Tomorrow’s biofuel: bio-gasoline production in FCC unit
N. Thegarid, G. Fogassy, G. Toussaint, C. Lorentz, Y. Schuurman, C. Geantet, C. Mirodatos
Institut de Recherches sur la Catalyse et Environnement (IRCELYON), UMR5256
CNRS/Université Claude Bernard Lyon1, 2 Av. A. Einstein, 69626 Villeurbanne, France
e-mail : nicolas.thegarid@ircelyon.univ-lyon1.fr
Due to the depletion of carbon fossil resources and increased efforts to mitigate CO 2 emissions,
new generations of transportation fuels have recently been proposed, involving a partial or
complete replacement of fossil resources by carbon-neutral renewable ones. As such, biomass is a
promising feedstock since it is abundant and cheap and can be transformed into fuels and
chemical products [1]. A major challenge to consider is the required mass production given the
huge capacities involved in transportation, which means that rapid change can be achieved only by
using existing infrastructures and guaranteeing the same quality of final fuels. For that reason, a
realistic scenario for bio-fuels mass production in the short term is to consider "co-processing" of
biomass-derived resources together with conventional crude oil in standard refineries. Coprocessing might allow refiners to adjust the content of bio carbon in the produced "hybrid" fuels at
a level compatible with international regulations (e.g. EC regulation for 10% of renewable
feedstock by December 2020 on energy content basis of “all petrol and diesel for transport
purposes” [2]). Fluid Catalytic Cracking (FCC) is one of the most important processes of a modern
refinery because of its flexibility to changing feedstock and product demands. Its principal aim is to
convert high molecular weight hydrocarbons to more valuable products mainly gasoline [3]. In the
present work, we investigate how co-feeding Vacuum Gasoil (VGO) with pre-treated pyrolysis-oil in
a fixed bed reactor can influence the product distribution and the product quality.
To simulate co-processing in a FCC unit, a mixture of 80% of pure VGO and 20 wt.% of up-graded
(partly deoxygenated and low water content) bio-oil (referred to as HDO-oil) was co-injected and
processed in a fixed bed reactor. The gasoline fraction is the primary objective of a FCC unit. Cofeeding HDO-oil gave comparable yields for gasoline to those corresponding to the cracking of
pure VGO. Detailed compositions of the gasoline at a given conversion (~85%) are compared in
Figure 1 for VGO and VGO/HDO-oil.
Full conversion of oxygenates remains challenging since their residual concentration must fulfil
environmental requirements. No significant activity loss was noted for the e-FCC catalyst after coprocessing sequence, tending to demonstrate close quality in coke formation and combustion.
benzene C3
benzene C2
toluene
benzene
VGO cracking
cyclopentane C3/C5
cyclohexane C2/C3
VGO + 20 wt% HDO-oil co-processing
C7-C13
branched paraffins
0
3
6
9
12
15
18
Yield in 100% gasoline range (wt%)
Co-processing favors much more branched
paraffin formation to the expenses of paraffins
as compared to the pure VGO cracking. Short
alkyl chain (C1-3) benzene derivatives are
more typical for the VGO/HDO feed than for the
pure VGO cracking. Mechanistic studies point
in the direction of a change in the acid sites
distribution and to the consumption of hydrogen
by HDO-oil conversion. The latter would limit
hydrogen transfer processes for the VGO
cracking process and favor aromatics at the
expenses of saturated products.
Figure 1. Gasoline detailed composition by
compounds at ~85% conversion level based on
GCxGC analysis.
[1] G. H. Huber, A. Corma, Angew. Chem. Int. Ed., 46 (2007) 7184–720.
[2] A. Oasmaa, D. Meier, in: A. V. Bridgwater (Ed.), “Fast Pyrolysis of Biomass: A Handbook”, Vol. 2, CPL
Press, Newbury, UK (2002) 41-58.
[3] C. N. Hamelinck, A. P. C. Faaij, H. dem Uil, H. Boerrigter, Energy, 29(11) (2004) 1743-1771.
Acknowledgement: FP6 European integrated project “BIOCOUP”, Contract no.: 518312 for partial financial support.