Supercritical fluid Extraction and it’s Applications

1. Supercritical fluid Extraction and it’s Applications Dr S. N. Naik Center For Rural Development and Technology IIT Delhi

2. Outline Supercritical fluid as a solvent Application of supercritical fluids Supercritical carbon dioxide extraction of botanicals Particle design using supercritical fluid Biomass conversion using Supercritical fluid SCF based Bio refinery

3. Supercritical fluid as a solvent • Solvent are used in large amount in chemicals, pharmaceutical, food and natural products industry • In search of environmental friendly solvent, attentation has been paid to supercritical fluid for wide application in extraction,chromatograhy, particle design, reaction, drying etc.

6. Physical properties of gas ,liquids and supercritical fluids

8. Typical Supercritical Solvents

9. Advantages of SCF

10. Application of SCF

17. Extraction of value added Chemicals from Biomass

18. Bioactive compounds from Botanicals

19. Particle design using supercritical fluid • Pharmaceutical, Nutraceutical, Cosmetic, Specialty chemistry industry • RESS: Rapid Expansion of Supercritical Solutions • Consist in solvating the product in the fluid and rapidly depressurizing this solution through an adequate nozzle(<100micro m to 20 micro m diameter) • Attractive due to the absence of organic solvent use • Its application is restricted to products that present a reasonable solubility • in supercritical carbon dioxide(low polarity compounds) • GAS or SAS: Gas(or Supercritical fluid) Anti-Solvent • Consist in decreasing the solvent power of a polar liquid solvent in which the substrate • is dissolved, by saturating it with carbon dioxide in supercritical conditions, • causing the substrate precipitation or recrystallization

20. Rapid expansion of supercritical solutions (RESS) • Depressurizing this solution through a heated nozzle into a low pressure chamber in order to cause an extremely rapid nucleation of the substrate(s) in form of very small particles • In the precipitation unit, the supercritical solution is expanded through a nozzle that must be reheated toavoid plugging by substrate(s) precipitation • The morphology of the resulting solid material both depends on the material structure crystalline or amorphous, composite or pure. • The RESS parameters; • temperature, pressure drop, distance of impact of the jet against the surface, • dimensions of the atomization vessel, nozzle geometry

21. RESS Process

22. RESS is a very attractive process as it is simple and relatively easy to implement at least at small scale when a single nozzle can be used. • Extrapolation to a significant production size requires either a multi-nozzle system or use of a porous sintered disk through which pulverization occurs, • In both the case, particle size distribution is not easy to control and may be much wider than in the case of a single nozzle. • Particle harvesting is complex • The most important limitation of RESS development lies in the too low solubility of compoundsin supercritical fluids • In most cases, use of a co-solvent to increase solubility in the fluid is not feasible

23. Supercritical anti-solvent and related process (GAS/SAS) • In this process, the supercritical fluid is used as an anti-solvent that causes precipitation of the substrate(s) dissolved initially in a liquid solvent. • A batch of solution is expanded several-fold by mixing with a dense gas in a vessel. • Due to the dissolution of the compressed gas the expanded solvent has a lower solvent strength than the pure solvent. • The mixture becomes supersaturated and solute precipitates in microparticles. • This process has been called gas anti-solvent(GAS) or supercritical anti-solvent(SAS) recrystallization

24. GAS/SAS Antisolvent Process

25. Spraying the solution through an atomization nozzle as fine droplets into compressed carbon dioxide. • The dissolution of the supercritical fluid into the liquid droplets is accompanied by a large volume expansion and, consequently a reduction in the liquid solvent power causing a sharp rise in the supersaturation within the liquid mixture and the consequent formation of small and uniform particles. This spray process has been called Aerosol solvent extraction system (ASES) process

26. ASES Process

27. Biomass conversion using Supercritical fluid

28. Cellulose degradation pathways by SCW

29. Dielectric constant and Density of Water at 1000 C

30. Ion product of Water

31. Hydrolysis of cellulose in SCW

32. Potential reaction products from the decomposition of Lignin

34. Bio refinery Bio refinery involves sustainable processing of biomass into a spectrum of value added products Bio-based chemicals, materials, food, feed etc. Bio energy (biofuels, power and heat) Bio refinery value chain: Biomass production, conversion, recycling, conformity of end products to user requirement

35. Bio-refinery Secondary metabolites (terpenoids, alkaloids,lipids) Bio- mass Hemicellulose Cellulose Lignin Ash Bio-fuels and Chemicals

36. Supercritical Fluid based Biorefinery

37. Advantages of Bio-refinery Conservation of fossil resources Renewable resources are CO2 neutral Products are bio-degradable Raw materials are non-toxic Producing chemicals from bio-mass requires newer clean technology

38. Extraction of Minor Constituents Waxes Long chain alkanes COSMETICS, COATINGS, ETC.. Polycosanols/ sterols INSECT SEMIOCHEMICALS CHOLESTEROL REDUCING AGENTS

39. Vanillin and analogues Energy PAPER, strawboard products, plastics HEMICELLULOSE CELLULOSE (45-55%) (25-35%) Ethanol, lactic acid,furfural derivatives, glucose, xylose Major Constituents conversion LIGNIN (15-20%) MINOR CONSTITUENTS (5-10%)

40. Production of biooil via fast pyrolysis process Feedstock Biooil Char Quench liquid Recycled gases Feedstock Cyclone/ Char Collector Bio-oil storage Pyrolysis reactor Quench system

41. Wood Bio-oil 100 cm3 of wood contains the same energy as 20 cm3 of Bio-oil

42. SC-CO2 Extraction of Bio-oil (set-up and samples)

43. Up gradation of Bio-oil using SCF Biooil as such can not be used as transportation fuel as it contains high percentage of water (~ 45 wt %). Also, water decreases its calorific value, It forms azeotrope with organic compounds, It increases percentage of oxygen and results in polymerization at room temperature in few weeks. Methods for removal of water: Solvent extraction Supercritical CO2 extraction (Green process)

44. Proximate analysis and calorific value of mixed biomass (wt. %) Measurement error : ± 0.2 Calorific value = 18.6 MJ/kg

45. Chemical Analysis of mixed Biomass C/H/N/S/O analysis results ICP-MS of major compounds in ash

46. Composition of Biomass* Hemi-cellulose 34.1 ± 1.2 wt % Cellulose 44.4 ± 1.4 wt % Lignin 21.5 ± 1.0 wt % * Calculated using acid (dilute H2SO4) –process and HPLC analysis

47. Comparative XRD analysis of mixed-biomass, cellulose and lignin a: biomass Intensity b: lignin c: cellulose 2Ф Biomass has crystalline character due to the presence of cellulose

48. Comparative TG Analysis of biomass, cellulose and lignin m (μg) T (oC) The range of main weight loss for biomass is 200-550 oC.

49. Comparative DTG Analysis of biomass, cellulose and lignin DTG (μg/min) T (oC) 100oC< loss of easily volatiles, 100-130oC (water), 250-320oC (hemicellulose), 300-400oC (cellulose) and 250-750oC (lignin)

50. HPLC Analysis (NREL Method) of structural Carbohydrate in Biomass