3.2. Fibre estimation by Van Soest method
Fibre analysis of the feedstocks was done to estimate the cellulose,
hemicellulose and lignin content. The cellulose content of
duckweed was found to be 55.2%, which is 6.3% higher than cattle
dung. It signifies higher sugar moieties and its potential for more
bioenergy conversion compared to cattle dung. Lignin content was
found to be lower in duckweed than cattle dung, 12.2% and 21.7%
respectively. The cellulose to lignin proportions of biomass is
important for biogas production. The biodegradability of cellulose
is greater than that of lignin; a determining factor when selecting
biomass plant species for biochemical processing (McKendry,
2001). Lower lignin content in duckweed makes it ideal lignocellulosic
biomass feedstock for biogas production as the pretreatment
step is completely avoided.