Tomorrow's biofuel: bio-gasoline production in FCC unit

Due to the depletion of carbon fossil resources and increased efforts to mitigate CO2emissions, 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.Co-processing 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]. Inthe 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 VGOand 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. Co-feeding 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 co-processing sequence, tending to demonstrate close quality in coke formation and combustion.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, “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

The fate of bio-carbon in FCC co-processing products

INGENIERIE+GFO:NTE:YSC:CMIA promising alternative to the first generation of bio-fuels is to produce mixed bio- and fossil fuels by co-processing mixtures of biomass pyrolysis oil with crude oil fractions obtained from distillation in a conventional oil refinery. This was demonstrated to be technically feasible for fluid catalytic cracking (FCC), which is the main refinery process for producing gasoline. However, co-processing leads to more coke formation and to a more aromatic gasoline fraction. A detailed understanding is necessary on how the oxygenated moieties effect the reaction mechanism to further improve the process/catalysts. Moreover, for technical and marketing reasons, it is absolutely required to accurately determine the proportion of renewable molecules in the commercialized products. The carbon-14 method (also called radiocarbon or C-14) has been used as the most accurate and powerful method to discriminate fossil carbon from bio-carbon, since fossil fuel is virtually C-14-free, while biofuel contains the present-day "natural" amount of C-14. This technique has shown that not all FCC products share bio-carbon statistically. The coke formed during a FCC cycle and to a lesser extent the gases are found richer in C-14 than gasoline. This result gives valuable information on the co-processing mechanism, supporting that the bio-oil oxygenated molecules are processed more easily at the expenses of the crude oil hydrocarbons, favouring the bio-coke and the bio-light gases production

Biomass derived feedstock co-processing with vacuum gas oil for second-generation fuel production in FCC units

Hydrodeoxygenated pyrolysis-oils (HDO-oil) are considered promising renewable liquid energy carriers. As such, it cannot be applied in in-stationary combustion engines so more “upgrading” is required. A considerable alternative is to co-process HDO-oil along with vacuum gas oil (VGO) in a Fluid Catalytic Cracking unit (FCC). This study evaluates the impact of adding 20 wt.% HDO-oil to a conventional FCC feedstock. The VGO and bio-oil mixtures were co-injected into a fixed-bed reactor simulating FCC conditions using an equilibrated industrial FCC catalyst. Co-processing of 20 wt.% HDO-oil with VGO gave comparable yields for the gasoline fraction to that of the pure VGO cracking. However, during co-processing oxygen removal from HDO-oil oxygenated components consumes hydrogen coming from the hydrocarbon feedstock. As a result the final product composition is poor in hydrogen and contains more coke, aromatics and olefins

Catalyzed ring opening of epoxides: Application to bioplasticizers synthesis

International audienceThe ring opening of mono, di or tri-substituted epoxides by acetic anhydride to corresponding diacetates is catalyzed by weak bases such as hydrotalcite in the carbonated form. This reaction is performed at 423 K without solvent and the solid catalyst is reused after simple regeneration for 4 runs with constant conversion. Ring-opening of methyl oleate epoxide leads to the formation of useful diacetate methyl oleate. Starting from vegetable oils, polyacetate derivatives are prepared in three catalytic steps (methanolysis, epoxidation then ring opening). Plastisol was prepared by mixing these products with PVC and their rheological properties were evaluated. The recorded data show that they can act as bioplasticizer with similar behaviour as phthalate reference. (c) 2010 Elsevier B.V. All rights reserved