Energy Characteristics of Prosopis Juliflora with Binary Combination of Maize Cobs and Bagasse Agricultural Waste on Briquette Production

Abstract

Cooking energy accounts for a significant part of the daily household energy needs in developing countries. The study aimed to investigate the use of Prosopis juliflora as a feedstock for briquette production and evaluate the influence of a binary combination of maize cobs and bagasse on the characteristics of the briquettes. Binary combination ratios were done at 25% and 50% of the total sample weights. Laboratory bench testing evaluated the physicochemical characteristics of Prosopis juliflora and its binary combinations to establish both proximate and ultimate elemental composition. Experimental analysis results showed that using Prosopis juliflora in its pure form for briquette production achieved moisture content of 5.59±0.09%; volatile matter of 77.49±1.98%; ash content of 3.12±0.16%; fixed carbon of 19.39±1.82% and calorific value of 18.99±0.21 MJ/kg; for ultimate analysis it achieved, 46.26% carbon, 5.75 % hydrogen, 0.27% nitrogen and 0.44% Sulphur; which are all within desirable range for briquette production; revealing that even without combinations of other feedstock, Prosopis juliflora is sufficient as an energy crop. The experiment went further to establish the impact of binary combinations of bagasse and maize cobs at 25% and 50 % of its sample on the energy characteristics of Prosopis juliflora. It was found that adding the binary combinations to Prosopis juliflora on briquette production increased its calorific value; it also increased carbon and hydrogen percentage compositions which play a key role in attaining high calorific values in a biomass fuel. Results obtained were 19.27±0.05 MJ/kg at 25% of maize cobs; 19.73±0.05 MJ/kg at 50% maize cobs; 19.07±0.07 MJ/kg at 25% of bagasse and 19.14±0.07 MJ/kg at 50% of bagasse, which were all higher than 18.99±0.21 MJ/kg that of using Prosopis juliflora in its pure form. This showed that bagasse and maize cobs combination to Prosopis juliflora at binary levels increased calorific value of the resulting briquette fuels. In finding out the desirable binary combination with better energy characteristics, the experimental analysis showed that the binary combination of 50% Prosopis juliflora and 50% Maize cobs is a better desirable fuel choice for briquette production. This combination had a high calorific value of 19.73±0.05 MJ/kg compared to other binary combinations under this study; making it the ideal binary combination fuel. Keywords: proximate analysis, ultimate analysis, Briquettes, Prosopis juliflora, maize cobs, bagasse