Production and Characterization of Fuel Briquettes Made from Agricultural Residue Blended with Organic Wastes Using a Hydraulic Press Designed and Manufactured Locally

Abstract

Alternative energy sources have gained attention in order to substitute the dwindling conventional energy sources. In this context, briquetting technology has been applied to utilize loosen organic feedstocks effectively through solid fuel production. The objective of this study was to produce briquettes from agro-industrial and organic wastes in different combination using simple hydraulic press machine and subsequently to study briquettes physical, chemical and mechanical properties. In this research, coffee husk and bagasse as agro-industrial wastes and sawdust, paper residue and Khat as organic wastes were used for briquette making experiment with a binary mixing weight ratio of 0:100, 25:75, 50:50, 75:25 and 100:0 respectively with three selected binders (10 % w/w) namely starch, molasses and gum Arabic. The effect of feedstock combination, variation of binder types and feedstock preheating were studied following standard procedures on briquettes’ physical, mechanical and energy content at ~7 MPa compaction pressure and particle size of < 1 mm (except mashed paper).From the experiment, bulk density of briquettes was ranged from 474 -1107 kg/m3 at preheating temperature of 140 0C. The effect of binders was analyzed using bagasse feedstock which had relatively low bulk density during preheating method. Thus, its highest bulk density was found to be 462.7 kg/m3 for starch binder. Coffee husk feedstock has been selected to study Mechanical strength of briquettes using selected binders and its maximum values was exhibited by starch binder as 80 % shatter resistance index and 9.5 MPa compressive strength next to preheating method at 140 oC. But, other binders’ effect was not that much deviated in the yield of good quality briquettes in terms of density and mechanical strength. Paper briquette alone had the highest value of 99.51 % and 23.10 MPa shatter resistance index and compressive strength respectively regardless of other binders effect. This indicated that paper itself could be a potential binder of other feedstocks. The moisture content, ash content, volatile matter and Fixed carbon of briquettes were ranged from 4.5-9.3 %, 0.45-11.8%, 70.1-83.5 % and 5.79, 18.5% respectively and the calorific values of briquetted fuels ranged from 15.44-18.34 MJ/kg. The significance of this study was meaning full in the production of briquettes with acceptable physical, mechanical and thermal properties by utilizing agro-industrial waste and discarded organic wastes in different combination.