Artykuły w czasopismach: „Fluidized Catalytic Cracker Units”

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WHITCOMBE, J. M., I. E. AGRANOVSKI, R. D. BRADDOCK, F. GANDOLA i A. P. HAMMOND. "CATALYST FRACTURE DUE TO THERMAL SHOCK IN FLUIDIZED CATALYTIC CRACKER UNITS". Chemical Engineering Communications 191, nr 11 (listopad 2004): 1401–16. http://dx.doi.org/10.1080/00986440490464165.

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Agranovski, I. E., J. M. Whitcombe i M. Swiericzuk. "STUDY OF EMISSION RATE FROM FLUIDIZED CATALYTIC CRACKER UNITS DURING START UP SITUATIONS". Journal of Aerosol Science 32 (wrzesień 2001): 625–26. http://dx.doi.org/10.1016/s0021-8502(21)00285-8.

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Souza, J. A., J. V. C. Vargas, O. F. Von Meien i W. P. Martignoni. "MODELING AND SIMULATION OF INDUSTRIAL FCC RISERS". Revista de Engenharia Térmica 6, nr 1 (30.06.2007): 19. http://dx.doi.org/10.5380/reterm.v6i1.61812.

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Risers are considered vital parts in Fluidized Catalytic Cracking (FCC) conversion units. It is inside the riser reactor that the heavy hydrocarbon molecules are cracked into lighter petroleum fractions such as liquified Petroleum gas (LPG) and gasoline. The FCC process is considered a key process in the world petroleum industry, since it is the main responsible for the profitable conversion of heavy gasoil into commercial valuable products. This work presents a simplified transient model to predict the response of a FCC riser reactor, i.e., the fluid flow, temperature and concentrations of the mixture components throughout the riser and at the exit. A bi-dimensional fluid flow field combined with a 6 lumps kinetic model and two energy equations are used to model the gasoil mixture flow and the cracking process inside the riser reactor. The numerical results are in good agreement with experimental data, as a result, the model can be utilized for design, and optimization of FCC units. The simulation herein presented shows the applicability of the proposed method for the numerical simulation and control of industrial riser’s units.

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Pereira, A. H. A., D. Y. Miyaji, M. D. Cabrelon, J. Medeiros i J. A. Rodrigues. "A study about the contribution of the α-β phase transition of quartz to thermal cycle damage of a refractory used in fluidized catalytic cracking units". Cerâmica 60, nr 355 (wrzesień 2014): 449–56. http://dx.doi.org/10.1590/s0366-69132014000300019.

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The deterioration of refractories used in fluidized catalytic cracking units (FCC-units) is responsible for high costs of maintenance for the petrochemical industry. This is commonly associated with coke deposition during the production of light hydrocarbons. However, other mechanisms responsible for causing damage may also occur, such as the generation of cracks by expansive phase transition. The aim of the work herein was to study the contribution of the a-b phase transition of quartz particles to the deterioration of a commercial aluminosilicate refractory used in a riser by the means of slow thermal cycles. Such damage may occur if the working temperature of the equipment fluctuates around the a-b transition temperature (573 °C). The current study considered the material with and without coke impregnation to evaluate the combined effect of coke presence and phase transition. To evaluate the damage, it was used the Young's modulus as a function of temperature by applying the Impulse Excitation Technique under controlled atmosphere. An equipment recently developed by the authors research group was applied. Specimens were prepared and submitted to slow thermal cycles of temperatures up to 500 °C and up to 700 °C, with a heating rate of 2 °C/min. Part of the specimens was previously impregnated with coke by a reactor using propen. To complete the evaluation, characterization by X-ray diffraction, as well as by dilatometry and scanning electron microscopy were performed. The findings of this study showed that the presence of quartz particles determine the thermo-mechanical behaviour of the material, as well as the thermocycling damage resistance. In spite of the fact that the a-b phase transition stiffens the material during the heating stage, it increases the damage by slow thermal cycling. The coke impregnation increases the resistance to slow thermal cycles, however it decreases the resistance to the damage evolution.

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Palazoglu, Ahmet, i Tanes Khambanonda. "Dynamic operability analysis of a fluidized catalytic cracker". AIChE Journal 33, nr 6 (czerwiec 1987): 1037–40. http://dx.doi.org/10.1002/aic.690330618.

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Cooper, D. A., i A. Emanuelsson. "Nitrogen oxide (N2O) emissions from a fluidized-bed catalytic cracker". Energy & Fuels 6, nr 2 (marzec 1992): 172–75. http://dx.doi.org/10.1021/ef00032a009.

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Boum, Alexandre, Jean Pierre Corriou i Abderrazak Latifi. "Comparison of model predictive control strategies for a fluidized catalytic cracker". International Journal of Engineering & Technology 6, nr 4 (28.11.2017): 181. http://dx.doi.org/10.14419/ijet.v6i4.7641.

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A FCC model is used to compare five different Model Predictive Control (MPC) strategies. The FCC process is a complex petrochemical unit with catalyst recycling that makes its behaviour highly nonlinear. The FCC comprises a riser, a separator and a regenerator with important heat coupling due to the endothermic cracking reactions of gas oil in the riser and the exothermic combustion reactions in the regenerator. The riser and the regenerator exhibit fast and slow dynamics respectively. The temperatures at riser top and in the regenerator should be controlled by manipulation of catalyst and air flow rates. All these nonlinear and coupled characteristics render the multivariable control problem difficult and thus the FCC process constitutes a valuable benchmark for comparing control strategies. Here, the performances of Dynamic Matrix Control, Quadratic Dynamic Matrix Control, MPC control with penalty on the outputs, NonLinear MPC control, Observer Based MPC control are compared.

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Sarma, Pramit, i Raghunathan Rengaswamy. "Multivariable gain-scheduled fuzzy logic control of a fluidized catalytic cracker unit". Computers & Chemical Engineering 24, nr 2-7 (lipiec 2000): 1083–89. http://dx.doi.org/10.1016/s0098-1354(00)00487-7.

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Rajeev, N., R. Krishna Prasad i U. B. Reddy Ragula. "Process Simulation and Modeling of Fluidized Catalytic Cracker Performance in Crude Refinery". Petroleum Science and Technology 33, nr 1 (8.12.2014): 110–17. http://dx.doi.org/10.1080/10916466.2014.953684.

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Souza, J. A., J. V. C. Vargas, J. C. Ordonez, W. P. Martignoni i O. F. von Meien. "Thermodynamic optimization of fluidized catalytic cracking (FCC) units". International Journal of Heat and Mass Transfer 54, nr 5-6 (luty 2011): 1187–97. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2010.10.034.

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Hall, William J., Norbert Miskolczi, Jude Onwudili i Paul T. Williams. "Thermal Processing of Toxic Flame-Retarded Polymers Using a Waste Fluidized Catalytic Cracker (FCC) Catalyst". Energy & Fuels 22, nr 3 (maj 2008): 1691–97. http://dx.doi.org/10.1021/ef800043g.

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Chen, Xinhe, Kai Wu, Andrew Bai, Cornelius M. Masuku, Jacques Niederberger, Fábio S. Liporace i Lorenz T. Biegler. "Real-time refinery optimization with reduced-order fluidized catalytic cracker model and surrogate-based trust region filter method". Computers & Chemical Engineering 153 (październik 2021): 107455. http://dx.doi.org/10.1016/j.compchemeng.2021.107455.

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de Lasa, Hugo. "The CREC Fluidized Riser Simulator a Unique Tool for Catalytic Process Development". Catalysts 12, nr 8 (12.08.2022): 888. http://dx.doi.org/10.3390/catal12080888.

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The CREC Riser Simulator is a mini-fluidized bench scale unit invented and implemented in 1992, at the CREC (Chemical Reactor Engineering Centre), University of Western Ontario The CREC Riser Simulator can be operated at short reaction times, in the 3 s to 20 s range. The present review describes and evaluates the original basic concept of the 1992-CREC Riser Simulator Unit, and the improved design of the 2019-CREC Riser Simulator. Both the initial and the enhanced units are specially engineered to allow the rigorous assessment of both catalyst performance and catalytic reaction kinetics. Kinetic parameters of relatively simple and accurate mathematical models can be calculated using experimental data from the CREC Riser Simulator. Since its inception in 1992, the CREC Riser Simulator has been licensed to and manufactured for a significant number of universities and companies around the world. Several examples of scenarios where the CREC Riser Simulator can be employed to develop fluidized bed catalytic and heterogeneous reactor simulations are reported in this review. Among others, they include (a) hydrocarbon catalytic cracking, (b) the catalytic conversion of tar derived biomass chemical species, (c) steam and dry catalytic methane reforming, (d) the catalytic oxydehydrogenation of light paraffins, (e) the catalytic desulfurization of gasoline, and (f) biomass derived syngas combustion via chemical looping. In this review, special emphasis is given to the application of the CREC Riser Simulator to TIPB (tri-iso-propyl-benzene) catalytic cracking and the light paraffins catalytic oxydehydrogenation (PODH).

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Lombardo, Gerard, Berit F. Fostås, Muhammad Ismail Shah, Anne Kolstad Morken, Odd Arne Hvidsten, Jan Mertens i Espen Steinseth Hamborg. "Results from Aerosol Measurement in Amine Plant Treating Gas Turbine and Residue Fluidized Catalytic Cracker Flue Gases at the CO2 Technology Centre Mongstad". Energy Procedia 114 (lipiec 2017): 1210–30. http://dx.doi.org/10.1016/j.egypro.2017.03.1377.

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Nafees, Tabassam, Adnan Ahmed Bhatti, Usman Khan Jadoon, Farooq Ahmad, Iftikhar Ahmad, Manabu Kano, Brenno Castrillon Menezes, Muhammad Ahsan i Naveed ul Hasan Syed. "Model-Based Quality, Exergy, and Economic Analysis of Fluidized Bed Membrane Reactors". Membranes 11, nr 10 (3.10.2021): 765. http://dx.doi.org/10.3390/membranes11100765.

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In petroleum refineries, naphtha reforming units produce reformate streams and as a by-product, hydrogen (H2). Naphtha reforming units traditionally deployed are designed as packed bed reactors (PBR). However, they are restrained by a high-pressure drop, diffusion limitations in the catalyst, and radial and axial gradients of temperature and concentration. A new design using the fluidized bed reactor (FBR) surpasses the issues of the PBR, whereby the incorporation of the membrane can improve the yield of products by selectively removing hydrogen from the reaction side. In this work, a sequential modular simulation (SMS) approach is adopted to simulate the hydrodynamics of a fluidized bed membrane reactor (FBMR) for catalytic reforming of naphtha in Aspen Plus. The reformer reactor is divided into five sections of plug flow reactors and a continuous stirrer tank reactor with the membrane module to simulate the overall FBMR. Similarly, a fluidized bed reactor (FBR), without membrane permeation phenomenon, is also modelled in the Aspen Plus environment for a comparative study with FBMR. In FBMR, the continuous elimination of permeated hydrogen enhanced the production of aromatics compound in the reformate stream. Moreover, the exergy and economic analyses were carried out for both FBR and FBMR.

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Chaparala, Sree Vidya, Abhijeet Raj i Suk Ho Chung. "Reaction Mechanism for the Formation of Nitrogen Oxides (NOx) During Coke Oxidation in Fluidized Catalytic Cracking Units". Combustion Science and Technology 187, nr 11 (11.06.2015): 1683–704. http://dx.doi.org/10.1080/00102202.2015.1059328.

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Alkhlel, Abdualkaber, i Hugo de Lasa. "Catalyst/Feedstock Ratio Effect on FCC Using Different Catalysts Samples". Catalysts 9, nr 6 (17.06.2019): 542. http://dx.doi.org/10.3390/catal9060542.

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The present study is a follow-up to a recent authors contribution which describes the effect of the C/O (catalyst/oil) ratio on catalytic cracking activity and catalyst deactivation. This study, while valuable, was limited to one fluidized catalytic cracking (FCC) catalyst. The aim of the present study is to consider the C/O effect using three FCC catalysts with different activities and acidities. Catalysts were characterized in terms of crystallinity, total acidity, specific surface Area (SSA), temperature programmed ammonia desorption (NH3-TPD), and pyridine chemisorption. 1,3,5-TIPB (1,3,5-tri-isopropyl benzene) catalytic cracking runs were carried out in a bench-scale mini-fluidized batch unit CREC (chemical reactor engineering centre) riser simulator. All data were taken at 550 °C with a contact time of 7 s. Every experiment involved 0.2 g of 1,3,5-TIPB with the amount of catalyst changing in the 0.12–1 g range. The resulting 0.6–5 g oil/g cat ratios showed a consistent 1,3,5-TIPB conversion increasing first, then stabilizing, and finally decreasing modestly. On the other hand, coke formation and undesirable benzene selectivity always rose. Thus, the reported results show that catalyst density affects both catalyst coking and deactivation, displaying an optimum C/O ratio, achieving maximum hydrocarbon conversions in FCC units.

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Aqar, Dhia Yasser. "A Study of the Dynamics and Control of the Model IV Fluidized Catalytic Cracking Process". Journal of Petroleum Research and Studies 5, nr 1 (1.06.2014): 1–26. http://dx.doi.org/10.52716/jprs.v5i1.103.

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Fluid catalytic cracking (FCC) is one of the most important chemical units in oil refineries due to its economic benefits. This research work concentrates on improving the control system of the Model IV FCC unit where dynamic modeling and the controllability based on the McFarlane et al. (1993) model. Different open-loop tests were carried out in the wash oil flow rate (F1) and the furnace fuel flow rate (F5) to find the FCC models using Sundaresan and Krishnaswamy (S&K) and fraction incomplete response (FIR) methods. The riser temperature (Tr) and the regenerator bed temperature (Tg) were chosen as the control variables while (F1 and F5) were selected as the corresponding manipulated variables based on the relative gain array (RGA). PI controller tuning parameters were evaluated using the internal model control (IMC) method and different closed-loop control responses were examined for both set point tracking and disturbance rejection changes. Additional adjustments to the IMC filter constant were employed to further improve the closed loop responses for the system.

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Shnaider, G. S. "Evaluation of the hydrodynamic conditions in multistaged fluidized countercurrent flow reactors in pilot and semicommercial catalytic Cracking units". Chemical Engineering Journal 38, nr 2 (czerwiec 1988): 97–109. http://dx.doi.org/10.1016/0300-9467(88)80066-2.

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Feuston, Maureen H., Stacy L. Kerstetter, Edward J. Singer i Myron A. Mehlman. "Developmental Toxicity of Clarified Slurry Oil Applied Dermally to Rats". Toxicology and Industrial Health 5, nr 3 (lipiec 1989): 587–99. http://dx.doi.org/10.1177/074823378900500313.

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Clarified Slurry Oil (CSO), the heavy residual fraction from the fluidized catalytic cracker, was applied to the shaven backs of groups of 10 pregnant rats at doses of 0, 4, 8, 30, 125, and 250 mg/kg I day. All groups received the test material on gestation days 0–19. CSO was applied undiluted and left uncovered on the skin; collars were placed on the rats to minimize ingestion of the test material. Signs of maternal toxicity, some of which were seen at dose levels as low as 8 mg/kg/day, included vaginal bleeding, decreased body weight gain, reduced food consumption, death, increased relative liver weights, atrophy of the thymus, and aberrant serum chemistry. The number of fetal resorptions / deaths was markedly increased and the number of viable offspring decreased by CSO at dosages of 30 mg/kg/day and above. The group receiving 250 mg/kg/day carried no viable offspring. Fetuses from pregnant females exposed to CSO at dose levels in excess of 8 mg/kg/day were smaller than those from control and 4 mg/kg/day groups, and their skeletons showed decreased ossification. Abnormal external development and visceral development were observed in living and dead fetuses exposed in utero to CSO at dose levels as low as 8 mg/kg/day. Based on these data, 4 mg/kg/day represents the No-Observed-Adverse-Effect-Level for both maternal and developmental toxicity.

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Singh, Madhu, Akshay Gharpure, Randy L. Vander Wal, James Kollar i Charles R. Herd. "Effect of Fuel Composition on Carbon Black Formation Pathways". Applied Sciences 12, nr 5 (1.03.2022): 2569. http://dx.doi.org/10.3390/app12052569.

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Differences in lamellae length, stacking, and particularly a difference in the core-to-shell radial structure are observed for carbon blacks produced using different feedstocks. Carbon black (CB) produced using a coal tar (CT) feedstock formed particles with amorphous cores exhibiting a sharp transition to extended lamellae oriented about the periphery of the particle. In contrast, the carbon black produced from fluidized catalytic cracker (FCC) decant oil as feedstock formed particles with a single nucleated core possess a rather uniform radial transition—reflecting the presence of ordered, concentric lamellae across most of the particle radius. Minimal disorder was observed in the core while the undulations in perimeter lamellae were fewer. Our interpretation for these structural dissimilarities is premised on differences in fuel composition, specifically component classes as found by saturate, aromatic, resin, asphaltene (SARA) analysis. These in turn lead to variation in the relative rates of particle nucleation and particle growth by pyrolysis products, moderated by temperature. Electron energy loss spectroscopy reveals radial variation in the sp2 content between the different feedstocks consistent with observed nanostructures. Collectively these results are interpreted in terms of an offset in nucleation and growth—dependent upon the relative contributions of feedstock aromatic content and pyrolysis processes to particle nucleation and growth. To further test the postulate of different formation conditions for the two carbon blacks pulsed laser annealing was applied. The high temperature heating accentuated the dissimilarities in nanostructure and chemistry—leading to stark dissimilarities. These differences were also manifested by comparing oxidative reactivity.

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Cunha, A. L. C., J. P. Gonçalves i J. Dweck. "Evaluating the Pozzolanic Activity of Spent Catalyst Partially Substituting Type II Portland Cement". Key Engineering Materials 634 (grudzień 2014): 131–38. http://dx.doi.org/10.4028/www.scientific.net/kem.634.131.

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The catalyst discarded from fluidized catalytic cracking (FCC) units of heavy oil fractions presents in its composition typically high concentrations of silica and alumina, which give to it the possibility to be used as a pozzolanic material. The pozzolanic activity of a spent FCC catalyst from a Brazilian refinery oil was evaluated by studying the influence of the substitution in different degrees of a type II cement, by this catalytic residue on the hydration process and on the compressive strength of the formed materials. The influence of different particle size fractions of the residue and of its milling process was studied as well. The pozzolanic activity was evaluated by thermogravimetry (TG), derivative thermogravimetry (DTG) and non-conventional differential-thermal analysis (NCDTA). The results show that the chemical pozzolanic activity is enhanced when the sample presents a higher specific surface, as well as, the milling of the residue it is fundamental in order to be accepted and used as a pozzolanic material on partial substitution to cement.

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Kim, Sung, Chae Yeo i Do Lee. "Effect of Fines Content on Fluidity of FCC Catalysts for Stable Operation of Fluid Catalytic Cracking Unit". Energies 12, nr 2 (18.01.2019): 293. http://dx.doi.org/10.3390/en12020293.

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Effect of fines content (weight % of particles with diameter less than 45 μm) on bed fluidity was determined to get a base for good fluidization quality in the fluid catalytic cracking (FCC) unit. The fines content in equilibrium FCC catalysts (Ecat) from commercial units were controlled by adding or removing the fines to simulate commercial situation. To get the fluidity values (Umb/Umf) of seven different FCC catalysts (2 Ecats and 5 fresh catalysts) and their mixture, minimum fluidization velocity (Umf) and minimum bubbling velocity (Umb) were measured in a fluidized bed reactor (0.05 m ID). The fluidity decreased with loss of fines content and increased with increments of makeup of fresh catalysts or additive with the controlled fines content. The fluidities of catalysts increase with increases of normalized particle diameter variation by the fines addition. The obtained fluidities have been correlated with the fines contents and the catalyst and gas properties. The proposed correlation could guide to keep good catalyst fluidity in the FCC unit.

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Hoberman, A. M., M. S. Christian, R. Roth, S. Lovre i F. Koschier. "Reproductive Toxicity Study of Clarified Slurry Oil in the Rat". Journal of the American College of Toxicology 14, nr 2 (kwiecień 1995): 119–28. http://dx.doi.org/10.3109/10915819509008686.

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Clarified slurry oil (CSO, CAS #64741–62-4; also termed carbon black oil), a residual product from the fluidized catalytic cracker in petroleum refining, has the potential to be absorbed through the skin. The reproductive toxicity of CSO in male and female rats was evaluated by the topical route of exposure. CSO was administered dermally to male rats at dosages of 0 (vehicle), 0.1, 1, 10, 50, and 250 mg/kg/day for 70 days before a cohabitation period with untreated female rats. CSO was administered also to female rats at the same dosages for 14 days prior to a 7-day cohabitation period and continuing until Day 0 of gestation (day spermatozoa was present in a smear of the vaginal contents or a copulatory plug was observed in situ). The dosage volume in both experiments was 1 ml/kg, adjusted on each day of dosage based on individual body weights recorded immediately before application of CSO. Under the conditions of these experiments, the paternal no-observable-adverse-effect-level (NOAEL) for CSO administered dermally was 1 mg/kg/day. The 10, 50, and 250 mg/kg/day dosages of CSO caused body weight losses and/or decreased body weight gains and reduced feed consumption. The 50- and 250-mg/kg/day dosages also caused adverse clinical effects. No mating, fertility, or testicular end points in male rats were affected by the highest dosages tested; therefore, the reproductive NOAEL for male rats is <250 mg/kg/day. The maternal NOAEL for CSO administered dermally was 10 mg/kg/day. The 50-and 250-mg/kg/day dosages of CSO reduced body weight gains; 250 mg/kg/day also reduced feed consumption. There were no adverse effects on gonadal function, estrous cycles, mating behavior, conception rates, or reproductive organ weights; therefore, the reproductive NOAEL for female rats administered CSO dermally is at least 250 mg/kg/day.

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Cruzan, George, Lawrence K. Low, George E. Cox, J. Ralph Meeks, Carl R. Mackerer, Peter H. Craig, Edward J. Singer i Myron A. Mehlman. "Systemic Toxicity From Subchronic Dermal Exposure, Chemical Characterization, and Dermal Penetration of Catalytically Cracked Clarified Slurry Oil". Toxicology and Industrial Health 2, nr 4 (październik 1986): 429–44. http://dx.doi.org/10.1177/074823378600200406.

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Clarified slurry oil (CSO), the heavy residual fraction from the fluidized catalytic cracker, was applied to the shaven backs of groups of 10 male and 10 female Sprague-Dawley rats 5 days/week for 13 weeks at doses of 8, 30, 125, or 500 mglkglday, and to another group for 2 weeks at doses of 2000 mg/kg/day. The rats were fitted with cardboard Elizabethan collars to minimize the ingestion of the test material, which was applied undiluted and remained uncovered on the skin. A similar group of rats served as controls; they were treated in the same manner except that no CSO was applied to their skin. There was a dose-related mortality and depression of body weight gain in the rats treated with CSO at doses of 30 mg/kg/day or greater; none of the rats dosed at 2000 mg/kg/day survived more than 2 weeks. The primary target organs ofCSO toxicity were the liver, thymus, and bone marrow. The effects on the liver included increased weight (250% at 500 mg/kg/day), cholangiolitis, diffuse liver cell degeneration and hypertrophy, necrosis, fibrosis, decreased serum glucose, increased levels of alkaline phosphatase, aspartate aminotransferase, alanine amino transferase, bilirubin, and triglycerides. The thymus was found to be small and upon microscopic examination to be atrophic or hypoplastic. Erythroid hypo plasia was found in the bone marrow of some of the rats dosed at 30 mg/ kg/day and increased in severity with increasing dose. The erythroid hypoplasia was accompanied by a dose-related anemia. Even in the rats dosed at 8 mg/kg/day, very slight abnormalities in the bile ducts were observed upon microscopic examination of the liver. Chromato-graphic separation and analyses demonstrated that CSO contains about 58% 3- to 5-ring polycyclic aromatic hydrocarbons (PAHS) and ap proximately 8-10% carbazole derivatives. In vitro and in vivo skin penetration studies demonstrated that the carbazole materials penetrate through the skin to a considerable extent (about 44 %) ; less penetration was observed with 2- or 3-ring (8-13%) or 5-ring PAHs (3%).

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Valadares, de, Guimarães Bachmann, Rafael Vieira, Araújo de, de Jerônimo, Carlos Yamamoto, de Ulson i Arruda de. "Regeneration study of ecat-R as adsorbent for denitrogenation and desulfurization of diesel fuels". Chemical Industry and Chemical Engineering Quarterly 26, nr 3 (2020): 277–85. http://dx.doi.org/10.2298/ciceq190322005v.

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The purpose of this paper is to present the third stage of regeneration for ecat: deactivated or equilibrium catalysts which are waste from fluidized catalytic cracking (FCC) units. This stage is going to compose a complete circular economy (CE) model and increase the life cycle of the catalyst. The third stage of regeneration, after the adsorption process for sulfur and nitrogen compounds from real diesel, was assessed using as solvents: acetone (propanone), ethanol, benzene and toluene. For sulfur and nitrogen compounds, ethanol achieved the best performance. The variations of physical and chemical properties of regenerated ecats in the cycles of adsorption and desorption were evaluated using x-ray diffraction, x-ray fluorescence, nitrogen adsorptiondesorpion, thermogravimetric and differential thermal analysis, scanning electron microscopy and Fourier-transform infrared spectroscopy. The recovery rate over four cycles is superior for sulfur compounds. After all cycles, ecat-R- -SA exhibited 5.09% reduction in the recovery for sulfur and 24.58% reduction in the recovery for nitrogen. The nitrogen adsorption-desorption analysis suggests the adsorption of compounds by ecat-R may be more correlated with the adsorption sites than with specific area. Overall, the results of this work are promising and allows for ecat to integrate a complete CE model.

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Vodička, Matěj, Kristýna Michaliková, Jan Hrdlička, Pavel Skopec i Jitka Jeníková. "Experimental verification of the impact of the air staging on the NOx production and on the temperature profile in a BFB". Acta Polytechnica 62, nr 3 (30.06.2022): 400–408. http://dx.doi.org/10.14311/ap.2022.62.0400.

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The results of an experimental research on air staging in a bubbling fluidized bed (BFB) combustor are presented within this paper. Air staging is known as an effective primary measure to reduce NOX formation. However, in the case of a number of industrial BFB units, it does not have to be sufficient to meet the emission standards. Then selective non-catalytic reduction (SNCR) can be a cost-effective option for further reduction of the already formed NOX. The required temperature range at the place of the reducing agent injection for an effective application of the SNCR without excessive ammonia slip is above the temperatures normally attained in BFBs. The aim of this paper is to evaluate the impact of staged air injection on the formation of NOX in BFB combustors and to examine the possibility of increasing the freeboard temperature. Several experiments with various secondary/primary air ratios were performed with a constant oxygen concentration in the flue gas. The experiments were carried out using wooden biomass and lignite as fuel in a 30 kWth laboratory scale BFB combustor. Furthermore, the results were verified using a 500 kWth pilot scale BFB unit. The results confirmed that the air staging can effectively move the dominant combustion zone from the dense bed to the freeboard section, and thus the temperatures for an effective application of the SNCR can be obtained.

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Waldheim, L., i E. Carpentieri. "Update on the Progress of the Brazilian Wood BIG-GT Demonstration Project". Journal of Engineering for Gas Turbines and Power 123, nr 3 (3.01.2000): 525–36. http://dx.doi.org/10.1115/1.1335482.

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Biomass integrated gasification-gas turbine (BIG-GT) technology offers the opportunity for efficient and environmentally sound power generation from biomass fuels. Since biomass is “carbon-neutral” it can be used in power generation equipment without contributing to the “greenhouse effect” if it is grown sustainably. The Brazilian BIG-GT initiative is one of a number of initiatives world-wide aimed at demonstrating, and thereby establishing, biomass as an energy resource for power production. The goal of the Brazilian BIG-GT project is to confirm the commercial viability of producing electricity from wood through the use of biomass-fueled integrated gasification combined-cycle (BIG-GT) technology. To fulfil this goal a 32 MWe eucalyptus-fueled demonstration power plant will be built in Brazil on the basis of a design made by TPS Termiska Processer AB (TPS). The first two phases of the project, which included experimental and engineering studies and the basic engineering of the plant, were completed in 1997. The next phase of the project, the construction and commissioning of the plant, is the recipient of a U.S. $35 million grant from the Global Environmental Facility (GEF) of the United Nations Development Program (UNDP), in addition to financing from the World Bank (WB). The plant will be built in Bahia, north-eastern Brazil. The customer of the plant is a consortium, SER—Sistemas de Energia Renova´vel, comprising of CHESF (Companhia Hidro Ele´trica do Sa˜o Francisco), a federally owned electricity generation and distribution company, Electrobras (Centrais Ele´tricas Brasileiras), a holding company comprising of the main Brazilian companies from the electric generation and distribution sector, and Shell Brasil. Start-up of the plant is scheduled for the year 2000. The plant will be based on a TPS designed atmospheric-pressure gasification/gas cleaning process. The product gas will be fired in a modified GE LM 2500 gas turbine. The gasification and gas cleaning process is based on the use of a circulating fluidized bed gasifier, secondary stage catalytic tar cracker and conventional cold filter and wet scrubbing technology. The feedstock to the plant will be mainly eucalyptus wood from a dedicated plantation which is harvested on a three-year cycle. This paper describes the background of the project leading up to the technology selection, the technology that will be employed in the plant and the outline of the economics of this “first-of-a-kind” plant. The progress made in establishing the organization and the formal framework (e.g., securing the electricity and fuel contracts) are also reported. Future projections of likely technological improvements and cost reductions, and their effect on the overall economics of an Nth plant, are presented.

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AL-Azzawi, Omar M., Harith I. Mohammed, Hussam J. Mousa, Assad O. Rabit i Sura K. Hussein. "Mathematical Model & Feasibility Study for Construction an Invested Refinery of 100,000 (bbl / Day) in AL-Nasiriya Governorate". Journal of Petroleum Research and Studies 12, nr 1(Suppl.) (21.04.2022): 150–67. http://dx.doi.org/10.52716/jprs.v12i1(suppl.).628.

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A mathematical Model and feasibility study of construction an invested Refinery with 100,000 (Bbl/day) in AL-Nasiriya governorate was performed. The project is composed of three Units, Atmospheric Column Distillation Unit (CDU), Catalytic Reformer Unit (CRU) and Residue Fluidized Catalytic Cracking Unit (RFCC) that produce different products. Based on the Platts prices of petroleum products which was provided by State Organization for Marketing of Oil (SOMO) for May of this year and by standard specifications and technical information of Petroleum Research and Development Center (PRDC), Material balance for feed and products as well as optimization process using LINGO software for these three Units were calculated in order to determine influential financial parameters: (NPV), (IRR), (PI) and Payback period of the project. Different calculation scenarios were prepared taking into account discount of crude oil and products prices, inflation indicator of Capital expenditure (CAPEX) and operation expenditure (OPEX) in addition to extending the life of the project and increase in the cost of capital as well. These scenarios are illustrated as followings: - 1- The refinery was considered non-feasible in case of the crude feed price is taken (65$) and the products prices still constant. Discounted of oil feed was taken gradually by 10% and the products prices stay constant turns the project to be feasible at (50%) discounted oil price which gives positive financial parameters as can be seen in scenario (1), (2) but no longer feasible when increasing inflation by (3%) and (5%) as shown in scenario (3) and (4). 2- The price of crude oil feed was taken constant (65$) and the products prices were gradually increased by (10%) till (50%) with constant other parameters gives negative financial parameters means non feasibility as can be seen in scenario (5). 3- Increasing products prices by 10% and discount crude oil price by 10% together makes the project feasible at (25%) for both as shown in scenario (6). Conversely, when inflation was taken into account for OPEX and cost of capital, the project shifted to be feasible at (40%) for both crude oil and products as seen in scenario (7, 8, 9). The crude oil feed price and products was increased gradually by (10%) and decreased by the same percent. Both scenarios give negative financial parameters as shown in (10) and (11). 4- Extending life of project from (4) to (6) years and let other parameters constant including CAPEX to study the impact on the financial parameters. It is noticed that the refinery gives negative income compared to previous period of project in scenarios (12), (13). The cost of capital was increased from 2,100 million to 3000 million with no change in the other parameters gives negative income as seen in scenario (14) and (15). On the other hand, cost of capital and life of project were changed together makes the project worse income due to decline in the financial parameters as illustrated in scenario (14) and (16).

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Chaouki, Jamal. "Catalytic Drying of Digested Sludge". International Journal of Chemical Reactor Engineering 2, nr 1 (2.04.2004). http://dx.doi.org/10.2202/1542-6580.1088.

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Recently, we patented an efficient process for the drying of digested sludge with zero liquid emission. The main components of this drying system are a conical spouted bed dryer and a natural gas combustion chamber that burns the Volatile Organic Compounds (VOC) in the drying gases. The proposed integrated spouted bed drying process is simple and safe. It is also robust and easy to maintain since there is no moving mechanical part in the set-up. Although the system is quite thermally efficient, the operating and the investment costs are still relatively high. In order to avoid the combustion chamber and its accessories operating at high temperature and to reduce the energy consumption, a catalytic fluidized bed dryer may replace these units. It is proposed, then, to produce in situ the energy for the drying by catalytic oxidation of hydrocarbons and to destroy catalytically the VOCs generated by the drying. The purpose of this paper is to show the feasibility of this new process, called the catalytic drying of digested sludge. Based on the experimental work, advantages and limitations of this process are also discussed.

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Jaimes, Lisette, Gabriela M. Tonetto, María Lujan Ferreira i Hugo de Lasa. "Desulfurization of FCC Gasoline: Novel Catalytic Processes with Zeolites". International Journal of Chemical Reactor Engineering 6, nr 1 (26.02.2008). http://dx.doi.org/10.2202/1542-6580.1667.

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New regulations aim to achieve a drastic sulfur emission reduction in fuels and impose very low sulfur concentration caps (30 ppm in gasoline and 15 ppm in diesel) that will be in full force in 2009. FCC gasoline represents almost 40% of the total gasoline pool and it is the major sulfur contributor, with up to 8595%. To deal with this situation, most refiners have adopted post-treating FCC gasoline processes given they are more viable and less costly for meeting sulfur environmental regulation limits. In this respect, one should notice that conventional hydro-treating of FCC gasoline removes sulfur decreasing gasoline quality with octane number losses. The use of hydrogen also adds important costs to the desulfurization. As a result, new promising catalytic desulfurization processes are being proposed using zeolites as adsorbents/catalysts. These new approaches may lead to novel technologies, for example, with the case of gasoline de-hydrosulfidation with no hydrogen addition and alternatively to adsorption processes with co-feeding of an H-donor being pioneered at CREC University of Western Ontario. In both approaches sulfur is efficiently removed leaving the gasoline octane number index intact. The zeolite structure, the framework composition and the properties of the charge compensating cations are all parameters with major impact on catalytic desulfurization. In particular, shape selectivity is expected to play an important role in determining product selectivity when condensation reactions are significant. In this respect, the H-ZSM5 zeolite appears to have the adequate balance of Brönsted acidity and Lewis basicity to efficiently convert thiophene to H2S, with minimal transformation of benzothiophene and oligomers into coke. From a chemical reactor engineering point of view, novel gasoline desulfurization can be implemented using both fixed and fluidized bed reactors. Fluidized circulating bed reactors display high sulfur removal ability allowing frequent catalyst removal from the catalytic bed and coke combustion in a twin fluidized regeneration unit. Fixed bed units with adsorption/desorption cycles, used in conjunction with and without H donor co-reactants, lead to selective adsorption and efficient removal of sulfur species.

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Valle, Beatriz, Ana Guadalupe Gayubo, Alaitz Atutxa, Ainhoa Alonso i Javier Bilbao. "Integration of Thermal Treatment and Catalytic Transformation for Upgrading Biomass Pyrolysis Oil". International Journal of Chemical Reactor Engineering 5, nr 1 (26.10.2007). http://dx.doi.org/10.2202/1542-6580.1559.

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The upgrading of bio-oil by catalytic transformation upon acidic catalysts is aimed at adapting its composition to that of conventional fuel, or at obtaining petrochemical raw materials, such as olefins and aromatics. A further alternative of growing interest for bio-oil upgrading is catalytic reforming for obtaining H2. The viability of any of these alternatives requires minimizing both the plugging problems that arise in the reactor when the bio-oil is fed and the rapid deactivation of the catalyst, which are associated with the thermal degradation of the lignocellulosic components. In this paper, the catalytic transformation of bio-oil (obtained by fast pyrolysis of vegetable biomass) in a fluidized bed reactor upon a Ni-HZSM-5 zeolite catalyst has been studied, and special attention has been paid to the design of the feed preheating zone. Operation in a single-unit (U-shaped steel tube) for the thermal treatment of the bio-oil (in the downward zone of the U-tube) and its catalytic transformation (in a fluidized bed located in the upward zone of the U-tube) has been compared with operation in a two-unit system, where both steps are carried out in separate units connected through a thermostated line (U-shaped tube for thermal treatment, followed by a fluidized bed reactor for catalytic transformation). It has been proven that a separate step of thermal treatment prior to the catalytic transformation notably improves the global process of bio-oil upgrading. Firstly, it contributes to minimizing coke deposition on the acidic catalyst, mainly the deposition of "thermal" coke (which is associated with the thermal degradation of the bio-oil components at high temperatures), leading to an important attenuation of catalyst deactivation. Secondly, the bio-oil components degraded in the thermal treatment can subsequently be subjected to another upgrading treatment (by steam activation or pyrolysis) in order to obtain a high quality char, which involves upgrading the entire bio-oil.

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Lombardo, Gerard, Muhammad Ismail Shah, Berit Fostås, Odd Arne Hvidsten, Leila Faramarzi, Thomas de Cazenove, Hélène Lepaumier i Pieter Rogiers. "Results from Testing of a Brownian Diffusion Filter for Reducing the Aerosol Concentration in a Residue Fluidized Catalytic Cracker Flue Gas at the Technology Center Mongstad". SSRN Electronic Journal, 2019. http://dx.doi.org/10.2139/ssrn.3366032.

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Mahmoud, Ahmed, i Jaka Sunarso. "A mixed integer nonlinear programming approach for integrated bio-refinery and petroleum refinery topology optimization". Chemical Product and Process Modeling, 20.07.2020. http://dx.doi.org/10.1515/cppm-2019-0124.

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AbstractThe conversion of biomass into gasoline and diesel in bio-refinery process is an attractive process given its carbon neutral and sustainable nature. The economics of bio-refinery can be improved via integration with petroleum refinery, whereby bio-refinery intermediates can be processed into gasoline and diesel in the well-established petroleum refinery processing units, i. e., hydrocracking (HC) and fluidized catalytic cracking (FCC) units. However, the integration of the new bio-refinery into the existing petroleum refinery may not give the optimum solution given the capacities constraints of the existing petroleum refinery upgrading units such as FCC and HC units. Thus, this work proposed a superstructure comprising new bio-refinery and new petroleum refinery block diagrams. The superstructure was formulated into mixed integer nonlinear programming (MINLP) model. The model was coded into general algebraic modeling system (GAMS) platform and solved using global optimum solver, LINDOGLOBAL. The model application was demonstrated using representative case study. The model results showed that the optimum integrated bio-refinery and petroleum refinery topology favors the upgrading of bio-refinery intermediates using petroleum refinery HC unit under one-through operation mode with a marginal increase in the profit of about 0.39% compared to the second optimum case of upgrading bio-refinery intermediate using petroleum refinery FCC unit under gasoline operation mode. Thus, the decision in selecting the most suitable topology can be made based on the market demand for gasoline and diesel as the topology that uses FCC maximizes gasoline production and the topology that uses HC maximizes diesel production.

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Gauthier, Thierry A. "Current R&D Challenges for Fluidized Bed Processes in the Refining Industry". International Journal of Chemical Reactor Engineering 7, nr 1 (14.07.2009). http://dx.doi.org/10.2202/1542-6580.1857.

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Fluidized bed processes are widely used in the refining industry, mostly for conversion applications (e.g. fluid catalytic cracking, fluid coking, residue hydroconversion, Fischer-Tropsch Synthesis, etc.). These are large scale processes operating under severe conditions. Fluidized bed processes involve many complex phenomena that need to be considered in order to ensure proper design, operation and reliability. There have been thousands of publications over many years in the field of fluidization, but some of the fundamentals of fluid-particle flows still remain to be clarified. As a consequence, scale-up and industrialization of new technologies or processes remain a difficult, challenging and risky task.IFP is deeply involved with fluidized bed processes used in the refining industry. Over the last twenty years, industrial developments and PhD studies were conducted to explore new concepts, to develop new technologies, to scale-up hydrodynamics, to understand and quantify key phenomena. This paper discusses R&D practices in the field and current challenges encountered, mostly based on IFP experience. It does not intend, however, to provide an extensive literature review of all topics addressed in this paper.Interactions between particles, multiphase flow and reactor geometries are complex issues in fluidized beds. Therefore, experimentation is required to study new concepts such as downflow systems, complex phenomena such as vaporization of droplets in contact with gas-particle systems. The design of the experiment and the development of appropriate instrumentation are never simple and in the absence of simple similarities, anticipation of the main flow features is unavoidable. Modeling of results is then mandatory in order to translate results to industrial perspectives. Over the last 15 years, CFD has appeared as a promising tool to describe multiphase flow phenomena in complex geometries. Unfortunately, the lack of theoretical models to describe gas particle flow, at least for Group A powders, still leads researchers to conduct experiments to validate simulations or to adjust the gas-particle closure equations to validate results. Furthermore, observation in industrial units, during start-up or under steady conditions, when possible, greatly aids in validating research efforts and methodology.Despite its maturity, our industry is moving forward. There are ongoing developments in the energy and fuels market as well as in environmental fields, but also in the scientific background available to describe multiphase flow. Therefore, evolutionary R&D in the field is still needed to progress in the description of complex phenomena in order to optimize reactors and technologies and to face the changes of our industry.

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