Results in Engineering (Sep 2022)
The continuous carbonisation of rice husk on the gasifier for high yield charcoal production
Abstract
The aim of this research was to new design and develop a metal kiln for a continuous carbonisation of rice husk on the downdraft gasifier, utilising flue gas, to produce high yield rice husk charcoal. The cylindrical metal kiln was constructed of a steel pipe, 114 mm in diameter and 510 mm in length. The screw conveyor, which rotates at 3 rpm inside a cylindrical metal kiln, is powered by a 24 V DC motor. The rice husk pyrolysis is caused by direct heating from the flue gas. The flue gas was obtained from the burning of some parts of the rice husk in combination with the pyrolysis gas in the reactor beneath. The results showed that the pyrolysis temperature ranged from 460 to 475 °C. The capacity operation of the reactor was 11.237 kg (rice husk)/h and the rice husk charcoal could produce 3.565 kg (charcoal)/h. The yield of rice husk charcoal was 36.97% (by weight). The proximate analysis properties of rice husk charcoal have a volatile matter of 12.75% (by weight), a fixed carbon value of 48.89% (by weight), and a high ash content of 36.13% (by weight). The higher heating value of the rice husk charcoal is 19,859 kJ/kg. The energy conversion efficiency from biomass to charcoal and the high reactor's thermal efficiency were 48.57% and 41.46%, respectively. The rice husk charcoal obtained from this research is suitable for use as a material in the production of charcoal briquettes, and it can be mixed with other organic materials to make organic fertilizers that can be used instead of chemical fertilizers. This cuts costs for farmers.
