Limitations in the energy balance when VGO/aqueous bio-oil mixtures are co-processed in FCC units

PANERO, MELISA; PUJRO, RICHARD; FALCO, MARISA; SEDRAN, ULISES; BILBAO, JAVIER; ARANDES, JOSÉ M.

FUEL

ELSEVIER SCI LTD

Año: 2022 vol. 324 p. 124798 - 124807

0016-2361

The effect on the energy balance of a FCC unit after co-feeding the aqueous fraction of a bio-oil together with avacuum gas oil (VGO) has been studied. The simulation program considers the interdependency relationshipbetween the reaction and regeneration sections in the unit, where the heat of coke combustion has to sustain theenergy requirements to preheat and vaporize the feedstock as well as the endothermic cracking reactions. Thecombustion of coke deposited on an equilibrium commercial FCC catalyst in cracking various bio-oil/VGOmixtures at 530 ◦C, with catalyst to oil relationships between 3 and 6 in a CREC Riser Simulator laboratoryreactor, was investigated by means of thermogravimetric analysis (TGA) and differential scanning calorimetry(DSC).Results showed that the heat from coke combustion is not enough to provide the energy needed in the unitwhen the amount of bio-oil in the feedstock is larger than 5 wt%, mainly due to the high content of water in theaqueous fraction of the bio-oil and to the lower heat of combustion of the coke formed in co-processing, ascompared to the VGO alone.