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Applied Catalysis A, General (v.341, #1-2)

Contents (pp. iii-ix).

Editorial Board (pp. co2).

Preparation and characterization of Ir-based catalysts on metallic supports for high-temperature steam reforming of methanol by Jingsheng Jia; Jin Zhou; Chunxi Zhang; Zhongshan Yuan; Shujuan Wang; Lei Cao; Shudong Wang (pp. 1-7).

Ir-based catalysts on heat-resisting foil supports with different washcoats were investigated for hydrogen production by high-temperature steam reforming of methanol. Al₂O₃, Ce_0.8Zr_0.2O₂–Al₂O₃, Ce_0.8Zr_0.2O₂/Al₂O₃ and Ce_0.8Zr_0.2O₂ coatings were prepared on the metallic supports and iridium was deposited on them as the active component. The samples were characterized by X-ray powder diffraction (XRD), ultrasonic vibration test, scanning electron microscope (SEM) and temperature-programmed reduction (TPR). The performance of the catalysts for steam reforming of methanol was evaluated with a fixed-bed reactor. It was found that the phase structure, the shape of the surface particles and the coating adherence were different from each other for the four kinds of coatings. The activities, selectivities and stabilities of these Ir-based catalysts on metallic supports were compared to select the optimal one for use in high-temperature methanol steam reforming. The results indicated that the Ir/Ce_0.8Zr_0.2O₂/Al₂O₃/FeCrAl catalyst showed better performance than the other catalysts, which is a promising candidate for hydrogen production via the methanol steam reforming process in Pd membrane reactors.Al₂O₃, Ce_0.8Zr_0.2O₂–Al₂O₃, Ce_0.8Zr_0.2O₂/Al₂O₃ and Ce_0.8Zr_0.2O₂ coatings were prepared on the FeCrAl metallic supports and iridium was deposited on them as the active component. The samples were characterized by X-ray powder diffraction (XRD), ultrasonic vibration test, scanning electron microscope (SEM) and temperature-programmed reduction (TPR). The activities, selectivities and stabilities of these Ir-based catalysts on metallic supports were compared to select the optimal one for use in high-temperature methanol steam reforming. ▪

Keywords: Metallic support; Hydrogen production; High temperature; Methanol; Steam reforming

MnS doped mesoporous silica catalysts for the generation of novel carbon nanocages by Louise Barry; Joseph Tobin; Mark Copley; Justin D. Holmes; David J. Otway; Michael A. Morris (pp. 8-11).

The use of novel MnS impregnated mesoporous silica systems as catalysts for the generation of carbon nanostructures via a simple catalytic vapour deposition (CVD) method is reported. This is the first time that a transition metal sulphide has been used for the synthesis of carbon nanostructures. ▪Novel MnS impregnated mesoporous silica systems have been originated for the generation of carbon nanocages. The procedure involves a simple catalytic vapour deposition (CVD) method. This is the first time that a transition metal sulfide has been used for the synthesis of carbon nanostructures.

Keywords: MnS; Mesoporous silica; Catalytic vapour deposition; Carbon nanostructures

The influence of dopants on the catalytic activity of hematite in the ethylbenzene dehydrogenation by Márcia de Souza Ramos; Manuela de Santana Santos; Lucimar Pacheco Gomes; Alberto Albornoz; Maria do Carmo Rangel (pp. 12-17).

The effect of neodymium, lanthanum, aluminum and zirconium on the textural and catalytic properties of hematite was studied to develop catalysts to ethylbenzene dehydrogenation to produce styrene. The neodymium-containing catalyst showed high activity and selectivity and was able to work up to 530°C, without deactivation, being the most promising for styrene production. Figure shows activity of the catalysts in ethylbenzene dehydrogenation as a function of time at different temperatures for neodymium-doped iron oxide. () 490°C; (■) 510°C; (▴) 530°C and (●) 550°C. ▪The effect of neodymium, lanthanum, aluminum and zirconium on the textural and catalytic properties of hematite was studied in this work, which aimed to develop catalysts to ethylbenzene dehydrogenation, in the presence of steam, the main commercial route to obtain styrene. Hematite and magnetite were found in fresh and spent catalysts, respectively. All dopants increased the specific surface area of the fresh and spent catalysts and made them more resistant against reduction, but only aluminum avoided sintering during reaction. The dopants increased the catalytic activity per area of hematite, except aluminum which acted only as a textural promoter. The selectivity was decreased due to zirconium and lanthanum while the other dopants did not change this parameter. The neodymium-containing catalyst showed high levels of activity and selectivity and was able to work up to 530°C, without deactivation, being the most promising with regard to styrene production.

Keywords: Styrene; Ethylbenzene; Hematite

The role of acidity in the decomposition of 1,2-dichlorobenzene over TiO₂-based V₂O₅/WO₃ catalysts by Stefania Albonetti; Sonia Blasioli; Rosa Bonelli; Joseph Epoupa Mengou; Salvatore Scirè; Ferruccio Trifirò (pp. 18-25).

The influence of Lewis and Brønsted acid sites on the performance of V₂O₅/TiO₂ and V₂O₅–WO₃/TiO₂ catalysts in the total oxidation of o-dichlorobenzene was investigated. Catalytic activity of these materials resulted strongly affected by their acidic properties. The presence of Brønsted acid sites significantly increases the o-DCB conversion but also leads to the uncompleted degradation of chlorinated compounds, promoting the formation of partial oxidation products, as dichloromaleic anhydride. On the contrary, Lewis acid sites, acting as absorbing sites, promote the further oxidation of intermediates to CO and CO₂, without any by-products desorption.Furthermore, the presence of water in the feed-stream was proven to decrease o-DCB conversion but also to play a positive role on process selectivity, increasing COx production. Plausible reasons for this effect are the reduction of Brønsted acid sites and the hydrolysis of anhydride during wet tests.This study demonstrated that V₂O₅/TiO₂ and V₂O₅–WO₃/TiO₂ catalysts are active for the total oxidation of o-dichlorobenzene and that the activity behaviour resembles the trend of Brønsted acidity, indicating that these sites are beneficial for o-DCB conversion. Nevertheless these materials lead, in some case, to the formation of partially oxidized compounds, in particular to o-dichloromaleic anhydride (DCMA). The production of this molecule resulted strongly affected by the acidic properties of the catalysts.▪

Keywords: Catalytic oxidation; o; -Dichlorobenzene; Vanadium supported catalysts; Brønsted and Lewis acid sites; FT-IR

Deactivation studies of the SCR of NO_x with hydrocarbons on Co-mordenite monolithic catalysts by Alicia V. Boix; Soledad G. Aspromonte; Eduardo E. Miró (pp. 26-34).

The catalytic reduction of NO_x with hydrocarbons (butane or methane) on CoMOR washcoated monolithic catalysts was studied in the presence of steam and excess oxygen. When the reducing agent was methane, a low concentration of water (2%) decreased the NO to N₂ conversion. However, when butane was used instead of methane, the maximum NO_x conversions increased.▪The catalytic reduction of NO_x with hydrocarbons (butane or methane) on CoMOR washcoated monolithic catalysts was studied in the presence of steam and excess oxygen. The significant changes observed in the catalytic behavior of CoMOR powder and monoliths depended essentially on the hydrocarbon nature (carbon number) and the concentration of water in the feed. When the reducing agent was methane, a low concentration of water (2%) decreased the NO to N₂ conversion. However, when butane was used instead of methane, the maximum NO_x conversions increased from 50 to 58% and from 52 to 64% for the CoMOR powder and monolith, respectively. The presence of water inhibited the NO adsorption when the reducing agent was methane but when butane was used, water helped to remove the surface-carbon deposits as indicated by TPO and XPS results. This fact explains the increase observed in the NO_x conversion. The characterization with TPR and UV–vis spectroscopy showed that the main Co species present in the selective catalysts were the Co(II) ions exchanged at different sites of the mordenite and highly dispersed Co_xO_y moieties. More rigorous reaction conditions, i.e. 10% of water, led to the irreversible deactivation with both reductants. The Co₃O₄ phase was detected in all the deactivated powder and monolithic catalysts. The Co₃O₄ spinel was formed from the cobalt ion migration, which was promoted in wet atmosphere. In addition, for monolithic catalysts washcoated with CoMOR, the silica binder inhibited the water deactivation effect probably due to the silica–cobalt interaction, as a Co_xO_ySi silicate.

Keywords: Hydrocarbon-SCR; Monolithic catalysts; CoMOR; Deactivation; Cobalt characterization; UV–vis; Raman

Synthesis, characterization and catalytic activity of ruthenium-doped cobalt catalysts by A. Infantes-Molina; J. Mérida-Robles; E. Rodríguez-Castellón; J.L.G. Fierro; A. Jiménez-López (pp. 35-42).

Hydrogenation, hydrogenolysis/hydrocracking of tetralin on supported cobalt-ruthenium bimetallic catalysts were evaluated. Catalysts with different loadings of ruthenium were tested at different temperatures and under the presence of dibenzothiophene. Ruthenium-doped catalysts improved the catalytic results previously obtained with a monometallic cobalt catalyst when dibenzothiophene was added to the feed as sulphur poison, due to ruthenium particle acting as sulphur trap.▪Cobalt-based catalysts doped with different amounts of ruthenium supported on Zr-MSU type materials were studied in the hydrogenation and hydrogenolysis/hydrocracking of tetralin at different temperatures. The catalytic tests were carried out in a high-pressure fixed-bed continuous-flow stainless steel catalytic reactor operating at a pressure of 6.0MPa. Textural, structural, acidic and metallic properties were studied by XRD, XPS, H₂-TPR, NH₃-TPD and Elemental Chemical Analysis. Five catalysts were prepared with 10wt% of cobalt and a ruthenium loading ranging from 0.5 to 5wt%, along with a monometallic ruthenium catalyst with 3wt% of metal, for comparison. From catalysts characterization, no interaction between cobalt and ruthenium can be established, however, the presence of ruthenium influences the reducibility of cobalt.Ruthenium-doped catalysts not only improve the catalytic activity of monometallic cobalt and ruthenium ones, but also ruthenium acts as a trap for sulphur organic molecules, preserving cobalt particles from sulphur poisoning and thus maintaining their high hydrogenation activity. The catalyst with a ruthenium loading of 3wt% is found to be the most active, both, with or without sulphur in the feed. The most striking improvement of ruthenium-doped catalyst properties is their greater resistance to sulphur molecules than in the case of monometallic cobalt catalysts, which are otherwise rapidly deactivated under the same experimental conditions.

Keywords: Mesoporous MSU; Cobalt catalysts; Tetralin hydrogenation; Hydrogenolysis/hydrocracking; Sulphur tolerance

Ni-olivine catalysts prepared by thermal impregnation: Structure, steam reforming activity, and stability by John N. Kuhn; Zhongkui Zhao; Allyson Senefeld-Naber; Larry G. Felix; Rachid B. Slimane; Chun W. Choi; Umit S. Ozkan (pp. 43-49).

The present work examines the structure and surface properties of the Ni-olivine catalysts prepared by thermal impregnation following preparation, during reduction by in-situ techniques, and following naphthalene-steam reforming in simulated biomass derived syngas. The figure shows the Raman spectra of olivine catalysts with and without Ni.▪Ni-olivine catalysts prepared by thermal impregnation are candidate materials for in-bed catalytic tar removal during fluidized bed biomass gasification. The present work examined the structure and surface properties of the Ni-olivine catalysts prepared by thermal impregnation following preparation, during reduction by in-situ techniques, and following naphthalene-steam reforming in simulated biomass derived syngas. Catalysts were characterized by BET surface area, laser Raman spectroscopy (LRS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). During the preparation, secondary phases containing Mg (i.e., (Mg,Fe)₃Si₂O₅(OH)₄ and MgFe₂O₄) reacted to form an olivine phase enriched in Mg and either MgO or Mg-enriched (Mg,Ni)O. The presence of excess steam in the naphthalene-steam reforming appeared to limit coking and also caused behavior to be different than was observed under reducing conditions. Post-reaction characterization indicated the loss of a metallic phase through a possible alloying process and the exchange of Fe for Mg in the olivine structure. Either can potentially explain the high coke resistance of the Ni-olivine catalysts prepared by thermal impregnation compared to Ni-olivine catalysts prepared by incipient wetness impregnation or the olivine support. Finally, the properties of the olivine catalysts with and without Ni were compared through activity for methanol- and ethylene-steam reforming.

Keywords: Tar removal; Biomass gasification; Ni-olivine; Catalytic stability/activation; Catalyst characterization

The impact of the “memory effect” on the catalytic activity of Mg/Al; Mg,Zn/Al; Mg/Al,Ga hydrotalcite-like compounds used as catalysts for cycloxene epoxidation by E. Angelescu; O.D. Pavel; R. Bîrjega; M. Florea; R. Zăvoianu (pp. 50-57).

Zn and Ga containing hydrotalcites present higher activity than the MgAl hydrotalcite for the oxidation of cyclohexene to cyclohexene oxide in the initial stages of the process. This effect is more pronounced for the activity of the derived mixed oxides. The reconstructed hydrotalcite structures obtained by rehydration have higher activity than the as-synthesized HT.▪The epoxidation of cyclohexene by hydrogene peroxide and benzonitrile, in methanol as solvent on solid base catalysts, hydrotalcites (HT) and corresponding mixed oxides (C-HT) was investigated. The employed catalysts were as-synthesized Mg/Al; Mg,Zn/Al; Mg/Ga,Al hydrotalcites, their derived mixed oxides and the corresponding reconstructed hydrotalcite forms (R-HT) obtained via the “memory effect” upon a rehydration treatment of C-HT. The catalysts were characterized by XRD, CO₂-TPD and N₂ adsorption–desorption measurements.The reconstructed HT samples exhibit higher activity in comparison to the as-synthesized carbonated HT samples. A tentative correlation of the catalytic properties with the base strength of the active sites, the structural and textural characteristics of the catalysts, has been explored.

Keywords: Epoxidation of cyclohexene; Hydrotalcites and mixed oxides catalysts; Memory effect

Kinetic study of heterogeneous catalytic hydrogenation of cyclohexene to cyclohexane in ionic liquid–alcohols mixtures by Mohammad Khodadadi-Moghaddam; Aziz Habibi-Yangjeh; Mohamad Reza Gholami (pp. 58-64).

Heterogeneous catalytic hydrogenation of cyclohexene by Pt/Al₂O₃, was carried out in solutions of 2-hydroxyethylammonium formate (a room temperature ionic liquid) mixed with methanol, ethanol and propan-2-ol. The rate constant of the reaction increases with the mole fraction of the ionic liquid. Increase of the reaction rate with π^* (dipolarity/polarizibility of solvent) is attributed to the non-polar nature of the reactants.▪Heterogeneous catalytic hydrogenation of cyclohexene, catalyzed by Pt/Al₂O₃, was carried out in solutions of 2-hydroxyethylammonium formate (a room temperature ionic liquid, RTIL) mixed with methanol, ethanol and propan-2-ol at 25°C. The rate constants of the reaction in ionic liquid alcohol mixtures were higher than alcohol alone. First-order rate constant of the reaction in the RTIL relative to propan-2-ol is approximately 28. Furthermore, the rate constant of the reaction increases with the mole fraction of the ionic liquid. Single-parameter correlations of log k vs. normalized polarity parameter (ETN), hydrogen-bond acceptor basicity ( β) and hydrogen-bond donor acidity ( α) do not give acceptable results in the solutions. In addition, log k does not show an acceptable dual-parameter correlation with π* (dipolarity/polarizibility, one of the Kamlet–Taft parameters for solvent that shows the dipolarity of the solvent) and α, π* and β andETN and β. However single-parameter correlation of log k vs. π^* gives reasonable results. The increase of the reaction rate with π^* is attributed to the non-polar nature of the reactants.

Keywords: Ionic liquid; Heterogeneous catalytic hydrogenation; Solvatochromic parameters; Solvent effects

Efficient multimetallic catalytic systems for the selective hydrogenation of nitric acid by Takuma Hara; Yosuke Nakamura; Jun Nishimura (pp. 65-69).

New multimetallic catalytic systems of Pd+Ni/C, Pd+Ni+Fe/C and Pd+Au+Fe/C (combined with GeO₂) were developed for the selective hydrogenation of nitric acid to hydroxylamine. The catalytic activity and selectivity of these multimetallic catalytic systems are definitely higher than those of not only the general non-doped Pd/C system but also the Pd+Fe/C system developed recently. ▪New multimetallic catalytic systems for the selective hydrogenation of nitric acid to hydroxylamine were developed by investigating the promoter effect of one or more additional metals from Group 8 to 11 on Pd/C (combined with GeO₂). Among various multimetallic catalytic systems investigated here, Pd+Ni/C, Pd+Ni+Fe/C, and Pd+Au+Fe/C (combined with GeO₂) were found to be particularly effective systems, which provided much higher catalytic activity as well as higher selectivity than those of not only the non-doped Pd/C system but also the Pd+Fe/C system developed recently.

Keywords: Nitric acid; Selective hydrogenation; Hydroxylamine; Pd/C; Ni-doping

Water modification of PEG-derived VPO for the partial oxidation of propane by Q. Jiang; J. Zhao; X.K. Li; W.J. Ji; Z.B. Zhang; C.T. Au (pp. 70-76).

The PEG-derived VPO precursors were subject to water refluxing and in situ activation in a water vapor-containing environment. The resulting effects are correlated to catalytic performance in the partial oxidation of propane to acrylic acid.▪In this study, the PEG-derived VPO precursors were subject to water refluxing (90°C, 8h) and in situ activation in a steam-containing environment. For comparison, the VPO precursors without water refluxing were also activated in a similar manner. The IR measurement indicated that the majority of PEG in the precursor has been removed during water refluxing, and the VPO is essentially unenwrapped by PEG. The consequence is an increase of particle size and crystallinity of VPO as well as decreases in surface acidity and site density. The activation of catalysts in a stream-containing environment has an influence on the content of V⁵⁺ species and on the reduction behavior of the VPO catalysts. The VPO catalyst activated with 20% water vapor (by volume) in the feed shows the highest crystallinity. Compared with the non-PEG-derived VPO precursor, the PEG-derived one undergoes structure changes of higher severity during the water/steam treatments. The VPO catalyst generated from the PEG-derived precursor with water refluxing and activated with steam (20%) exhibited a propane conversion of 25% and a (AA+HAc) selectivity of ∼70%. The superior catalyst behavior can be interpreted in terms of the higher crystallinity of the (VO)₂P₂O₇ phase, the lower content of V⁵⁺ species, and the milder surface acidity as caused by the water/steam treatments.

Keywords: Vanadium phosphorus oxide; Propane; n; -Butane; Oxidation; Acrylic acid; Maleic anhydride

Ca and Zn mixed oxide as a heterogeneous base catalyst for transesterification of palm kernel oil by Chawalit Ngamcharussrivichai; Prangsinan Totarat; Kunchana Bunyakiat (pp. 77-85).

Ca–Zn mixed oxides have been investigated in transesterification of palm kernel oil at 60°C and 1atm. The mixed oxides consist of nano clusters of CaO and ZnO, and possess small particle sizes and high surface areas. The combination of Ca and Zn reduces the calcination temperature required for decomposition of CaCO₃ to active CaO. Under the suitable conditions, the methyl ester content of >94.2% can be achieved.▪Transesterification of palm kernel oil with methanol over mixed oxides of Ca and Zn has been investigated batchwise at 60°C and 1atm. CaO·ZnO catalysts were prepared via a conventional co-precipitation of the corresponding mixed metal nitrate solution in the presence of a soluble carbonate salt at near neutral conditions. The catalysts were characterized by using techniques of X-ray diffraction (XRD), scanning electron microscope (SEM), and thermogravimetric analysis (TGA). The results indicated that the mixed oxides possess relatively small particle sizes and high surface areas, compared to pure CaO and ZnO. Moreover, the combination of Ca and Zn reduced the calcination temperature required for decomposition of metal carbonate precipitates to active oxides. Influences of Ca/Zn atomic ratio in the mixed oxide catalyst, catalyst amount, methanol/oil molar ratio, reaction time, and water amount on the methyl ester (ME) content were studied. Under the suitable transesterification conditions at 60°C (catalyst amount=10wt.%, methanol/oil molar ratio=30, reaction time=1h), the ME content of >94% can be achieved over CaO·ZnO catalyst with the Ca/Zn ratio of 0.25. The mixed oxide can be also applied to transesterification of palm olein, soybean, and sunflower oils. Furthermore, the effects of different regeneration methods on the reusability of CaO·ZnO catalyst were investigated.

Keywords: Biodiesel; Transesterification; Mixed metal oxide; Heterogeneous catalyst

Needle in a haystack catalysis by Xiaolin Zheng; John T. Gleaves; Gregory S. Yablonsky; Thomas Brownscombe; Anne Gaffney; Mike Clark; Scott Han (pp. 86-92).

Comparison of CO₂ produced during TAP vacuum pump-probe experiments and atmospheric flow experiments for CO oxidation over single Pt particle with the same composition of reactants. (A) A typical set of pump-probe CO₂ responses ( m/ e=44) for reaction at 140, 170, and 350°C. There is a shift in the amount of CO₂ produced during both CO and oxygen pulses as temperature increases. (B) CO₂ production observed from atmospheric flow experiment. The CO₂ produced while increasing reactor temperature is less than the CO₂ produced during reactor temperature decrease as shown by the counter-clockwise hysteresis loop. (C) CO₂ production observed from vacuum pump-probe experiment. The black line represents the total CO₂ yield. The red and blue lines represent the CO₂ yield on the oxygen pulse and CO pulse, respectively.▪A new configuration of catalyst loading in the Temporal Analysis of Products (TAP) reactor is presented. It is a single Pt particle packed in a bed with approximately 100,000 inert quartz particles. In TAP studies, the single particle configuration was proven to be sensitive enough to monitor and compare kinetic characteristics of the same catalyst particle at both high vacuum and atmospheric pressures. Catalytic CO oxidation reaction over platinum was used to illustrate these new possibilities. In the TAP single particle experiments under high vacuum conditions, a single particle provides high conversion (up to a total conversion of 95%) despite the catalyst particle occupies less than 0.1% of the total reactor volume. This phenomenon was proven in a variety of pulse response experiments. A mathematical probabilistic theory of this counterintuitive phenomenon will be published in the next paper. Also, an interesting similarity was found from both TAP vacuum and atmospheric pressure data, i.e. both sets of data are characterized by a “turning point” at the same temperature of 170°C indicating a transition from an O₂ dominated regime to a CO dominated regime. This observation of pressure independent characteristic of the Pt particle creates a new possibility for bridging across the pressure gap.

Keywords: Heterogeneous catalysis; Single particle catalysis; CO oxidation; Temporal Analysis of Products (TAP); Platinum

Performance of Pt-Fe/mordenite monolithic catalysts for preferential oxidation of carbon monoxide in a reformate gas for PEFCs by Nobutaka Maeda; Takaaki Matsushima; Hiroyuki Uchida; Hisao Yamashita; Masahiro Watanabe (pp. 93-97).

Pt-Fe/mordenite catalysts coated on ceramic straight-channel monoliths were evaluated for the preferential oxidation of carbon monoxide (PROX) in hydrogen-rich gas streams. In a feed gas containing 1% CO, 1% O₂, with the balance H₂, CO conversion reached almost 100% at temperatures ranging from 100 to 130°C, i.e., an outlet CO concentration of less than 10ppm. Even in a synthetic reformate gas (1% CO, 1% O₂, 15% H₂O, 20% CO₂, balance H₂), the monolithic catalyst exhibited excellent activity, reducing the CO concentration to less than 100ppm. In particular, under optimized conditions, an outlet CO concentration of less than 10ppm was realized. This is the first report that has demonstrated that monolithic catalysts could achieve the 10-ppm target level at a low O₂/CO ratio and a high space velocity in a single-stage reactor. Excellent durability of the monolithic catalyst is expected, based on a lack of deterioration in performance during 500h of operation.Pt-Fe/mordenite catalysts coated on ceramic monoliths were evaluated for the preferential oxidation of carbon monoxide (PROX) in hydrogen-rich gas stream. The monolithic catalyst exhibited an excellent activity, reducing CO concentration to less than 10ppm under optimized conditions. This is the first report that has demonstrated that monolithic catalysts could achieve the 10ppm target level at a low O₂/CO ratio and a high space velocity.▪

Keywords: Preferential oxidation of carbon monoxide; Pt-Fe/mordenite catalyst; Monolith; Long-term durability; PEFC

A novel conceptional process for residue catalytic cracking and gasoline reformation dual-reactions mutual control by Gang Wang; Guang-fu Yang; Chun-ming Xu; Jin-sen Gao (pp. 98-105).

Based on the subsidiary riser FCC (SRFCC) process for gasoline reformation, a novel conceptional process for residue catalytic cracking and gasoline reformation dual-reactions mutual control (DMC) was proposed and relevant experimental researches were carried out in a Technical Pilot Scale Riser (TPSR) FCC apparatus. The goals of DMC were to improve product distribution and increase desirable product yield in residue catalytic cracking as well as in FCC gasoline upgrading.▪Based on the subsidiary riser FCC (SRFCC) process for gasoline reformation [Y.H. Bai, J.S. Gao, S.C. Li, C.M. Xu, Petrol. Process. Petrochem. (China) 35 (2004) 17–21, J.S. Gao, C.M. Xu, Y. Mao, et al., Petrol. Refin. Eng. (China) 35 (2005) 7–9], a novel conceptional process for residue catalytic cracking and gasoline reformation dual-reactions mutual control (DMC) was proposed and relevant experimental researches were carried out in a Technical Pilot Scale Riser (TPSR) FCC apparatus. The goals of DMC were to improve product quality and increase desirable product yield in residue catalytic cracking as well as in FCC gasoline upgrading. The experiments showed that the decrease of temperature difference between feedstock and regenerated catalysts in DMC by directly leading the cooled regenerated catalysts into riser reactor or feeding gasoline into riser reactor in vapor phase could decrease the amount of dry gas and coke and obtain a better quality of upgraded gasoline. Moreover, the spent catalysts still retaining high level of activity could be recycled to the base of the main riser reactor treating heavy oil and mixed with regenerated catalysts in DMC, it allows residue catalytic cracking to operate at high catalyst-to-oil ratio and the relatively low inlet catalysts temperature. The experimental results also showed that the mixed catalysts could improve the product selectivity in residue catalytic cracking, especially for light oil (gasoline and diesel). In addition, compared with the routine RFCC, the product distribution from the residue catalytic cracking in DMC contains more liquid products, less dry gas, and a better gasoline quality.

Keywords: Fluid catalytic cracking; Subsidiary riser; Gasoline reformation; Dual-reactions; Product distribution

ZnBr₂–Ph₄PI as highly efficient catalyst for cyclic carbonates synthesis from terminal epoxides and carbon dioxide by Shui-Sheng Wu; Xiao-Wen Zhang; Wei-Li Dai; Shuang-Feng Yin; Wen-Sheng Li; Yan-Qun Ren; Chak-Tong Au (pp. 106-111).

The catalysts composed of ZnBr₂ and Ph₄PI have been found to be highly efficient for solvent-free synthesis of cyclic carbonates from CO₂ and terminal epoxides under mild reaction conditions. We report for the first time that the coupling reaction is very sensitive to water. The reaction conditions have been optimized and a plausible mechanism for the target reaction proposed.▪The catalyst systems composed of ZnBr₂ and different phosphonium salts were examined for solvent-free synthesis of cyclic carbonates from CO₂ and terminal epoxides under mild conditions. Among the catalysts investigated, ZnBr₂–Ph₄PI was found to be the best while those of ZnBr₂–phosphine oxide (Bu₃PO or Ph₃PO) show no catalytic effect. It is apparent that the halide ions of phosphonium salts have an essential role to play in the reaction. The catalytic activity of ZnBr₂–Ph₄PI increases with a rise of Ph₄PI to ZnBr₂ molar ratio up to 6, above which there is little change in catalytic activity. We observed that with a rise in ZnBr₂ to Ph₄PI molar ratio, there is increase in epoxide conversion but decline in TOF_PO (estimated based on the site number of Zn²⁺). The effect of water on the reaction was investigated for the first time. We found that the presence of even a trace amount of water would result in a marked decline in reactivity, and the observation provides a valid explanation for why reproducibility of results is poor among researchers so far. The influences of other parameters such as reaction temperature and CO₂ pressure on the catalytic performance of ZnBr₂–PPh₄I were also studied. It is shown that the catalyst is sensitive to reaction temperature, and a rise of reaction temperature up to 130°C favors the formation of cyclic carbonates. We observed that activity increases with rise in CO₂ pressure and reaches a maximum at an initial CO₂ pressure of 2.5MPa. Moreover, a plausible reaction mechanism has been proposed.

Keywords: Zinc bromide; Tetraphenylphosphonium iodide; Carbon dioxide; Terminal epoxide; Cyclic carbonate

In situ synthesis of SAPO-34 crystals grown onto α-Al₂O₃ sphere supports as the catalyst for the fluidized bed conversion of dimethyl ether to olefins by Huaqun Zhou; Yao Wang; Fei Wei; Dezheng Wang; Zhanwen Wang (pp. 112-118).

SAPO-34 crystals in situ synthesized and grown under hydrothermal conditions on the surface of an α-Al₂O₃ support. The SAPO-34 crystals are tiny cubes easily distinguished from the support, but a magnified view indicated that most the of SAPO-34 crystals were imperfect cubes where the crystal faces conjoint to the support because these kept to the growth steps to affix itself on the support.▪SAPO-34 is an excellent catalyst for the conversion of dimethyl ether (DME) to olefins, but because conventionally synthesized SAPO-34 crystals are too small to be used directly in a fluidized bed, they have to be used as, and have the disadvantages of, a spray-dried catalyst. In this study, SAPO-34 crystals were synthesized in situ to grow on the surface of small α-Al₂O₃ spheres to produce a zeolite catalyst for a fluidized bed reactor. The influences of the composition of the crystal gel and surface structure of the support were investigated. The catalytic performance of the zeolite crystals grown on the support (surface zeolite) for the conversion of DME to olefins was investigated in a fixed bed microreactor and a fluidized bed reactor. The experiments showed that these surface SAPO-34 crystals gave the same activity and product selectivity as conventionally synthesized free SAPO-34 crystals and a higher reaction rate (normalized to the weight of SAPO-34) than the spray-dried catalyst. In situ synthesis is a simple and effective way to produce a SAPO-34 catalyst for a fluidized bed reactor.

Keywords: SAPO-34; In situ; synthesis; Supported zeolite; Fluidized bed; DME-to-olefins

Alumina supported Mo–V–Te–O catalysts for the ammoxidation of propane to acrylonitrile by M. Olga Guerrero-Pérez; Luis J. Alemany (pp. 119-126).

The effect of Te addition over Mo–V–O catalysts supported on alumina is discussed for the ammoxidation of propane to acrylonitrile. Catalyst composition and atmosphere of activation are evaluated. Catalysts are characterized before and after catalytic reaction by XPS, XRD and in situ Raman spectroscopies. The absence of Te in catalysts formulation and the presence of a high amount of vanadium induce the presence of V⁵⁺ species and the formation of V₂O₅ oxide; associated with a decrease in acrylonitrile selectivity. The presence of Mo-based polyacids structures decreases the selectivity to acrylonitrile. V⁵⁺ sites are responsible of propane activation and of the subsequent α-H abstraction to form the intermediate propylene. Then, a Mo–V rutile-like structure in which vanadium species are reduced as V⁴⁺, is responsible for nitrogen insertion and acrylonitrile formation. The formation of such structure is favoured when Te is added to catalysts and is promoted during propane ammoxidation.The effect of Te addition over Mo–V–O catalysts is discussed for the ammoxidation of propane. V⁵⁺ sites are responsible of propane activation and of the subsequent α-H abstraction to form the intermediate propylene. A Mo–V structure in which vanadium is reduced, is responsible for nitrogen insertion and acrylonitrile formation. The formation of such structure is favoured when Te is added.▪

Keywords: V–Mo–O; V–Mo–Te–O; V–Mo–Al–O; V–Mo–Te–Al–O; Ammoxidation; Structure–activity relationship; In situ; Raman; XRD; XPS

Oxygen-induced activation of silica supported silver in acrolein hydrogenation by M. Bron; D. Teschner; U. Wild; B. Steinhauer; A. Knop-Gericke; C. Volckmar; A. Wootsch; R. Schlögl; P. Claus (pp. 127-132).

Acrolein hydrogenation has been studied over Ag/SiO₂ catalysts in a pressure range from 266mbar to 10bar. Oxygen pre-treatment of the catalysts enhances activity as well as selectivity to allyl alcohol. This effect is ascribed to the formation of electropositive silver sites and/or restructuring of the catalyst.▪The effect of oxygen pre-treatment of Ag/SiO₂ catalysts used in the acrolein hydrogenation has been investigated from sub-atmospheric (266mbar) to 10bar reaction pressure. The pre-treatment has a profound influence on the overall hydrogenation activity, inasmuch the activity increased two- to three-fold. Oxygen pre-treatment also enhanced the selectivity towards the desired allyl alcohol. The beneficial effect of oxygen pre-treatment is ascribed to the formation of electronically modified Ag and/or morphology changes of the nanoparticles as no modification in particle size or dispersion was found.

Keywords: Acrolein; Silver; Selective hydrogenation; Electropositive adsorption sites

Heterogeneous base catalyzed synthesis of 2-oxazolidinones/2-imidiazolidinones via transesterification of ethylene carbonate with β-aminoalcohols/1,2-diamines by Sachin R. Jagtap; Yogesh P. Patil; Shin-Ichiro Fujita; Masahiko Arai; Bhalchandra M. Bhanage (pp. 133-138).

Several heterogeneous basic metal oxide catalysts were screened for the synthesis of 2-oxazolidinones and 2-imidiazolidinones via transesterification of ethylene carbonate with different β-aminoalcohols or 1,2-diamines. Among the several catalysts screened, MgO was found to be the best catalyst, as it has excellent recyclability. Various reaction parameters were studied in detail. Excellent yields of the products were obtained using MgO as catalysts at 80°C within 6h in ethanol. Basic properties of the metal oxide catalysts were compared using temperature programmed desorption (TPD) studies with CO₂. The relationship between the catalyst performance and the basic property of each catalyst has been discussed.Syntheses of 2-oxazolidinones and 2-imidiazolidinones via transesterification of ethylene carbonate with different β-aminoalcohols or 1,2-diamines using several basic metal oxides were studied. The basic properties of the various metal oxide catalysts were compared using TPD studies with CO₂. Among the several catalysts screened, MgO was found to be best catalyst, for it has excellent recyclability. Various reaction parameters were studied in detail. Excellent yields of the products were obtained using MgO as catalyst at 80°C within 6h in ethanol. ▪

Keywords: Oxazolidinones; Imidiazolidinones; Ethylene carbonate; Heterogeneous catalysis; Basic metal oxide

Cu-based spinel catalysts CuB₂O₄ (B=Fe, Mn, Cr, Ga, Al, Fe_0.75Mn_0.25) for steam reforming of dimethyl ether by Kajornsak Faungnawakij; Naohiro Shimoda; Tetsuya Fukunaga; Ryuji Kikuchi; Koichi Eguchi (pp. 139-145).

Cu-based spinel-oxides CuB₂O₄ (B=Fe, Mn, Cr, Ga, Al, or Fe_0.75Mn_0.25) were prepared, and their activity as well as durability were evaluated in DME steam reforming reaction. The descending order of the activity was as follows: CuFe₂O₄, CuFe_1.5Mn_0.5O₄>CuAl₂O₄>CuCr₂O₄>CuMn₂O₄>CuGa₂O₄. Among the spinel catalysts, CuFe₂O₄, CuFe_1.5Mn_0.5O₄, CuCr₂O₄, and CuMn₂O₄ were highly stable at a reforming temperature of 350°C. ▪Cu-based spinel-oxides CuB₂O₄ (B=Fe, Mn, Cr, Ga, Al, or Fe_0.75Mn_0.25) were synthesized via a sol–gel method and subsequent solid-state reaction. The spinels mechanically mixed with γ-Al₂O₃ were evaluated for production of hydrogen from dimethyl ether steam reforming (DME SR). The reduction behavior and crystal property of these spinel-oxides, and the Cu oxidation state in spinel catalysts were investigated by temperature-programmed reduction, X-ray diffraction, and X-ray photoelectron spectroscopy techniques. The reduced phases of the Cu-based spinel catalysts that strongly affected the catalytic activity and durability were composed of metallic copper with metal oxides (MnO (B=Mn), Cr₂O₃ (B=Cr), and Al₂O₃ (B=Al)) or with spinels (CuGa₂O₄ (B=Ga), Fe₃O₄ (B=Fe), and MnFe₂O₄ (B=Fe_0.75Mn_0.25). The stability of B metal oxides and the interaction between copper species and B metal oxides significantly contributed to the reforming performance.

Keywords: Cu-based spinel; Steam reforming; Dimethyl ether; Hydrogen; Fuel cell

Fischer–Tropsch synthesis with promoted iron catalyst: Reaction pathways for acetic acid, glycol, 2-ethoxyethanol and 1,2-diethoxyethane by Amitava Sarkar; Robert A. Keogh; Shiqi Bao; Burtron H. Davis (pp. 146-153).

Reaction pathways of acetic acid, ethylene glycol (EG), 2-ethoxyethanol (2-EE) and 1,2-diethoxyethane (1,2-DEE) added during Fischer–Tropsch synthesis (FTS) over a promoted iron catalysts were studied in a continuous stirred tank reactor (CSTR) at 100psig, 270°C and ca. 90% CO conversion. The results suggest that acetic acid undergoes some CC bond rupture while 2-EE and 1,2-DEE undergoes cleavage of the ether linkage (COC bond). On the contrary, EG undergoes fast and equally probable COC chain growth in both terminal positions. The results indicate that neither of these oxygenates is a significant intermediate in FTS with an iron catalyst. Product distribution in most of the oxygenate compounds are consistent with the hydrogenation of the added oxygenate to acetaldehyde and/or ethanol as primary products followed by secondary reaction of these two primary oxygenate products.▪Reaction pathways for oxygenates, acetic acid, ethylene glycol (EG), 2-ethoxyethanol (2-EE) and 1,2-diethoxyethane (1,2-DEE) added during Fischer–Tropsch synthesis (FTS) over a doubly promoted fused iron catalysts were studied. The addition of acetic acid, EG and 2-EE affected only slightly the CO conversion but resulted in a significant reduction in H₂ conversion while addition of 1,2-DEE results in slight increase in both H₂ and CO conversion. Addition of these oxygenates caused a large decrease in the alkene ratio for C₂ hydrocarbons as compared to an increase for the C₃ and C₄ hydrocarbons suggesting a direct formation pathway of ethane from added oxygenate molecules. The 1-alkene/2-alkene fraction was found to increase significantly when these oxygenates were added and then return to the original value once the addition is terminated, indicating inhibition of secondary reactions of 1-alkene by added oxygenates. Added acetic acid reversibly increased the CO₂ production rate while EG, 2-EE and 1,2-DEE reversibly decreased the CO₂ selectivity. Addition of these oxygenates reduced the production rate of methane. Addition of acetic acid and 1,2-DEE decreased methanol selectivity significantly while added EG results in a significant increase in methanol production. In the case of 2-EE addition, methanol selectivity was nearly constant. Reaction of acetic acid during FTS was found to produce products such as ethyl butanoate, ethylene glycol and its ether, 1,2-diethoxyethane, which are not generally observed in the normal FTS product spectrum. Addition of EG results in a significant increase in the production rate of 1,2-DEE only and no measurable amount of 2-EE was found. While addition of 2-EE caused a significant increase in the production rate of glycol, the addition of 1,2-DEE indicated a significant increase in 2-EE production rate without any measurable change in EG selectivity. The results suggest that acetic acid undergoes some CC bond rupture while 2-EE and 1,2-DEE undergoes cleavage of the ether linkage (COC bond). On the contrary, EG undergoes fast and equally probable COC chain growth in both terminal positions. The results indicate that neither of these oxygenates is a significant intermediate in FTS with an iron catalyst. Product distribution in most of the oxygenate compounds are consistent with hydrogenation of the added oxygenate to acetaldehyde and/or ethanol as primary products followed by secondary reaction of these two primary oxygenate products.

Keywords: Fischer–Tropsch synthesis; Iron catalyst; Oxygenates; Reaction pathways; Acetic acid; Ethylene glycol; 2-Ethoxyethanol; 1,2-Diethoxyethane

Controlling selectivity in catalysis: Selective greener oxidation of cyclohexene under microwave conditions by Rafael Luque; Sushanta K. Badamali; James H. Clark; Macarena Fleming; Duncan J. Macquarrie (pp. 154-159).

A smart and greener approach to the selective oxidation of cyclohexene is reported whereby, depending on the reaction conditions, the epoxide, the enol or the enone can selectively be obtained. A cobalt-salen-SBA-15 material was employed as catalyst. The reported protocol was simple, greener and more efficient compared to any reported cyclohexene oxidations.▪A smart and greener microwave approach to the selective oxidation of cyclohexene is reported whereby, depending on the reaction conditions, the epoxide (65% conversion, 75% selectivity), the enol (70% conversion, 80% selectivity) or the enone (>99% conversion, 89% selectivity) can be obtained in a short period of time ranging from 1 to 20min. A cobalt-salen-SBA-15 material was employed as catalyst. The reported solventless microwave protocol was simple, greener and more efficient compared to any other reported cyclohexene oxidations.

Keywords: Selectivity; Heterogeneous catalysis; Co-salen-SBA-15; Oxidation of cyclohexene; Microwaves

The catalytic reactions of n-pentane and 1-pentene on different molybdenum oxides and metal surfaces by S. Al-Kandari; H. Al-Kandari; F. Al-Kharafi; A. Katrib (pp. 160-167).

Hydrogen exposure of the equivalent 5 monolayers of MoO₃ deposited on TiO₂ as a function of temperature up 873K, enabled us to partially reduce the molybdenum trioxide on the sample surface to three distinct, Mo₂O₅, bifunctional MoO₂(H_x)_ac and metallic Mo(0) states. Catalytic behavior of these phases towards n-pentane and 1-pentene were studied. Figure shows XRD for MoO₃/TiO₂ after reduction at 653K. (★) MoO₃; (▪) MoO₂; (▪) TiO₂ anatase; (▪) TiO₂ rutile.▪Catalytic reactions of n-pentane and 1-pentene were performed as a function of reaction temperature, on different molybdenum oxides and metal surfaces. These oxides such as Mo₂O₅ and MoO₂ were obtained following the exposure of MoO₃/TiO₂ to hydrogen at different temperatures up to 673K. Metallic Mo(0) state is obtained at reduction temperatures beyond 723K. Identification of the Mo chemical species was performed using in situ XPS-UPS surface techniques. The combination of both techniques provides valuable information on the chemical composition of the upper 10 atomic monolayers. X-ray diffraction and HRTEM techniques were also employed. The reduction procedure of MoO₃ does not follow the same pathway when it is deposited on an Al₂O₃ support. A strong electronic interaction between the two species promotes the formation of an Al₂(MoO₄)₃ complex as revealed by XRD measurements. Catalytic active functions present on the different Mo species surfaces are of the acidic type (Lewis and Brönsted) on Mo₂O₅, metal-acid (bifunctional) on MoO₂ and metal function on metallic Mo(0). Consequently, a specific catalytic reaction of n-pentane, such as hydroisomerization to iso-pentane, which is rationalized in terms of a bifunctional mechanism, is expected to occur on MoO₂. Different isomerization reactions of 1-pentene were obtained in the case of MoO₃/TiO₂ and MoO₃/Al₂O₃ at reduction temperatures below 573K. However, in the case of Mo on the alumina support, the conversion of 1-pentene to iso-pentane is low and irreproducible, contrary to what has been observed for Mo on titania.

Keywords: XPS-UPS; XRD; HRTEM; MoO; ₃; MoO; ₂; TiO; ₂; Al; ₂; O; ₃; Hydroisomerization of 1-pentene and; n; -pentane; Iso-pentane

Stability and catalytic properties of encapsulated subtilisin in xerogels of alkoxisilanes by K. Sangeetha; Viola B. Morris; T. Emilia Abraham (pp. 168-173).

Subtilisin was encapsulated in glass sol–gel matrices using alkoxysilane precursors of different chain lengths. The activity retention of the sol–gel glass was about 80%. The sol–gel subtilisin having high catalytic efficiency with high thermal stability and was used for single step peptide synthesis.▪Subtilisin was encapsulated in glass sol–gel matrices using alkoxysilane precursors of different chain lengths. The entrapment efficiency of the sol–gel glass was about 80%. The resultant glass enzyme had the same optimum pH of 7.0, but the optimum temperature was shifted to a higher temperature of 60°C. The biocatalyst sol–gel particles retained 50% of the original activity even after 11 cycles of repeat use. The scanning electron micrograph of the immobilized enzyme showed uniform round particles of 5–20μm. The specific surface area by BET measurement of the immobilized subtilisin in vinyl tri methoxy silane (VTMS) was found to be 38m²g⁻¹. This immobilized enzyme was useful for the synthesis of peptides either in a mixture of acetonitrile: dimethyl formamide (DMF) or in 1-butyl 3-methyl imidazolium hexaflurophosphate, an ionic liquid. The formation of dipeptides and tripeptides ofl-alanine was confirmed by TLC, HPLC and FT-IR analysis.

Keywords: Abbreviations; VTMS; vinyl tri methoxy silane; MTMS; methyl tri methoxy silane; TEOS; tetra ethoxy silane; DMF; dimethyl formamide; IL; ionic liquid; BIMMPF; ₆; 1-butyl-3-methylimidazolium hexafluorophosphate; TLC; thin layer chromatography; HPLC; high performance liquid chromatography; SEM; scanning electron microscope; FT-IR; Fourier transform infrared spectroscopyImmobilization; Subtilisin; Xerogel; Ionic liquid; Peptide synthesis

Sulphur poisoning of transition metal oxides used as catalysts for methane combustion by Salvador Ordóñez; José R. Paredes; Fernando V. Díez (pp. 174-180).

The thioresistance of different bulk transition metal oxides used as catalysts for the combustion of methane–air lean mixtures is studied in this work. A superb behaviour of Cr₂O₃ was found. The pictogram shows the conversions obtained at 625°C for the combustion of 5000ppm of CH₄ in presence of 45ppm of SO₂. Each bar correspond (from left to right) to fresh catalyst in absence of SO₂, in presence of SO₂, catalyst after 20h on stream in absence of SO₂, and catalyst after 20h on stream in presence of SO₂.▪Different bulk metal oxides (NiO, CuO, Mn₂O₃, Cr₂O₃ and Co₃O₄) were prepared and tested for the combustion of methane–air lean mixtures (5000ppmV of CH₄) in presence of SO₂ (40ppmV). Methane combustion experiments were carried out at ambient pressure, 425 and 625°C and a space time of 93.3ghmol_CH4⁻¹. Catalysts aged (60h on stream) both in absence and in presence of SO₂, were characterised by nitrogen physisorption (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature-programmed desorption (TPD-MS) and infrared spectroscopy (DRIFTS). It was observed that Cr₂O₃ is not deactivated at the studied conditions, whereas all the other materials present fast deactivation in presence of SO₂. Aged catalysts characterisation reveals that the outstanding behaviour of the Cr₂O₃ catalyst is caused by the absence of formation of surface sulphates. By contrast, Mn₂O₃ and Co₃O₄ are more active than Cr₂O₃ for methane oxidation in absence of sulphur species, but they are strongly deactivated in presence of SO₂.Finally, the performance of the Cr₂O₃ catalysts was compared to the corresponding to Pd/Al₂O₃ catalyst and to a highly sulphur-tolerant perovskite (La_0.9Ce_0.1CoO₃) for the oxidation of methane in a real industrial emission from a coke oven, containing different inorganic gases (NH₃, N₂, H₂, H₂O, CO, CO₂, SO₂ and H₂S). Cr₂O₃ catalyst shows to be also the most stable catalyst for the treatment of these emissions.

Keywords: Catalytic oxidation; Bulk metal oxides; Chromium catalysts; Sulphur poisoning

Degradation of LDPE/VGO mixtures to fuels using a FCC equilibrium catalyst in a sand fluidized bed reactor by Antonio Marcilla; M del Remedio Hernández; Ángela N. García (pp. 181-191).

An interesting alternative of plastic recycling is shown in the present paper. Blends of low-density polyethylene (LDPE) and vacuum gas oil (VGO) are pyrolyzed under catalytic conditions. A wide range of LDPE percentages is evaluated. The reactor used is a laboratory scale sand fluidized bed reactor at 500°C and the catalyst is a FCC equilibrium catalyst with a catalyst:blend ratio of 7:1. All these conditions are typical in an industrial scale fluid catalytic cracking, and the process simulates the polymers addition into a refinery stream and the degradation of the blend in the petrochemical installations.The results obtained indicate that it is possible to produce valuable products by pyrolyzing LDPE/VGO blends. ▪Plastic degradation for recovery of useful products or raw materials is a very interesting alternative for reducing the plastic accumulation. This paper explores the possibility of using refinery facilities to carry out the plastic cracking as well as to take the most of the products obtained. In the present work, LDPE/VGO blends with different percentages of polymer are degraded in presence of a FCC equilibrium catalyst. The reactor used in this study is a laboratory scale sand fluidized bed reactor at 500°C, and a 7:1 catalyst:LDPE/VGO blend ratio in order to simulate the operating conditions in a large scale industrial reactor. Polyethylene blends evaluated show relative proportions of LDPE of 0, 6, 25, 75 and 100% (w/w). Gas and liquid compounds were collected and quantified. The results obtained are compared with those generated in a thermal cracking.In all cases, the FCC equilibrium catalyst showed a high selectivity to the production of isobutane and isopentane in the volatile compounds as well as to aromatics in the liquid products.Results shown in this paper evidences the viability of introducing plastics into FCC unit, producing potential valuable products from low value materials.

Keywords: Low-density polyethylene; Vacuum gas oil; Low-density polyethylene–vacuum gas oil blend; Fluid catalytic cracking catalyst (FCC); Equilibrium catalyst; Flash pyrolysis; Fluidized bed reactor

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Applied Catalysis A, General (v.341, #1-2)