Evaluation of some Combustion properties of Rice Husk Briquettes Produced at Varying Binder Concentrations from a Modified Block Briquetting Machine

Abstract

Some combustion properties of rice husk briquettes produced at varying binder concentrations from a modified block briquetting machine that was designed and fabricated in the Federal University of Technology Minna, Niger State, Nigeria, were assessed with a view to ascertaining the best binder concentration that produced the best briquettes in terms of their combustibility. 10 kg of rice husk was collected from Onyx rice mill, Bida, Niger State Nigeria. They were manually cleaned to remove minor rice bran particles and other impurities using sieve of hole size 3 mm diameter. The rice husk were  dried in the sun to 5% and mixed with five different concentrations: 10 g, 20 g, 30 g, 40 g and 50 g and mixed uniformly. The resultant aggregates were used to produce briquettes and sun dried for 3 days at an average daily temperature of 32°C to a moisture content of 5%. The process was replicated three times and their combustion properties: percentage volatile matter, ash contents, fixed carbon and heating values were evaluated. The briquettes with lower starch concentration, 10% and 20 % had higher and similar volatile matter value of 72.00±0.01^d and 73.20±0.00^e respectively while the volatile matter percentage reduce with increase in starch concentration value from 68.49±0.04^c to 57.14±0.01^a at 30% and 50%. Ash content values of the briquettes produced increased from 9.73±0.00^a at 10% binder concentration to 22.15±0.00^e at 50%.Fixed carbon percent reduced from 18.27±0.01^b to 16.59±0.01^a at 10% and 20% binder concentration levels and increased from 16.59±0.01^a at 20% to 20.71±0.02^e at 50% binder concentration, while heating value of briquettes reduced with increase in binder concentration from 30.39±0.01^e MJ/kg to 26.25±0.00^a MJ/kg at 10% and 50% binder concentrations respectively.