CHARCOAL BRIQUETTE PRODUCTION FROM TWIGS OF FOUR EXOTIC TREE SPECIES

Abstract

Charcoal briquettes were made from branches and twigs of ten years old exotic tree species planted at Angkhang Highland Reforestation Project, Chiangmai Province. They are Acacia confusa, Cinnamomum camphora, Fraxinus griffithii and Liquidambar formosuna. The experiment was carried on as follows: proximate analyses of raw material, carbonized at 450 ° C, analyses of charcoal and charcoal briquette. The results revealed as follows. The average properties of wood and charcoal from all species were: volatile matter contents 81.0 - 87.8 % and 18.8 - 23.7 %, fixed carbon centents 11.9 - 17.2 % and 66.8 - 76.4 %, ash contents 0.54 - 2.41 % and 2.01 - 9.53 %, and heat of combustion 4,416-4,746 cal / g and 6,561 - 7,473 cal / g, respectively. Average charcoal yield was 28.9 - 31.8 %. The charcoal from each species was ground to pass 5 x 5 mm screen, mixed with 7.5 % tapioca starch, compressed in a mold and seasoned to reduce moisture content below 10 % before determining physical, mechanical and energy properties.  The average physical and mechanical properties of all charcoal briquettes were: diameter 3.19 - 3.22 cm, length 4.99 - 6.05 cm, bone dry weight 12.5 - 19.1 g, density 0.306 - 0.465 g / cc, number of drops of briquette into concrete floor at 1.0 m height 1.7 - 6.8. and height of 1.6 kg-weight of vertical impact test 2.9 - 7.3 cm. The Water boiling test of all charcoal briquettes confirmed that no smoke was observed when ignited. The time required to boil 3.7 litre of water was 14.3 - 20.5 minutes and heat utilization efficiency of all tests was 27.6 - 32.0 %.