Gasification is a process that converts biomass into syngas through partial combustion with oxygen and/or steam at high temperatures. This involves several chemical reactions: drying around 100°C, pyrolysis from 200-400°C which produces char and volatiles, and combustion and gasification reactions above 700°C which produce carbon monoxide, hydrogen, and other gases from reactions between char, steam, and carbon dioxide. Gasification has advantages over burning solid fuels as it produces a cleaner-burning fuel similar to natural gas. There are different types of gasifiers such as fixed or moving bed gasifiers and updraft or downdraft gasifiers that vary the direction of fuel and air/oxygen flow.

1. Gasification
Er. Arvind Kumar Verma, Senior Lecturer,Department of Mechanical
Engineering ,
Email: hod.dip.me@srmu.ac.in
Dr. N.C Sarcar, Director, Institute of Diploma Studies,
Email: director.diploma@srmu.ac.in
Shri Ramswaroop Memorial University, Barabanki, 225003
2020-11-11

2. 1.0 Gasification
• Gasification is a process that converts biomass into carbon
monoxide, hydrogen and carbon dioxide. This is achieved by
reacting the material at high temperatures (>700 °C), without
combustion, with a controlled amount of oxygen and/or steam.
• The resulting gas mixture is called syngas (from synthesis gas) or
producer gas and is itself a fuel.
• The power derived from gasification and combustion of the
resultant gas is considered to be a source of renewable energy if
the gasified compounds were obtained from biomass
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3. 1.1Chemical reactions
In a gasifier, the carbonaceous material undergoes several
different processes:
• The dehydration or drying process occurs at around 100 °C.
Typically the resulting steam is mixed into the gas flow and may
be involved with subsequent chemical reactions.
• The pyrolysis process occurs at around 200– 400 °C. Volatiles
are released and char is produced, resulting in up to 70% weight
loss.
• The combustion process occurs as the volatile products and some
of the char react with oxygen to primarily form carbon dioxide and
small amounts of carbon monoxide, which provides heat for the
subsequent gasification reactions. C+O2 CO2020-11-11

4. • The gasification process occurs as the char reacts with
steam and carbon dioxide to produce carbon monoxide
and hydrogen, via the reactions
• C+H2O=H2+CO, C+CO2=2CO
• CO+H2O CO2+H2
• 4CO+2H2O CH4+3CO2
The output is a mix of gases such as carbon monoxide,
carbon dioxide, nitrogen, hydrogen and methane that is
good source of eneegy.
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5. Source:
https://www.deingenieu
r.nl/artikel/construction-
of-wood-gasification-
plant-has-begun
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6. 1.2 Complete gasification process
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7. 1.3 Advantages
• Gasification has several advantages over burning solid
fuel.
• One is convenience – one of the resultant gases,
methane, can be treated in a similar way as natural gas,
and used for the same purposes.
• Another advantage of gasification is that it produces a fuel
that has many impurities removed and will therefore
cause fewer pollution problems when burnt.
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8. 2.0 Different types of gasifire
2.1 Fixed bed gasifiers/Mooving bed gasifire: In this type
the grate is fixed or bed is mooving
Moving(fixed) bed gasifiers are countercurrent flow reactors
in which the coal enters at the top of the reactor and air or
oxygen enters at the bottom.
As the coal slowly moves down through the reactor, it is
gasified and the remaining ash drops out of the bottom of
the reactor.
Because of the countercurrent flow arrangement, the heat
of reaction from the gasification reactions serves to pre-
heat the coal before it enters the gasification reaction zone.
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9. Fixed bed gasifiers/Mooving bed gasifire
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10. 2.1.1 Updraft and Down daft gasifire
Source: https://www.researchgate.net/figure/Comparative-schematic-of-updraft-and-downdraft-
fixed-bed-gasifiers-77_fig21_316772405
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11. 2.1.1 Updraft and Down daft gasifire
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12. References:
• https://www.deingenieur.nl/artikel/construction-of-wood-gasification-plant-has-
begun
• http://cturare.tripod.com/pro.htm
• https://www.researchgate.net/figure/Comparative-schematic-of-updraft-and-
downdraft-fixed-bed-gasifiers-77_fig21_316772405
• https://www.sciencedirect.com/topics/engineering/fixed-bed-gasifiers
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