PRESENTED BYARCHANA GAUTAM

M.Sc. BIOTECHNOLOGYI—SEM

BBAU LKO

Biofuel are the fuel of biological origin these constitute renewable from of energy.

CONT….

Energy crisis

Based on the current consumption of about 11.6 million

tons of crude oil per day, it is expected that the entire

resources can only suffice for a rather short time period.

Global warming and global climate changes

The use of oil can cause the risks of the rise of greenhouse

effect, which can result in all kinds of disasters to our

planet Earth and its inhabitants.

Biodiesel

Biobutanol

Biogasoline etc.

It is a biofuel consisting of monoalkyl esters that are derived from organic oils , plant or animal through the process of transesterification.

BIODIESEL PRODUCTION

FROM MICROALGAL OIL

Cont….

A. The triglycerides methanol and catalyst are placed in a controlled reaction chamber to undergo transesterification.

B. The initial product is laced in a separator to remove the glycerin by product.

C. The excess methane ,oils removed from the methyl ester through evaporation.

Open Pond System Pond consist of closed loop

recirculation channel in which mixing and circulation are provided by paddle wheel.

Depth=0.2—0.5 Limitation= Loss of water due to

evaporation Unwanted algal &

microorganism growth.

.

Closed Photo bioreactor System(PBR)

Provide a controlled environment

Tubular shape & Flat shape

Biological &Physiological control

Reducing contamination level

Limitation=

High operating cost

1-Energycrisis

2-Global Warming

3-Incresing Industrialization

4-Heigh Cost Of Fossils Fuel

ALGAE HARVESTING

The term algae harvesting refers to concentration of diluted algae suspension

until a thick algae paste is obtained.

Harvesting method is based upon size and properties of algae strain.

Harvesting of microalgae from algae cultivation pond or photobioreactors

employ several techniques:

FLOTATION

CENTRIFUGATION

FILTRATION

These processes are aided by cell flocculation. It causes the cells to become

aggregated into larger clumps which are more easily filtered and/or settle

more rapidly. It is done by addition of chemical flocculants or through

autoflocculation.

Filtration

Suitable for larger algal species with cell diameters >70 µm. For smaller

algal species membrane ultrafiltration can be employed.

Limitation is that biomass settles on the filter and eventually block filter

pores, which makes filtration less efficient, thus increasing energy

consumption.

In addition membrane replacement and pump operation increase operating

expenses therefore better suitable to handle smaller volumes.

Centrifugation

Method of separating algae from the medium by using a centrifuge to cause

the algae to settle to the bottom of a flask or tank.

Quick and effective method.

Limitation is very high energy consumption .

Flotation

It is performed using compressed air to inject air microbubbles at the

bottom of the culture medium, algae adhere to the microbubbles and

accumulate on the medium surface.

ALGAE OIL EXTRACTIONExtraction can be broadly classified into two categories:-

MECHANICAL METHOD

Expeller press

CHEMICAL METHOD

Hexane Solvent Method

Soxhlet extraction

Supercritical fluid Extraction

EXPELLER PRESS –

Algae is dried .

Oil content can be "pressed" out with an oil press

HEXANE SOLVENT METHOD –

Uses chemicals (such as hexane).

Can be harmful and explosive.

Cold press & hexane solvent = extract 95% of oil

SOXHLET EXTRACTION -

In this method, oils from the algae are extracted through repeated washing,

or percolation, with an organic solvent such as hexane , under reflux in a

special glassware.

The value of this technique is that the solvent is reused for each cycle.

SUPERCRITICAL FLUID EXTRACTION –

CO2 is liquefied under pressure and heated to the point that it has the

properties of both a liquid and gas.

This liquefied fluid then acts as the solvent in extracting the oil.

Can Extract almost 100% of the oils.

Expensive equipment.

Sodium ethanolate is used as catalyst, ethanol is reacted with the algal oil (

the triglyceride) to produce bio-diesel & glycerol. The end products of this

reaction are hence biodiesel, sodium ethanolate and glycerol.

End-mixture is separated as follows: Ether and salt water are added to the

mixture and mixed well. After sometime, the entire mixture get separated

into two layers, with the bottom layer containing a mixture of ether

and biodiesel. This layer is separated.

Biodiesel is in turn separated from ether by a vaporizer under a high

vacuum. As the ether vaporizes first, the biodiesel will remain. The

biodiesel from algae is now ready for use.

Mechanical method

Expeller Press

Chemical method

Hexane Solvent Method

Soxhlet Extraction

Supercritical Fluid Extraction

CONCLUSION

Algae are promising source for biodiesel production, as they can

perform photosynthesis, grow in heterotrophic conditions, grow

faster, do not require a special growth medium, and contain 50 % or

more of their mass as oil.

Carbon dioxide necessary for photosynthesis can be obtained from

stationary sources of environment air pollution such as fuel

combustion units, which would help to reduce emissions of

greenhouse gases.

Algal oil is similar to vegetable oil, the existing traditional biodiesel

production technologies can be easily adjusted to use this new raw

material.