A Seperation technique Super critical fluids.pptx

knowldeg about super critical fluids which is a sepration techniqes use in industires

1. Duration: 30 min MSc Chemical Engineering Maham Fatima Reg#2023-MS-CH-04 Supercritical Fluid Extraction Innovating Industries with Solvent Superpowers " Separation Process

2. Table of Contents Introduction to SCF Properties Supercritical Fluid Extraction Working Principal Modifiers Modes of process Factor that effects the process Limitation Advantages & disadvantages Furter Trends

3. At a certain temperature and pressure condition, liquid and vapor phase of substance become indistinguishable. Known as Critical Condition Common SCF Most Common super critical fluid is CO2 and Water Supercritical Fluids ? Supercritical fluids are substances that are in a state where they have characteristics of both a gas and a liquid. This state occurs when a substance is above its critical temperature and pressure .

4. Carbon dioxide Supercritical Fluid formation Increasing temperature and pressure One homogenous phase is called Supercritical fluid Extraction conditions for supercritical carbon dioxide are above the critical temperature of 31 °C and critical pressure of 74 bar.

5. Properties of Super Critical Fluids Density: H ave intermediate densities between liquids and gases. Viscosity: Have low viscosity, This means they can flow more easily, like a gas, allowing them to penetrate into tiny spaces or porous materials. Solvating Power: E xcellent solvating power, meaning they can dissolve a wide range of substances , like a liquid do so

6. Cont… 4 . Diffusivity: Supercritical fluids exhibit high diffusivity, which means they have a higher ability to disperse and mix with other substances. 5. Temperature and Pressure Sensitivity: The properties of supercritical fluids are highly dependent on temperature and pressure, allowing for control and adjustment. 6. Environmental Friendliness : Supercritical fluid extraction processes are often environmentally friendly, as they require fewer or no organic solvents, reducing waste generation.

7. Supercritical Fluid Extraction

8. Basic Components required for SCF Pumps For small scale extractions (up to a few grams / minute) reciprocating CO2 pumps or syringe pumps are often used. For larger scale extractions, diaphragm pumps are most common . Pressure vessels The vessel must be equipped with a means of heating. It can be placed inside an oven for small vessels, or an oil or electrically heated jacket for larger vessels Pressure control valves Separators Collection vessel

9. Process Steps The solid or liquid matrix is prepared by grinding, milling, or drying to increase the surface area available for extraction. The system must contain a pump for the CO2, a pressure cell to contain the sample, a means of maintaining pressure in the system and a collecting vessel. The liquid is pumped to a heating zone, where it is heated to supercritical conditions. It then passes into the extraction vessel, where it rapidly diffuses into the solid matrix and dissolves the material to be extracted. Once the extraction process is complete, the supercritical fluid containing the dissolved compounds is separated from the matrix. This can be done by reducing the pressure, allowing the supercritical fluid to revert to its gaseous state, leaving behind the extracted compounds. Finally, the extracted compounds are collected, and the supercritical fluid can be recycled for future extractions. This makes the process environmentally friendly and efficient.

10. Decaffeinated Coffee process

11. Use of modifiers In Supercritical Fluid Modifiers are substances that we add to the supercritical fluid to enhance its properties and improve its performance One common type of modifier is a co-solvent . Co-solvents are substances that we mix with the supercritical fluid to increase its solubility for certain compounds Used to control the selectivity of the supercritical fluid . In a nutshell, they enhance solubility, improve selectivity , and ultimately make the supercritical fluid more effective in its intended application. Examples: Ethanol, Methanol, acetic acid etc.

12. Modes of Supercritical Fluid Extraction Static Mode Super critical fluid and sample are kept in contact for a fixed time. During this time, the supercritical fluid dissolves the desired components from the sample. Suitable for samples that require longer extraction times. Useful when extraction efficiency is not the primary concern. Dynamic Mode Super critical fluid continuously flows through the sample. Faster and more efficient extraction compared to the static mode. Suitable for samples where time is a constraint. Enhanced extraction efficiency due to continuous movement of the fluid’s. Semi-continuous Mode C ombination of static and dynamic modes. Initial static phase followed by dynamic extraction. Provides the benefits of both modes. Efficient extraction with reduced time compared to the static mode.

13. Here are the limitations of supercritical fluid extraction High Initial Cost: Equipment can be expensive. Limited Solubility: Not all compounds are easily soluble in supercritical fluids, which can limit the range of substances that can be effectively extracted. Matrix Complexity: Complex matrices, such as those containing high levels of impurities or complex mixtures, can pose challenges for efficient extraction. Safety Considerations: Proper handling and safety measures are necessary. Limitations of Process

14. Lets talk about Applications

15. Advancements in Green Chemistry: Focus on developing environmentally friendly processes using recyclable solvents. Expansion into New Industries: Adoption of supercritical fluid technology in emerging fields like energy, advanced materials, and biotechnology. Process Optimization and Efficiency: Continuous improvement and automation to enhance extraction efficiency, reduce costs, and improve overall performance. These trends will shape the future of supercritical fluid processes.

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