Halaban (Vitex Pubescens vahl) charcoal and coal bottom ash briquettes with pressure variations

Abstract

Moisture content, ash content and heating value have been measured on briquettes which were made from a mixture of halaban charcoal and coal bottom ash with variations in pressures and form factor. Factors that influence the characteristics of briquettes were powder fineness and pressure. And so both materials were made in the form of powder on a 250 mesh sieve and pressure variations (150, 200, 250, 300, and 350) kg / cm2. The composition of the mixture of halaban charcoal and coal bottom ash was with a ratio of 90%: 10%, while 5% of starch adhesive was added. Briquettes were made in the form of solid cylinders and hollow cylinders. From the measurements, the moisture content, ash content and heating value of solid cylinder briquettes were yielded 3.831-5.892%, 7.178-10.507% and 5,607.467-5,732.033 cal/g, respectively. While for hollow cylinder briquettes were 4.564-5.621%, 8.688-11.191% and 5,620.833-5,685.100 cal/g. All briquette samples meet Indonesian national standards requirements for moisture content and heating value, but not all briquette samples meet the requirements for ash content. Higher pressure gave lower water and ash content, but higher heating value. Based on the results, it is recommended that the pressure given in making the briquette was 200 kg/cm2. This is based on consideration of the highest heating value obtained when the pressure was 200 kg / cm2.