Avaliação de diferentes processos oxidativos avançados no tratamento de resíduos de petróleo

The petroleum industry deals with problems which are difficult to solve because of their relation to environmental issues. This is because amounts of residue are generated which vary in type and danger level. The soil contamination by non aqueous liquid phase mixtures, specifically hydrocarbon petroleum has been a reason for great concern, mainly the aromatic and polycyclic aromatic, which present risk to human health due to its carcinogenic and mutagenic character. The Advanced Oxidative Processes (AOP) are efficient technologies for destruction of organic compounds of difficult degradation and, often, they are present in low concentrations. They can be considered clean technologies, because there is no formation of solid by-products or the transfer of pollutor phases. This work focuses on the study of the degradation of petroleum industrial waste, by Advanced Oxidation Processes. Treatments tackling petroleum residues, contaminated soil, and water occurring in the production of petroleum reached the following Polycyclic Aromatic Hydrocarbons (PAH) degradation levels: solid residues 100% in 96 treatment hours; water residue - 100% in 6 treatment hours; soil contamination (COT degradation) - 50.3% in 12 treatment hours. AOP were effective in dealing with petroleum residues thus revealing themselves to be a promising treatment alternative

Síntese e caracterização de aluminofosfato impregnado com molibdênio/zinco visando a dessulfurização por adsorção

Discussions about pollution caused by vehicles emission are old and have been developed along the years. The search for cleaner technologies and frequent weather alterations have been inducing industries and government organizations to impose limits much more rigorous to the contaminant content in fuels, which have an direct impact in atmospheric emissions. Nowadays, the quality of fuels, in relation to the sulfur content, is carried out through the process of hydrodesulfurization. Adsorption processes also represent an interesting alternative route to the removal of sulfur content. Both processes are simpler and operate to atmospheric temperatures and pressures. This work studies the synthesis and characterization of aluminophosphate impregnate with zinc, molybdenum or both, and its application in the sulfur removal from the gasoline through the adsorption process, using a pattern gasoline containing isooctane and thiophene. The adsorbents were characterized by x-ray diffraction, differential thermal analysis (DTG), x-ray fluorescence and scanning electron microscopy (SEM). The specific area, volume and pore diameter were determined by BET (Brunauer- Emmet-Teller) and the t-plot method. The sulfur was quantified by elementary analysis using ANTEK 9000 NS. The adsorption process was evaluated as function of the temperature variation and initial sulfur content through the adsorption isotherm and its thermodynamic parameters. The parameters of entropy (ΔS), enthalpy variation (ΔH) and free Gibbs energy (ΔG) were calculated through the graph ln(Kd) versus 1/T. Langmuir, Freundlich and Langmuir-Freundlich models were adjusted to the experimental data, and the last one had presented better results. The thermodynamic tests were accomplished in different temperatures, such as 30, 40 and 50ºC, where it was concluded the adsorption process is spontaneous and exothermic. The kinetic of adsorption was studied by 24 h and it showed that the capability adsorption to the adsorbents studied respect the following order: MoZnPO > MoPO > ZnPO > AlPO. The maximum adsorption capacity was 4.91 mg/g for MoZnPO with an adsorption efficiency of 49%.

Determinação de Dados de Equilíbrio Líquido-Vapor para Sistemas Hidrocarbonetos e Desenvolvimento de uma Nova Célula Dinâmica

In the present work are established initially the fundamental relationships of thermodynamics that govern the equilibrium between phases, the models used for the description of the behavior non ideal of the liquid and vapor phases in conditions of low pressures. This work seeks the determination of vapor-liquid equilibrium (VLE) data for a series of multicomponents mixtures of saturated aliphatic hydrocarbons, prepared synthetically starting from substances with analytical degree and the development of a new dynamic cell with circulation of the vapor phase. The apparatus and experimental procedures developed are described and applied for the determination of VLE data. VLE isobarics data were obtained through a Fischer's ebulliometer of circulation of both phases, for the systems pentane + dodecane, heptane + dodecane and decane + dodecane. Using the two new dynamic cells especially projected, of easy operation and low cost, with circulation of the vapor phase, data for the systems heptane + decane + dodecane, acetone + water, tween 20 + dodecane, phenol + water and distillation curves of a gasoline without addictive were measured. Compositions of the equilibrium phases were found by densimetry, chromatography, and total organic carbon analyzer. Calibration curves of density versus composition were prepared from synthetic mixtures and the behavior excess volumes were evaluated. The VLE data obtained experimentally for the hydrocarbon and aqueous systems were submitted to the test of thermodynamic consistency, as well as the obtained from the literature data for another binary systems, mainly in the bank DDB (Dortmund Data Bank), where the Gibbs-Duhem equation is used obtaining a satisfactory data base. The results of the thermodynamic consistency tests for the binary and ternary systems were evaluated in terms of deviations for applications such as model development. Later, those groups of data (tested and approved) were used in the KijPoly program for the determination of the binary kij parameters of the cubic equations of state original Peng-Robinson and with the expanded alpha function. These obtained parameters can be applied for simulation of the reservoirs petroleum conditions and of the several distillation processes found in the petrochemistry industry, through simulators. The two designed dynamic cells used equipments of national technology for the determination Humberto Neves Maia de Oliveira Tese de Doutorado PPGEQ/PRH-ANP 14/UFRN of VLE data were well succeed, demonstrating efficiency and low cost. Multicomponents systems, mixtures of components of different molecular weights and also diluted solutions may be studied in these developed VLE cells

Estudo da adsorção de hidrogênio e sulfeto na superfície de paládio: aspectos experimentais (eletroquímica) e teóricos (ab initio e Teoria do Funcional da Densidade)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Síntese, caracterização e aplicação de MCM-41 funcionalizado com diisopropilamina no processo de adsorção do dióxido de carbono

Emissions of CO2 in the atmosphere have increased successively by various mechanisms caused by human action, especially as fossil fuel combustion and industrial chemical processes. This leads to the increase in average temperature in the atmosphere, which we call global warming. The search for new technologies to minimize environmental impacts arising from this phenomenon has been investigated. The capture of CO2 is one of the alternatives that can help reduce emis ions of greenhouse gases. The CO2 can be captured through the process of selective adsorption using adsorbents for this purpose. Were synthesized by hydrothermal method, materials of the type MCM-41 and Al-MCM-41 in the molar ratio Si / Al equal to 50. The synthesis of gels were prepared from a source of silicon, sodium, water and aluminum in the case of Al-MCM-41. The period of synthesis of the materials was 5 days in autoclave at 100°C. After that time materials were filtered, washed and dried in greenhouse at 100 º C for 4 hours and then calcined at 450 º C. Then the calcined material was functionalized with the Di-isopropylamine (DIPA) by the method of wet impregnation. We used 0.5 g of material mesopores to 3.5 mL of DIPA. The materials were functionalized in a closed container for 24 hours, and after this period were dried at brackground temperature for 2 hours. Were subsequently subjected to heat treatment at 250°C for 1 hour. These materials were used for the adsorption of CO2 and were characterized by XRD, FT-IR, BET / BJH, SEM, EDX and TG / DTG. Tests of adsorption of CO2 was carried out under the following conditions: 100 mg of adsorbent, temperature of 75°C under flow of 100 mL/min of CO2 for 2 hours. The desorption of CO2 was carried out by thermogravimetry from ambient temperature to 900ºC under flow of 25 mL min of He and a ratio of 10ºC/min. The difratogramas X-ray for the synthesized samples showed the characteristic peaks of MCM-41, showing that the structure of it was obtained. For samples functionalized there was a decrease of the intensities of these peaks, with a consequent reduction in the structural ordering of the material. However, the structure was preserved mesopores. The adsorption tests showed that the functionalized MCM-41 is presented as a material promising adsorbent, for CO2 capture, with a loss of mass on the desorption CO2 of 7,52%, while that in Al-MCM- 41 functionalized showed no such loss

Síntese, caracterização e aplicação do MCM-41 e A1-MCM-41 na pirólise do resíduo atmosférico de petróleo

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

Utilização de sílica gel organofuncionalizada para adsorção de íons metálicos em solução aquosa

In this work the organosilanes aminopropyltriethoxysilane, 3-mercaptopropyltryethoxisilane and n[-3-(trimetoxisilyl)propyl]ethylenetriamine, as well as tetraethylortosilicate (TEOS), were employed to produce, by sol-gel method, organofuncionalized silicon samples. The prepared samples were characterized by elementar analys by thermogravimetry and infrared spectroscopy. Those samples were employed to adsorb Cd2+, Pb2+, Ni2+ and Zn2+ from aqueous solutions (10, 20, 40, 60 and 80 mg L-1). In typical experiments, 50 mg of the organometrix was suspended in 20 mL of metal cation solutions at four different contact times: 30, 60, 90 and 120 minutes. The total amount of adsorbed cations were measured by atomic absorption spectrometry. To all investigated matrices, the following adsorption capacity was observed: Ni2+ > Zn2+ > Cd2+ > Pb2+. Such sequence is closely related with the cation radius, as well as the cation hardness

Tratamento eletroquímico de água produzida sintética para remoção de hidrocarbonetos policíclicos aromáticos

The aim of this work is the treatment of produced water from oil by using electrochemical technology. Produced water is a major waste generated during the process of exploration and production in the oil industry. Several approaches are being studied aiming at the treatment of this effluent; among them can be cited the biological process and chemical treatments such as advanced oxidation process and electrochemical treatments (electrooxidation, electroflotation, electrocoagulation, electrocoagulation). This work studies the application of electrochemical technology in the treatment of the synthetic produced water effluent through the action of the electron, in order to remove or transform the toxic and harmful substances from the environment by redox reactions in less toxic substances. For this reason, we used a synthetic wastewater, containing a mixture H2SO4 0,5M and 16 HPAs, which are: naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo (a) anthracene, chrysene, benzo(b)fluoranthene, benzo(k) fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene, dibenzo(a, h)anthracene, benzo(g, h, i)perylene. Bulk electrochemical oxidation experiments were performed using a batch electrochemical reactor containing a pair of parallel electrodes, coupled with a power supply using a magnetic stirrer for favoring the transfer mass control. As anodic material was used, a Dimensionally Stable Anode (DSA) of Ti/Pt, while as cathode was used a Ti electrode. Several samples were collected at specific times and after that, the analysis of these samples were carried out by using Gas Chromatography Coupled to Mass Spectrometry (GC - MS) in order to determine the percentage of removal. The results showed that it was possible to achieve the removal of HPAs about 80% (in some cases, more than 80%). In addition, as an indicator of the economic feasibility of electrochemical treatment the energy consumption was analyzed for each hour of electrolysis, and based on the value kWh charged by ANEEL, the costs were estimated. Thus, the treatment costs of this research were quite attractive

Preparação de membranas de acetato de celulose organomodificadas para adsorção dos íons Cu(II), Cd(II), Mn(II) e Ni(II)

Cellulose acetate polymeric membranes had been prepared by a procedure of two steps, combining the method of phase inversion and the technique of hydrolysis-deposition. The first step was the preparation of the membrane, and together was organomodified with tetraethylortosilicate and 3-aminopropyltrietoxysilane. Parameters that exert influence in the complexation of the metallic ion, as pH, time of complexation, metal concentration, had been studied in laboratory using tests of metal removal. The membranes had presented resistance mechanics and reactivity to cations, being able to be an alternative for the removal, daily pay-concentration or in the study of the lability of metals complexed.

Adsorção de Mn (II) e Zn (II) em soluções aquosas usando perlita expandida revestida com quitosana

In this work, chitosan was used as a coating of pure perlite in order to increase the accessibility of the groups OH- e NH2+the adsorptionof ions Mn2+ e Zn2+.The characterization results of the expanded perlite classified as microporous and whose surface area 3,176 m2 g-1after the change resulted in 4,664 m2g-1.From the thermogravimetry(TG) it was found that the percentage of coating was34,3%.The infrared analysis can prove the presence of groups Si-OH, Si-O e Al-O-Siresulting from the perlite and C=O, NH2and OH characterization of chitosan. The experiments on experiments on the adsorption of Mn and Zn were performed in the concentration range of10 a 50 mgL-1and the adsorption capacity inpH 5,8 e 5,2 was 19,49 and 23,09 mgg-1to 25 oC,respectively.The adsorption data were best fitted to Langmuir adsorption model to Langmuir adsorption model for both metalionsisindicative of monolayer adsorption. The kinetics of adsorption were calculated from the equation of Lagergren fitting the model pseudo-second-order for all initial concentrations, suggesting that adsorption of ions Mn2+ and Zn2+ follows the kinetics of pseudo-second-order and whose constant Speedk2(g/mg.min) are 0,105 e 3,98 and capacity and maximum removal qe 4,326 e 3,348,respectively.In this study we used a square wave voltammetry cathodic stripping voltammetry to quantify the adsorbed ions, and the working electrode glassy carbon, reference electrode silver / silver chloride and a platinum auxiliary electrode. The attainment of the peaks corresponding to ions Mn2+ and Zn2+ was evaluated in and electrochemical cell with a capacity of 30 mL using a buffer system (Na2HPO4/NaH2PO4)at pH 4 and was adjusted with solutionsH3PO4 0,1molL-1and NaOH 0,1 molL-1and addition of the analyte has been a cathodic peak in- 0,873 Vand detection limit of2,55x10-6molL-1para Zn.The dough used for obtaining the adsorption isotherm was 150 mg and reached in 120 min time of equilibrium for both metal ions.The maximum adsorption for 120 min with Mn concentration 20 mgL-1 and Zn 10 mgL-1,was91, 09 e 94, 34%, respectively

Estudo do equilíbrio e cinética de adsorção de um corante aniônico em quitosana

The phenomenon of adsorption is of fundamental importance for the treatment of textile effluents and removal of dyes. Chitosan is characterized as an excellent adsorbent material, not only for its adsorption capacity but also the low cost production. Equilibrium and kinetic studies were developed in this study to describe the mechanism of adsorption of the anionic azo dye Orange G in chitosan, with the isotherms obtained from the variation of the concentration of dye in the continuous phase. The kinetics of the process was analyzed based on models involving the adsorption of molecules of the dye in nonpolar and polar sites. Adsorption experiments were carried out in water and in saline media with different NaCl concentrations, both for the determination of the equilibrium time as isotherms for making kinetic curves in which the amount of dye adsorbed measured indirectly varied with time. The experiments revealed the opening of the biopolymer structure with increasing concentration of Orange G, accompanied by high pH values and change on the type of interaction between the dye and the adsorbent surface, suggesting behavior advocated by the Langmuir equation in a certain range of concentration of the adsorbate and following the Henry's Law at higher concentrations, from the increased number of sites available for adsorption. The studies conducted showed that the saline medium reduces the chitosan s adsorption capacity according to a certain concentration, the occurrence of the cooperative adsorption process steps kinetic mechanism suggested as a new alternative for the interpretation of the phenomenon

Aplicação da parafina e do óleo de linhaça como hidrofobizantes da vermiculita, para remoção de derivados de óleo diesel resentes em água produzida sintética

Produced water has lately aroused interest due to their high degree of salinity, suspended oil particles, chemicals added in various manufacturing processes, heavy metals and radioactivity sometimes. Along with oil and due to its high volume production, water production is one of the pollutants of most concern in the process of oil extraction. PAHs due to their ubiquity and their characteristics carcinogenic or mutagenic and teratogenic even have attracted the attention of every scientific society. Formed from the incomplete combustion of organic matter may be natural or anthropogenic. Some materials have been researched with the goal of cleaning up environmental matrices that may be contaminated by hydrocarbons. Among these materials researched various clays have been employed, of which highlights the vermiculite. The family of phyllosilicates, vermiculite for its potential and its high hydrophobic surface area has been a tool widely used in the decontamination of water in processes of oil spills. However, when it loses its capacity expanded hydrophobic having the necessity of using a hidrofobizante to make it organophilic. Among the numerous hidrofobizantes researched and used the linseed oil was the pioneer. In this study sought to evaluate the capacity of removal of PAHs using the vermiculite hydrofobized with linseed oil and wax also, for it was made use of the 24 full factorial design as the main tool for the experiments. We also evaluated the clay grain size (-20 +48 and -48 +80 #), the percentage of hidrofobizante applied (5 and 10%) and salinity of the water produced synthesized in our laboratory (35,000 and 55,000 ppm). The molecular fluorescence spectroscopy due to its sensitivity and speed was used to verify the adsorption capacity of clay, as well as gas chromatography served as an auxiliary technique to identify and quantify the PAHs in solution. In order to characterize the vermiculite was made use of X-ray fluorescence and X-ray diffraction. The infrared and thermogravimetry were essential to note hydrophobization and the amount of coating of clay. According to the fluorescence analysis showed that the test 12 was the best result in about 98% adsorption of fluorescent compounds, however the high salinity, the smallest particle size, the highest percentage of hidrofobizante and the use of linseed oil showed greater efficiency in the removal capacity of these hydrocarbons, in accordance with the trend followed by the analysis of the major factors of the factorial design. To verify the adsorption capacity of clay using a fixed volume of water produced synthetically, used as the test base 12, at their respective levels and factors. Thus, it was observed that after adding about 1 ½ liters of water solution produced synthetically, about 300 times its volume in mass, the vermiculite was able to adsorb 80% of fluorescent species present in solution

Aplicação de argila branca comercial pura e modificada para adsorção de sulfeto de hidrogênio

In this work were synthesized matrix-based commercial white clay in its composition having large amounts of kaolinite and quartz, with a certain percentage of iron oxide for use as an adsorbent for hydrogen sulfide (H2S). To characterize the effect of initial matrix techniques were used to characterize XRD, FTIR, XRF and TG. The initial clay mineral matrix was placed in contact with 0.1 molar solutions of the salts of Co2+, Ni2+, Cr3+ and a solution 0.1 g / 100ml rhodamine B. During the synthesis process, the solutions were placed in contact with the initial matrix for a period of 48 hours in order to have ion exchange with the clay mineral. To check the amount of exchanged metals, we used the technique of X-ray Fluorescence (XRF). After synthesis was initiated the process of adsorption of H2S, where the arrays were placed in the reactor, then by passing a stream of hydrogen sulfide. The matrix along with the reactor was weighed before and after to measure the amount of gas adsorbed. Based on the gravimetric data the matrix which had the highest performance of the adsorption matrix was exchanged with Ni2+ ions, obtaining a result of 11.13 mg H2S / g matrix, then the matrix coated with rhodamine B which was reached 10.13 mg H2S / g matrix

Hidróxidos duplos lamelares de magnésio e alumínio modificados com carbonato e p123 para adsorção de dióxido de carbono

Muitos mecanismos provocados pela ação humana vêm gerando um aumento na queima de combustíveis fósseis e processos químicos (produtos orgânicos, carvão, madeira, óleo diesel, gasolina e outros derivados de petróleo) e, consequentemente, há um aumento na emissão de CO2 na atmosfera. Uma das alternativas para a captura desse poluente é o processo de adsorção, o qual pode ajudar na redução do CO2. As hidrotalcitas ou hidróxidos duplos lamelares (HDL s) estão dentre esses materiais estudados, já que apresentam alta estabilidade e uma boa porosidade, tornando-se assim um promissor adsorvente de gases poluentes. Os HDL s formam um grupo de argilas do tipo aniônico que consiste em camadas positivamente carregadas de óxido de metal (ou hidróxido de metal) com intercamadas de ânions. Foi constatado que ânions que possuem duas cargas negativas, estabilizam muito mais que ânions monovalentes, sendo o carbonato o mais estável dos ânions divalentes. Neste trabalho, foi proposta uma modificação na síntese direta através da co-precipitação a pH constante utilizando sais de cátions divalentes (Mg2+) e trivalentes (Al3+) reportados na literatura. Durante a síntese dos HDL s retirou-se o carbonato, bem como, utilizou-se um copolímero como um template para o alargamento das lamelas. As amostras foram caracterizadas utilizando as técnicas de DRX, TG/DTG, FTIR, MEV/EDX, MET e adsorção e dessorção de N2. Os dados obtidos indicam que a estrutura, mesmo após a modificação, apresentou resultados condizentes com os encontrados na literatura. Dentre as várias aplicações dos HDL s foi realizado o estudo da adsorção do CO2. A capacidade de adsorção do material foi testada de acordo com o tempo de contato entre o adsorvente e o adsorbato, sendo esperado que os materiais tratados com template apresentassem um maior desempenho

Estudos de adsorção de tetraciclina e cromoglicato em partículas de quitosana

Among the polymers that stand out most in recent decades, chitosan, a biopolymer with physico-chemical and biological promising properties has been the subject of a broad field of research. Chitosan comes as a great choice in the field of adsorption, due to their adsorbents properties, low cost and abundance. The presence of amino groups in its chain govern the majority of their properties and define which application a sample of chitosan may be used, so it is essential to determine their average degree of deacetylation. In this work we developed kinetic and equilibrium studies to monitor and characterize the adsorption process of two drugs, tetracycline hydrochloride and sodium cromoglycate, in chitosan particles. Kinetic models and the adsorption isotherms were applied to the experimental data. For both studies, the zeta potential analyzes were also performed. The adsorption of each drug showed distinct aspects. Through the studies developed in this work was possible to describe a kinetic model for the adsorption of tetracycline on chitosan particles, thus demonstrating that it can be described by two kinetics of adsorption, one for protonated tetracycline and another one for unprotonated tetracycline. In the adsorption of sodium cromoglycate on chitosan particles, equilibrium studies were developed at different temperatures, allowing the determination of thermodynamic parameters