Comparison of dilute acid and ionic liquid pretreatment of switchgrass: Biomass recalcitrance, delignification and enzymatic saccharification.
The efficiency of two biomass pretreatment technologies, dilute acid hydrolysis and dissolution in an ionic liquid, are compared in terms of delignification, saccharification efficiency and saccharide yields with switchgrass serving as a model bioenergy crop. When subject to ionic liquid pretreatment (dissolution and precipitation of cellulose by anti-solvent) switchgrass exhibited reduced cellulose crystallinity, increased surface area, and decreased lignin content compared to dilute acid pretreatment. Pretreated material was characterized by powder X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and chemistry methods. Ionic liquid pretreatment enabled a significant enhancement in the rate of enzyme hydrolysis of the cellulose component of switchgrass, with a rate increase of 16.7-fold, and a glucan yield of 96.0% obtained in 24h. These results indicate that ionic liquid pretreatment may offer unique advantages when compared to the dilute acid pretreatment process for switchgrass. However, the cost of the ionic liquid process must also be taken into consideration.
Li
Chenlin
C
Joint BioEnergy Institute, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Emeryville, CA, USA.
Knierim
Bernhard
B
Manisseri
Chithra
C
Arora
Rohit
R
Scheller
Henrik V
HV
Auer
Manfred
M
Vogel
Kenneth P
KP
Simmons
Blake A
BA
Singh
Seema
S
D000143:Acids / Q000737:chemistry*; D018533:Biomass; D002241:Carbohydrates / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry; D005936:Glucans / Q000737:chemistry; D006868:Hydrolysis; D052578:Ionic Liquids / Q000737:chemistry*; D008031:Lignin / Q000737:chemistry; D008855:Microscopy, Electron, Scanning / Q000379:methods; D012997:Solvents / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods; D013997:Time Factors; D014961:X-Ray Diffraction
D000143:Acids; D002241:Carbohydrates; D005936:Glucans; D052578:Ionic Liquids; D012997:Solvents; D002482:Cellulose; D008031:Lignin