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Abstract The main purpose of this study is to elucidate the effect of catalyst on asphaltene molecular structure during hydrocracking of C 5 -isolated asphaltene. Remained asphaltene and coke were obtained after hydrothermal and catalytic hydrothermal cracking of C 5 -isolated asphaltene at 380–430 °C, using 1000 ppm Mo from Mo-octoate precursor. XRD and NMR analyses were used to investigate the change of molecular structure of asphaltene during the reaction. It was revealed that aggregation of asphaltene increased with increasing the reaction severity resulted in coke formation. The presence of catalyst reduced the aggregation of asphaltene molecules in comparison with the hydrothermal cracking. It was also observed that the average number of stacked polyaromatic sheets in the remained asphaltene decreased with increasing the reaction temperature because of the transformation of high stacked asphaltene into coke during the reaction. Moreover, it was confirmed that the main reason for asphaltene aggregation was the reduction of steric hindrance of asphaltene molecules by the change in molecular structure of asphaltenes. [ABSTRACT FROM AUTHOR]

Highlights • A new six-lump kinetics scheme was developed. • New six-lump activation energies, frequency factors and heat of reactions developed. • The estimated parameters can be used to simulate any type of FCC riser. Abstract In this work a simulation of detailed steady state model of an industrial fluid catalytic cracking (FCC) unit with a newly proposed six-lumped kinetic model which cracks gas oil into diesel, gasoline, liquefied petroleum gas (LPG), dry gas and coke. Frequency factors, activation energies and heats of reaction for the catalytic cracking kinetics and a number of model parameters were estimated using a model based parameter estimation technique along with data from an industrial FCC unit in Sudan. The estimated parameters were used to predict the major riser fractions; diesel as 0.1842 kg-lump/kg-feed with a 0.81% error while gasoline as 0.4863 kg-lump/kg-feed with a 2.71% error compared with the plant data. Thus, with good confidence, the developed kinetic model is able to simulate any type of FCC riser with six-lump model as catalyst-to-oil (C/O) ratios were varied and the results predicted the typical riser profiles. [ABSTRACT FROM AUTHOR]

Petroleum coke is often shortened as pet coke. Petroleum coke or pet coke is a product obtained from oil of all kinds during the oil refining process. Petroleum coke is a carbon-rich solid originating from petroleum refining and is obtained by cracking process. Petroleum coke is a byproduct of the coking unit, a residual fuel upgrader. The coke quality depends on the crude oil processed in refinery. The mixture of oil, solids and water deposited at the bottom of the storage deposit is known as waste oil sludge. Oil sludge is one of the solid wastes produced in petroleum refinery and it is a complex emulsion composed of various petroleum hydrocarbons, heavy metals, solid particles, and water. As a result of the refining process of crude oil, the contaminated sludge is biodegraded and converted into waste products that damage the environment and human health. In the coke processing, the assessment of oil sludge fraction is based on the principle of heating to high temperatures and the removal of light fractions from the breakdown. If the oil sludge initially contains low levels of sulfur and metal, the resulting petroleum coke is then calcined before use. The high quality needle type coke produced on convenient conditions in the coking unit. [ABSTRACT FROM AUTHOR]

A kinetic model of the isothermal initiated cracking of tar has been developed, and parameters of the reactions have been found. A computer model of isothermal thermo-oxidative cracking of tar is implemented to determine kinetic constants, and a criterion for mismatching the calculated and experimental data is minimized. The kinetic simulation of the process has been carried out in isothermal regime so that the parameters that allow for increase in yield of target products have been determined. [ABSTRACT FROM AUTHOR]

Since the discovery of petroleum as a source of raw materials for many processes, many techniques able to convert it into different types of products have been developed. One of these methods is thermal cracking, which is based on heating the initial mixture with the purpose of dividing long carbon chains into small chains. In this way, the economic value of the stream highly increased. The reaction of molecular breakdown or decomposition is carried out in a furnace reactor at high temperatures. In order to provide energy to the stream and to increase his internal energy, the equipment uses methane as fuel. The resultant mixture is cooled to promote phases separation inside a splitter. The thermodynamic properties of the system are defined using Chao Seader model and kinetic reaction. The temperature in the furnace was studied to increase the isobutane mass fraction at the end of the reaction. Two sensibility analysis were realized, in the furnace-reactor and in the cooler pre-stripper, to determine their optima! points. In the first case, a temperature of 793.15 K was determined as optimal point to achieve an adequate conversion into isobutane. In the second case, the behavior of the inlet feed temperature in the stripper was obtained. The stripper operation was defined in 6 stages. The inlet stream should be fed at the third stage with a temperature of 400.0 K. At this point, the use of the reboiler is not necessary. [ABSTRACT FROM AUTHOR]

The process of the atmospheric-oxygen-induced cracking of heavy oils of various nature and compositions in a continuous flow reactor has been studied. The process variables for conversion of heavy oils into gasoline and diesel fractions have been determined that ensure the maximum yield of the above fractions with simultaneous production of marketable heavy residues. The developed technology can be applied in industry upon minor upgrading of the operating thermal cracking or visbreaking units. This upgrade will result in a considerable increase in the oil refining depth. [ABSTRACT FROM AUTHOR]

A novel process design for a more cost-effective, greener process for making chemicals from shale gas and bioethanol is presented. The oxidative coupling of methane and cocracking technologies are considered for converting methane and light natural gas liquids, into value-added chemicals. Overall, the process includes four process areas: gas treatment, gas to chemicals, methane-to-ethylene, and bioethanol-to-ethylene. A simulation-optimization method based on the NSGA-II algorithm for the life cycle optimization of the process modeled in the Aspen HYSYS is developed. An energy integration model is also fluidly nested using the mixed-integer linear programming. The results show that for a 'good choice' optimal design, the minimum ethylene selling price is $655.1/ton and the unit global-warming potential of ethylene is 0.030 kg CO2-eq/kg in the low carbon shale gas scenario, and $877.2/ton and 0.360 kg CO2-eq/kg in the high carbon shale gas scenario. © 2014 American Institute of Chemical Engineers AIChE J, 61: 1209-1232, 2015 [ABSTRACT FROM AUTHOR]

Main failure modes and application limit of low alloy steel oil country tubular goods (OCTG) for sour service by relevant international standard were analyzed in this paper. The influences of metallurgical and environmental factors upon sulfide stress cracking (SSC) resistance property were discussed, and selection of SSC evaluation methods were described from the point f stress analysis and fitting for service. [ABSTRACT FROM AUTHOR]

This paper focuses on the fluid catalytic cracking (FCC) process and reviews recent developments in its modeling, monitoring, control, and optimization. This challenging process exhibits complex behavior, requiring detailed models to express the nonlinear effects and extensive interactions between input and control variables that are observed in industrial practice. The FCC models currently available differ enormously in terms of their scope, level of detail, modeling hypothesis, and solution approaches used. Nevertheless, significant benefits from their effective use in various routine tasks are starting to be widely recognized by the industry. To help improve the existing modeling approaches, this review describes and compares the different mathematical frameworks that have been applied in the modeling, simulation, control, and optimization of this key downstream unit. Given the effects that perturbations in the feedstock quality and other unit disturbances might have, especially when associated with frequent changes in market demand, this paper also demonstrates the importance of understanding the nonlinear behavior of the FCC process. The incentives associated with the use of advanced model-based supervision strategies, such as nonlinear model predictive control and real-time optimization techniques, are also presented and discussed. [ABSTRACT FROM AUTHOR]

The article presents a study that determines the selection of refractory castables for fluidized catalytic cracking units used in the petrochemical industry. It explores the five high-alumina castables that are characterized under cold crushing strength and cold erosion tests. It notes the result of the study, which indicates that material selection is limited by the absence of tests for the performance evaluation of the next to in-service condition.

Fluidized-bed catalytic cracking of heavy petroleum distillates is one of the most important processes in petroleum refining; because of its large scale, estimation of the kinetic rate constants is performed at the laboratory level. Several experimental devices are commonly used, including fixed-bed reactors, fluidized-bed reactors, and riser emulator reactors. Despite the different hydrodynamics of the reactors mentioned, when compared to the industrial unit, the production of the main products (gasoline, gases, and coke) can be predicted and emulated accurately in the laboratory. Taking advantage of this fact, prediction of the kinetic rate constants and catalyst activity parameters has been performed at the laboratory level; however, frequency factors are larger than those necessary to simulate the industrial unit. This situation could arise because of the lack of fundamental modeling of transport phenomena and catalyst activity decay due to coke deposition; these phenomena have been modeled using side functions associated with “time-on-stream”, “coke-on-catalyst”, or “feedstock conversion”. The objective of this work is to improve accuracy during estimation of the frequency factors at the laboratory level, via the estimation of catalyst activity, based on the effectiveness factor; which has been included in the mathematical model of a fixed-bed laboratory bench-scale reactor. It is shown that following activity evolution along the experiment time helps to calculate frequency factors that are very similar to those needed to simulate industrial units; moreover, this model estimates different catalyst activity for each reactant and each reaction, and, therefore, it is selective. Frequency factors for a lumped kinetic scheme obtained at the laboratory level are used to simulate an industrial unit, showing good agreement during prediction of the product yields. [ABSTRACT FROM AUTHOR]

Abstract: Condensates and natural gases in South Pars, world''s largest gas field in Persian Gulf were studied for their geochemical characteristics and possibility of secondary cracking as a major gas producing mechanism. Carbon isotopic analysis of gas components proposes thermogenic origin for South Pars gas field. However, δ13C values of Methane and Ethane are slightly depleted in comparison with generated gas from primary thermogenic gas whereas gases from secondary cracking of oils are systematically depleted in 13C in Methane and Ethane compared to gases from primary cracking. Gas composition of Head-Space gas samples were plotted in Ln(C1/C2) vs. Ln(C2/C3) diagram that all the data points indicate a noticeable shift toward trend of secondary cracking, indicating frequency of higher components i.e. C2+. Silurian black shales are recognized as most important source rock for the South Pars field. Biomarker analysis of hydrocarbon liquid samples indicates Pristane to Phytane ratio is >1 that could confirm mentioned shaly source rock which is deposited in suboxic to oxic marine environment. Considering of δ13C of Silurian shales the “δ13C Methane-δ13C Source” was calculated and plotted against C1/ΣC1–5 indicating effect of secondary cracking of oil as producing mechanism for South Pars gas field. Moreover, pyro-bitumen as product of the secondary cracking was found filling secondary porosities in bottom part of the reservoir. [Copyright &y& Elsevier]

Fluidized-bed catalytic cracking (FCC) units, are one of the most complex and interactive processes in the refining industry, hence they are difficult to operate and to control; on the other hand they are one of the main producers of gasoline, which is an incentive to improve operation policies. Control of the FCC has been and continues to be a challenging and important problem. A control system is composed of several interacting control loops. The number of feasible alternative configurations of control loops is very large. Multiloop control systems are often used for industrial multivariable processes because of their simplicity. Relative gain array is used to minimize the interaction and to select the variable pairings. This work is concerned with the design of multivariable feedback control configurations for FCC units. Sufficient conditions to achieve regulation in terms of the steady-state gain matrix are provided, allowing to obtain a systematic procedure for analyzing multiloop control configurations of complex and interacting processes. Numerical simulations on a dynamical model based on a FCC unit operating in the partial-combustion mode are used to show the effectiveness of several control configurations under disturbances. [ABSTRACT FROM AUTHOR]

Abstract: Instrumental neutron activation analysis (INAA) of fluid catalytic cracking (FCC) catalyst samples was carried out with an objective to identify activable elements and evaluate its suitability for use as an intrinsic radiotracer for tracing catalyst itself in Fluid Catalytic Cracking Units (FCCUs) used in petroleum refining. Two catalyst samples obtained from two different refineries were analyzed. Twelve different elements were identified in each catalyst sample and their respective concentrations were determined. From the recorded gamma-ray spectra, it was found that lanthanum-140 (140La) and sodium-24 (24Na) were the predominantly present and suitable radionuclides that could be used as radiotracers for tracing catalyst in FCCUs. Lanthanum being present in much higher concentration forms the major component of the radiotracer after irradiation. Based on the results of INAA, appropriate quantities of the catalyst samples were irradiated with neutrons to produce the desired amount of activity of lanthanum-140 and sodium-24 to be used as radiotracers for tracing the catalyst itself in a pilot as well as an industrial-scale FCCU. The residence time distribution (RTD) of catalyst was measured and analyzed to determine mean residence time (MRT). The axial dispersion model (ADM) was used to simulate the measured RTD data and investigate the degree of axial mixing. The results of the experiments were used to improve the design of pilot-scale FCCU and optimize the performance of the industrial-scale FCCU. [Copyright &y& Elsevier]

Abstract: This paper provides a kinetics model for thermal cracking of various oils over time frames which correspond to the long term storage at temperatures up to those experienced in an in situ combustion process. The model describes detailed kinetic mechanisms and concentration changes of individual species during the thermal cracking reactions. Also the modeling results are compared with the experimental data to verify their validity. [Copyright &y& Elsevier]

Formulas are derived for the weighted mean number of preliminary cavitation processing cycles for crude oil. It is shown that the mean number of cavitation cycles can be varied widely in accordance with the cycle period, the volume of the circulation vessel, and the volume flow rates, up to several hundred cycles. An optimistic forecast is made on the scope for increasing the extent of oil processing by 20–30% by intensifying the cracking by cavitation. [ABSTRACT FROM AUTHOR]

This article discusses research into the use of olefin oligomerization in the synthesis of diesel fuels low in aromatic compounds and sulfur. The use of a solid acid catalyst consisting of γ-Al2O3 with magnetic Fe3O4, impregnated with NiSO4 is described. The characterization of the catalyst by x-ray diffraction, NH3-temperature programmed desorption, and thermal analysis is described. The product of these reactions, magnetic NiSO4/γ-Al2O3, was used to catalyze olefin oligomerization of light fluid catalytic cracking gasoline feedstocks in fixed-bed and molecular sieve bed reactors.

Abstract: This paper presents the results of an experimental study in which molded gypsum and Carrara Marble specimens containing a pre-existing flaw were tested in uniaxial compression. The main purpose of this study was to observe and characterize the cracks that emanate from a single pre-existing flaw. Seven different crack types were identified based on their geometry and propagation mechanism (tensile/shear). Specifically, they include three types of tensile cracks, three types of shear cracks, and one type of mixed tensile–shear crack. In addition to the geometry and mechanism, it was also possible to determine the temporal sequence of different crack types. These observations form the basis for a re-evaluation of cracking processes reported in the literature. It is possible to apply the classification obtained in the present research to previously conducted experiments by others. This eliminates much of the confusion that has existed when comparing different research results. [Copyright &y& Elsevier]

A new convenient synthetic protocol for the one-pot stereoselective synthesis of bis[( E)-4-bromo(or chloro)styryl]arene derivatives via the sequential reaction of silylative-coupling of 4-halostyrenes with vinylsilanes followed by palladium-catalyzed cross-coupling 4-halostyrylsilanes with diiodoarenes, is described. The reaction leads to symmetrical bis[( E)-4-halostyryl]arene derivatives obtained in a stereocontrolled manner with high efficiency. [ABSTRACT FROM AUTHOR]

Lewis acid catalyzed isomerization of 7-oxabicyclic alkenes into 1-naphthol derivatives in high yields (87-98%) under mild reaction conditions has been developed. The mechanism of this reaction is briefly postulated. [ABSTRACT FROM AUTHOR]

A kinetic model of complex reaction systems such as DCC-I in molecular level was built by the method that combined Monte Carlo simulation and structural-oriented lumping. Seventy-five reaction rules, including the reactions of paraffins, olefins, naphthenics, and aromatics, were made to build the reaction networks of complex reaction system DCC-I. The results showed that the relationship of product yields with reaction extent was reasonable, the yields and properties of major products, propylene and gasoline, in optimized reaction extent gave a good agreement with the plant data, and the reaction rules and the reaction network could very well reflect the characters of DCC-I. Simulations of two sets of molecules produced by the same regular plant data were parallel, and the kinetic model had good repeatability, convergence, robustness, and sensitivity. [ABSTRACT FROM AUTHOR]

In this article we analyze quantitatively and discuss in detail a number of reactions that take place on a C 3H 5potential. These reactions include the reaction of hydrogen atoms with allene and propyne, the reaction of methyl with acetylene, the isomerization of cyclopropyl to allyl, and the dissociation of allyl, 1-propenyl, and 2-propenyl. The theory employs high-level electronic-structure methods to characterize the potential energy surface, RRKM theory to calculate microcanonical, J-resolved rate coefficients, and master-equation methods to determine phenomenological rate coefficients, k( T, p). The agreement between our theory and the experimental results available is very good. The final theoretical results are cast in a form that is convenient for use in chemical kinetics modeling. [ABSTRACT FROM AUTHOR]

The feasibility analysis of integrating methanol to olefins (MTO) with fluidized catalytic cracking (FCC) process is based on their similarities and compatibility. Feeding methanol in FCC is proposed to produce more light olefins. According to the characters of FCC, the effects of reaction temperature, water co-feed, and the coke content of catalyst in methanol conversion were studied systematically. It is concluded that high light olefins yields from methanol conversion were obtained on the FCC condition. Feeding methanol in FCC at the bottom of riser as the proper position was suggested on the ground of comparison with MGD process of FCC. The research proved the feasibility of feeding methanol in FCC and provided important reference for its commercial application in a certain degree. [ABSTRACT FROM AUTHOR]

A new application field of Pt-Pd/USY zeolite is presented. PtPd/USY was used to desulfurize selectively catalytically cracked naphtha of various sulfur contents. Selective HDS and HDN performance of PtPd/USY was found to be superior compared to a commercial CoMo/Al2O3 (KF-756) and a new CoMo/Al2O3 being industrially applied for selective HDS of cracked gasoline. [ABSTRACT FROM AUTHOR]

Thermal cracking of Fischer−Tropsch waxes at mild conditions (430−500 °C) has been reconsidered as a possible refining technology for the production of fuels and chemicals. In this study, the description of paraffin cracking, which was historically developed using material no heavier than C40, was extended to C20−C120wax. In this carbon number range, cracking rate increased with increasing carbon length and thermal cracking resulted in a bimodal product distribution. Using the Rice−Kossiakoff mechanism as a basis, a relationship could be derived between carbon number distribution and conversion that described the observed behavior. The application of thermal cracking to fuels production was evaluated, and it was shown to be less efficient than hydrocracking, although it requires no hydrogen co-feed and has a lower gas make. Thermal cracking is better suited for the production of chemicals such as candle wax and linear -olefins. The study also investigated the formation of deposits during wax cracking. The deposits were inorganic in nature and originated from material produced in the Fischer−Tropsch process. It was found that stripping gases (steam, H2, and N2) were ineffective in reducing these deposits. [ABSTRACT FROM AUTHOR]

In catalytic cracking of vacuum gasoils, the yields of products are correlated with their hydrogen content. A correlation that allows predicting the yields of products of this process was elaborated based on the results of cracking of 11 gasoils of different origin and data on their density, refractive index, and 50% distillation temperature. However, it is not possible to predict the octane number of the naphtha obtained in cracking with the group hydrocarbon composition of the feedstock. [ABSTRACT FROM AUTHOR]

Different catalytical hydrogen sources were compared with molecular hydrogen gas in the hydrocracking of Gudao residue in the presence of catalysts (PMA). The results showed that alternative hydrogen sources were effective in catalytic hydroconversion of heavy oil. The hydroconversion of residue in supercritical water-syngas system showed similar results when performed with molecular hydrogen. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this paper is to apply fuzzy/possibilistic optimization focus in the context of the water conservation in a petroleum industry. The idea is assessing the water requirements of the refining industry in the operational areas: topping, cracking, petrochemicals and lubes. The result showed that the raw water consumption is 25% and the reused water consumption is 75% approximately in refineries with daily crude capacities from 94 to 1500bbls/day. [Copyright &y& Elsevier]

Abstract: The laboratory findings were presented for a single-stage hydrocracking process of vacuum residue (VR) of Ural crude. The Ni–Mo/Al2O3 catalyst in suspension was used in tests. The amounts and quality of the obtained products were related to process parameters. Hydrocracking of VR was carried out in a continuous flow reactor, at the temperature of 410–450 °C and pressure of 12–20 MPa, at the liquid space velocity (LHSV) of 0.25–0.75 h−1, and at the gas space velocity of 2500 h−1. The studied catalyst Ni–Mo/Al2O3 was found moderately active in the VR cracking process, while it turned out an efficient catalyst for the hydrofining processes. The catalyst concentration and hydrogen pressure had no effect on hydrocracking of VR, and hydrofining of cracking products was affected slightly only over the studied scope of parameters. The reaction temperature and LHSV exerted dramatic effects on hydrocracking of VR and on the asphaltenes and CCR contents, while their effect on hydrofining of cracking products was much lower. The temperature of 430 °C resulted in VR conversion to distillates (b.p.<538 °C) of 61.6–88.7 wt.% and in sulphur conversion of 70–85 wt.%. [Copyright &y& Elsevier]

Relationships of diagnostic parameters characterizing accumulated local damages with the number of thermal cycles have been obtained by experimental studies of development of thermal fatigue cracks in a pipe specimen. [ABSTRACT FROM AUTHOR]

In this first part, the failure of smooth specimens in tension-compression is examined from the viewpoint of fine-crack mechanics, which has some detailed features different from those of traditional crack mechanics. An expression is given for the equivalent J integral for the stress intensity coefficient. Allowance is made for the effects of crack width on the growth rate in elastic and elastoplastic deformation. [ABSTRACT FROM AUTHOR]

In the experiment, the furfural added compound agent was applied to treat catalytic cracking slurry oil in order to utilize the saturated hydrocarbon and condensed-nuclei aromatics reasonably and soundly. The added agent could improve the dissolubility and selectivity of furfural and enhance the recovery and quality of treated oil. The optimum condition was as follows: compound ratio was 0.5:1; the added quantities were 8% relative to furfural volume; the temperature was 50°C; the solvent/oil ratio was 0.5:1. Under the condition, compared with that of furfural extraction, the recovery of treated oil was increased 14.8 wt%, the quality of treated oil also had been improved to some extent, and thus, the treated oil could be used as good stockfeed of catalytic cracking. The extract oil contained abundant condensed-nuclei aromatics, which could be used as good stockfeed to produce a high value-added chemical engineering product. [ABSTRACT FROM AUTHOR]

Heavy oil upgrading is a very important process in the petroleum industry, but is very difficult because it has a high impurity content. A variety of heavy oil upgrading technologies have been developed in the world, including the catalytic hydrocracking process, which can process various heavy oils with a high yield of liquid products. Although this technology is one of the most widely used methods for upgrading heavy oil, the use of expensive molecular hydrogen is costly. The heavy oil upgrading technology with alternative hydrogen is very important. The catalytic hydroconversion of Gudao residue with different catalysts using water-syngas as an alternative hydrogen was investigated in this study. Hydrogen is provided in-situ for hydrocracking through the water-gas shift reaction (WGSR). The experimental results show that catalysts play a very important role in catalytic hydroconversion of Gudao residue using water-syngas as an alternative hydrogen. Addition of catalysts to residue was found to improve the distribution or properties of cracking products and inhibit the asphaltene or TI formation. [ABSTRACT FROM AUTHOR]

Hydrocracking is a very important secondary refining process used to convert low value vacuum gas oils into high value fuels. The chemistry of the hydrocracking process is very complex due to the involvement of high molecular weight complex hydrocarbons in the reactions. Process modeling and simulation of the hydrocracking unit is very challenging due to the complexities of chemistry and the process. In the present work, a mathematical model is described to analyze the performance of the hydrocracking process in terms of product yields. A four lump discrete lumping approach is employed with a hydrocracking reaction scheme involving six reactions. The kinetic constants for the reactions were estimated by minimizing the error between the experimental and predicted yields of kinetic lumps. Experimental data reported by Ali et al. (2002) were used to validate the proposed model. The model predictions were found to agree well with the experimental data. The proposed model can be used to simulate the performance of commercial hydrocrackers using kinetic parameters estimated from pilot plant experiments. [ABSTRACT FROM AUTHOR]

Focuses on the goals in revamping the internals of the main tower of the IA/1M unit. Performance of the process design of the tower, the hydraulic design, and manufacture and delivery of the internals; Version of revamping after modeling operation of the tower; Details of the main process scheme for the tower.

The present investigation deals with the composition and properties of gaseous products of the oxidative cracking process that are applied to fulfill the disposal and utilization of shredded automotive tire scrape and spent lubricating oils mixed at different proportions. Cracking of these mixtures has been performed in an autoclave in an air atmosphere under a pressure of 7 atm, using 0.8 wt% phenols as a catalyst under different conditions of temperatures and time of reaction. The main products of pyrolysis are pyrolytic gases, pyrolytic oils and pyrolytic char. The gases were identified as C 1 , CO 2 , C 2 , C 3 , olefins C 4 , i-C 4 , n-C 4 , olefins C 5 , I-C 5 , n-C 5 , C 6 , and C 7 . Gas chromatography analysis showed that an increase in temperature and time of reaction led to an increase in the light fraction and decreases of the proportion of heavy fraction. The optimum cracking conditions were fulfilled when using oil-rubber ratio 1/0.5, and was, respectively, 0.7 Mpa air pressure, 450°C, and a reaction time of 45 min. The produced gases could be used as a natural gas in heating and as a chemical source based on calorific value and olefins content nature. [ABSTRACT FROM AUTHOR]

Modernization of cat cracker reactor block equipment in the G-43-107M/1 combined unit, which significantly increases the unit’s efficiency and reliability, is described. [ABSTRACT FROM AUTHOR]

Revamping of the catalytic cracking reactor block on the combined G-43-107M/1 unit with introduction of a set of new technological elements and equipment units that significantly increase the efficiency and reliability of operation of the unit and create conditions for its conversion to two-year operation between maintenances is described. [ABSTRACT FROM AUTHOR]

This article focuses on throttling device for deep cracking of heavy petroleum products. To deepen the cracking of crude and heavy petroleum products, they are heated in tube furnaces, and the decomposition products are subsequently held in an external reaction chamber. The possibility of deepening the cracking of petroleum products and destructive processing of polymeric wastes by organizing those conditions for which the heating and thermal decomposition of the products are separated in time and space, while heating of the liquid products will ensure attainment of the boundary of the phase state by the most thermally stable components. This process takes place as a result of heating of the reaction mixture at a temperature and pressure, which are sufficient to throttle the evaporation processes and the reaction in the tube furnace, and which are required to convert the mixture to a state of attainable superheat of the most thermally stable components in the reaction chamber.

The preparation of light alkenes by the gas phase oxidative cracking (GOC) or catalytic oxidative cracking (COC) of model high hydrocarbons (hexane, cyclohexane, isooctane and decane in the GOC process and hexane in the COC process) was investigated in this paper. The selection for the feed in the GOC process was flexible. Excellent conversion of hydrocarbons (over 85%) and high yield of light alkenes (about 50%) were obtained in the GOC of various hydrocarbons including cyclohexane at 750°C. In the GOC process, the utilization ratio of the carbon resources was high; CO dominated the produced COX (the selectivity to CO2 was always below 1%); and the total selectivity to light alkenes and CO was near or over 70%. In the COC of hexane over three typical catalysts (HZSM-5, 10% La2O3/HZSM-5 and 0.25% Li/MgO), the selectivity to COX was hard to decrease and the conversion of hexane and yield of light alkenes could not compete with those in the GOC process. With the addition of H2 in the feed, the selectivity to COX was reduced below 5% over 0.1% Pt/HZSM-5 or 0.1% Pt/MgAl2O4 catalyst. The latter catalyst was superior to the former catalyst due to its perfect performance at high temperature, and with the latter, excellent selectivity to light alkenes (70%) and the conversion of hexane (92%) were achieved at 850°C (a yield of light alkenes of 64%, correspondingly). [ABSTRACT FROM AUTHOR]

A naphtha cut hydrotreating unit with output of 750,000 tons/year was started up in October 2003 at Slavneft'—Yaroslavnefteorgsintez OJSC. The unit was “turnkey” designed and built by Kedr–89 SIC on order of YaRVAZ CJSC — a subsidiary of Slavneft' OGC. [ABSTRACT FROM AUTHOR]

The results of an in-tube inspection of two gas pipelines of a single 110-km section of a multiline pipeline route are analyzed. The manifestations of the corrosive and stress-corrosive forms of damaging in the pipeline section are quantitatively compared. It is shown that for the existing differences between the gas pipelines with respect to the number of corrosive flaws and the nature of their distribution, the data for one of the gas pipelines of the route are insufficiently representative for the other pipelines in order to judge unambiguously the location and the degree of the damage development by the stress-corrosive cracking mechanism or in the result of corrosion. [ABSTRACT FROM AUTHOR]

It has been observed that yields of gasoline and other petroleum fraction in a catalytic cracking process depends significantly upon the reaction temperature besides on other operating conditions. In this work, first the model was developed with the help of literature data with out considering the temperature effect. The important optimum parameters like relative rate constant (K1), rate of coke deactivation or decay constants (Kd), order of reaction (m) etc. over suitable catalysts of cracking process were obtained using suitable numerical analysis techniques. On comparing the error based on the least square criteria, it has been noticed that the results from the first model show about 4% improvement in predicted error against literature results on cracking of normal Heptane [Corma, A., Wojciechowsky, B. W. (1983). Recent work on the fundamentals of catalytic cracking. American Chemical Society Reprints, Div. Chem. 28(3):861–874.] for fifteen data points. In the second step the software was modified to simulate the effect of reaction temperature by using two sets of laboratory data for the reaction of normal Hexadecane over ReY-Zeolite, a commercial cracking catalysts at two different reaction temperatures of 400 and 450°C respectively. Validation of modified software has been checked with the above system at 500°C and found that the predictions are quite close to experimental values. Such analytical model will be useful for finding optimum operating conditions to achieve maximum yields of potential products on cracking of a given feed without resource to conducting large number of experiments. [ABSTRACT FROM AUTHOR]

Type 1A/1M, GK–3, and G–43–107 cat crackers (CC) with pulverized catalysts are important in the oil refining industry. A special feature of these cat crackers is the presence of parts subject to significant abrasive wear at 400–700°C. In the last ten years, CC have been actively revamped with the participation of the leading American firms (in Ryazan' and Yaroslavl') and domestic specialists (in Angarsk, Ufa, Lisichansk, and Turkmenbashi) to improve the process parameters. After revamping, the rate of movement of the catalyst in transport lines and cyclones and consequently the rate of abrasive wear increase, and this must be taken into consideration in designing and manufacturing CC. This article reports the experience of Aliter–Aksi CJSC in manufacturing abrasion–resistant parts obtained since the mid–1980s. [ABSTRACT FROM AUTHOR]

Granulated adsorbents with elevated sorption and separating properties for gas mixtures in a wide temperature range are manufactured with a multifunctional substance — thermal cracking resid. Their sorption capacity and selectivity in sorption of precious metals from multicomponent solutions is higher than the sorption capacity for industrial adsorbents. Crushed adsorbents are superior to industrial granulated adsorbents due to their high mechanical strength and developed porosity, but another energy–intensive production stage is issued for their manufacture. Cracking resid copolymers are radiation–resistant ion exchangers. [ABSTRACT FROM AUTHOR]

The demand for high quality middle distillates is increasing world wide while the demand for residue and fuel oil is decreasing. Hydrocracking is the major conversion process that meets the twin objectives of producing more middle distillates of very high quality. Since hydrocracking is a capital-intensive process, many refiners consider the option of converting their existing vacuum gas oil hydrotreating units into mild hydrocracking units. The use of mild hydrocracker bottom as FCC feedstock can improve the quality of FCC products. In view of the advantages of mild hydrocracking process, it is essential to understand the process, catalysts used, reactions, kinetics, and advantages. This article reviews recent literature on MHC process, various catalysts used, reactions involved and advantages of mild hydrocracking process in terms of improved product qualities and increased distillates. The kinetics of the mild hydrocracking process and kinetic challenges with respect to aromatic saturation have been summarized. The limitations of the process and future scope of work in this area are also discussed briefly. [ABSTRACT FROM AUTHOR]

Revamping of the 1A/1M cat cracker with introduction of new technologies and equipment units is described: feedstock and sludge nozzles, single–stage reactor cyclones, two–stage catalyst stripping, air– and steam–distributing devices, and two–stage regenerator cyclones. The output of the unit increased by 40%, and the yield and octane characteristics of the naphtha cut increased as a result, and grounds were created for converting the unit to a two–year operating cycle between repairs. [ABSTRACT FROM AUTHOR]

Heavy feed cracking is certain to play an increasingly important role in oil refining. Against this backdrop, this work aims to gain some understanding of how thermolysis affects the manner in which a heavy Arabian vacuum resid droplet vaporizes in fluid catalytic cracking (FCC). Specifically, we study the vaporization history of the droplet under two limiting conditions that bracket the actual vaporization process. One is a high-temperature environment in which the catalyst heats up only the resid droplet. Another is a low-temperature environment in which the catalyst vaporizes a gas oil before heating the resid droplet. Key findings are as follows: (1) Droplet life can go through one, two, or three stages, depending on the drop size and environment. A large droplet in the high-temperature environment goes through the heat-up, thermolysis and evaporation stages. A small droplet at low temperatures goes through only the heat-up stage. (2) The effect of thermolysis increases with temperature and the initial drop size. (3) Thermolysis can significantly lower the drop’s steady-state temperature—the larger the drop, the greater the effect and, hence, the longer the drop lifetime and (4). During the evaporation stage, the drop’s surface area decrease can be approximated by the classical D2-law. [Copyright &y& Elsevier]