2. Pyrolysis
Pyrolysis is a thermo chemical decomposition
of organic material in to liquid, gases and
char(solid residue)at elevated temperature in
the absence of oxygen(or any halogen).
3. Characters??
Temperature : 500-800˚c
Greek word : pyro- ‟ fire”
lysis-‟seperatingˮ.
Involves the simultaneous change of
chemical composition & physical phases.
4. Process is irreversible.
Pyrolyses process is an endothermic
process.
7. Biomass
Biomass is an organic material produced
directly from plants & animals or indirectly
from industrial,commercial,domestic or
agricultural products.
8. Agricultural waste :- crop & vegetable
residuals(rice husk, straw)
livestock :- butchery waste, bone material, dead
animals.
forestry :- forest residue, processing waste,
sawdust.
Fishery :- processing waste, fishbone meal,
dead fish.
Industrial & house hold organic residuals :-
sewage sludge, waste food etc.
10. Slow pyrolysis
Slow biomass heating rates→low
temperatures→lengthy gas and solids
residence times.
Temperature :- around 500˚C.
Main product :- bio-char.
11. Fast pyrolysis
Yield 60% bio-oil.
Takes only seconds to complete the
pyrolyses.
Very high heating and heat transfer rates,
which require a finely ground feed.
Residence time of pyrolysis vapours in the
reactor less than 1 sec.
Quenching (rapid cooling) of the pyrolysis
vapours to give the bio-oil product.
Calorific value :- 3500kcal.
12. Rice husk
The outermost layer of the paddy grain is the
rice husk, also called rice hull.
Still often considered as a waste product in
the rice mill & therefore often either burned
in the open or dumped on wasteland.
Rice husk has high calorific value and often
can be used as a renewable fuel.
13. Pyrolysis of rice husk
hhhbgg
jig
k
Rice husk
Pyrolysis at 400 - 650 OC
Uncondensed gas
kchar
Gaseous mixture
sorting
drying
condensation
Bio-oil
14. PROCESS
moisture free rice husk sample was taken in
to a perforated holder and was introduced in
to the tube furnace.
The furnace was made air tight & heated
electrically.
Reactor temperature was recorded using a
digital thermometer.
Pyrolyses were performed under
vaccum.(710-720mm Hg).
15. A centrifugal pump was set to create &
maintain the vaccum inside the pyrolyser.
Temperature of pyrolyser was varied within
400-650°C.
The mixture of liquid & gas was allowed to
come out through vaccum line & set at one
side of the pyrolyser.
The fluid from the pyrolyser was condensed
in a series of ice cooled condenser & bio-oil
was obtained.
16. Uncondensed gas was blown off.
The solid bio-char was collected from the
pyrolyser as residue at the end of each batch
of pyrolysis.
17. Advantages of pyrolysis
Simple.
Low cost technology.
Capable of processing a wide variety of
feedstock's producing gases,bio-
oil,biochemical & charcoal.
Reduces greenhouse gas emissions and
waste going to landfill .
18. Produces a marketable product (electricity).
Low risk of water pollution .
Low risk of odours .
High recovery rate of resources .
Minimal risk of health consequences .
Commercially proven technology.
19. Disadvantages
Technology is still evolving.
Market are yet to be developed for char
product and pyrolysis liquid.
