantee the attainment of a true optimum of the extraction conditions. • In the other hand, the chemometric approach based on a rational experimental design allowing the simultaneous variation of all experimental factors guarantee this and also allows saving time and materials. • This last point was very important in this study for two reasons: a small quantity of plant material was available and the compound of interest, i.e.; tagitine C, was present at a low amount in the material provided.
  36. 36. • Central composite designs (CCD) are probably the most widely used experimental designs for fitting a second order response surface. • A total of 13 random experiments, in which the central point was replicated five times, were carried out to optimize the influence of the pressure and temperature of SCCO2 on the extractogram area of tagitinin C. Generally, the following polynomial model is used to express the dependent variable as a function of independent variables: • Y = α + β P 2 + β T 2 + β P + β T + β PT • However, the response was not sufficiently explained by the regression model.
  37. 37. • The result can be explained by the fact that the density of the supercritical fluid decreases with the increase in temperature at low pressure whereas at higher pressure, changes in temperature have much less effect on den- sity. • a second order poly- nomial model involving interactions terms between the pressure and the temperature was used to express the area as a function of independent variables: • Y = α+β1P2 +β2T2 +β3P2T2 +β4P2T +β5PT2 +β6P +β7T +β8 PT • Unlike the previous model, the response was sufficiently explained by the regression model. Indeed the coefficient of determination and the adjusted coefficient of determination were equal to 0.99 in both cases.
  38. 38. • The response surface estimated for the model by using the two variables, the pressure and temperature of the supercritical fluid, was drawn to look for the optimum values of these variables. • it can be seen that, while the pressure was increasing up to 12.0 MPa, the extractogram area increased dramatically. • This can be explained by an enhanced solvent strength of SCCO2 when the pressure grows. On the other hand, the extractogram area decreased with a rise of temperature. However, this negative influence of the temperature was reduced with higher pressure values. In addition, the optimal domain for extraction is large: between 14.0–20.0 MPa and 40–60 ◦ C.

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