The most significant change was observed in the amount of levoglucosan: the content of levoglucosan increased in all the pretreatments. The untreated oil had 7.54 mss% levoglucosan, which increased to 8.44 mass% for hot water pretreated bio-oil and to 9.7 mass% in torrefied bio-oil. Acid and salt pretreaments produced bio-oils having the highest amount of levoglucosan of 13.21 and 11.90%, respectively.
for
increase
amount
was
attributed
removal alkali
alkaline earth metals
catalyse
biochar
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