Utilização de bagaço de caju desidratado e complexo enzimático na ração para codornas japonesas em postura

Given the significant share of food costs of poultry production, it is necessary to use strategies and techniques to maximize the utilization and biological value of the components of the diets, keeping constant or improving animal performance. In this context, seeking partial substitution of corn and the best use of the constituents of the diet, the present study aimed to evaluate the effects of inclusion of cashew pomace dehydrated (BCD) and enzyme complex (EC) in the diet on performance and quality eggs of Japanese quails. A total of 200 Japanese quail at 87 days of age, in 25 cages in a completely randomized design in a factorial 2 x 2 + 1 (two levels of cashew bagasse x two levels of enzymes) + control diet without cashew bagasse totaling five treatments with five replicates of eight birds each repetition. The experiment lasted 84 days, divided into four periods of 21 days. The treatments consisted of T1-Ration Control, T2-ration with 7.5% without EC BCD, T3-ration with 7.5% BCD with CE, T4-Ration with 15% BCD without EC and T5-Feed with 15% of BCD with EC. The enzyme complex (EC) is used fermentation product of Aspergillus niger, and cashew bagasse was obtained from the juice industry, passed through drying and crushing process for producing the bran. The performance and egg quality of quails, and performance variables: feed intake (FI), feed conversion ratio per dozen eggs (CAKDZ) and egg mass (CAMO), egg production (OP% bird / day), average egg weight (PMO) and egg mass (MO), and variables were egg quality, specific gravity (SG), Haugh unit (HU), yolk index, and the relationships between components eggs (%albumen,% yolk and %shell). Data were analyzed with the Statistical SAEG (2007). The 7.5 and 15% of cashew bagasse, independent of the enzyme complex decreased feed intake and improved the average egg weight. The two levels with the addition of EC showed significant differences for feed conversion by egg mass. The 7.5 with the addition of enzyme complex obtained the lowest average feed conversion per dozen eggs. The inclusion of up to 15% of cashew bagasse dehydrated with or without addition of enzyme complex in the diet of Japanese quails not interfere in the internal and external quality of eggs. The 7.5 and 15% BCD without added enzyme complex gave better means for specific gravity. Under conditions in which the experiment was conducted, it can be stated that the inclusion of up to 15% of cashew bagasse dehydrated with added enzyme complex feeding quail is economically viable, with the level of 7.5% with the addition of complex enzyme presented the best economic indices

Caracterização comportamental e avaliação da qualidade de leite em caprinos da raça saanen no semiárido nordestino

Goats are social animals which groups are organized from dominance hierarchies, established by agonistic behaviors. The quality and productivity of the goat s milk can be influenced by the dominance hierarchy. In this context, the objectives of our work were describe the social and food behavior of Saanen goats in a semi-extensive production system; characterize the social organization from the assessment of dominance hierarchies in two seasonal periods and correlate the physicochemical quality of the goats milk according hierarchical position. The experiment was conducted in the EMPARN s experimental station, located in the district of Cruzeta/RN. We utilized 17 multiparous goats of the Saanen race, with different age and weight. The observations were performed in precipitation and drought phases. The scan method recorded the trough permanence and agonistic interactions by method "all occurrences" in the pasture the alimentary behaviors of eat, ruminate on foot, ruminate lying, leisure on foot, leisure lying and walk, by the focal animal sampling method. The goats milk was submitted to analyzes of: density, protein, fat, lactose, CSS and total solids. The animals spend most of the time feeding themselves, and the activities that demand greater energy expenditure are done in the morning. The animals changed the hierarchical structure during the seasonal periods because of the withdrawal of some individuals of the group, having more aggressive behavior in the rainy season. The dominant animal the lowet production, the more CSS and the lesser fat, the goat in the middle of the hierarchy was the one that obtained the best production and quality. We conclude that the Saanen goats adapt to the environment and the conditions of the group to ensure better survival and its production is influenced by the internal dynamics of the group

Avaliação do comportamento termoanalítico e oxidativo do biodiesel de mamona

In this work biodiesel was gotten through the transesterification reaction using the oil of castor as source of triglycerides and using the methylic route for obtaining of esters. For the characterization of biodiesel and its mixtures with mineral diesel oil, physical chemical parameters and several analytical techniques had been used, as well as: gas chromatography (GC), nuclear magnetic resonance of proton (1H NMR), infrared spectroscopy (IR) and thermal analysis. The chromatography confirmed the complete reaction of esters in biodiesel presenting a 97,08% conversion. The 1H - NMR presented singlet in 3,6 ppm corresponding to the hydrogen of the group ester RCOO CH3. The infrared presented a strong band in 1741 cm-1 referring to stretching C=O of ester and an average band in 1175 cm-1 referring C O deformation. With the data of thermal analysis it was possible to observe the thermal and oxidative stability of the samples changing the atmospheres of synthetic air and nitrogen, where stages of the thermal decomposition had been verified and had been attributed to the volatilization and/or decomposition of the triacylglycerides. The thermal degradation of the samples was carried through 150 and 210°C during 1, 12, 24 and 48 hours and was observed change in the thermogravimetric profile, therefore an increase in the number of stages of the thermal decomposition also occurred indicating characteristic intermediate composites of polymerization, being this confirmed through the rheological study that presented brusque increase of viscosity. The kinetic study showed that the activation energy has the following order: biodiesel > mineral diesel oil > mixtures biodiesel/diesel

Síntese, caracterização e avaliação catalítica do silicoaluminofosfato SAPO-11 sulfatado

Due to environmental restrictions around the world, clean catalytic technology are of fundamental importance in the petrochemical industry and refineries. Creating the face of this a great interest in replacing the liquid acids for solid acids, so as molecular sieves have been extensively studied in reactions involving the acid catalysis to produce chemical substances with a high potential of quality. Being the activity of the catalysts involved in the reaction attributed to the acid character of them involved for the Lewis and Brönsted acid sites. Based on this context, this study aimed to prepare catalysts acids using a molecular sieve silicoalumino-phosphate (SAPO-11) synthesized in hidrotermical conditions and sulphated with sulphuric acid at different concentrations, using to it the method of controlled impregnating. The samples resulting from this process were characterized by x-ray difratometry (DRX), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermal analysis (TG-DTG) and determination of total acidity (by n-butilamin adsorption). The results show that the synthesis method used was efficient in the formation of AEL structure of SAPO-11 and when being incorporated the sulfate groups in this structure the acidity of the material was increased, pointing out that to very high concentrations of acid there is a trend of decrease the main peaks that form the structure. Finally they were tested catalytictly by the reaction model of conversion of m-xylene which showed favorable results of conversion for this catalyst, showing to be more selective of cracking products than isomerization, as expected, in order that for the o-xylene selectivity there was no positive change when to sulfate a sample of SAPO-11, while for light gases of C1-C4 this selectivity was remarkably observed

Hidróxidos duplos lamelares aplicados à obtenção de biodiesel

In this paper, the Layered Double Hydroxides (LDH s) type hydrotalcite were synthesized, characterized and tested as basic heterogeneous catalysts for the production of biodiesel by transesterification of sunflower oil with methanol. The synthesis of materials Layered Double Hydroxides (LDH s) by co-precipitation method from nitrates of magnesium and aluminum, and sodium carbonate. The materials were submitted to the variation in chemical composition, which is the amount of Mg2+ ions replaced by Al3+. This variation affects the characteristic physico-chemical and reaction the solid. The molar ratio varied in the range of 1:1 and 3:1 magnesium / aluminum, and their values between 0.2 and 0.33. This study aims to evaluate the influence of variation of molar ratio of mixed oxides derived from LDH s and the influence of impregnation of a material with catalytic activity, the KI, the rate of conversion of sunflower oil into methyl esters (biodiesel) through transesterification by heterogeneous catalysis. .The catalysts were calcined at 550 ° C and characterized by X-ray diffraction (XRD), scanning electron microscopy and energy dispersive spectroscopy of X-ray (SEM / EDS), thermogravimetric analysis (TG) and test basicity. The transesterification reaction was performed for reflux is a mixture of sunflower oil and methanol with a molar ratio of 15:1, a reaction time of 4h and a catalyst concentration of 2% by weight. The physical-chemical characterization of sunflower oil and biodiesel obtained by the route methyl submitted according NBR, EN, ASTM. Subsequently, it was with the chromatographic and thermogravimetric characterizations of oils. The results of chromatographic analysis showed that the catalysts were effective in converting vegetable oil into biodiesel, in particular the type hydrotalcite KI-HDL-R1, with a conversion of 99.2%, indicating the strong influence of the chemical composition of the material, in special due to presence of potassium in the structure of the catalyst

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

Estudo da estabilidade térmica de adoçantes naturais e artificiais

Sweeteners provide a pleasant sensation of sweetness that helps the sensory quality of the human diet, can be divided into natural sweeteners such as fructose, galactose, glucose, lactose and sucrose, and articial sweeteners such as aspartame, cyclamate and saccharin. This work aimed to study the thermal stability of natural and artificial sweeteners in atmospheres of nitrogen and syntetic air using thermogravimetry (TG), derivative thermogravimetry (DTG), Differential Thermal Analysis (DTA) and Differential Scanning Calorimetry (DSC). Among the natural sweeteners analyzed showed higher thermal stability for the lactose and sucrose, which showed initial decomposition temperatures near 220 ° C, taking advantage of the lactose has a higher melting point (213 ° C) compared to sucrose (191 ° C). The lower thermal stability was observed for fructose, it has the lowest melting point (122 °C) and the lower initial decomposition temperature (170 °C). Of the artificial sweeteners studied showed higher thermal stability for sodium saccharin, which had the highest melting point (364 ° C) as well as the largest initial decomposition temperature (466 ° C under nitrogen and 435 ° C in air). The lower thermal stability was observed for aspartame, which showed lower initial decomposition temperature (158 ° C under nitrogen and 170 ° C under air). For commercial sweeteners showed higher thermal stability for the sweeteners L and C, which showed initial temperature of thermal decomposition near 220 ° C and melting points near 215 ° C. The lower thermal stability was observed for the sweetener P, which showed initial decomposition temperature at 160 ° C and melting point of 130 °C. Sweeteners B, D, E, I, J, N and O had low thermal stability, with the initial temperature of decomposition starts near 160 °C, probably due to the presence of aspartame, even if they have as the main constituent of the lactose, wich is the most stable of natural sweeteners. According to the results we could also realize that all commercial sweeteners are in its composition by at least a natural sweeteners and are always found in large proportions, and lactose is the main constituent of 60% of the total recorded

Obtenção de biodiesel através da transesterificação do óleo de farelo de arroz utilizando KI/Al2O3

This study proposes to find a biodiesel through transesterification of rice bran oil with KI/Al2O3 checking the influence of two types of alumina (Amorphous and Crystalline) for conversion into methyl esters. The catalyst was synthesized by the wet impregnation method. Adding 30 mL of 35% KI(aq.) in 10 g of alumina, under stirring at 80 °C for 3 hours. The reaction conditions used in this study were optimized, with a molar ratio methanol:oil of 15:1, 8 h of reaction time and reflux temperature. The catalyst amount was varied in the range of 1 to 5 % wt. The solid catalysts materials were analyzed by: x-ray diffraction (XRD), thermogravimetry (TG), N2 adsorption/desorption, scanning electron microscopy (SEM) and basicity, for the identification of its structure and composition, verifying the presence of basic sites. The results showed that Al2O3(A) presents an amorphous structure, high surface area and a better catalytic activity, in relation to the catalyst synthesized with Al2O3(C) support that proved to have a more crystalline structure, having as well, a lesser surface area, enabling difficulties for the incorporation of active sites. The obtained biodiesel with 5% wt. KI/Al2O3(A) presented physicochemical properties within the standards specified by the Resolution No 7/2008 ANP and obtained the best reaction yield with 95.2%, according to quantitative measurement from the TG, which showed 96.2% conversion into methyl esters. It was furthermore found that with the increasing amount of the quantity of the catalyst in the reaction, there was also an increase in the ester content obtained. The specific mass and the kinematic viscosity were reduced with the increase of the amount of quantity of the catalyst, indicating an increase in the conversion of triglycerides

Estudo termoanalítico de medicamentos de referência, genérico e similar

This study aimed to apply, thermogravimetriy /derivative Thermogravimetriy (TG/DTG), differential scanning calorimetry (DSC), Differential Thermal Analysis (DTA), to conduct a comparative study on drug reference, generic and whose active principles are similar captopril hydrochlorothiazide, ampicillin, paracetamol, aspirin and mebendazole sold in local pharmacies. Samples of the active ingredients and dosage forms were also characterized by absorption infrared spectroscopy (IR), X-ray diffraction (XRD) and microscopy scanning electron (SEM). The TG / DTG curves showed a general similarity in the thermal behavior of the samples, but also showed the influence of excipients on the thermal stability. The DSC curve of the generic base hydrochlorothiazide showed no peak on the fusion of the drug due to interference of lactose as a diluent, which causes interaction with the active principle causing their degradation before the merger. The DSC curves of the drugs consisting of paracetamol showed reproducibility at the melting point of the active and the other thermal events. The DSC result of binary mixtures involving captopril / magnesium stearate and mebendazole/magnesium stearate showed possible interactions or incompatibilities evidenced by the displacement of the melting point of both drugs. The other mixtures showed no change. The infrared spectra presented were very similar, indicating the presence of functional groups characteristic of the constituents of the samples. The X-ray diffraction showed peaks indicative of crystalline structure of the active ingredients as well as some of the ingredients in the formulation of the drug and the micrographs indicate a general heterogeneity in the size distribution of particles in the samples

Eficiência do processo de obtenção do biodiesel de girassol usando o catalisador KNO3/Al2O3

It is known that the head office world energetics is leaning in the fossil fuels. However, the world panorama is changing quickly, for linked reasons to three of the humanity's great concerns in that century beginning: environment, global economy and energy. The biodiesel production is based on the transesterificação of vegetable oils or animal fats, using catalysts homogeneous or heterogeneous. The process of heterogeneous transesterificação presents lower conversions in comparison with the homogeneous, however, it doesn't present corrosion problems and it reduces to the occurrence of parallel reactions as saponification. In this sense, this work has for purpose the synthesis of a heterogeneous catalyst, KNO3/Al2O3, that soon afterwards was used in the reaction of transesterificação of the oil of the Helianthus annuus L. (sunflower). The solid materials (it supports and catalyst) they were analyzed by diffraction of ray-X (XRD) and electronic microscope of sweeping (MEV). After the analysis of Al2O3, a structure monophase amorphous tetragonal was verified, with characteristic patterns of that material, what could not be visualized in the difratograma of the catalyst. The biodiesel obtained with 4% wt. of KNO3/Al2O3 it was what obtained a better cinematic viscosity 8,3 mm2/s, comparing with the norms of ANP, and it also presented the best conversion tax in ethyl ésteres, in accordance with the quantitative measure starting from TG, that was of 60%. While the biodiesel with 6% wt. and with 8% wt. of KNO3/Al2O3 it was it that no transesterificou, because it was observed in the analysis termogravimétrica of those two materials, a single thermal event, that it corresponds the decomposition or volatilization of the triglycerides

Extração e análise da fração lipídica da microalga monoraphidium sp., síntese e caracterização do seu biodiesel

The cultivation of microalgae biomass in order to produce biodiesel arises as an extremely promising aspect, in that the microalgae culture includes short cycle of reproduction, smaller areas for planting and residual biomass rich in protein content. The present dissertation evaluates the performance and features, through spectrometry in the region of infrared with transformed Fourier (FTIR) and spectrometry in the region of UVvisible (UV-Vis), of the extracted lipid material (LM) using different techniques of cell wall disruption (mechanical agitation at low and at high spin and agitation associated with cavitation). The technique of gas chromatography (GC) brought to light the success of alkaline transesterification in the conversion of oil into methyl monoesters (MME), which was also analyzed by spectroscopic techniques (FTIR, proton magnetic resonance (1H NMR) and carbon (13C NMR). Through thermogravimetric analysis (TGA) were analyzed the lipid material (LM), biodiesel and the microalgae biomass. The method which provided the best results concerning the efficiency in extraction of the LP of Monoraphidium sp. (12,51%) was by mechanical agitation at high spin (14 000 rpm), for 2 hours being the ideal time, as shown by the t test. The spectroscopic techniques (1H NMR, 13C NMR and FTIR) confirmed that the structure of methyl monoesters and the chromatographic data (CG) revealed a high content of saturated fatty acid esters (about 70%) being the major constituent eicosanoic acid (33,7%), which justifies the high thermal stability of microalgae biodiesel. The TGA also ratified the conversion rate (96%) of LM into MME, pointing out the quantitative results compatible with the values obtained through GC (about 98%) and confirmed the efficiency of the extraction methods used, showing that may be a good technique to confirm the extraction of these materials. The content of LM microalgae obtained (12,51%) indicates good potential for using such material as a raw material for biodiesel production, when compared to oil content which can be obtained from traditional oil for this use, since the productivity of microalgae per hectare is much larger and requires an extremely reduced period to renew its cultivation

Avaliação oxidativa do biodiesel de pinhão manso em diferentes processos de purificação

The objective of this study was to analyze the oxidative stability of biodiesel from jatropha obtained from different purification processes, three wet processes with different drying (in a vacuum oven, conventional oven and in anhydrous sodium sulfate) and dry (purification with magnesium silicate adsorbent). Raw materials of different qualities (jatropha crop ancient and recent crop) were used. The Jatropha oil was extracted by mechanical extraction and refined. The Jatropha biodiesel was obtained by the transesterification reaction in ethyl route using alkaline catalysis. The biodiesel samples were characterized by analysis of water content, carbon residue, Absorption Spectroscopy in the Infrared Region and Thermogravimetry. Thermogravimetric curves of purified PUsv* PUsq* and had higher initial decomposition temperatures, indicating that the most stable, followed by samples PU* and PUSC*. Besides the sample SP* is a smaller initial temperature, confirming the sample without purification to be less thermally stable. The percentage mass loss of the purified samples showed conversion of about 98.5%. The results of analyzes carbon residue and infrared suggested that contamination by impurities is the main factor for decreased oxidative stability of biodiesel. The oxidative stability was assessed from periodic monitoring, using the techniques of Rancimat, peroxide index, acid value and Pressurized Differential Scanning Calorimetry. Samples of biodiesel from jatropha which showed better oxidative stability were of the best quality raw material and wet scrubbing: PUsq* with dry chemical, using anhydrous sodium sulfate and PUsv* with vacuum drying, which had oxidative stability 6 hours in Rancimat time 0 days, within the limits established by the Technical Regulation No. 4/2012 of the ANP, without the addition of antioxidant, suggesting that these procedures the least influence on the oxidative stability of biodiesel

Craqueamento térmico e termocatalítico do óleo de girassol (Hellianthus annus L.) sobre materiais micro e mesoporosos

Microporous materials zeolite type Beta and mesoporous type MCM-41 and AlMCM-41 were synthesized hydrothermally and characterized by methods of X-ray diffraction, Fourier transform infrared, scanning electron microscopy, surface acidity, nitrogen adsorption, thermal analysis TG / DTG. Also we performed a kinetic study of sunflower oil on micro and mesoporous catalysts. The microporous material zeolite beta showed a lower crystallinity due to the existence of smaller crystals and a larger number of structural defects. As for the mesoporous materials MCM-41 and AlMCM-41 samples showed formation of hexagonal one-dimensional structure. The study of kinetic behavior of sunflower oil with zeolite beta catalysts, AlMCM-41 and MCM-41 showed a lower activation energy in front of the energy of pure sunflower oil, mainly zeolite beta. In the thermal cracking and thermocatalytic of sunflower oil were obtained two liquid fractions containing an aqueous phase and another organic - organic liquid fraction (FLO). The FLO first collected in both the thermal cracking as the thermocatalytic, showed very high level of acidity, performed characterizations of physicochemical properties of the second fraction in accordance with the specifications of the ANP. The second FLO thermocatalytic collected in cracking of sunflower oil presented results in the range of diesel oil, introducing himself as a promising alternative for use as biofuel liquid similar to diesel, either instead or mixed with it

Estudo do desempenho de catalisadores tipo Ni/CexM1-xO2 (M = Zr ou Mn) na reação de oxidação parcial do metano

One of the main applications of methane is in the production of syngas, a mixture of hydrogen and carbon monoxide. Procedures used in this process are steam reforming, CO2 reforming, partial oxidation and autothermal reforming. The present study evaluated and compared the behavior of nickel catalysts supported on mixed oxides of cerium and manganese in the partial oxidation of methane with that of nickel catalysts supported on mixed oxides of cerium and zirconium. Mixed oxides of cerium and zirconium or cerium and manganese were synthesized using two different preparation methods, the polymeric precursor based on Pechini method and combustion reaction using a microwave. This was followed by impregnation with nickel content of 15 %. Samples were calcined at 300, 800 and 900 °C and characterized by specific surface area (SSA), X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), temperature programmed reduction (TPR) and the reaction of partial oxidation of methane. The specific areas of samples decrease with the rise in calcination temperature and after nickel impregnation. Metal-cerium solid solution was formed and the presence of other manganese species outside the solid solution structure was confirmed in the compound with the highest amounts of manganese oxides showed. With regard to scanning electron microscopy, supports based on cerium and zirconium prepared by Pechini method exhibited agglomerated particles without uniform geometry or visible pores on the surface. However, compounds containing manganese presented empty spaces in its structure. Through synthesis by combustion reaction, morphology acquired independently of the proposed composition demonstrated greater porosity in relation to Pechini synthesis. Although catalysts were prepared using different synthesis methods, the insertion of nickel showed very similar reduction profiles (TPR). In relation to nickel catalysts supported on mixed oxide of cerium and zirconium, there is an initial reduction of NiO species that present certain interaction with the support. This is followed by the reduction of Ce4+ in Ce3+ surface, with subsequent bulk reduction. For catalysts containing manganese, a reduction of nickel oxide species occurs, followed by two stages of reduction for species Mn2O3 in Mn3O4 and Mn3O4 in MnO, with subsequent reduction of bulk. With respect to partial oxidation reactions, the nickel catalyst supported on mixed oxide of cerium and zirconium, prepared using the Pechini method, exhibited CH4 conversion of approximately 80 %, with conversion of 81 % when prepared by combustion. This behavior continued for 10 hours of reaction. Manganese content was also found to directly influence catalytic activity of materials; the greater the manganese oxide content, the faster deactivation and destabilization occurred in the catalyst. In both synthesis methods, the nickel catalyst supported on mixed oxide of cerium and zirconium maintained an H2/CO ratio very close to 2 during the 10 hours of partial oxidation reaction. Samples containing manganese displayed smaller H2/CO ratios and lower performance in partial oxidation.

Estudo comparativo entre a pirólise do polietileno de baixa densidade, utilizando vermiculita modificada e SBA-15

Catalytic processes are widely present in everyday life. This results in large number of studies seeking materials that may combine the low cost catalytic efficiency. Based on this assumption, the clays have long been used as catalysts, with its huge availability, diversity and possibility of improving their properties from structural changes, primarily responsible for this great use. Among the natural clays, vermiculite due to their characteristic properties (high cation exchange capacity and expansion), is suitable for various applications including as catalysts and catalyst supports. In this work, the acid leaching of clay vermiculite was performed, coming from Santa Luzia-PB, with nitric acid (2, 3 and 4 mol / L) and subsequent calcination of the materials obtained. The materials were named as Vx/400, where x is the acid concentration employed and 400 used in calcination temperature. The effectiveness of changes made was determined by XRD techniques, FT-IR, EDS, TG/DTG, nitrogen physisorption and DTP of n-butylamine. Acid leaching has improved some properties of the clay - specific area and acidity - but the control of the acid concentration used is of vital importance, since the highest concentration caused the partial destruction of vermiculite entailing a decline in their properties. For analysis of the catalytic activity of the modified clay was made a comparative study with the SBA -15 mesoporous materials, synthesized via hydrothermal method, using the pyrolysis of low density polyethylene (LDPE). The results showed that the acid plays a fundamental role in the conversion of the polymer into smaller molecules, the material V3/400 was more selective for the source monomer (ethylene) due to their increased acidity, which promotes more breaks bonds in the polymeric chain, while materials and V0/400 V2/400, lower acidity, showed higher selectivity to light hydrocarbons, the range of fuel (41.96 and 41.23%, respectively), due to less breakage and secondary condensation reactions chains; already V4/400 SBA-15/550 and resulted in lower percentages of light hydrocarbons and the partial destruction of the structure and low acidity, respectively, responsible for the inefficiency of materials