Ketones make up the second major organic group in the bio-oil.
This chemical family is made up of two kinds of ketones: cyclopentenones
(1,3-cyclopentanedione and so on) and open chain ketones
(acetone, 2-butanone and so on). As observed in Table 3, both
groups decrease with temperature, especially at 600 C, at which
the total yield of ketones decreases to 4.1 wt.% in the liquid.
Ketones are formed by condensation reactions of the carbohydrate-
derived fraction [21] and decomposition of the miscellaneous
oxygenates, sugars and furans [62]. When the pyrolysis
temperature is raised, cracking reactions are more severe and
lighter compounds are formed. Ketones are present in nature and
they are synthesized for many applications. They are used mainly
as solvents and intermediates in chemical industry.