FCC Products Research Articles

Refining of chlorine-containing plastic wastes by traditional hydrotreating and catalytic cracking processes

The present report is devoted to refining of thermolysis oil (TO), which was obtained from the mixture of different plastics and contained 2.24% of chlorine. The process of refining of thermolysis oil includes combination of hydrotreating of TO (80%) and SR VGO (20%) mixture with NiMo supported catalysts. The following process includes FCC treatment of the obtained hydrotreating products. All used conditions were typical for industrial FCC process of SR VGO with its preliminary hydrotreating. The influence of hydrotreating catalyst type and hydrotreating temperature on the composition and properties of hydrotreating products was studied. Moreover, the effect of these parameters on the composition and yields of FCC products was established. The main reasons of hydrotreating catalysts deactivation during refining of Cl containing thermolysis oil were investigated by XPS, HAADF, HCNS-analysis. It was revealed that the best hydrotreating temperature was 360 °C, while the best used catalyst was NiMoP/Al2O3.

Volatile organic compounds released in the mainstream smoke of flavor capsule cigarettes

In this study, the composition of mainstream smoke was investigated with an emphasis on a list of volatile organic compounds (VOCs: e.g., isoprene, acrylonitrile, methyl ethyl ketone, benzene, toluene, m-xylene and styrene) using the two types of flavor capsule cigarettes (FCCs, here coded as F1 and F2) in reference to one commercial, non-flavored (NF) and 3R4F cigarette. The concentrations of all the target compounds from FCCs were quantified under two contrasting conditions (i.e., with and without breaking the capsules). The effect of breaking the capsule was apparent in the FCC products with the enhancement of VOC levels, specifically between after and before breaking the capsules (e.g., 1.10–1.58 folds (benzene) and 1.30–1.53 folds (acetonitrile)). Such increases were apparent in both FCC samples if assessed in terms of the total amount of VOCs (TVOC): (1) F1 (from 2159 to 2530 μg cig−1 (p = 9.42 × 10−6)) and (2) F2 (from 1470 to 2014 μg cig−1 (p = 0.05)). In addition, these TVOC levels determined from the FCCs were 1.62- to 1.83- and 1.29- to 1.46-fold higher than those of the NF cigarette and the 3R4F cigarette, respectively. Thus, these FCC products are suspected to play a role as stronger sources of VOCs than the general cigarette products.

Five-Lump Kinetic Model for the Catalytic Cracking Process\

The main objectives of the present paper are to adaptation the five-kinetic model of the catalytic cracking process and simulation the riser to predicts the FCC products yields when one of the major input variable of the process is change. The simulation and adaptation are based on the industrial data from Romanian refinery. The adaptation is realize using a computational method from Optimization Toolbox from Matlab programming language. The new model can be used for optimization and control of FCC riser.

Effects of gamma irradiation on microbial safety and quality of stir fry chicken dices with hot chili during storage

The purpose of this study was to investigate effects of irradiation with different doses on microbial safety, sensory quality and protein content of ready-to-eat stir fry chicken dices with hot chili (FCC) during one year storage. Fresh chicken meat was cut into small dices and fried at approximately 180°C for 10min for preparation of FCC samples. The samples were vacuum-packaged and gamma irradiated at 10, 20, 30 and 40kGy. The results suggest that irradiation with the doses of 10 and 20 kGy could ensure microbiological safety of the samples without deterioration of sensory quality. Microbial counts, sensory qualities and protein contents of the samples were investigated during one year storage. No viable cells were observed and the samples were completely sterilized. Sensory qualities showed no significant difference after irradiated at the doses of 10 and 20kGy during the storage period. Protein contents were also not affected by irradiation at the same doses. Our results indicate that gamma irradiation of 10 and 20kGy are effective to maintain shelf stability of ready-to-eat FCC products with microbial safety, sensory quality and nutritional value.

Coke chemistry under vacuum gasoil/bio-oil FCC co-processing conditions

This study presents an in depth investigation of the coke chemistry occurring in FCC and USY catalysts during co-processing of fossil feeds (VGO type) blended with various types of upgraded bio-oils produced by fast pyrolysis of lignocellulosic bio-mass. It includes a brief survey of previous studies devoted to the effect of co-processing on FCC products yield and quality. A combination of two main processes is proposed to account for the marked increase in coke formation in the presence of oxygenated molecules in the reacting feed: (i) the conventional cracking route for the VGO fossil hydrocarbons leading to essentially graphitic coke deposited preferentially in the USY zeolite micropores, and (ii) the conversion of lignin fragments into hydrocarbons, residual light oxygenates (essentially phenolic type) and finally “bio-coke” which accumulates in mesopores as less structured coke as compared to the harder coke issued from hydrocarbons condensation. These two routes which are monitored by the catalysts structure, texture and acidity are strongly interacting via hydrogen transfer between light hydrocarbons and phenolic type fragments. A tentative mechanistic scheme is proposed.

Advanced Reaction-Terminating Technique for FCC Riser Reactor

Numerical simulation of the performance of a commercial FCC riser reactor was carried out by using a three-dimensional gas-particle, two-phase, turbulent flow-reaction model. Results showed that overcracking of desired products, such as diesel or light fuel oil, occurs and the optimum yields of desirable FCC products could be achieved at a critical riser height of less than 20 m above the feed inlet. This suggests that injection of quenching media above the critical riser height can be an effective option for optimizing the yields of desirable products. The reaction-terminating technique conducted in a commercial FCC riser reactor, using light waste oil, straight-run gasoline, and desalted water as quenching media produced favorable results. Light fuel oil yields increased by 1.3 wt% and 0.95 wt% for using the first two quenching media. Liquefied cracking gas yields increased by 0.43 wt% and 1.03 wt%, whereas the yields of dry gas and coke decreased slightly. Desalted water produced better results than either light waste oil or straight-run gasoline. The improvements of gasoline and liquefied gas yields using desalted water are 0.95% and 0.49% more than those of using straight-run gasoline, respectively.

Mild Hydrocracking—A Review of the Process, Catalysts, Reactions, Kinetics, and Advantages

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.

Effect of metals poisoning on FCC products yields: studies in an FCC short contact time pilot plant unit

In this work the effects of two metal poisons (Ni, V) on FCC products were investigated in an FCC pilot plant. The most important effects of metals were found on the gasoline, coke and H 2 yields. A comparison study of the metal distribution in the catalyst particles aged in the FCC pilot plant, a CDU and an industrial FCCU was also performed using a SEM–EDS method. SEM results showed that the metal profiles from CDU samples simulate more satisfactorily the profiles of the E-cat than that from the FCC pilot plant.

Future directions in modeling the FCC process: An emphasis on product quality

A new generation FCC process model has been developed that describes fundamental cracking chemistry of FCC feedstocks using over 3000 molecular species. FCC reaction chemistry is specified using the methods of structure-oriented-lumping (SOL) with over 60 reaction rules. Application of these rules results in a complex network of over 30,000 elementary chemical reactions. Both monomolecular reactions such as cracking, isomerization, and cyclization and bimolecular reactions such as hydrogen transfer, coking, and disproportionation are included. The effects of thermal cracking and metals-catalyzed dehydrogenation are also represented. Reactivity relationships have been developed to reduce the number of parameters required to specify the kinetic model. The kinetic parameters are regressed from data spanning a wide range of FCC process conditions, feed compositions, and catalyst formulations. The riser kinetic model is coupled with equipment models for key FCC components to form an integrated FCC process model. The model accurately predicts product yields, product composition, and product quality over a wide range of FCC process conditions and is capable of predicting the complex non-linear phenomena exhibited in commercial FCC operations such as steady-state multiplicity. The model can be used to predict the quality of FCC products made from different crudes as well as to scope novel processing schemes for improving FCC product quality.

Advanced model for turbulent gas–solid flow and reaction in FCC riser reactors

AbstractA 3‐D two‐phase flow‐reaction model was developed for predicting the performance of FCC riser reactors. This model combines two‐phase turbulent flow with 13‐lump reaction kinetics. The simulated results show that the gas–particulate turbulent reacting flow regime in the riser reactor is extremely complex, especially at the feed inlet zone of the riser reactor. The distributions of velocities, temperature, and yields are not homogeneous in the riser reactor. The model predictions were used as a design tool for operational case studies. The optimum yields of desirable FCC products, gasoline and light fuel oil were achieved at a critical riser height that is less than 10 m above the feed inlet. Beyond the critical riser height, excessive cracking reactions resulted in the increased yields of by‐products, cracking gas and coke, at the expense of desirable products. Model simulations carried out to determine the parametric effects on product yields suggest that injection of water as a reaction‐terminating medium above the critical riser height can be an effective option for optimizing the yields of desirable products.

Synthetic Or Reformulated Fuels: a Challenge for Catalysis

Despite comparative figures for wordwide crude oil and natural gas proven reserves, present time contribution of syngas chemistry to motorfuels remains marginal when the refining industry is faced to main constraints: market demand evolution, stringent specifications and environmental issues. Actually natural gas upgrading via syngas chemistry yields key products (e. g. methanol) among which clean motorfuels (ethers, FT products) should develop despite the huge investments required, mostly for syngas production. Main challenges and corresponding issues for catalysts and related technologies are identified for Fischer-Tropsch synthesis and motorfuels long-term reformulation. Among other, mastering the chain-growth (FT synthesis) improving the FCC products: gasoline, and LCO for Diesel pool. All these issues need significant progresses in catalyst and technology to be solved. Lastly, our economical study, focused on Diesel-fuel production, shows up that clean diesel (from SR-LCO mixtures) and FT Diesel reach similar production costs when cheap NG is available. In the future, FT middle distillates should amount to a few percent (5-150 Mt) of the 1700-2000 Mt of transport middle distillates expected from oil refining. However they should more and more be a compulsory part of diesel pool if the level of investment for an FT process continues to decrease significantly.

FCC and BCC Solidification Products in a Rapidly Solidified Austenitic Steel.

ABSTRACTThe microstructures and local composition variations in centrifugally atomized high-sulfur stainless steel powder are investigated. Both fcc and bcc are found to be primary solidification phases in the as-solidified powder of this nominally austenitic steel where the smaller powder particles (≲ 70 micron diameter) tend to be bcc.Cellular solidification structures, with sulfide precipitates (100 to 200 nm diameter in size) at the cell walls, are observed in both fcc and bcc particles. The bcc structure, however, has many small sulfide precipitates (10 to 20 nm diameter) in the cell interior with few larger sulfide precipitates at the cell walls. The small precipitates, observed only in the bcc structures, form on cooling from a supersaturated solid solution that results from reduced solute partitioning during solidification. Partitioning of chromium and nickel is minimal in these cellular structures. A non-cellular bcc structure is also observed with small sulfide precipitates throughoutthe entire structure. This non-cellular bcc structure results from smooth-front massive solidification. Analysis of the nucleation process for solidification indicates that a transition from fcc nucleation to bcc nucleation occurs with increasing wetting angle in heterogeneous nucleation. Thus bcc should nucleate in the smaller droplets of a liquid dispersion where catalytic surfaces of low potentcy (large wetting angle) tend to be the only heterogeneous nucleants available.