The performance of the gasification process depends on the types
of feedstock and its characteristics such as moisture content, composition
(ultimate analysis), equivalence ratio and so on.
Inappropriate selection of these parameters may lead to excessive
presence of tar and soot in the producer gas. These unwanted materials
in the producer gas may disturb the continuous and smooth
operation of gas engines [7,8]. The fixed bed gasifiers are classified
depending on the supply of gasifying agent into the reactor. They
are updraft, downdraft, cross draft and multistage. Among the commercially
produced gasifiers, downdraft, fluidised bed, updraft and
other gasifiers have the share of 75%, 20%, 2.5% and 2.5% respectively
[9]. Compared to other gasification technologies, the downdraft
gasifier is the most sustainable option for decentralised heat and
power generation because the producer gas obtained from it contains
very low content of tar and particulates.