This document discusses the production of algae using photobioreactors. It reviews different types of photobioreactors including open systems like raceway ponds and closed systems. Closed photobioreactors have advantages over open systems like better environmental control and prevention of contamination. The document describes various closed photobioreactor designs - vertical tubular, flat panel, horizontal tubular, bubble column, airlift, helical, and stirred tank. It notes that hybrid designs that combine features may be most suitable for mass algae cultivation.

1. PRODUCTION OF ALGAE USING
PHOTO BIOREACTORS...
Development of suitable photobioreactor for
algae production – A review
R.N. Singh, Shaishav Sharma∗ School of Energy and Environment Studies, Devi Ahilya Vishwa Vidyalaya,
Takshashila Campus, Khandwa Road, Indore-452001, India
By:
S.Nandini Parkavi
15bbt028
III- Year (Bio Tech)
1

2. NEED OF THE HOUR.....
 Food and Fuel
2
FOR FOOD...
FOR FUEL...
 Morden Farming
 Hybrid Technology
 First generation fuel -(fossils and food)
 Second generation fuel -(biomass)
 Third generation fuel –(microbes)

3. MICROALGAE THE SPOTLIGHT FOR BIO FUELS LIKE
BIODIESEL, BIO ETHANOL AND BIO HYDROGEN.....
Algae...
 Green algae and cyanobacteria (photosynthetic organisms)
 Grow in damp places or bodies of water.
 Lacks the various structures that characterize land plants.
 Unique microorganism (chlorophyll).
 They have....
defined nucleus.
cell wall.
chloroplast containing chlorophyll and other pigments, pyrenoid,
a dense region containing starch granules on its surface, stigma, and flagella
These are the major components of green algae
3

4. ALGAE CULTIVATION....
 Open system
 Closed system
4

5. OPEN SYSTEM....
 Open trench or pond
 Large production
 Cost efficient way
 Simplicity
 Different species require different conditions.
 eg:
 Spirulina sp- high concentration of sodium bicarbonate
 Dunaliella salina grow in extremely salty water
 The open pond is called Raceway pond
5

6. RACEWAY POND...
6
14 m
77 m

7. DISADVANTAGE...
 Uneven light intensity
 Evaporative losses
 Diffusion of CO2 to the atmosphere
 Requirement of large areas of land
 Contamination by predators and other fast growing
heterotrophs.
 Mass transfer rates are very poor resulting to low
biomass productivity.
 No control over environment.
 Restricted to tropical area.
7

8. CLOSED SYSTEM....
 Called Photo bioreactors.
 An enclosed,
 Illuminated culture vessel.
 No direct exchange of gases and contaminants with
the environment.
 Control over environment.
8

9. ADVANTAGE....
• Minimize contamination and allow the cultivation of
monocultures.
• Better control over conditions such as pH,
temperature, light, CO2 concentration etc.
• Less CO2 loss.
• Prevent water evaporation.
• Permit higher cell concentrations.
• Permit the production of complex
biopharmaceuticals.
9

10. THE REACTOR SHOULD....
10
• Permit the cultivation of various microalgae species.
• Design must provide uniform illumination and the fast
mass transfer of CO2 and O2.
• The reactor design must prevent or minimize the fouling of
the reactor, particularly on the light transmitting surfaces.
• High rates of mass transfer without the damage to the
cultured cells or suppress their growth.
• Must work under conditions of intense foaming.
• Minimum non-illuminated part.

11. TYPES OF PHOTO BIOREACTORS....
 Vertical tubular photo bioreactor
 Flat panel photo bioreactor
 Horizontal tubular photobioreactor
 Horizontal tubular photobioreactor
 Stirred tank photobioreactor
 Hybrid type photobioreactor
 Promising bioreactors
11
•Bubble column photo bioreactor
•Airlift photo bioreactor

12.  Bubble column photo bioreactor.....
 Cylindrical vessel with height greater than twice
twice the diameter.
 Low capital cost.
 Ligh surface area to volume ratio.
 Lack of moving parts, satisfactory heat and mass
transfer.
 Relatively homogenous culture environment.
 Efficient release of O2 and residual gas mixture.
 Sparger present but no agitator.
 Efficiency greatly depends on gas flow rate.
VERTICAL TUBULAR PHOTO BIOREACTOR
12

13. AIRLIFT PHOTOBIOREACTOR
13
Two interconnecting zones  One called riser the other down comer.
Advantage:- Mixing
Disadvantage:- Complexity and difficulty in scale-up

14. FLAT PANEL PHOTOBIOREACTOR......
 Minimal light path.
14
A continuous culture of Chlorella sorokiniana

15. HORIZONTAL TUBULAR PHOTOBIOREACTOR
 Advantage in outdoor
culture for their orientation
towards sunlight resulting
in high light conversion
efficiency
15

16. HELICAL TYPE PHOTOBIOREACTOR...
 Consists of coiled
transparent and flexible tube
of small diameter with
separate or attached
degassing unit
16

17. STIRRED TANK PHOTOBIOREACTOR.....
 Baffles are used in order to
reduce vortex.
 Disadvantage:- Low surface area
to volume ratio which in turn
decreases light harvesting
efficiency.
17

18. HYBRID TYPE PHOTOBIOREACTOR.....
 The advantages of the two different types of reactor
and one overcomes the disadvantage of other.
18

19. CONCLUSION....
 Developed bioreactor requires detail knowledge of
light distribution, mass transfer, shear stress,
scalability and biology of algae cells. None of the
single bioreactor fulfills all the requirements of a
complete bioreactor. However, hybrid reactors have
proved to be useful in mass production of algae as
compared to single bioreactors. Efforts may be
made to combine different types of bioreactors to
develop suitable bioreactors for mass algal culture.
19