10. Slow pyrolysis
Slow biomass heating rates→low
temperatures→lengthy gas and solids
Temperature :- around 500˚C.
Main product :- bio-char.
11. Fast pyrolysis
Yield 60% bio-oil.
Takes only seconds to complete the
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
Pyrolysis at 400 - 650 OC
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
Reactor temperature was recorded using a
Pyrolyses were performed under
15. A centrifugal pump was set to create &
maintain the vaccum inside the pyrolyser.
Temperature of pyrolyser was varied within
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
16. Uncondensed gas was blown off.
The solid bio-char was collected from the
pyrolyser as residue at the end of each batch
17. Advantages of pyrolysis
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.