Abstract:
Biomass produced in these days has never been produced in the past as it
is an important source of energy and the most important fuel worldwide after coal,
oil and natural gas. Its advantage is that it can be used to generate electricity with
the same equipment or power plants that are now burning fossil fuels. However,
the low energy density of the biomass requires developments and advances in
conversion technologies in order to increase process efficiency and reduce
pollution. One of the most promising converting methods for treatment of
biomass and waste feedstock is gasification. In this study oxygen is used as a
gasifying agent and introduced at the bottom of the gasifier whereas mustard
(weed family) seeds are fed from the quarter half of the gasifier with feeding rate
of 0.5kg/hr.
The system is designed to work as a continuous type updraft gasifier. The
aim of the studies was to test the performance of an updraft configuration in
various operating conditions using biomass as feedstock, and facing primarily
technological difficulties and process limitations. Determining the temperature
distribution along the reactor with and without circulation of gases and syngas
composition of the process is reported at various operating parameters.
During the experiment it is observed that the temperature
profiling/distribution are improved using circulation. Equivalence ratio (ER) of
0.15 to 0.33 whereas temperature >800oC and >600oC for circulation is observed.
Increase of ER increases the amount of H2/CO whereas it is decreased in case of
circulation. CO2 produced is considerably less than the experimentation without
circulation. Increasing ER reduces the fluctuating amount of NOx and SO2 under
normal conditions whereas NOx shows the reducing behavior and SO2 is almost
zero for circulation. Increasing temperature favors H2/CO whereas circulation
shows the reducing trend of H2/CO with increasing temperature. The LHV and
HHV without circulation were observed to be 7743 Btu/lb and 8995 Btu/lb while
3801 Btu/lb and 4397 Btu/lb for circulation at the optimum ER which is 0.23.
