Catalytic Cracking of C2–C3 Carbonyls with Vacuum Gas Oil

Abstract

The fluid catalytic cracking (FCC) route could be considered for the co-processing of biomass-derived pyrolysis oil with petroleum-derived vacuum gas oil (VGO) in a typical refinery unit by integrating it with a biomass fast pyrolysis process. This paper aims to study the effect of co-processing pyrolysis oil representative model compounds (C2–C3 carbonyls such as hydroxyacetone and glycolaldehyde dimer) with VGO in a FCC advanced cracking evaluation (ACE-R) unit, using an industrially available FCC equilibrium catalyst (E-CAT). The blending ratios of C2–C3 carbonyls and VGO were varied from 5:95, 10:90, 15:85, and 20:80. The reactor was operated in close to industrial FCC process at a temperature of 530 °C and atmospheric pressure with a catalyst-to-oil ratio of 5.0. The blended FCC feedstock and their liquid distillates were structurally characterized by 1H and gated decoupled 13C NMR techniques. The average structural parameters like branchiness index, substitution index, average length of alkyl chains, and fraction of aromaticity per molecule was obtained from NMR data. A linear increase in FCC conversion was observed with increase in hydroxyacetone blending ratio with VGO from 5% to 20%, which may be due to an increase in propylene and a decrease in heavy cycle oil. Increasing the glycolaldehyde blending ratio from 5% to 10% increased the FCC conversion, while the conversion decreased at ratios of 15% and 20%. The 1H NMR and 13C NMR data indicated that there is an increase in the amount of monoaromatics with increases in the amount of hydroxyacetone, whereas in the case of glycolaldehyde, the monoaromatics increased for blending ratios up to 10% and decreased upon further increases in blending ratio. The equilibrium FCC catalyst is capable of cracking oxygenates presents in pyrolysis oil such as hydroxyacetone and glycolaldehyde toward the production of liquefied petroleum gas (LPG) range products. Furthermore, a scheme has been proposed for the processing of pyrolysis oil in petroleum refinery units.

Catalytic cracking of jatropha-derived fast pyrolysis oils with VGO and their NMR characterization

“…The previous studies on the co-processing of aliphatic oxygenates like acetic acid, hydroxyacetone and glycolaldehyde with VGO for similar conditions also indicated the coke yield to be within the limits, except on the co-processing of lignin-derived monomer (guaiacol) with VGO. 32,38 Water formation was also observed on the coprocessing of FPO with VGO; however, the yield is not shown.…”

“…The commercially available VGO was used for the co-processing studies, and its characteristics are given in our previous paper. 38 The catalyst used in the advanced cracking evaluation unit was also an industrially available equilibrium uid catalytic cracking (FCC) catalyst, i.e. E-CAT.…”

“…The physicochemical characteristics of E-CAT are listed in our previous paper. 38 E-CAT contains synthetic faujacite zeolite (USY or REUSY), silica-alumina matrix, clay (e.g. Kaolin clay) with binder and special additives.…”

Molecular Modeling of Coprocessing Biomass Fast Pyrolysis Oil in Fluid Catalytic Cracking Unit

“…8,17 More recently, model compounds are used in several experimental studies in order to develop an understanding of reaction pathways and reaction network for bio oil components on the surface of FCC catalysts. 12,19 To develop better understanding of the effect of reaction conditions, blending ratios and feed properties on product yields and qualities, kinetic modelling of FCC units is necessarily required. There are three types of kinetic models available to describe the catalytic cracking kinetics in an oil refinery FCC process 20 including correlation-based approaches, mechanistic approaches, and lumping modelling approaches.…”

“…In addition, FCC catalysts are known to be tolerant to oxygenates, water, carbon monoxide, and carbon dioxide, which is superior to other processes with oxygenates-sensitive catalysts. Extensive experimental research has been carried out on coprocessing biomass pyrolysis liquids with gas oil fractions in FCC units. , A number of these efforts try to look over the promising aspects of coprocessing bio-oil in FCC units. − This is done by identifying the effects of reaction conditions and blending ratios on products’ yields and quality. , More recently, model compounds are used in several experimental studies to develop an understanding of reaction pathways and reaction network for bio-oil components on the surface of FCC catalysts. , …”