Details of the dual downdraft reactors along with its components
In stage I of the gasification reactor the fuel woodwas converted
into charcoal and producer gas is generated. The gas generated at
this stage is similar to the quality from a single stage Imbert gasifiers.
The tar content of the gas from the conventional single stage
gasifier is in the range of 500e700 mgNm3 [13]. To improve the
quality two-stage or multi-stage gasifiers were developed. These
gasifiers produce the gas with low tar content in the range of 19e
34 mgNm3 [13]. The two-stage gasifier generates the gas with a
tar content of less than 25 mgNm3 [12]. The present study is
focused on developing dual fired gasification reactor (with two
stages) for generating a good quality gas from biomass.
Three types of reactors were developed and improved during
the study. These reactors are fixed bed downdraft type with dual air
supply nozzles. Tar and dust content in the gas are considered as
indicators for performance assessment of these three reactors.
Based on these assessments, improvements in the reactor design
were carried out. Details of the components of the reactors that
were modified are shown in Fig. 1. The rector I is built with single
layer of insulation. The reactor II is built with two layers of