Catalytic Cracking Of Heavy Oil Research Articles

The Catalyst Selectivity Index (CSI): A Framework and Metric to Assess the Impact of Catalyst Efficiency Enhancements upon Energy and CO2 Footprints

AbstractHeterogeneous catalysts are not only a venerable part of our chemical and industrial heritage, but they also occupy a pivotal, central role in the advancement of modern chemistry, chemical processes and chemical technologies. The broad field of catalysis has also emerged as a critical, enabling science and technology in the modern development of “Green Chemistry”, with the avowed aim of achieving green and sustainable processes. Thus a widely utilized metric, the environmental E factor—characterizing the waste-to-product ratio for a chemical industrial process—permits one to assess the potential deleterious environmental impact of an entire chemical process in terms of excessive solvent usage. As the many (and entirely reasonable) societal pressures grow, requiring chemists and chemical engineers not only to develop manufacturing processes using new sources of energy, but also to decrease the energy/carbon footprint of existing chemical processes, these issues become ever more pressing. On that road to a green and more sustainable future for chemistry and energy, we note that, as far as we are aware, little effort has been directed towards a direct evaluation of the quantitative impacts that advances or improvements in a catalyst’s performance or efficiency would have on the overall energy or carbon (CO2) footprint balance and corresponding greenhouse gas (GHG) emissions of chemical processes and manufacturing technologies. Therefore, this present research was motivated by the premise that the sustainability impact of advances in catalysis science and technology, especially heterogeneous catalysis—the core of large-scale manufacturing processes—must move from a qualitative to a more quantitative form of assessment. This, then, is the exciting challenge of developing a new paradigm for catalysis science which embodies—in a truly quantitative form—its impact on sustainability in chemical, industrial processes. Towards that goal, we present here the concept, definition, design and development of what we term the Catalyst Sensitivity Index (CSI) to provide a measurable index as to how efficiency or performance enhancements of a heterogeneous catalyst will directly impact upon the fossil energy consumption and GHG emissions balance across several prototypical fuel production and conversion technologies, e.g. hydrocarbon fuels synthesized using algae-to-biodiesel, algae-to-jet biofuel, coal-to-liquid and gas-to-liquid processes, together with fuel upgrading processes using fluidized catalytic cracking of heavy oil, hydrocracking of heavy oil and also the production of hydrogen from steam methane reforming. Traditionally, the performance of a catalyst is defined by a combination of its activity or efficiency (its turnover frequency), its selectivity and stability (its turnover number), all of which are direct manifestations of the intrinsic physicochemical properties of the heterogeneous catalyst itself under specific working conditions. We will, of course, retain these definitions of the catalytic process, but now attempt to place discussions about a catalyst’s performance onto a new foundation by investigating the effect of improvements in the catalyst’s efficiency or performance on the resulting total energy and total CO2footprint for these prototypical fuel production and fuel conversion processes. The CSI should help the academic and industrial chemical communities, not only to highlight the current ‘best practice catalysts’, but also draw specific conclusions as to what energy and CO2emissions saving one could anticipate with higher efficiency/higher performance from heterogeneous catalysts in a particular fuel synthesis or conversion process or technology. Our aim is to place discussions about advances in the science and technology of catalysis onto a firm foundation in the context of GHG emissions. We believe that thinking about (and attempting to quantify) total energy and CO2emissions reductions associated with advances in catalysis science from a complete energy life cycle analysis perspective is extremely important. The CSI will help identify processes where the most critical advances in catalyst efficiency are needed in terms of their potential impact in the transition to a more sustainable future for fuel production and conversion technologies.

Kinetic study of catalytic cracking of heavy oil over an in-situ crystallized FCC catalyst

The kinetic characteristics of an in-situ crystallized FCC catalyst were reported for the first time. A six-lump kinetic model containing 24 kinetic parameters, one parameter for basic nitrogen poisoning, another parameter for aromatics adsorption and other two parameters for catalyst deactivation was established. Kinetic parameters were estimated based on experimental data at 460, 480, 500 and 520°С by fourth order Runge–Kutta algorithm and the least square method. Frequency factors and apparent activation energies were then calculated according to Arrhenius equation. The predicted data of product distribution showed good agreement with experimental data, and the relative errors were mainly within 10%. Model analysis indicated that a relative low temperature was more suitable for the production of light oil.

A multiple-assembly/one-pot-crystallization strategy for a relatively more eco-friendly synthesis of hydrothermally stable mesoporous aluminosilicates

Mesoporous aluminosilicates (MA) with high hydrothermal stability obtained by assembly of zeolite Y precursors are attractive for the potential application in heavy oil catalytic cracking. A relatively more eco-friendly synthesis of MA with low synthesis cost and waste water discharge is particularly appealing. We report on the green synthesis of MA via a multiple-assembly/one-pot-crystallization (MA/OC) process by recycling the non-reacted reagents in the assembly mother liquor after separating the assembly solid product. This approach was achieved by exact supplementary compensation of the consumed raw materials and correct pH adjustment for the assembly liquor after each cycle of assembly. The assembly solid products in 5 cycles were collected and crystallized in one-pot in the mother liquor. Characterization results indicated that consumption of P123 and water discharge of MAOC-5 could be reduced to 51.5% and 27.3% of those of conventional MA-1. Meanwhile, the product yield of MAOC-5 is 102.66 g L−1, 4.8 times that of MA-1. This strategy suggests a relatively more eco-friendly and low cost route for the synthesis of hydrothermally stable MA.

No.41 キュリー・ポイント・パイロライザー法を用いたゼオライト含有ミクロ-メソ多孔性複合体による重質油接触分解の解析(重質油・バイオマス・コプロセッシング(3))

No.41 キュリー・ポイント・パイロライザー法を用いたゼオライト含有ミクロ-メソ多孔性複合体による重質油接触分解の解析(重質油・バイオマス・コプロセッシング(3))

Advances of two-stage riser catalytic cracking of heavy oil for maximizing propylene yield (TMP) process.

Two-stage riser catalytic cracking of heavy oil for maximizing propylene yield (TMP) process proposed by State Key Laboratory of Heavy oil Processing, China University of Petroleum, can remarkably enhance the propylene yield and minimize the dry gas and coke yields, and obtain high-quality light oils (gasoline and diesel). It has been commercialized since 2006. Up to now, three TMP commercial units have been put into production and other four commercial units are under design and construction. The commercial data showed that taking paraffinic based Daqing (China) atmospheric residue as the feedstock, the propylene yield reached 20.31 wt%, the liquid products yield (the total yield of liquefied petroleum gas, gasoline, and diesel) was 82.66 wt%, and the total yield of dry gas and coke was 14.28 wt%. Moreover, the research octane number of gasoline could be up to 96.

ROTATING MACHINERY FAULT DETECTION BASED ON IMPROVED ENSEMBLE EMPIRICAL MODE DECOMPOSITION

An improved EEMD approach is introduced in this paper based on automatically obtaining the adding white noise amplitude and the ensemble number according to different analyzing signal characteristics. The adding white noise affects decomposition effect is researched in detail, a criterion of adding white noise in EEMD is established, and the improved EEMD algorithm is described. Simulated signals demonstrate the effectiveness of the improved EEMD in diagnosing the faults of rotating machinery. The improved EEMD is successfully applied to an early rub-impact fault detection of machine unit for catalytic cracking of heavy oil, with the fault reason being analyzed in detail. A gear fault detection of hot strip finishing mills is also analyzed utilizing the improved EEMD method. The results show that the improved EEMD can obtain more precise diagnosis results than the original EMD and FFT spectrum.

Facile Synthesis of Mesoporous Zeolite Y with Improved Catalytic Performance for Heavy Oil Fluid Catalytic Cracking

A facile and direct approach for the synthesis of mesoporous zeolite Y by using [(CH3O)3SiC3H6N(CH3)2-C18H37]Cl as template is presented. Under the basic condition of the Y synthesis system, (CH3O)3Si– bonds hydrolyze to −Si–OH, and yield −Si–O–Al– and −Si–O–Si– linkages that anchor the template in zeolite framework. Afterward, micelles formed by −C18H37 lead to the formation of mesoporosity within zeolite Y crystals. This material, which introduces intracrystalline mesoporosity into zeolite Y, shows superior catalytic performance when used in heavy oil catalytic cracking.

Hydrothermally stable mesoporous aluminosilicates with moderate acidity via degradation-assembly process and improved catalytic properties

Mesoporous aluminosilicates with hydrothermal stability and moderate acidity are synthesized via assembly of microporous zeolite precursors obtained by the degradation of zeolite NaY, denoted as “degradation-assembly” (DA) technique. By controlling the degradation degree of matrix NaY, precursors with larger spatial volume and stronger rigidity will be obtained. The characterization results showed that the walls of the mesophase in MDA (mesoporous aluminosilicate obtained by “DA” method) composed of the preformed zeolite Y building units and the moderate acidity was inherited from the introduced precursors. It was suggested that the more mature assembly units accounted for the increased acidity of MDA with more Al species retained in the framework of mesophases. The resulting aluminosilicates with simultaneously moderate acidity and hydrothermal stability showed superior catalytic properties when used in heavy oil catalytic cracking catalysts.

キュリーポイント・パイロライザーを用いたゼオライト含有ミクロ-メソ多孔性複合体による重質炭素資源の接触分解反応

キュリーポイント・パイロライザーを用いたゼオライト含有ミクロ-メソ多孔性複合体による重質炭素資源の接触分解反応

Understanding and direct strategy to synthesize hydrothermally stable micro-mesoporous aluminosilicates with largely enhanced acidity

A general synthetic route of bimodal micro-mesoporous aluminosilicates with strong acidity and excellent hydrothermal stability has been developed. This method is built on the understanding that mesoporous aluminosilicates with high hydrothermal stability can be obtained via assembly of zeolite precursors in acidic conditions by copolymer templates, and the acidity can be improved by the introduction of Al species in neutral and alkaline systems. It is proposed that in order to obtain the mesoporous aluminosilicates with simultaneously strong acidity and excellent hydrothermal stability, an important requirement is that the paradox between stability and acidity must be harmonized. In this article, the crystallization of the resulting aluminosilicates was significantly improved by taking advantage of the Beta zeolite precursors in acidic media. When the mesostructure was basically formed, the pH of the reaction system was adjusted from strong acid to neutral, followed by a second hydrothermal crystallization, during which a large amount of Al could be introduced into the mesophases. XRF and Al NMR show that BPs possessed a high tetrahedrally coordinated Al loading. Py-IR results reveal that the total amount of Brønsted and Lewis acid sites increases 7.23 times. Such bimodal micro-mesoporous aluminosilicates demonstrated superior catalytic properties for heavy crude oil catalytic cracking, because of the increased hydrothermal stability and acidity. Our achievements have added new contributions to understanding the preparation of mesoporous aluminosilicates with strong acidity and excellent hydrothermal stability, which sheds a light on the practical application of mesoporous zeolites in petrochemical industry.

Catalytic Cracking Reaction of Heavy Oil in the Presence of Cerium Oxide Nanoparticles in Supercritical Water

Catalytic cracking of Canadian oil sand bitumen in supercritical water was performed to clarify the effect of CeO2 nanoparticles. The cracking was performed at 723 K to promote a redox reaction between the water, bitumen, and catalyst for the production of hydrogen and oxygen. As the catalyst, CeO2 with two different morphologies was employed because the redox reaction of CeO2 with water and organics is expected and its activity can be controlled by its structure. In this study, two roles of water were considered as well. Water is attractive as a high potential medium with low dielectric constant and density at near the critical point (374 °C, 22.1 MPa) that allows formation of highly crystalline smaller metal oxides particles. However, the chemical effects of water are investigated with heavy oil catalytic cracking. Transmission electron microscopy images indicated that CeO2 nanoparticles with cubic and octahedral shape were synthesized using a plug-flow reactor under hydrothermal conditions. The particles sizes were 8 and 50 nm for cubic and octahedral CeO2, respectively. At 773 K, it was found that the oxygen storage capacity (OSC) of the cerium oxide nanoparticles with cubic {100} facets was nearly 3.4 times higher than that of the cerium oxide nanoparticles with octahedral {111} facets. Heavy oil fractions of bitumen were cracked in a batch-type reactor at 723 K in order to produce as much light oil as possible, and the effect of the catalyst loading and reaction conditions on the conversion rate and coke formation were investigated. As a result, it was demonstrated that it is possible to obtain a high conversion rate by increasing the exposed surface area and reducing the particle size of the catalyst. The highest conversion was obtained in the presence of 20 mg loading of cubic CeO2 nanoparticles (8 nm) with reaction time of 1 h.

Mesoporous zeolites as efficient catalysts for oil refining and natural gas conversion

Zeolites have been regarded as one of the most important catalysts in petrochemical industry due to their excellent catalytic performance. However, the sole micropores in zeolites severely limit their applications in oil refining and natural gas conversion. To solve the problem, mesoporous zeolites have been prepared by introducing mesopores into the zeolite crystals in recent years, and thus have the advantages of both mesostructured materials (fast diffusion and accessible for bulky molecules) and microporous zeolite crystals (strong acidity and high hydrothermal stability). In this review, after giving a brief introduction to preparation, structure, and characterization of mesoporous zeolites, we systematically summarize catalytic applications of these mesoporous zeolites as efficient catalysts in oil refining and natural gas conversion including catalytic cracking of heavy oil, alkylation, isomerization, hydrogenation, hydrodesulfurization, methane dehydroaromatization, methanol dehydration to dimethyl ether, methanol to olefins, and methanol to hydrocarbons.

Multidimensional Reaction Control with Beta Type Zeolites in Heavy Oil Catalytic Cracking

Residual feeds to the RFCC process could be well upgraded by catalyst containing FAU (USY) zeolite with higher hydrogen transfer activity, resulting in lower bottom and higher gasoline yields. However, the hydrogen transfer reaction has been shown to have negative aspects among the various reaction elements occurring simultaneously in the catalytic cracking process, because octane loss or coke formation were accelerated in most cases of inappropriate application of catalysts. Multifunctional catalyst was developed by adding beta (*BEA) zeolite to RFCC catalyst, and resulted in improved octane number without sacrificing gasoline yield. Addition of *BEA zeolite to the RFCC catalyst maintained the octane number even in use of catalyst with high hydrogen transferring activity by further isomerizing single branched to multiple branched isoparaffins.

Multifunctional Two-Stage Riser Catalytic Cracking of Heavy Oil

The continuous deterioration of feedstocks, the increasing demand of diesel, and the increasingly strict environmental regulations on gasoline call for the development of fluid catalytic cracking (FCC) technology. To increase the feed conversion and the diesel yield as well as produce low-olefin gasoline, the multifunctional two-stage riser (MFT) FCC process was proposed. Experiments were carried out in a pilot-scale riser FCC apparatus. Results show that a higher reaction temperature is appropriate for heavy cycle oil (HCO) conversion, and the semispent catalyst can also be used to upgrade light FCC gasoline (LCG). The synergistic process of cracking HCO and upgrading LCG in the second-stage riser can significantly enhance the conversion of HCO while reducing the olefin content of gasoline at less expense of gasoline yield. Furthermore, the novel structure riser reactor can increase the conversion of olefins in gasoline. Because of the significant increase of HCO conversion, the fresh feedstock can be cr...

No.16 水蒸気を水素・酸素源として利用した酸化鉄系触媒による重質油の軽質化反応(重質油・コプロセッシング)

No.16 水蒸気を水素・酸素源として利用した酸化鉄系触媒による重質油の軽質化反応(重質油・コプロセッシング)

Study on the Catalytic Cracking of Heavy Oil by Proper Cut for Higher Conversion and Desirable Products

To improve the product distribution in the residue fluid catalytic cracking (RFCC) process, two representative heavy oils were, respectively, cut into five fractions by true boiling point (TBP) distillation and their catalytic cracking performance was tested in a fixed fluidized bed reactor. The results indicated that they appeared to have diverse reaction characteristics and that about 6.3–19.3 wt % fractions with better crackability were still contained in the vacuum residual (VR). On the basis of the above, a feasible cut temperature of heavy oil was determined and the fractions were classified into two groups: the high-quality fraction (HF) group and the poor-quality fraction (PF) group. Compared with heavy oil before being cut, the product distribution of heavy oil after being cut was improved. With the increase in the blend levels of VR in the vacuum gas oil (VGO), the desired products yield of heavy oil after being cut was enhanced gradually, especially under the optimal reaction conditions. To describe the reaction behavior of the PF catalytic cracking, a six-lump kinetic model was proposed. Kinetic constants and apparent activation energies were determined with the improved Marquardt method. The effect test showed that the kinetic model could predict product yields well.

The Lumping Kinetic Model for the Heavy Oil Catalytic Cracking MIP Process

Based on the characteristics of heavy oil catalytic cracking and maximizing iso-paraffins (MIP) process, a 12-lumping kinetic model was developed in this article to simulate the MIP process. According to the published data from a commercial MIP process, 36 kinetic parameters of the model were determined by the stepwise method. The verification result with industrial data showed that the model could predict not only the distribution of products but also the quality of main products and describe the reaction rules of the MIP process correctly.

Evaluation of the Multiphase Behavior in Binaries Using a New Technique for Describing Solid Phases Based on the Soave−Redlich−Kwong Equation of State

In the petroleum industry, knowledge of phase behavior is essential to solve many problems, such as the design of the catalytic cracking of heavy oil. The catalyst tends to lose activity as a result of the formation of the solid phase, so the calculation of multiphase behavior of systems containing solid phases will serve to solve the problem. The Soave−Redlich−Kwong equation of state is widely employed to evaluate multiphase behavior, but cubic equations of state are incapable of calculating the properties of solid phases and thus cannot evaluate the multiphase behavior of systems containing solid phases. In this research, a new technique for describing the solid phase has been developed. The multiphase behavior of propane binaries with ployaromatic hydrocarbons was then explored. To evaluate the critical end point, which is difficult to calculate, an algorithm combining the method of Heidemann and Khalil (AIChE J. 1980, 26, 769−780) to compute the critical point and the tangent-plane criterion was developed previously (Yang et al. Ind. Eng. Chem. Res. 2009, 48, 6877−6881). Setting the initial guesses with the values at the obtained critical end points, the three-phase loci were then computed successfully. The calculation results show that the three-phase loci terminate at a lower critical end point (LCEP), which is wrong according to the experimental data. To correct this mistake, the newly developed technique was employed, and the quadruple points where the three-phase loci really end were evaluated successfully.

Kinetic Model for Catalytic Cracking of Heavy Oil with a Zirconia−Alumina−Iron Oxide Catalyst in a Steam Atmosphere

A kinetic model was proposed to represent the catalytic cracking of heavy oil with a zirconia−alumina−iron oxide catalyst in a steam atmosphere. The model includes four lumps: heavy oil (boiling point above 350 °C), gas oil (boiling point of 250−350 °C), gasoline + kerosene (boiling point less than 250 °C), and gas. In this reaction, heavy oil fractions reacted with lattice oxygen in iron oxide and the active oxygen species, which were incorporated from the steam into the iron oxide lattice. Hence, lighter fractions, such as gasoline, kerosene, and gas oil, and carbon dioxide were produced with almost no coke. Kinetic parameters were determined using a nonlinear least-squares regression of the experimental results obtained under the reaction conditions of 450−500 °C and a time factor, W/FR, of 3.8−28 h. The evaluated activation energy of heavy oil cracking was lower than those reported in the literature on the hydrocracking process. Accordingly, it is supposed that active oxygen species generated from steam and the lattice oxygen in iron oxide promoted the cracking of heavy oil.

Fault diagnosis of rotating machinery using an improved HHT based on EEMD and sensitive IMFs

A Hilbert–Huang transform (HHT) is a time–frequency technique and has been widely applied to analyzing vibration signals in the field of fault diagnosis of rotating machinery. It analyzes the vibration signals using intrinsic mode functions (IMFs) extracted using empirical mode decomposition (EMD). However, EMD sometimes cannot reveal the signal characteristics accurately because of the problem of mode mixing. Ensemble empirical mode decomposition (EEMD) was developed recently to alleviate this problem. The IMFs generated by EEMD have different sensitivity to faults. Some IMFs are sensitive and closely related to the faults but others are irrelevant. To enhance the accuracy of the HHT in fault diagnosis of rotating machinery, an improved HHT based on EEMD and sensitive IMFs is proposed in this paper. Simulated signals demonstrate the effectiveness of the improved HHT in diagnosing the faults of rotating machinery. Finally, the improved HHT is applied to diagnosing an early rub-impact fault of a heavy oil catalytic cracking machine set, and the application results prove that the improved HHT is superior to the HHT based on all IMFs of EMD.