Palm kernel shell (PKS) and palm empty fruit bunch (PEFB) are among the biggest wastes
from oil palm industry. Bio-oils from these wastes can be utilised as a source of renewable
feedstock to produce various value-added chemicals. The present study focuses on the
production of PKS and PEFB bio-oils from fast pyrolysis, which is known to maximize biooil yield. The main objective of this work was to obtain a comprehensive understanding of
fast pyrolysis (heating rate: 1000 °C s-1) behaviour of PKS and PEFB in a wire-mesh reactor
(WMR), which was designed to diminish secondary reactions. The maximum bio-oil yields
of PKS and PEFB pyrolysis were obtained at the at 650 °C and 500 °C, respectively. GC-MS
analysis showed that PKS bio-oil mainly contains phenolic compounds, levoglucosan and
esters, while PEFB bio-oils mainly contains acids, esters, and levoglucosan. Most bio-oil
production for both samples occurred at 350-425 °C, which coincides with cellulose
decomposition and, to lesser extent, lignin decomposition. Levoglucosan has also been found
to be mainly produced at the same temperature. The concentration of phenolic compounds in
the bio-oil rise with pyrolysis temperature, at least for PKS. The analysis of chars with TGA
and FTIR showed dramatic changes in mass and chemical functionalities at 425 °C for PKS
and 350 °C for PEFB, further suggesting the key role of cellulose decomposition during fast
pyrolysis. The produced chars from fast pyrolysis exhibit residual functionalities, indicating
minimum carbonisation. The difference in pyrolysis behaviour between both biomass is
attributed to the variation of lignocellulosic make-up of the biomass. The second objective of
this work is to assess the effect of washing on fast pyrolysis. Acid (H2SO4 and HCl) washing
and water (DI water) washing reduces the amount of ash. The catalytic effect of ash is clearly
observed during fast pyrolysis. It has been found that lower amount of ash increases bio-oil
production in the expense of gas. Acid washed samples produce bio-oils rich in levoglucosan.
The significant reduce of Ca were observed exclusively in acid washed samples. Ca appears
to play a key role in promoting pyrolysis reaction pathway that reduces levoglucosan
formation. FTIR analysis indicate minimum physicochemical alteration in the solid samples
of biomass after washing. The final objective is to test the effect of acid presence during fast
pyrolysis. It has been found that H2SO4 appreciably reduces the temperature required for
biomass thermal decomposition. Yield and GC-MS analysis of bio-oil showed that H2SO4
seems to not significantly influence bio-oil production and levoglucosan concentration.