Calorific value analysis, reduction of period weight, reaction rate, activation energy of old coconut, young coconut waste briquette burning, cocoa

Abstract

Indonesia was a country with considerable biomass energy potential. Biomass energy could be explored from agricultural waste, abundant and easily obtained biomass, for example: old coconut waste, young coconut waste and cocoa waste. This study aims to obtain the heating value of charcoal briquettes from biomass of old coconut waste, young coconut waste and cocoa waste. The study was conducted on a laboratory scale, and used a complete randomized design with 3 repetitions. The procedure of this study begins with sorting raw materials, cutting and drying. Next carbonize, grind, filter, add tapioca glue, then print, and press at 115 kg/cm2. Carbonize at 400°C, for 30, 60, 90 and 120 minutes. The briquettes produced would be analyzed for density analysis, calorific value, and highest calorific value. Then analyzed for reducing the mass and rate of the combustion reaction. The test results of the old coconut briquette density were 0.937 g/l, the highest calorific value was 6.927 kal/g with a 90 minute carbonization time. Old coconut briquettes had the lowest or lowest combustion reaction rate compared to the level of combustion reaction rate of young coconut briquettes and cocoa briquettes. The effect of a higher density value, the higher the briquette heat value and the slower or lower the combustion rate. In the Thermogravimetry test using Thermal Gravimetry Analyzer (TGA), the highest decrease in mass of old coconut waste briquettes compared to young coconut waste briquettes and cacao waste briquettes was 55.34% from 590.5°C to 599.2°C. In Thermal Gravimetric Differentials. (DTG) shows the rate of combustion reaction in old coconut waste briquettes is 0.10%/minute with an air speed of 5 ml/minute.