Abstract:
Trends internationally have shown that about 60% of power in developed coun-
tries of Europe, America and Asia is from coal. Combustion of coal generates huge
quantities of gaseous emissions. The rules governing emissions have become more
stringent and therefore, alternative techniques of coal utilization are required for
clean power generation. Recent research is geared towards higher e ciency coal
gasi cation plants as well as fuel synthesis from syngas. In this research a bench
scale gasi er was designed, fabricated and its performance analyzed. The main
aim of the research was to gasify sub-bituminous coal under
uidized conditions
to produce a combustible gas whose composition was to be analyzed and optimum
working conditions established. Air
ow rate was varied and the reactor temper-
ature and gas composition were measured at each
ow rate. Results from this
research showed a 13.73% reduction in CO concentration with increase in air
ow
rate from 1.0 to 2.5 m3/min. CO reduction was attributed to fact that more air
enhanced conversion of CO to CO2. As the air
ow rate was increased from 1.0
to 2.5 m3/min, the HHV of the syngas was observed to decrease from 5.667 to
4.106MJ/Nm3. This was attributed to the reduction of CO and the increase of
nitrogen composition which do not add to the calori c value of the syngas. The
cold gas e ciency(CGE) and carbon conversion e ciency (CCE) of the gasi er
were obtained as 64.29% and 89.89% respectively. This research can be applied
in power generation by channeling the syngas produced to power gas turbines
and engines. The research gives insightful information that can contribute to
improved design of gasi cation systems.
