Abstract:
Lignocellulosic biomass especially from nonfood
crops is widely regarded as a sustainable second-generation
bioethanol raw material. However, production of bioethanol
from the abundant and inexpensive sources of lignocellulosic
biomass such as Prosopis Juliflora requires that the latter
undergo pretreatment processes. A new pretreatment method
by use of Ionic Liquids has shown to be promising. This
research work analyzed pretreatment of Prosopis Juliflora
stem
using
1-butyl-3-methylimidazolium
chloride
([BMIM]Cl),1-butyl-4-methylpyridinium chloride ([4MBP]Cl)
and trihexyltetradecylphosphonium chloride ([P66614]Cl).
Regeneration of cellulose from the Ionic Liquids was carried
out and the performance of the Ionic Liquids established
through analysis of glucose concentrations upon hydrolysis.
Pretreatment of Prosopis Juliflora was carried out at varied
temperatures (80°C–140°C), pretreatment periods (40min–
160min) and a biomass loading of 6%wt. Simple acid
hydrolysis was then performed at a temperature of 130°C for a
duration of 10 minutes. Finally glucose measurement was
done using a Shimadzu UV–Vis Spectrophotometer at a
wavelength of 520nm. Pretreatment of the biomass with the
ionic liquids resulted in an increase in glucose yield of 1.78
times with phosphonium IL, 18.1 times with imidazolium IL
and 15.21 times with pyridinium IL as compared to the
unpretreated biomass. Ionic liquid pretreatment is therefore
an effective and viable process that can be applied towards
unlocking lignocelluloses recalcitrance. However [BMIM]Cl
and [4MBP]Cl showed better performance generally as
compared to P66614]Cl with respect to maximum glucose
yield obtained with each of the ILs (7.19% in the P66614]Cl
pretreated case, 73.27% in the [BMIM]Cl pretreated case and
61.63% in the [4MBP]Cl pretreated case. Prosopis Juliflora
yielded a substantial amount of glucose hence qualifying as a
potential non food-based biomass substitute suitable for
bioethanol production.
