Thermogravimetric Investigation of The Behaviour of Malaysian Oil Palm Biomass, Sub-Bituminous Coal And Their Blends During Pyrolysis

An experimental study on co-pyrolysis of Malaysian palm biomass (mesocarp fibre and empty fruit bunches (EFB)) and Senakin bituminous coal was performed in a Thermogravimetry Analyser. All the tests were carried out in nitrogen atmosphere under dynamic conditions at heating rates of 20, 40, and 60°C/min. The operation temperature was in a range of 25 – 900 °C, and the biomass to coal blend was in a weight ratios of 80:20 and 50:50. The thermal events of EFB and mesocarp fibre show one thermal event only. The thermal events correspond to the disintegration of hemicelluose. Pyrolysis of coal/EFB and coal/palm fibre blends generates a bimodal derivative thermogravimetry (TG) curve. The thermal events of coal/palm fibre and coal/EFB blends during pyrolysis, however, showed the domination of the biomass pyrolysis at lower temperature, with the coal pyrolysis (i.e. volatile matter released) occurred at much higher temperature. Apparently, no interactions were seen between the coal and biomass indicating a general lack of synergistic effects. As such, the yield of the major pyrolysis products is linearly proportional to the weight ratio of biomass and coal in the blend mixture in an additive manner at a constant heating rate. Likewise, an increased in the coal reactivity was observed with increasing heating rates as the coal ratio increases in the blends. First order equations were used to determine the biomass and coal component thermal decomposition kinetics. The results showed that for 50:50 wt% blends, with respect to the coal volatile matter released, revealed the lowest activation energies of 118.6 and 112.6 kJ/mol for coal/EFB and coal/mesocarp fibre blends, respectively. These findings will provide useful data for power generation industries for the development of co-firing.