Pyrolysis is the thermal decomposition of carbonaceous material
with a absence of oxygen. It produces a char, gas and liquid
product that is rich in oxygenated hydrocarbons. Dry EFB is fed
to the fluidized pyrolysis reactor operated at 500 C and 1 atm,
and then is rapidly cooled to stop the reaction for less than two
seconds. The model of the pyrolysis reactor includes two areas:
pyrolysis and combustion. These are heat-connected by the sand
flow. The sand flow is a closed loop as depicted in Fig. 1 with the
dashed line. Sand is heated up in the combustor, transported to
the pyrolysis reactor to transfer heat, and recycled to the combustor
after being separated from the gas. The flow rate of sand is
equal to 20 times that of dry biomass. The combustion of both
gases recycled from the quencher and char is modeled as the stoichiometric
reactions. Air enters in from the bottom of the combustor
to supply oxygen. 100% of the gases and 97% of char are
assumed to be combusted. If the heat generated by gas and char
combustion exceeds the amount required for pyrolysis, the excess
heat is considered as a by-product due to potential applications to
generate electricity or hot water. In the 1 kton-dry EFB/yr plant,
the excess heat rate is 156 kW.