Levoglucosan Production by Fast Pyrolysis of Biomass After Dilute Acid Pretreatment

Fermentable sugars are valuable intermediates that can be produced from lignocellulosic biomass, in which hemicellulose and cellulose are favorable candidates for their production. In this chapter, the adaptability of a comprehensive strategy for lignocellulose saccharification is presented. Hemicellulose of reed pole can be hydrolyzed for xylose production by dilute acid first, and then the retained residue from acid hydrolysis, rich in cellulose, can be pyrolyzed for levoglucosan production. Such a process highlighted in this chapter exhibits several attractive features: (1) hemicellulose can be nearly and completely saccharified, giving a xylose yield as high as 92.2 wt%, (2) due to the alteration of chemical composition and physical structure by dilute acid pretreatment, the levoglucosan yield from acid pretreated biomass can be as high as 45.9 wt% as compared with that of un-pretreated reed pole (4.8 wt%), (3) improvement of levoglucosan formation and the inhibition of acetic acid formation from acid pretreated biomass can improve fermentability of its pyrolysate. Furthermore, it is demonstrated that the effect of demineralization, hydrolysis of hemicellulose and improvement of levoglucosan yield is ordered as HCl > H2SO4 > H3PO4.