6.3.2. Gasification technology
Incineration of solid waste under oxygen deficient conditions
is called gasification. The objective of gasification has
generally been to produce fuel gas, which would be stored
and used when required. In India, there are few gasifiers in
operation, but they are mostly for burning of biomass such
as agro-residues, sawmill dust, and forest wastes. Gasification
can also be used for MSW treatment after drying,
removing the inerts and shredding for size reduction.
Two different designs of gasifiers exist in India. The first
one (NERIFIER gasification unit) is installed at Nohar,
Hanungarh, Rajasthan by Narvreet Energy Research and
Information (NERI) for the burning of agro-wastes, sawmill
dust, and forest wastes. The waste-feeding rate is about
50–150 kg/h and its efficiency about 70–80%. About 25% of
the fuel gas produced may be recycled back into the system
to support the gasification process, and the remaining is
recovered and used for power generation. The second unit
is the TERI gasification unit installed at Gaul Pahari campus,
New Delhi by Tata Energy Research Institute (TERI)
(CPCB, 2004; Ahsan, 1999).