Determination of Combustion Characteristics of Densified Biomass Fuels from Agricultural and Domestic Wastes

Abstract

The combustion characteristics of two carbonized biomass briquettes fuels samples (sample A and B) from two bio-wastes have been presented. Sample A is comprised of Agro-waste (residues) mainly rice husk, groundnut shell, corn cob, bagasse, rice straw, coconut coir, branches, wheat straw, maize husk, grass from the field, cassava stem while Sample B comprised of decaying domestic wastes material from wastes disposal/collection points mainly garbage, vegetables/fruits, protein, groundnut shell, maize cob, waste papers, all sorts of discarded foods etc. Analysis of briquettes fuels samples in terms of proximate analysis, ultimate analysis and calorific values were necessary to determine suitability of such material as reliable and sustainable energy sources. These parameters analyzed are unique fundamental code that characterizes and determines the properties, quality, potential applications and environmental problems related to any fuel. The result of the analysis placed sample B above sample A in terms of heating value. The proximate analysis indicated that the sample B had a better ignition characteristic at 77% volatile matter against 44% of sample A. Also, sample B have better heating value with fixed carbon 32% against 21% of sample A. This was also confirmed by ultimate analysis where sample B recorded a higher value of percentage Carbon and percentage Oxygen at 47.04% and 41.6% respectively. The bulk densities were in the range of 499kg/m2 to 502kg/m2 which is very good in terms of handling and transportation of the fuels. Moreso, calorific value of both samples were appreciably high at 18704 KJ/Kg for sample A and 18901.3 Kj/Kg by sample B. The ratio FC:VM for sample A is 0.477 which is higher than that of sample B, indicating that sample A will have a better yield and formation of biochar. Therefore the carbonised biomass briquettes are of good quality and exhibited good combustion properties as an alternative energy feedstock for domestic and industrial applications. It is a better source of energy for cooking, replacing fuel wood (firewood) and it is eco friendly.