2021 年 100 巻 8 号 p. 122-126
Coconut jelly, the solid waste from ready-to-drink industry, was used to produce solid fuel pellets. Pelletization was done by a single 10-ton hydraulic press unit without any binders. The characteristics of the pelletized fuel including pellet dimensions, bulk density, pellet density, proximate analysis, higher heating value, energy density, combustion rate, heat release rate, compressive strength and durability were investigated. The pellets had an average diameter and length of 10 mm. Pelletization significantly increased the bulk density from 30 kg/m3 of the original coconut jelly and 70 kg/m3 of ground dried coconut jelly to 659 kg/m3 of the pellets. Proximate analysis values of pellets (moisture 8.05 wt%, ash 2.06 wt%, volatile matter 77.04 wt% and fixed carbon 12.85 wt%) indicated good combustion parameters. The higher heating value of the pellets was 15.995 MJ/kg, which increased by 19.05% from its original form. The pellet density was 1,100 kg/m3 and the resulting energy density was 17.59 GJ/m3. The fuel pellets also increased the combustion rate and heat release rate from 0.05 to 0.17 g/min and 672 to 2,719 J/min, respectively, when compared with the original form. The pellets had a high durability (98 wt%) and high compressive strength in horizontal direction (4.84 MPa). Overall, the properties of coconut jelly pellets meet the requirements of Thai and European standards of the pellet properties for non-woody materials. Thus, coconut jelly waste could be considered as a potential raw material to manufacture pellets as an alternative energy source.
