CHARACTERIZATION OF FUEL BRIQUETTES FROM COFFEE GROUNDS
MIXED WITH CASSAVA PEEL

The aim of this research is to characterize the fuel briquettes from coffee
grounds mixed with cassava peel and to determine the suitable mixing ratio
between both substances. Adhesive for forming fuel briquette was prepared
from dry cassava peel which was mashed, boiled and stirred in the hot water
bath until it had turned to gel. Coffee ground wastes were collected from
coffee shops according to three favorite coffee brands (A, B and C) in the
market. The mixing ratio by mass, dried coffee ground to dried cassava peel,
varied from 90 : 10, 70 : 30 and 50 : 50 with additional adhesive 10 % by
total mass for each sample. Hydraulic press of 1,000 psi was used for making
cylindrical briquette with 20 mm in diameter and 50 mm in length. Proximate
and Ultimate analyses of fuel briquette were performed, complying with
ASTM D 3172-3175 and LECO methods, respectively. Carbonization was
carried out with a modified steel charcoal kiln of 100 liter. The experimental
results showed that the sample derived from coffee ground brand A with the
mixing ratio of 90 : 10 is a suitable ratio. It gave the highest high heating
value (HHV) with high percentage of fixed carbon. Additionally, it has a
good strength, without crack and fracture and burning well with very low
smoke.