Bioreactors classifications.pptx

This presentation will help to freshers in the field of upstream process development. In UPD bioreactor operations are crucial and understanding various aspects also has the same importance. Hence, this PPT will brief the introduction about bioreactors followed by their classifications. Eventually, the body construction.

1. Shubham A. Chinchulkar M.Tech (Pharm.) National Institute of Pharmaceutical education and Research (NIPER), Mohali [phone]/9730748384 [email protected] Bioreactor Design and Control 1

2. BACKGROUND TO BIOREACTORS Bioreactor : An apparatus in which a biological reaction or process is carried out, especially on an industrial scale De Beeze and Liebmann (1944) used the first large scale (above 20 litre capacity) fermenter for the production of yeast A British scientist named Chain Weizmann (1914-1918) developed a fermenter for the production of acetone Function : To achieve optimal growth and or product formation with controlled environmental conditions 2 Bioreactor Fermenter May use microorganism or biochemical active substrate such as enzymes or catalyst Always use microorganism to carry out the reaction Can use mammalian or insect cell population Use fungal or bacterial cell population Aerobic or anaerobic conditions Anaerobic conditions only Doubling time is 24 hours Doubling time is 20 min. Used in the production of medicines, antibodies, and vaccines Used to produce lactic acid and ethanol Preferable agitation RMP has to be maintained due to absence of cell wall Considerable agitation rate RMP can be used as both bacteria and fungi have cell wall

3. 3 Inoculums/seed generation Production Vial (1 ml) Shake flasks (40 mL- 500 mL) Bioreactor (2L-150L) Harvest

4. Size of fermenter (litres) Industrial product 1-20,000 Diagnostic enzymes, substances for molecular biology 40-80,000 Some enzymes, antibiotics 100-1,50,000 Pencillins , proteases , amino acids, steroid transformation, wine, and bear 2,00,000-5,00,000 Amino acids, wine, and bear. 4

5. 5

6. Sartorius biostat b dcu II 6

7. DASGIP® Parallel Series Bioreactor Systems from Eppendorf ambr ® 250 high throughput Single-Use Bioreactor Vessels 7

8. Types of Bioreactor Airlift bioreactor Stirred tank bioreactor Fluidized bed bioreactor Packed-bed bioreactor Trickle bed bioreactor Bubble column fermenter Multiphase bioreactor Disposable bioreactor Wave bioreactor 8

9. Factors of Bioreactors 9

10. Bioreactor A glass vessel with round or flat bottom and a top flanged carrying a plate It is sterilize by autoclaving A glass cylinder with stainless steel top and bottom plates It is sterilize in situ 10

11. 11

12. As large scale fermenters are sterilized in situ and made up from stainless steel Less than 4% chromium – steel alloy & more than 4% chromium – stainless steel Thin hydrous oxide film on the surface of metal and the film is stabilized by chromium (10-13%) which is considered to be continuous, non-porous, insoluble, and self healing & it starts healing once come in contact with oxygen or oxidizing agent Molybdenum presence in stainless steel provide resistance to solution of halogen salts Chromium 18%, Nickel 10%, and molybdenum 2-2.5% - commonly used fermenter BODY CONSTRUCTION 12

13. The thickness will increase with scale For 300000 to 400000 dm 3 - 0.7 mm plate for side wall and 10 mm plate for top and bottom which is hemisphere to withstand pressure Reliable aseptic seal – Glass and glass - Glass and metal - seal can be made with compressible gasket a lip seal or ‘O’ ring Metal and metal - Only ‘O’ ring is suitable Nitryl or butyl rubbers are normally used for these seals as they withstand with fermentation condition 13

14. TEMPERATURE CONTROL Heat will be produce throughout the fermentation process If microbial activity and mechanical agitation are responsible for heat generation then this is not ideal for manufacturing process, further will be achieved by following approaches - Place fermenter in thermostatically controlled bath Use internal heating coil Use heating jacket through which water is circulated Use silicone heating jacket – heating wires between two mats For fermenter of 55000 dm 3 the cooling area will be 50 to 70 m 2 with coolant temperature 14°C, which may be cooled from 120°C to 30°C in 2.5h from 4h without stirring The consumption of cooling water also depends on the culture present inside (bacterial – 500 to 2000 dm 3 per hour & fungal – 2000 to 10,000 dm 3 per hour ) 14

15. To find accurate estimate of heating/cooling requirement we have to consider following parameters - Q exch = Q met + Q ag + Q gas – Q acc – Q scn – Q evap Where, Q met = heat generation rate due to microbial metabolism Q agt = heat generation rate due to mechanical agitation Q gas = heat generation rate due to aeration power input Q acc = heat accumulation rate by system Q exch = heat transfer rate to the surroundings and/or heat exchanger Q evap = heat loss by evaporation Q sen = rate of sensible enthalpy gain by flow streams When designing large fermenter, The operating temperature and flow condition will determine Q evap and Q sen The choice of agitator, its speed and the aeration rate will determine Q agt The sparger design and aeration rate will determine Q gas 15

16. The cooling requirement calculated by following formula – U . Where, A = surface available for heat transfer m 2 Q = heat transferred W U = Overall heat transfer coefficient W/m 2 K = temperature difference between heating and cooling K U represent the conductivity of the system and it is influenced by vessel geometry, wall material, flow velocity, fluid properties, and thickness Hence 1/U (reciprocal of overall heat transfer coefficient) is the overall resistance to heat transfer h o = outside film coefficient W/m 2 K h i = inside film coefficient W/m 2 K h of = outside fouling film coefficient W/m 2 K h if = inside fouling film coefficient W/m 2 K h w = wall heat transfer coefficient = k/x, W/m 2 K k = thermal conductivity of wall W/ mK ; x = wall thickness m   16

17. Three methods to determine (the temperature driving force) depending on the operating circumstances If one side of the wall is at a constant temperature , as is often case in stirred fermenter and the coolant temperature rises in the direction of the coolant flow along a cooling coil: If the fluids are in counter or co-current flow and the temperature varies in both fluids then a log mean temperature difference is appropriate: Where, T e = Temperature of coolant entering the system T i = Temperature of coolant leaving the system T f = bulk liquid temperature in the vessel U .   17

18. Aeration and Agitation Provide sufficient oxygen for metabolic requirement, while agitation will helps in uniform oxygen distribution Aeration without agitation and aeration with agitation If vessel is of height/diameter ratio of 5:1 then it is suitable for non-agitated fermentation In such vessel aeration is sufficient to produce high turbulence Components involved in aeration and agitation – The agitator (impeller) Stirrer glands and bearings Baffles The aeration system (sparger) 18

19. The agitator (impeller) Agitator is require to achieve following objectives – Mixing of bulk fluid and gas phase Air dispersion Oxygen transfer Heat transfer Suspension of solid particles Uniform environment The proper designing of bioreactor requires to achieve objectives demands for knowledge of most appropriate agitator, air sparger, baffles, and the best position of feed The agitator size, number, speed, and power input need to specify and also crucial factor in bioreactor designing The agitator classified as - 19

20. Disc turbines: Rectangular vanes Vanned disc Open turbine variable pitch Marine propeller 20

21. Air from sparger hit the undersite of disc and is displaced towards the vane where bubbles are broken up into smaller bubbles The vanes of Open turbine variable pitch and the blades of marine propeller are attached directly to a boss on the agitator shaft In such cases air bubbles do not initially heat any surface before dispersion by vanes or blades The propeller being flooded at lower velocity and also less efficient in breaking up a stream of air bubbles the flow it produces axial rather than radial The disc turbine will help to break the bubble occurs at the tip It has been show that similar oxygen transfer efficiencies are obtained at the same power input per unit volume, regardless of agitator type To achieve efficient bulk blending in high viscosity fermentation number of agitators have been developed The Scaba 6SRGT can handle high flow rate before flooding at a given power input This is good in bulk blending but not enough for top to bottom mixing in a large fermenter which leads to lower concentration of oxygen in broth 21

22. Another Prochem Maxflo agitator, which consists four, five or six hydrofoil blades Dual impeller combination to achieve good blending and aeration Lower impeller acts as gas disperser and upper impeller acts primarily as a device for helping in circulation of vessel content Multi-rod mixing impeller were used in a 15000 dm 3 vessel having good efficiency in blending and oxygen transfer rate but not to come in general use 22

23. Thank you 23