This study provides information on proximate analysis, heating values, and
ultimate analysis for seven kinds of biomass from agriculture and forest so
urces, such as rice husk, coffee husk sugar cane bagasse and straw, and fir
ewood. The results have shown excessive volatile content ranging from 61.2%
to 82.6%, fixed carbon content ranging from 14.6% to 20.7%, and high ash c
ontents over 22.5% for rice husk and 93% for sugar cane straw. Other biomas
s studied did not reach 3%. The lower heating values ranged from 15.2 to 21
.2 MJ/kg (dry weight basis), with firewood presenting higher values. The ul
timate analysis indicated that the weight fraction of carbon ranged from 38
.2% to 48.8%, the hydrogen fraction ranged from 5.6% to 7.0%, and the oxyge
n fraction ranged from 33.8% to 43.7%. Estimates have indicated that the en
ergy potential of agricultural residues is around 366,700 tonnes of oil ann
ually, which is almost 25% of the cuban annual crude oil production.