Properties of Solid Fuel Briquettes Produced from Rejected Material of Municipal Waste Composting

This research was conducted to determine the optimum mixing ratio for solid fuel briquettes produced by extrusion of rejected material of municipal waste composting char (MWCC) and sawdust char (SC). Experiments were performed on briquettes made from various ratios of rejected material of MWCC to SC: 100:0, 80:20, 60:40, 50:50, 40:60 and 20:80 by weight. Slop waste (either 10%, 15% or 20%wt) was added as a binder. The solid fuel briquettes were formed into cylindrical shapes 3.8 cm in external diameter, 1.3 cm in internal diameter and 15 cm in length. The briquettes were evaluated for the following properties: moisture, ash, volatile matter, fixed carbon, calorific value, sulfur, combustion calorific value, compressive strength, water resistance, and bulk density. The experimental results indicated that calorific value and combustion calorific value of the solid fuel briquettes increased with increasing ratios of sawdust char. Compressive strength, water resistance and bulk density of the solid fuel briquettes also increased, and depended both on increased ratios of sawdust char and on a higher percentage of binder. From the research results, it can be concluded that a MWCC to SC ratio of 20:80 with 20% slop waste was most suitable for production of solid fuel briquettes. This study demonstrates that the rejected material of municipal waste composting can be used as an alternative fuel for industrial use. This will not only promote the reuse of waste material for optimal benefit, but will also reduce the use of landfill space.