evaluated the feasibility of producing bioethanol from SCG through
fermentation using three different yeasts, while the ethanol production
yield was only 26.0% mass fraction. Other researchers
[18e20] used a fast pyrolysis process to convert SCG into the bio-oil.
The results were very promising, with an oil yield as high as 54.9%
mass fraction. Unfortunately, SCG has a fairly high moisture content
(50e60% mass fraction) [12], and thus a pre-drying process is
required before SCG is fed to a pyrolysis system. This leads to a large
energy consumption and decreases the overall economic viability.
Moreover, the quality of the pyrolysis bio-oil is not satisfactory. A
relatively high oxygen (35.2e59.5% mass fraction) resulted in lower
HHVs in a range of 17 MJ kg1 to 23 MJ kg1, depending on the
composition of feedstock and pyrolysis conditions. Therefore, it is
essential to explore other pathways to utilize this waste stream
effectively, efficiently and economically.