![1.Batch reactor
Stirred tank batch reactor [STBR]
Plug flow batch reactor [PFBR]
Packed-bed batch reactor[PBBR]
Fluidised-bed batch reactor [FBBR]
2.Continous reactor
Continous Stirred tank reactor [CSTR]
Continous Plug flow reactor [CPFR]](https://image.slidesharecdn.com/immobilizedenzymesreactors-180404113104/85/Immobilized-enzymes-reactors-5-320.jpg)
![Batch reactor – Stirred tank [STR]](https://image.slidesharecdn.com/immobilizedenzymesreactors-180404113104/85/Immobilized-enzymes-reactors-12-320.jpg)
Immobilized enzymes reactors
- 1. What Is Enzyme Immobilization ? Enzyme immobilization may be defined as a process of confining the enzyme molecules to a solid support over which a substrate is passed and converted to products.
- 2. TECHNIQUE OF ENZYME IMMOBILIZATION:- 1.Carrier binding · Physical adsorption · Covalent bonding · Ionic bonding 2. Cross linking 3. Entrapment · Occlusion within a cross linked gel · Microencapsulation
- 3. Bioreactor :- device, usually a vessel, used to direct the activity of a biological catalyst to achieve a desired chemical transformation. Fermenter : Type of bioreactor in which the biocatalyst is a living cell.
- 4. Batch ◦ No flow of material in or out of reactor ◦ Changes with time Fed- Batch ◦ Either an inflow or an outflow of material but not both ◦ Changes with time Continuous ◦ Flow in and out of reactor ◦ Continuous Stirred Tank Reactor (CSTR) ◦ Plug Flow Reactor (PFR) ◦ Steady State Operation
- 5. 1.Batch reactor Stirred tank batch reactor [STBR] Plug flow batch reactor [PFBR] Packed-bed batch reactor[PBBR] Fluidised-bed batch reactor [FBBR] 2.Continous reactor Continous Stirred tank reactor [CSTR] Continous Plug flow reactor [CPFR]
- 6. Common when soluble enzymes are used. Fitted with fixed baffles that improve the stirring efficiency. Entire product is removed. Enzymes & Substrate molecule have identical residence time.
- 7. Enzymes are not separated & not re-used. Operation costs of batch reactors are higher than for continuous processes. Expensive & in some cases are not productive also labor & service demand increases. Small scale experimental studies
- 8. The rate of reaction (v) may be expressed in terms of the volume of substrate solution within the reactor (VolS) and the time (t): Fractional conversion is given by
- 9. The flow rate (F) is equivalent to VolS/t for a batch reactor.
- 10. Simplest form.. Good mixing, ease of temperature & pH control Loss of some enzyme activity may occur Modified form – Basket Reactor Basket reactor – enzymes are retained over the impeller blades or baffles of the tank reactor Both have a well mixed flow pattern
- 11. High shear forces may damage cells Requires high energy input Application :- free & immobilized enzyme reactions Recovery of products produced by enzymes like lipase, glucose isomerase & B-galactosidase
- 12. Batch reactor – Stirred tank [STR]
- 13. Alternative to flow pattern type of reactors. Flow rate controlled by a plug system. Plug flow – Packed bed or Fluidized bed Used when inadequate product formation in flow type reactors
- 14. Advantage – external mass transfer effects can be reduced by the operational high fluid velocities. Application :- used for obtaining kinetic data on the reaction systems.
- 15. Modified form, Widely used. When equipped with external heating & cooling coils is also called as PFR Substrate stream flows at same velocity, parallel to reactor with no back-mixing.
- 16. 3 substrate flow possibilities – downward flow method, upward, & recycling method. Packed-bed reactors are used with immobilized or particulate biocatalysts. Medium can be fed either at the top or bottom & forms a continuous liquid phase.
- 18. Intermediate between CSTRs & PBRs. Consist of a bed of immobilized enzymes which is fluidized by rapid upwards flow of the substrate or in combination with a gas or Secondary liquid stream. Fluidization requires large power input. Heating & cooling coils are located outwards.
- 19. Baffles are used to decrease stirring efficiency. Useful if the reaction involves the utilization or release of gaseous material. Disadvantage – difficulty in scaling-up these reactors
- 21. Substrate added continuously & product removed simultaneously. Certain advantages over batch reactors. Control over the product formation, convenient operation of the system & easy automation of the entire process.
- 22. 2 types – Continuous stirred tank reactor (CSTR) & Plug flow reactor (PFR). Choice of continuous reactor is based on the Kinetic considerations. CSTR is ideal for good product formation
- 23. Flow rate of continuous reactor
- 24. Continuously operated version of STR. Degree of conversion is independent of the position in the vessel, as complete mixing is obtained with stirring & conditions within CSTR is same as the outlet stream. Readily obtained. Requires more enzyme.
- 25. More favorable than PFR if substrate inhibition occurs. Enzymes are covalently linked to a carrier by cyanogen bromide activation. Application :- used for obtaining kinetic data on the reaction systems.
- 27. Degree of conversion is dependent on the length of the reactor as no mixing device exist & the conditions within the reactor are never uniform. Requires less enzyme to obtain the same degree of conversion as in CSTR. Application :- used for obtaining kinetic data on the reaction systems
- 30. Batch High operating costs Batch-to-batch variations PFR Difficult to control pH and Temperature CSTR Simple pH, Temperature control Simple catalyst charging and replacement
- 31. High Stability. Reusable. Products are enzyme free. Controls of enzyme function is easy. Suitable for industrial & medical use. Minimize effluent disposal problems.
- 32. Possible loss of biological activity of an enzyme during immobilization or while it is in use Immobilization is expensive technique requires sophisticated equipment
- 33. Immobilized glucosidase & glucose isomerase are used in production of fructose from starch. Immobilized L-Aminoacylase which resolves a mixture of D- and L- amino acids. Immobilization of Microbial cells.
- 36. Conversion of 99.25% 120 L reactor required Increase conversion by 0.5% to 99.75% 360 L reactor required