968 resultados para CATALYTIC CRACKING


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Työssä tutkittiin typen oksidien (NOx) päästöjen muodostumista ja NOx-päästöjen poistomenetelmiä leijukatalyyttisessa krakkausyksikössä (FCC). Koeajossa Porvoon öljynjalostamon FCC-yksikössä tutkittiin NOx-päästöjen hallintaa CO-promoottorin (CO:n palamista edistävä lisäaine) annostelun avulla. Kirjallisuusosassa käsiteltiin NOx-päästöjen muodostumista FCC-yksikön regeneraattorissa. Katalyyttisten lisäaineiden vaikutusta NOx-päästöjen muodostumiseen tarkasteltiin laajasti. Katalyyttisten lisäaineiden ohella käsiteltiin muitakin NOx-päästöjen poistomenetelmiä. Koeajojen tarkoituksena oli optimoida FCC-yksikön katalyyttikiertoon annosteltavan CO-promoottorin määrä. CO-promoottorin sisältämä platina lisää NOx-päästöjen muodostumista regeneraattorissa, mutta vähentää jälkipalamista. Jälkipalamisen vuoksi regeneraattorin ylimenolinjan lämpötila nousee. Regeneraattorin ylimenolinjan lämpötila oli CO-promoottorin vähentämistä rajoittava tekijä, NOx-päästöjä pyrittiin vähentämään ilman merkittävää jälkipalamisen kasvua. Tuorekatalyytin platinapitoisuuden pienentäminen vähentää merkittävästi NOx-päästöjä.

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In this work, cracking experiments were performed to carry out the thermal conversion of the mixture of used frying oil and textile stamping sludge in continuous reactor. The textile stamping sludge was used to catalyze the reaction of thermal cracking. The physical and chemical properties of the oil produced were analyzed. Among the results of this analysis the level of acidity in the range of 12 mg KOH/g stands out. Low levels of acidity as this particular mean better quality oil. In this regard it is important that further researches on processes of conversion of residual oil occur.

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This research was motivated by the need to examine the potential application areas of process intensification technologies in Neste Oil Oyj. According to the company’s interest membrane reactor technology was chosen and applicability of this technology in refining industry was investigated. Moreover, Neste Oil suggested a project which is related to the CO2 capture from FCC unit flue gas stream. The flowrate of the flue gas is 180t/h and consist of approximately 14% by volume CO2. Membrane based absorption process (membrane contactor) was chosen as a potential technique to model CO2 capture from fluid catalytic cracking (FCC) unit effluent. In the design of membrane contactor, a mathematical model was developed to describe CO2 absorption from a gas mixture using monoethanole amine (MEA) aqueous solution. According to the results of literature survey, in the hollow fiber contactor for laminar flow conditions approximately 99 % percent of CO2 can be removed by using a 20 cm in length polyvinylidene fluoride (PDVF) membrane. Furthermore, the design of whole process was performed by using PRO/II simulation software and the CO2 removal efficiency of the whole process obtained as 97 %. The technical and economical comparisons among existing MEA absorption processes were performed to determine the advantages and disadvantages of membrane contactor technology.

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The main objective of this work is to analyze the importance of the gas-solid interface transfer of the kinetic energy of the turbulent motion on the accuracy of prediction of the fluid dynamic of Circulating Fluidized Bed (CFB) reactors. CFB reactors are used in a variety of industrial applications related to combustion, incineration and catalytic cracking. In this work a two-dimensional fluid dynamic model for gas-particle flow has been used to compute the porosity, the pressure, and the velocity fields of both phases in 2-D axisymmetrical cylindrical co-ordinates. The fluid dynamic model is based on the two fluid model approach in which both phases are considered to be continuous and fully interpenetrating. CFB processes are essentially turbulent. The model of effective stress on each phase is that of a Newtonian fluid, where the effective gas viscosity was calculated from the standard k-epsilon turbulence model and the transport coefficients of the particulate phase were calculated from the kinetic theory of granular flow (KTGF). This work shows that the turbulence transfer between the phases is very important for a better representation of the fluid dynamics of CFB reactors, especially for systems with internal recirculation and high gradients of particle concentration. Two systems with different characteristics were analyzed. The results were compared with experimental data available in the literature. The results were obtained by using a computer code developed by the authors. The finite volume method with collocated grid, the hybrid interpolation scheme, the false time step strategy and SIMPLEC (Semi-Implicit Method for Pressure Linked Equations - Consistent) algorithm were used to obtain the numerical solution.

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In this study, was used a very promising technique called of pyrolysis, which can be used for obtaining products with higher added value. From oils and residues, since the contribution of heavier oils and residues has intensified to the world refining industry, due to the growing demand for fuel, for example, liquid hydrocarbons in the range of gasoline and diesel. The catalytic pyrolysis of vacuum residues was performed with the use of a mesoporous material belonging the M41S family, which was discovered in the early 90s by researchers Mobil Oil Corporation, allowing new perspectives in the field of catalysis. One of the most important members of this family is the MCM-41, which has a hexagonal arrangement of mesopores with pore diameters between 2 and 10 nm and a high specific surface area, making it very promising for use as a catalyst in petroleum refining for catalytic cracking, and their mesopores facilitate the access of large hydrocarbon molecules. The addition of aluminum in the structure of MCM-41 increases the acidity of the material, making it more positive for application in the petrochemical industry. The mesoporous material of the type Al-MCM41 (ratio Si / Al = 50) was synthesized by hydrothermal method starting from the silica gel, NaOH and distilled water added to the gel pseudobohemita synthesis. Driver was used as structural CTMABr. Removal of organic driver (CTMABr) was observed by TG / DTG and FTIR, but this material was characterized by XRD, which was observed the formation of the main peaks characteristic of mesoporous materials. The analysis of adsorption / desorption of nitrogen this material textural parameters were determined. The vacuum residues (VR's) that are products of the bottom of the vacuum distillation tower used in this study are different from oil fields (regions of Ceará and Rio de Janeiro). Previously characterized by various techniques such as FTIR, viscosity, density, SARA, elemental analysis and thermogravimetry, which was performed by thermal and catalytic degradation of vacuum residues. The effect of AlMCM-41 was satisfactory, since promoted a decrease in certain ranges of temperature required in the process of conversion of hydrocarbons, but also promoted a decrease in energy required in the process. Thus enabling lower costs related to energy expenditure from degradation during processing of the waste

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In present work, mesoporous materials of the M41S family were synthesized, which were discovered in the early 90s by researchers from Mobil Oil Corporation, thus allowing new perspectives in the field of catalysis. One of the most important members of this family is the MCM-41, which has a hexagonal array of mesopores with pore diameters ranging from 2 to 10 nm and a high surface area, enabling it to become very promising for the use as a catalyst in the refining of oil in the catalytic cracking process, since the mesopores facilitate the access of large hydrocarbon molecules, thereby increasing the production of light products, that are in high demand in the market. The addition of aluminum in the structure of MCM-41 increases the acidity of the material, making it more beneficial for application in the petrochemical industry. The mesoporous materials MCM-41 and Al-MCM-41 (ratio Si / Al = 50) were synthesized through the hydrothermal method, starting with silica gel, NaOH and distilled water. CTMABr was used as template, for structural guiding. In Al-MCM-41 the same reactants were used, with the adding of pseudoboehmite (as a source of aluminum) in the synthesis gel. The syntheses were carried out over a period of four days with a daily adjustment of pH. The optimum conditions of calcination for the removal of the organic template (CTMABr) were discovered through TG / DTG and also through analysis by XRD, FTIR and Nitrogen Adsorption. It was found that both the method of hydrothermal synthesis and calcination conditions of the studies based on TG were promising for the production of mesoporous materials with a high degree of hexagonal array. The acidic properties of the materials were determined by desorption of n-butylamine via thermogravimetry. One proved that the addition of aluminum in the structure of MCM-41 promoted an increase in the acidity of the catalyst. To check the catalytic activity of these materials, a sample of Atmospheric Residue (RAT) that is derived from atmospheric distillation of oil from the Pole of Guamaré- RN was used. This sample was previously characterized by various techniques such as Thermogravimetry, FTIR and XRF, where through thermal analysis of a comparative study between the thermal degradation of the RAT, the RAT pyrolysis + MCM-41 and RAT + Al- MCM-41. It was found that the Al-MCM-41 was most satisfactory in the promotion of a catalytic effect on the pyrolysis of the RAT, as the cracking of heavy products in the waste occurred at temperatures lower than those observed for the pyrolysis with MCM-41, and thereby also decreasing the energy of activation for the process and increasing the rates of conversion of residue into lighter products

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The catalytic cracking of triglycerides presents itself as a possible alternative to the production of biofuels with low emission of pollutants. In this work were synthesized the SAPO-5, the catalysts for the cracking reaction of soybean oil is presented. The solids were powder X-ray diffraction (XRD), thermogravimetric analysis (TG/DTG) and infrared spectroscopy (FTIR). The analyses indicated that the synthesis method has employed to obtain materials with high surface area and high acid. The soybean oil thermal and thermal catalytic cracking, realized from the room temperature to 450 ºC in a simple distillation system, has allowed obtaining two liquid fractions, each consisting of two phases, one aqueous and another organic, organic liquid (OL). The OL obtained from first fractions has shown high acid index, even in the thermal catalytic process. The products obtained in the cracking of soybean oil were analyzed by distillation, acid number, infra-red spectroscopy, density, viscosity, carbon residue, cetane number determination and characterization. The analysis of the products obtained in the presence and in the absence of the SAPO-5 permitted to conclude that all the solids tested presented catalytic activity in the deoxygenation of final products only at the second step of the cracking process

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In order to obtain a biofuel similar to mineral diesel, lanthanum-incorporated SBA- 15 nanostructured materials, LaSBA-15(pH), with different Si/La molar ratios (75, 50, 25), were synthesized in a two-steps hydrothermal procedure, with pH-adjusting of the synthesis gel at 6, and were used like catalytic solids in the buriti oil thermal catalytic cracking. These solids were characterized by X-ray fluorescence (XRF), powder X-ray diffraction (XRD), thermogravimetric analysis (TG/DTG), infrared spectroscopy (FTIR), nitrogen porosimetry and ethanol dehydration, aiming to active sites identify. Taken together, the analyses indicated that the synthesis method has employed to obtain materials highly ordered mesostructures with large average pore sizes and high surface area, besides suggested that the lanthanum was incorporated in the SBA-15 both into the framework as well as within the mesopores. Catalytic dehydration of ethanol over the LaSBA-15(pH) products has shown that they have weak Lewis acid and basic functionalities, indicative of the presence of lanthanum oxide in these samples, especially on the La75SBA-15(pH) sample, which has presented the highest selectivity to ethylene. The buriti oil thermal and thermal catalytic cracking, realized from the room temperature to 450 ºC in a simple distillation system, has allowed obtaining two liquid fractions, each consisting of two phases, one aqueous and another organic, organic liquid (OL). The OL obtained from first fractions has shown high acid index, even in the thermal catalytic process. One the other hand, OL coming from second ones, called green diesel (GD), have presented low acid index, particularly that one obtained from the thermal catalytic process realized over LaSBA-15(pH) samples. The acid sites presence in these samples, associated to their large average pore sizes and high surface areas, have allowed them, especially the La75SBA-15(pH), to present deoxygenating activity in the buriti oil thermal catalytic cracking, providing an oxygenates content reduction, particularly carboxylic acids, in the GD. Furthermore, the GD comes from the second liquid fraction obtained in the buriti oil thermal catalytic cracking over this latest solid sample has shown hydrocarbons composition and physic-chemical properties similar to that mineral diesel, beyond sulfur content low

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The nanostructured molecular sieve SBA-15 was synthesized by the hydrothermal method, and modified with lanthanum with Si/La molar ratios of 25, 50, 75 and 100. The materials were evaluated as catalysts for the cracking of n-hexane model reaction. Type SBA- 15 and LaSBA-15 mesoporous materials were synthesized using tetraetilortosilicato as a source of silica, hydrochloric acid, heptahydrate lanthanum chloride and distilled water. Pluronic P123 triblock. polymer was used as structure template. The syntheses were carried out by 72 hours. The obtained SBA-15 samples were previously analyzed by thermogravimetry, in order to check the conditions of calcination for removal of organic template. Then, the calcined materials were characterized by X-ray diffraction, infrared spectroscopy, adsorption and desorption of nitrogen, scanning electron microscopy and X-ray microanalysis by dispersive energy. The acidity of the samples was determined using adsorption of n-bulinamina and desorption followed by thermogravimetry. It was found that the hydrothermal synthesis method was suitable for the synthesis of the SBA-15 mesoporous materials, with an excellent degree of hexagonal ordering. The reactions of catalytic cracking of n-hexane were carried out using a fixed bed continuous flow microreactor, coupled on-line to a gas chromatograph. From the catalytic evaluation, it was observed that the mesoporous materials containing lanthanum showed different results for the reaction of cracking of nhexane compared to the unmodified mesoporous material SBA-15. As a result of cracking was obtained as main products hydrocarbons in the range of C1 to C5. The catalyst that showed better properties in relation to the acidity and catalytic activity was LaSBA-15 with the ratio Si/La = 50

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In this work were synthesized and characterized the materials mesoporous SBA-15 and Al- SBA-15, Si / Al = 25, 50 and 75, discovered by researchers at the University of California- Santa Barbara, USA, with pore diameters ranging from 2 to 30 nm and wall thickness from 3.1 to 6.4 nm, making these promising materials in the field of catalysis, particularly for petroleum refining (catalytic cracking), as their mesopores facilitate access of the molecules constituting the oil to active sites, thereby increasing the production of hydrocarbons in the range of light and medium. To verify that the materials used as catalysts were successfully synthesized, they were characterized using techniques of X-ray diffraction (XRD), absorption spectroscopy in the infrared Fourier transform (FT-IR) and adsorption nitrogen (BET). Aiming to check the catalytic activity thereof, a sample of atmospheric residue oil (ATR) from the pole Guamaré-RN was performed the process by means of thermogravimetry and thermal degradation of catalytic residue. Upon the curves, it was observed a reduction in the onset temperature of the decomposition process of catalytic ATR. For the kinetic model proposed by Flynn-Wall yielded some parameters to determine the apparent activation energy of decomposition, being shown the efficiency of mesoporous materials, since there was a decrease in the activation energy for the reactions using catalysts. The ATR was also subjected to pyrolysis process using a pyrolyzer with gas chromatography coupled to a mass spectrometer. Through the chromatograms obtained, there was an increase in the yield of the compounds in the range of gasoline and diesel from the catalytic pyrolysis, with emphasis on Al-SBA-15 (Si / Al = 25), which showed a percentage higher than the other catalysts. These results are due to the fact that the synthesized materials exhibit specific properties for application in the process of pyrolysis of complex molecules and high molecular weight as constituents of the ATR

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A catalyst of great interest to the scientific community tries to unite the structure of ordered pore diameter from mesoporous materials with the properties of stability and acid activity to microporous zeolites. Thus a large number of materials was developed in the past decades, which although being reported as zeolites intrinsically they fail to comply with some relevant characteristics to zeolites, and recently were named zeolitic materials of high accessibility. Among the various synthesis strategies employed, the present research approaches the synthesis methods of crystallization of silanized protozeolitic units and the method of protozeolitic units molded around surfactant micelles, in order for get materials defined as hierarchical zeolites and micro-mesoporous hybrid materials, respectively. As goal BEA/MCM-41 hybrid catalysts with bimodal pore structure formed by nuclei of zeolite Beta and cationic surfactant cetyltrimethylammonium were developed. As also was successfully synthesized the hierarchical Beta zeolite having a secondary porosity, in addition to the typical and uniform zeolite micropores. Both catalysts were applied in reactions of catalytic cracking of high density polyethylene (HDPE), to evaluate its properties in catalytic activity, aiming at the recycling of waste plastics to obtain high value-added raw materials and fuels. The BEA/MCM-41 hybrid materials with 0 days of pre-crystallization did not show enough properties for use in catalytic cracking reactions, but they showed superior catalytic properties compared to those ordered mesoporous materials of Al-MCM-41 type. The structure of Beta zeolite with hierarchical porosity leads the accessibility of HDPE bulky molecules to active centers, due to high external area. And provides higher conversion to hydrocarbons in the gasoline range, especially olefins which have great interest in the petrochemical industry

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Bifunctional catalysts based on zircon oxide modified by tungsten (W = 10, 15 and 20 %) and by molybdenum oxide (Mo= 10, 15 e 20 %) containg platinum (Pt = 1%) were prepared by the polymeric precursor method. For comparison, catalysts the tungsten base was also prepared by the impregnation method. After calcinations at 600, 700 and 800 ºC, the catalysts were characterized by X-ray diffraction, fourier-transform infrared spectroscopy, thermogravimetric and differential thermal analysis, nitrogen adsorption and scanning electron microscopy. The profile of metals reduction was determined by temperature programmed reduction. The synthesized catalysts were tested in n-heptane isomerization. X-ray diffractogram of the Pt/WOx-ZrO2 and Pt/MoOx-ZrO2 catalysts revealed the presence of tetragonal ZrO2 and platinum metallic phases in all calcined samples. Diffraction peaks due WO3 and ZrO2 monoclinic also were observed in some samples of the Pt/WOx-ZrO2 catalysts. In the Pt/MoOx-ZrO2 catalysts also were observed diffraction peaks due ZrO2 monoclinic and Zr(MoO4)2 oxide. These phases contained on Pt/WOx-ZrO2 and Pt/MoOx-ZrO2 catalysts varied in accordance with the W or Mo loading and in accordance with the calcination temperature. The infrared spectra showed absorption bands due O-W-O and W=O bonds in the Pt/WOx-ZrO2 catalysts and due O-Mo-O, Mo=O and Mo-O bonds in the Pt/MoOx-ZrO2 catalysts. Specific surface area for Pt/WOx-ZrO2 catalysts varied from 30-160 m2 g-1 and for the Pt/MoOx-ZrO2 catalysts varied from 10-120 m2 g-1. The metals loading (W or Mo) and the calcination temperature influence directly in the specific surface area of the samples. The reduction profile of Pt/WOx-ZrO2 catalysts showed two peaks at lower temperatures, which are attributed to platinum reduction. The reduction of WOx species was evidenced by two reduction peak at high temperatures. In the case of Pt/MoOx-ZrO2 catalysts, the reduction profile showed three reduction events, which are attributed to reduction of MoOx species deposited on the support and in some samples one of the peak is related to the reduction of Zr(MoO4)2 oxide. Pt/WOx-ZrO2 catalysts were active in the n-heptane isomerization with high selectivity to 3-methyl-hexane, 2,3- dimethyl-pentane, 2-methyl-hexane among other branched hydrocarbons. The Pt/MoOx-ZrO2 catalysts practically didn't present activity for the n-heptane isomerization, generating mainly products originating from the catalytic cracking

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Neste trabalho foi estudado o processo de destilação do produto líquido orgânico, obtido no craqueamento catalítico do óleo de palma (Elaeis guineensis, Jacq) bruto em escala piloto, empregando os catalisadores carbonato de sódio (Na2CO3) e a lama vermelha, variando o percentual de catalisador em 10% m/m e 15% m/m em relação à matéria prima utilizada, sendo fixada uma temperatura operacional de 450ºC, visando obter frações de biocombustíveis (bio-gasolina, bio-querosene e bio-óleo) semelhantes aos combustíveis derivados do petróleo. Os catalisadores foram submetidos a um pré-tratamento de desidratação durante 2 horas em uma estufa à 300ºC, posteriormente foram realizadas as análises de DRX, IR e TG. Quanto à matéria prima, foram realizadas análises físico-químicas, visando à caracterização do óleo de palma. Os produtos líquidos orgânicos (PLOs) obtidos foram submetidos a operações unitárias de separação, decantação e filtração simples em escala de bancada, para posteriormente serem realizadas análises físico-químicas e composicionais. Os PLOs foram destilados em uma coluna Vigreux de seis (06) estágios, e as frações condensadas foram coletadas de acordo com as faixas de destilação da gasolina (60ºC - 190ºC), querosene (190ºC - 235ºC) e diesel (235°C - 370ºC), para posteriormente serem caracterizadas. Verificou-se uma melhor eficiência para o catalisador carbonato de sódio a 15% m/m quanto a redução do índice de acidez, cerca de 1,7 mgKOH/g, assim como uma conversão mássica de 97% do óleo em PLO, notou-se também que, ao aumentar a quantidade de catalisador, isto favoreceu a obtenção de um produto final com uma melhor qualidade. A lama vermelha por outro lado, apresentou rendimentos de até 64% m/m e produtos com baixa acidez cerca de 62,90 mgKOH/g, comparando este resultado com dados encontrados na literatura. A partir dos resultados finais, verificou-se a eficiência dos catalisadores, no qual o catalisador carbonato de sódio forneceu produtos com baixa acidez e com boas características para uso como combustível.

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2,25Cr-1Mo alloy steels are widely used in petrochemical plant equipments working in high temperature conditions because of their good mechanical proprieties in these conditions. Although, when exposed for a long time at high temperature, in the rage of 343 °C to 593 °C, may present the temper embrittlement phenomenon. The component named stripper of assembly converter of fluid catalytic cracking unit (UFCC) of studied plant is manufactured using this material, which is subject to temper embrittlement. The phenomenon of temper embrittlement refers to progressive lose of toughness, making the material brittle. With embrittlement, equipaments manufactured with this material are under risks to suffer brittle fracture in the cool down and start-up situations of them, which can cause catastrophic failures. By this reason, this research studies presence of temper ebrittlement phenomenon on this material. To verify the toughness of the material is conventionally used charpy V-notch test. However, this test requires the removing of samples of the material to make specimens. This fact becomes critical when talk about structural components of an equipment. So, this research also studies a non-destructive test that can be executes in-situ, known as instrumented indentation, as an alternative detection of the phenomenon at the component stripper, by comparative of the mechanical proprieties obtained by conventional tests in similar samples

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One of the biggest environmental problems of today is the climate change. Experts affirm that this global warming is related to the greenhouse effect. Its causes are directly related to human activity, especially the use of fossil fuels. In this context, companies around the world are challenged to improve energy efficiency in order to reduce the environmental impact and work toward the so-called tripod of sustainable development that focuses on the social, economic and environmental aspects of a business strategy. The first step a company can make in this regard is to conduct an inventory of emissions of greenhouse gases (GHGs). The reduction of GHG emissions in a refinery can be achieved by replacing steam turbines with electric motors to drive big machines, this reduction is achieved by relieving the steam consumption for electric power available or purchased. An important aspect associated with the reduction of GHG emissions is the best performance of the Energy Intensity Index (ERI). The objective of this study was to analyze the feasibility of the blower motorization in the regenerative cycle of a fluidized catalytic cracking unit at a specific refinery. For development work, two methods were used, the initial screening and optimization scenarios with the help of software Butyl. The results indicate that after a certain cost of natural gas this substitution becomes favorable. In addition, there is a large reduction of CO2 emissions avoided by burning fuel