Catalytic Cracking Of Vacuum Gas Oil Research Articles

Effects of the FCC catalyst binder type on propylene production during catalytic cracking of VGO

Effects of the fluid catalytic cracking (FCC) catalyst binder type on catalytic properties were studied. SiO2 and Al2O3 were used for the FCC catalysts as a binder. Although the yield of olefins in gasoline, which is easily cracked to light olefins such as a propylene over the ZSM-5 additive, over the SiO2 binder catalyst was lower than that over the Al2O3 binder catalyst during vacuum gas oil (VGO) cracking, however, when the ZSM-5 additive was blended, the SiO2 binder catalyst showed higher propylene yield as compared with the Al2O3 binder catalyst. In terms of the difference in the properties of catalyst, the SiO2 binder catalyst indicated higher SAmicro than the Al2O3 binder catalyst after steaming. Moreover, the acid properties of the FCC catalysts after steaming also were affected by the binder type. In results, the SiO2 binder catalyst indicated higher propylene yield as compared with the Al2O3 binder catalyst.

Solution of the inverse kinetics problem for the catalytic cracking process based on a 16-component kinetic model

This article presents a 16-lump model of catalytic cracking of vacuum gasoil, which allows to take into account the quantity and quality of the main products of the process: gasoline, propane-propylene and butane-butylene fractions; and by-products of the process: light and heavy catalytic gasoil. To solve the direct problem of solving a system of differential equations, the Runge-Kutta method of order 4 is used, to solve the inverse problem of choosing the constants of the rate of chemical transformations, the method of direct search for minimizing the function of the sum of deviations of calculated values from experimental ones is applied. Thus, the reaction rate constants were chosen for the developed model.

Scrap tires pyrolysis oil as a co-feeding stream on the catalytic cracking of vacuum gasoil under fluid catalytic cracking conditions

The co-feeding of scrap tires pyrolysis oil (STPO) on the catalytic cracking of vacuum gasoil (VGO) has been investigated with the aim of exploring the capacity of the refinery fluid catalytic cracking (FCC) unit to upgrade discarded tires at large-scale. The runs have been carried out in a CREC (Chemical Reactor Engineering Centre) riser simulator reactor that mimics the behavior of the industrial unit at the following conditions: 500–560 °C; catalyst/oil ratio, 3–7 gcat goil−1; contact time, 6 s. Obtained results with the blend of 20 wt% STPO in VGO have been compared with those obtained in the cracking of the pure streams, i.e., STPO and VGO, to get a proper idea of the synergetic effects that could be involved in the co-feeding. This way, when the STPO is co-fed with the VGO the production of naphtha (C5–C12) and light cycle oil (C13–C20) lumps are maximized, as the over-cracking reactions that convert them into gaseous products (C1–C4) are mitigated. Consequently, the co-feeding promotes the production of high-interest hydrocarbons for refineries. Additionally, the naphtha obtained in the cracking of the blend shows a lower content of paraffins and naphthenes than that obtained with the VGO, and higher of olefins and aromatics.

The hydrothermal stability of the alkali-treated ZSM-5 and it’s catalytic performance in catalytic cracking of VGO

To enhance the heavy oil cracking ability of ZSM-5, desilication by alkali has been adopted in this study. The results showed that desilication by NaOH, NaOH/Al(NO3)3, NaOH/(NH4)3PO4 solutions all can induce some mesoporous structure to ZSM-5 zeolite. Among them, the sample ZSM-5/NaOH/(NH4)3PO4-F showed the highest mesoporous surface area. The hydrothermal stability of the desilicated ZSM-5 samples was also measured. The NaOH-modified ZSM-5 sample exhibited worse hydrothermal stability than the parent ZSM-5, while NaOH/(NH4)3PO4 modified ZSM-5 sample maintained the higher relative crystallinity and more acidic sites than the parent ZSM-5 after the hydrothermal treatment. The micro-activity tests showed that the NaOH/Al(NO3)3, NaOH/(NH4)3PO4-modified ZSM-5 samples exhibited higher catalytic activity than the parent ZSM-5 sample and NaOH-modified ZSM-5 sample in catalytic cracking of vacuum gas oil (VGO). Especially, for the sample ZSM-5/NaOH/(NH4)3PO4, the conversion of VGO increased from 78.91 to 85.13%, and the yield of propylene increased from 15.01 to 18.83% compared to the unmodified ZSM-5 catalyst.

Destructive Conversion of Gas Oil in the Presence of a Nickel-Based Nanosized Catalyst

The decomposition of nickel 2-ethylhexanoate by heating in a vacuum gas oil (VGO) medium at 355–365°С has been found to yield nickel and nickel sulfide nanoparticles. The size of the particles is 20–120 nm. The catalytic cracking of VGO in the presence of these nickel-containing particles provides a 70.15% yield of the distillate with a boiling point up to 220°C. The structural-group composition of the products of VGO cracking in the presence of nickel-based nanoscale catalysts has been studied using gas chromatography–mass spectrometry. The group composition of samples containing cracked products has been analyzed to cover eleven classes of organic compounds. The structural composition of the test samples has been considered with respect to eight groups of compounds, of which three include two to three classes of compounds. In the catalytic cracking of VGO, the concentration of alkanes increases by 3.11% and that of alkenes and alkylbenzenes decreases by 1.31 and 2.59%, respectively, as compared to their content in the products of VGO distillation without a catalyst.

Catalytic cracking of vacuum gasoil over -SVR, ITH, and MFI zeolites as FCC catalyst additives

The cracking behaviour of three medium-pore zeolites -SVR, ITH, and MFI, with varying Si/Al molar ratio, was evaluated using an equilibrium FCC catalyst (E-Cat) and a hydrotreated vacuum gasoil (VGO) in a microactivity test unit (MAT). The increase in the yield of light olefins (21–29wt% over E-Cat/additive vs. 16wt% over E-Cat) was accompanied by a drop in the yield of gasoline (26–39wt% over E-Cat/additive vs. 43wt% over E-Cat) due to the cracking of reactive species in gasoline fraction (mainly olefins and isoparaffins). With increasing Si/Al ratio in zeolites MFI-280 and –SVR-120, propylene yield passed through maxima reaching 13.5wt% and 12.8wt%, respectively, compared with 7.0wt% over E-Cat. Maximum propylene yield occurred partially due to gasoline over-cracking to light olefins (inverse relation with Si/Al ratio). The effect of MFI crystal size showed that large size crystals enhanced the yield of light olefins as compared to small size crystals due to secondary cracking of gasoline molecules. Results of kinetic study based on 4-lump model showed proportional relation between MFI Si/Al ratio and activation energy for the conversion of gasoline to gases. Activation energy increased from 14.2kcal/mol to 16.3kcal/mol as Si/Al ratio increased from 30 to 2000.

Acidic and basic properties of zeolite-containing cracking catalyst in the process of butene-1 isomerization

The process of butene-1 isomerization in the presence of two groups of samples of zeolite-containing catalyst (ZCC) that earlier participated in the traditional and oxidative catalytic cracking of vacuum gasoil is investigated. It is established that the nature of the reaction mixture and conditions of the cracking process are key factors in forming the acidic and basic properties of the catalyst. It is shown that the highest activity in the butene-1 isomerization into cis-/trans-butene-2 is demonstrated by ZCC samples that participated in the oxidative catalytic cracking (oxycracking). It is suggested that the enhanced catalytic activity of this group of ZCC samples was related to the availability of acid–base centers in the form of radical-like oxygen along with protic- and aprotic-type acidic centers in the structure of the oxidative compaction products.

Synthesis of ZSM-5 zeolite from diatomite for fluid catalytic cracking (FCC) application

In this study, ZSM-5 zeolite was successfully synthesized hydrothermally from cheap and easily accessible natural mineral diatomite in the presence of tetrapropyl ammonium bromide. The pore structure, acidic sites and surface features of as-synthesized ZSM-5 zeolite were well characterized by X-ray diffraction, scanning electron microscopy, pyridine-adsorbed Fourier transform infrared spectroscopy, and N2 adsorption. The analysis results revealed that the as-synthesized ZSM-5 zeolite exhibited excellent hydrothermal stability, high specific surface area (223 m2 g−1) and more acidic cites than diatomite. After mixing ZSM-5 zeolite with a FCC base catalyst, the catalytic performance was evaluated in a micro-fixed bed reactor using vacuum gas oil (VGO) as feedstock. The high surface area and more acidic sites of as-synthesized ZSM-5 zeolite played an important role in the production of light olefins (propylene and butylene) during catalytic cracking of VGO.

The effects of magnesium of Zn–Mg–Al additives on catalytic cracking of VGO and in situ reduction of sulfur in gasoline

The scope of the present study is to describe the cracking behavior of hydrocarbons and the reduction of sulfur in gasoline in fluid catalytic cracking (FCC) process using Zn–Mg–Al additives with varying the Mg/Al molar ratios. Experiments have been carried out on a micro-activity-test (MAT) reactor using high-sulfur vacuum gas oil (VGO) feed and zinc impregnated Mg–Al spinels as additive and the commercial cracking catalyst. It was found that Zn–Mg–Al additives exhibited enhanced Lewis acidity compared with the corresponding Zn-free Mg–Al spinels. The MAT results indicated that the addition of additives reduced the yields of liquid petroleum gas and coke at low Mg contents but increased the coke yield at high Mg contents. Overall, the additives improved the yields of gasoline and diesel. It has also been shown that the rich Lewis acidity had a positive effect on the conversion of aromatic sulfur species of gasoline and the maximum reduction of gasoline sulfur was achieved with Zn/Mg4.0Al2O3 due to the synergistic effect of basicity and Lewis acidity.

Modified HZSM-5 as FCC additive for enhancing light olefins yield from catalytic cracking of VGO

HZSM-5 with varying Si/Al2 ratios were modified with Mn and alkaline treatment and tested as FCC catalyst additives to enhance the yield of light olefins (in particular, propylene) from catalytic cracking of hydrotreated Arab Light vacuum gas oil (VGO). The performance of the Mn/HZSM-5 and alkaline treated HZSM-5 additives were assessed using a commercial equilibrium USY FCC catalyst (E-Cat) in a fixed-bed micro-activity test unit at 550°C and various catalyst/oil ratios. The yield of light olefins over E-Cat containing parent HZSM-5 increased to 18.1, 25.4 and 27.4wt% for Si/Al2 of 30, 80 and 280, respectively, compared with 15.4wt% over E-Cat (at 75wt% conversion). Further increase in light olefins yield was achieved upon using Mn modified HZSM-5 as an additive. The highest light olefins yield of 29.2wt% was achieved over E-Cat-Mn/HZSM-5 (Si/Al2=80, 2.0wt% Mn). The enhanced production of light olefins over the Mn/HZSM-5 additive is mainly attributed to the decrease in the acid density and the amount of strong acid sites, and (possibly) the partial narrowing of ZSM-5 micropore. Alkaline treated HZSM-5 also exhibited high light olefins yield compared with parent HZSM-5, due to the formation of hierarchical micro-meso topology. The highest light olefins yield of ∼28.3wt% was obtained over E-Cat-containing alkaline treated HZSM-5 (Si/Al2=80–280, using the appropriate desilication conditions).

Mesopore-modified mordenites as catalysts for catalytic pyrolysis of biomass and cracking of vacuum gasoil processes

Mesopore-modified mordenite zeolitic materials with different Si/Al ratios have been prepared and tested in the biomass pyrolysis and catalytic cracking of vacuum gasoil. Alkaline treatment was carried out to generate mesoporosity. Severity of alkaline treatment was found to be of paramount importance to tune the generated mesoporosity, while it significantly affected the crystallinity of treated mordenites. It was moreover observed that the alkaline treatment selectively extracted Si decreasing the Si/Al ratio of treated samples. Catalytic activity of parent and alkaline treated mordenites was studied in the pyrolysis of biomass. All zeolitic based materials produced less amounts of bio-oil but of better quality (lowering the oxygen content from ∼40% to as much as 21%) as compared to the non-catalytic pyrolysis experiments. On the other hand, it was found that the combination of mesopore formation and high surface area after alkaline treatment of the mordenite with a high Si/Al ratio resulted in the enhancement of its catalytic activity, despite the reduction of its acidity. The increment of the decarboxylation and dehydration reactions, combined with a reduction of carbon deposition on the catalyst, resulted in a remarkable decrease in the oxygen content in the organic fraction and therefore, resulted in a superior quality liquid product. Alkaline treated mordenites were additionally acid treated targeting dealumination and removal of the extra framework debris, thus generating mesopore-modified mordenite samples with stronger acid sites and higher total acidity, as candidate catalysts for catalytic cracking of vacuum gasoil. Desilicated and especially desilicated and dealuminated mordenites exhibited the highest activity and selectivity towards LCO with the best olefinicity in gases and higher bottoms conversion. Therefore, an optimized desilicated–dealuminated mordenite additive could be an interesting candidate as a component of the FCC catalyst for a high LCO yield.

Development of a catalytic cracking process with a high yield of light olefins: study of the structure of the yield of products

The structure of the yield of products of catalytic cracking of vacuum gasoil and repeated cracking of light naphtha in the high-temperature region was investigated. The results of the studies served as the basis for developing catalytic cracking technology with a high yield of light olefins.

In-situ synthesis and catalytic activity of ZSM-5 zeolite

ZSM-5 zeolite has been hydrothermally synthesized in-situ on the external surface of calcined kaolinite in the presence of n-butylamine. This supported zeolite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy and N 2 adsorption. Several synthesis variables were systematically investigated, including SiO 2 to Al 2O 3 ratio, pH, crystallization time, and crystallization temperature. After mixing the ZSM-5 with a Fluid Catalytic Cracking (FCC) catalyst, catalytic performance was evaluated by cracking vacuum gas oil (VGO) in a micro-fixed bed reactor. ZSM-5 addition was favorable for the production of light olefins by catalytic cracking of VGO.

Catalytic cracking of vacuum gas-oil in the presence of pyrolysis resin

Catalytic cracking of vacuum gas-oil in the presence of pyrolysis resin

Catalytic cracking of vacuum gasoil in the presence of activating additives

These authors perform catalytic cracking of vacuum gas oil in a singlepass laboratory flow unit with mechanized mixing of a bed of the microbead zeolitic catalyst KMTsR. They present data in a series of three tables and in a set of three charts. Analysis of these data leads them to conclude that the use of activating additives makes it possible to reduce the coke yield and bring coke deposition down to a preassigned level. They further conclude that their method for intensifying catalytic cracking is especially promising for heavy types of feed with high carbon residues.

Catalytic cracking of vacuum gasoil from Mangyshlak crude on zeolitic catalysts

Catalytic cracking of vacuum gasoil from Mangyshlak crude on zeolitic catalysts

Effect of subdivision of the reaction zone on the distribution and quality of the desired products during catalytic cracking in a fluid bed

The results of a study on the effect which subdivision of the reactor zone has on the selectivity, yield, and quality of the products of a first-order process are described for the example of catalytic cracking of vacuum gasoil in a fluid bed of synthetic catalyst. It has been shown that subdivision of the reactor raises the yield of gas and gas-oline, and reduces the yield of light gasoil. An increase of the number of reactor sections raises the concentration of unsaturated compounds in the gas, improves the gasoline quality (lower contents of sulfur and unsaturated compounds) and raises the degree of aromatization of the 205–350°C fraction.