The Preparation of Briquettes from Architectural Waste Wood Charcoal and Evaluation of their Characteristics

Abstract

Every year, 4.6 million tons of architectural waste wood is collected, and its recycling rate, including thermal recycling, is only about 60%. We examined the preparation of cooking charcoal from waste wood charcoal as a new means of utilization. In general, the combustion rate of charcoal is strongly affected by its specific surface area so that a heavy charcoal, such as bincho charcoal, burns moderately and offers favorable control over combustion heat. In contrast, the charcoal from architectural waste wood burns faster because it is predominantly composed of coniferous tree wood, which has lower density and larger specific surface area.
In this study, briquettes with high densities were prepared by molding and calcination of the charcoal powder from coniferous tree wood through the addition of some binders. Then, the burning characteristics of the briquettes were evaluated. Wood tar and waste saccharine were used as the binders. The briquettes obtained this way had high density, high mechanical strength and improved burning characteristics equivalent to those of bincho charcoal. In addition, the mechanical strength and burning characteristics of the prepared briquettes were revealed to be strongly influenced by the properties of the chars derived from the binders.