Carbon and
hydrogen content in the biomass samples was determined with a
CHN LECO-800 elemental analyzer from Leco Corporation. Oxygen
content was determined by difference. The total ash content was
measured by combustion via the following procedure: a sample of
2 g was placed in a furnace. In the presence of ambient air, the
temperature was raised to 550 C where it was maintained for 3 h.
The ash content was calculated based on the final biomass weight,
which was considered to be the ash in the biomass, compared to
the initial sample weight. The moisture content was measured by
drying a pre-weighed sample at 105 C for 4 h. The calorific value
was determined by burning a pre-weighed sample in an oxygenbomb
calorimeter (Parr 1261) under controlled conditions (ASTM
D4809). Inductive coupled plasma-atomic emission spectroscopy
(ICP-AES) was used for the determination of the ash composition of
the untreated and the demineralized biomass samples, utilizing a
Perkin Elmer Plasma 400 spectrometer, equipped with a
Cetac6000AT þ ultrasonic nebulizer.