Binderless Solid Fuel Pellets from by–product of Sugar Industry

Abstract

This research studied the compression of filter cake, which is a by-product from the sugar industry, into pellet form of solid fuel. The effects of compression pressure, pellet diameter as well as temperature and time of torrefaction were investigated. The results showed that solid fuel in the pellet form had higher heating value than the original form. The minimum pressure for forming pellets with the diameter and height of 1 cm was 30 bar, whereas the pellets with a larger diameter (1.5 cm) with the same height needed a higher pressure (40 bar). At the same pellet diameter, increasing the compression pressure resulted in the solid fuel pellets with higher heating value, pellet density, moisture and ash contents. Torrefaction at 250 and 300 °C for 0.5–2 h yielded the samples with higher heating values (21,689–22,642 kJ/kg) when compared with the values belonging to the original sample (13,954 kJ/kg). On the contrary, density of the pellets decreased from 0.72 g/cm³ to 0.48–0.89 g/cm³. Increased torrefaction temperature and time increased the heating value but decreased the pellet density.