Characteristics of biomass briquettes from coffee husk as sustainable fuel

Abstract

Coffee husk is a waste from coffee milling, which is usually used by farmers as a natural fertilizer. However, it is not uncommon that coffee husk is entirely discarded despite their potential as fuel briquette. Furthermore, coffee husk may replace tapioca as a non-edible binder alternative to tapioca. As such, this study aims to determine the potential of coffee husk waste as briquette material and binder. Manufacturing parameters that include the particle size, the biomass-to-binder ratio, and the press pressure, were varied, and the briquettes were analyzed based on the high heating value (HHV), and using proximate and ultimate analyses under ASTM standards. In addition, common combustion characteristics, such as flame temperature, ignition time, burning duration, and burning rate were determined. The highest HHV was found in coffee husk briquettes without adhesive at 3811 Kcal/Kg. The combustion characteristic test showed that briquettes with a particle size of 60 mesh and a press pressure of 2 MPa have the most desired combustion characteristics.