Hydrocarbon Cracking Selectivities with Dual-Function Zeolite Catalysts

Rajagopalan, K.; Young, George W.

doi:10.1021/bk-1988-0375.ch003

Cited by 11 publications

(16 citation statements)

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“…When the gaseous products (Figure 5a) are focused on the most pronounced monotonic effect of an increase of the total number of additive acid sites, it concerns ethylene, propane, propene, isobutane, n-butane, and isobutene, which may undergo an increase of up to 2 or even 3 times their initial yield. Such an effect of ZSM-5 on C 3 and C 4 is well-known and documented, 1,4,7 and the extent of the effect is always dependent on the deactivation state of the additive. 1 This is shown by the gradual increase in the yield of LPG gases with an increase of ZSM-5 acidity presented in this study.…”

Section: Physicochemical Characteristics Of the Zsm-5mentioning

confidence: 88%

“…Such an effect of ZSM-5 on C 3 and C 4 is well-known and documented, 1,4,7 and the extent of the effect is always dependent on the deactivation state of the additive. 1 This is shown by the gradual increase in the yield of LPG gases with an increase of ZSM-5 acidity presented in this study. On the other hand, ethylene always undergoes a small increase in relative studies, which has been either not discussed 4 or attributed to the activity of the insufficiently deactivated matrix.…”

Section: Physicochemical Characteristics Of the Zsm-5mentioning

confidence: 88%

“…3 The performance of ZSM-5 as an FCC catalyst additive was examined in a great number of previous works and was found to be dependent not only on feedstock quality, catalyst type, and unit operating conditions but also on the chemical composition, the preatreatment of ZSM-5 zeolite, and the type of the ZSM-5 additive. 1,2,[4][5][6][7][8][9][10] The microactivity test (MAT) 1,6,7,9 has been widely used in most of the previous works. It is the most widely used method to predict FCC catalyst activity and product selectivities, instead of performing time-consuming and costly test runs in pilot plants or commercial units.…”

Section: Introductionmentioning

confidence: 99%

“…However, different reaction mechanisms have been proposed to predominate, depending on the ZSM-5 pretreatment. For unsteamed ZSM-5, selective cracking of gasoline range alkanes is important, 5,8,11 while for steamed pentasils, isomerization and monomolecular cracking of the reactive carbenium ions or olefin intermediates 1,4,9 are the predominant reaction pathways.…”

Section: Introductionmentioning

confidence: 99%

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Performance of ZSM-5 as a Fluid Catalytic Cracking Catalyst Additive: Effect of the Total Number of Acid Sites and Particle Size

Triantafillidis¹,

Evmiridis²,

Nalbandian³

et al. 1999

Ind. Eng. Chem. Res.

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The performance of ZSM-5 as a fluid catalytic cracking (FCC) catalyst additive has been tested in a microactivity test unit for the cracking of gas oil. Laboratory-synthesized ZSM-5 samples, with various Si/Al ratios, fresh or hydrothermally dealuminated were tested. A 2 wt % ZSM-5, on total catalyst weight, found by previous investigators to be the optimum additive concentration, was used for all of the experiments. It has been found that a direct and smooth correlation exists between the product yields and the total number of ZSM-5 acid sites measured by ammonia temperature-programmed desorption tests. This is a unique function of the aluminum content of fresh samples as well as the temperature of the hydrothermal deactivation of steamed ZSM-5 zeolite samples. Previous works have been qualitatively compared to the results of this work and have been classified on the basis of different total acidity regions of the ZSM-5 used in each case. Higher total acidity results in gasoline loss, liquified petroleum gases (LPG) and ethylene increases, and research octane number gain. The C5 aliphatics are increased in the low acidity region because of cracking and isomerization of larger alkenes, while an increase of the total ZSM-5 acidity resulted in a monotonic decrease of all of the gasoline range hydrocarbons, except of n-C5 alkane, C6−C7 aromatics, and C5 naphthenes. The branched/linear (B/L) ratios for C5−C6 alkenes were found to increase with acidity, while the B/L ratios for C5−C9 alkanes decrease. The number and strength of the additive's acid sites control the contribution of the different reaction paths, through which cracking, isomerization, and aromatization occur, to the final product distribution. The sizes of the ZSM-5 particles have a strong effect on the changes in product yields and gas and gasoline compositions. Smaller particles favor a decrease in gasoline and an increase in LPG yield more than larger particles. The effect is more pronounced in the high acidity region where the decrease in the yields of C7+ isoalkanes, naphthenes, and aromatics is favored by small particle additives, while the effect of particle size on gasoline range hydrocarbons is clearly evident on the yields of gaseous products.

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Section: Physicochemical Characteristics Of the Zsm-5mentioning

confidence: 88%

Section: Physicochemical Characteristics Of the Zsm-5mentioning

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Performance of ZSM-5 as a Fluid Catalytic Cracking Catalyst Additive: Effect of the Total Number of Acid Sites and Particle Size

Triantafillidis¹,

Evmiridis²,

Nalbandian³

et al. 1999

Ind. Eng. Chem. Res.

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“…In a study, Rajagopalan et al 8 used a rare earth Y (REY)based catalyst, with steam-deactivated ZSM-5. It was reported that for gas oil cracking, this leads to a loss of normal and branched C 7 −C 12 paraffins.…”

Section: Introductionmentioning

confidence: 99%

ZSM-5 Additive Deactivation with Nickel and Vanadium Metals in the Fluid Catalytic Cracking (FCC) Process

Gusev

Psarras

Triantafyllidis

et al. 2019

Ind. Eng. Chem. Res.

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We investigated the roles of nickel and vanadium in the properties of ZSM-5 additives and in the fluid catalytic cracking (FCC) products, yielding 4000 and 12 000 ppm loadings of Ni + V. The ZSM-5 additive was deactivated in a cyclic deactivation unit (CDU), where cracking–regeneration reactions were carried out with vacuum gas oil (VGO) spiked with Ni and V naphthenates. Characterization of the deactivated ZSM-5 additives with N2 physisorption, SEM, and pyridine FTIR techniques showed a uniform Ni distribution across a particle, little variation in the Brønsted acidity, and an increase in Lewis acidity, when Ni and V were added. Tests were carried out in a short contact time microactivity test (SCT-MAT) unit with ZSM-5 and n-hexane and blends of equilibrium catalyst (ECAT) and ZSM-5 with VGO. With hexane Ni and V, the dehydrogenation, aromatization, and coking reactions are enhanced. With VGO, the metals were found to decrease the propylene selectivity whereas that of butylene increased.

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Fluid Catalytic Cracking

Cheng¹,

Habib²,

Rajagopalan³

et al. 2008

Handbook of Heterogeneous Catalysis

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The sections in this article are Introduction and Overview History FCC Today Position in a Modern Petroleum Refinery Environmental Issues FCC Unit Hardware and Operations Unit Types Heat Balance Modes of Operation Regeneration Mode—Partial Burn vs. Full Burn Resid Processing Petrochemical Mode (Light Olefins) FCC Feeds Sources and Trends Molecular Types Characterization Effects on FCC Unit Operation Conradson Carbon and Feed Heaviness Feedstock Composition Metals: Ni , V , Na and Fe Sulfur Nitrogen The Chemistry of Catalytic Cracking Carbocations Formation of Carbocations Isomerization Reactions CarbonCarbon Bond Breaking by Beta‐Scission Hydride Transfer (also Referred to as Hydrogen Transfer) Heteroatom Chemistry: Sulfur FCC Catalysts Description and Formulation Zeolite Component Zeolite Modifications Zeolite Activity and Selectivity Effects Matrix Commercial Matrices Effect of Matrix on Selectivity Characterization ZSM ‐5 Additives FCCU Environmental Emissions Controls Overview—Catalyst Versus Hardware Particulates Carbon Monoxide ( CO ) Sulfur Oxides ( SO x ) Nitrogen Oxides ( NO x ) Laboratory Evaluations and Pilot Plant Testing Accelerated Aging of Catalysts Simulation of Metals Poisoning Reactor Types—Fixed Bed vs. Fluid Bed vs. Transport Phase Temperature Profile and Isothermal vs. Adiabatic Testing Summary and Future Trends in Catalytic Cracking

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Hydrocarbon Cracking Selectivities with Dual-Function Zeolite Catalysts

Cited by 11 publications

References 0 publications

Performance of ZSM-5 as a Fluid Catalytic Cracking Catalyst Additive: Effect of the Total Number of Acid Sites and Particle Size

Performance of ZSM-5 as a Fluid Catalytic Cracking Catalyst Additive: Effect of the Total Number of Acid Sites and Particle Size

ZSM-5 Additive Deactivation with Nickel and Vanadium Metals in the Fluid Catalytic Cracking (FCC) Process

Fluid Catalytic Cracking

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