Effect of Formulation, Binder and Compaction Pressure of Rice Husk-Bagasse Briquettes on Thermal and Physical Properties

Aims: This study investigated the use of agro-wastes for the production of briquettes. It was carried out to investigate the effect of formulation, binder and compaction pressure of rice husk-Bagasse briquettes on thermal and physical properties.

Study Design: The experimental design for this study was 6x5x2 Randomized Complete Block Design

Place and Duration of the Study: Rice husks and bagasse were collected from Lake Basin Development Authority’s rice mill and Kibos sugar and Allied company respectively. The binders were sourced locally in Kisumu. The study was conducted between March 2019 and February 2020. The fabrication and laboratory analysis were carried out in the engineering and laboratory departments of Kenya Industrial Research and Development institute, Kisumu.

Methodology: The experimental design for this study was 6x5x2 Randomized Complete Block Design. This study involved six formulations ratios (0:100, 20:80, 40:60, 60:40, 80:20, 100:0), five compaction pressure levels (108kPa, 180kPa, 253kPa, 325kPa, 397kPa) and two binders (clay, cassava) They were arranged in Randomize Complete Block Design with three replications per experiment.

Results: The briquettes bulk density was in the range of 849 to 1001 kg.m−3, while the calorific value ranged from 5.541 kcal/g for 100% Rice husk clay binder to 7.345 kcal/g 20% Rice Husk cassava binder. Briquettes with blend ratio of 40-60% Rice Husk took longer time to burn. Briquette formulations with clay binder had burning rates ranging from 0.28 g/min to 0.15 g/min while with cassava binder from 0.52 g/min to 0.37 g/min. The ignition time of the briquettes ranged from 62 sec to 95 sec with cassava binder and 110 sec to 191sec with clay binder. The shatter index ranged from 0.94 to 0.99 with cassava and 0.9 to 0.98 with clay binder.

Conclusion: Higher compaction pressures and use of cassava binder produced stronger briquettes with higher calorific values. Briquettes with higher percentage of bagasse had low ignition time and low bulk densities. The bulk densities and ignition time showed significant rise with increase in the compaction pressure but inversely affected the burning rate. The binder used significantly affected both the thermal and physical properties of all the formulations.