1 Dept. of Agricultural Engineering, AC & RI, TNAU, Madurai 625 104.
2 AEC & RI, TNAU, Coimbatore 641 003.
Coir pith is considered as an undesirable waste of coir industries. It is difficult to burn coir pith in normal atmospheric conditions. It decomposes slowly, taking 8–10 years for complete decomposition due to higher lignin content of 37 to 45%. Being dust, it is easily blown by wind. When ignited, it does not burn completely and emits continuous smoke for several days polluting the environment. Therefore, the study was conducted to produce combustible gas from coir pith through fluidized bed gasification process. A fluidized bed gasifier was developed. Coir pith of 0.511 mm mean particle size was used as feed material. Thermogravi:netric studies were also conducted to determine the combustion behaviour of coir pith. Thermograms obtained for raw coir pith revealed distinct stages of thermal degradation and the ignition temperature was found to be 550°C. Minimum fluidizing velocity of 0.1 m/s was adopted for sand bed. A general trend of increasing gas yield with increasing air factor and slightly decreasing trend of calorific value were noticed. The average gas composition was found to be 2.3 to 6.5%, 9.1 to 16.2% and 6.4 to 20.5% for CH4, H2, and CO, respectively. The combustible gas was well burnt in a low calorific burner, which will fulfill the thermal needs, or the combustible gas can be used in the dual fuel engine to produce mechanical power or electricity. The average calorific value of the gas was found to be 4.23 MJ/m3.
