pyrolyses

1. PYROLYSiS
AJNAALAVUDEEN
2011-06-001

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.

5. Pyrolytic products
 fuels
Feedstock for chemical & material
industries
 bio-char
Gases(methane,hydrogen,carbondioxide,ca
rbonmonoxide).

6. Materials used??
coal
animal waste
food scraps
paper
rubber
biomass

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.

9. Types of pyrolysis
1.Slow pyrolysis
2.Fast pyrolysis

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.

20. THANK YOU