Análise do desempenho de um queimador infravermelho funcionando com gás liquefeito de petróleo e glicerina

The use of infrared burners in industrial applications has many advantages in terms of technical-operational, for example, uniformity in the heat supply in the form of radiation and convection, with greater control of emissions due to the passage of exhaust gases through a macro-porous ceramic bed. This paper presents an infrared burner commercial, which was adapted an experimental ejector, capable of promoting a mixture of liquefied petroleum gas (LPG) and glycerin. By varying the percentage of dual-fuel, it was evaluated the performance of the infrared burner by performing an energy balance and atmospheric emissions. It was introduced a temperature controller with thermocouple modulating two-stage (low heat / high heat), using solenoid valves for each fuel. The infrared burner has been tested and tests by varying the amount of glycerin inserted by a gravity feed system. The method of thermodynamic analysis to estimate the load was used an aluminum plate located at the exit of combustion gases and the distribution of temperatures measured by a data acquisition system which recorded real-time measurements of the thermocouples attached. The burner had a stable combustion at levels of 15, 20 and 25% of adding glycerin in mass ratio of LPG gas, increasing the supply of heat to the plate. According to data obtained showed that there was an improvement in the efficiency of the 1st Law of infrared burner with increasing addition of glycerin. The emission levels of greenhouse gases produced by combustion (CO, NOx, SO2 and HC) met the environmental limits set by resolution No. 382/2006 of CONAMA

Análise de um queimador infravermelho funcionando com combustível híbrido : GLP/Bio-óleo

Biomass is considered the largest renewable energy source that can be used in an environmentally sustainable. From the pyrolysis of biomass is possible to obtain products with higher energy density and better use properties. The liquid resultant of this process is traditionally called bio-oil. The use of infrared burners in industrial applications has many advantages in terms of technical-operational, for example, uniformity in the heat supply in the form of radiation and convection, with a greater control of emissions due to the passage of exhaust gases through a macroporous ceramic bed. This paper presents a commercial infrared burner adapted with an ejector proposed able to burn a hybrid configuration of liquefied petroleum gas (LPG) and bio-oil diluted. The dilution of bio-oil with absolute ethanol aimed to decrease the viscosity of the fluid, and improving the stability and atomization. It was introduced a temperature controller with thermocouple modulating two stages (low heat / high heat), and solenoid valves for fuels supply. The infrared burner has been tested, being the diluted bio-oil atomized, and evaluated its performance by conducting energy balance. The method of thermodynamic analysis to estimate the load was used an aluminum plate located at the exit of combustion gases and the distribution of temperatures measured by thermocouples. The dilution reduced the viscosity of the bio-oil in 75.4% and increased by 11% the lower heating value (LHV) of the same, providing a stable combustion to the burner through the atomizing with compressed air and burns combined with LPG. Injecting the hybrid fuel there was increase in the heat transfer from the plate to the environment in 21.6% and gain useful benefit of 26.7%, due to the improved in the efficiency of the 1st Law of Thermodynamics of infrared burner

Caracterização físico-química de complexo de inclusão entre hidroximetilnitrofurazona e hidroxipropil-beta-ciclodextrina

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

Análise numérica do efeito de fatores influentes da reação álcali-agregado no desempenho de estruturas de concreto

The aim of this work is the numerical simulation of the mechanical performance of concrete affected by Alkali-Aggregate Reaction or RAA, reported by Stanton in 1940. The RAA has aroused attention in the context of Civil Engineering from the early 80, when they were reported consequences of his swelling effect in concrete structures, including cracking, failure and loss of serviceability. Despite the availability of experimental results the problem formulation still lacks refinement so that your solution remains doubtful. The numerical simulation is important resource for the assessment of damages in structures caused by the reaction, and their recoveries The tasks of support of this work were performed by means of the finite element approach, about orthotropic non-linear formulation, and, thermodynamic model of deformation by RAA. The results obtained revealed that the swelling effect of RAA induced decline of the mechanical performance of concrete by decreasing the margin of safety prior to the material failure. They showed that the temperature influences, exclusively, the kinetics of the reaction, so that the failure was the more precocious the higher the temperature of the solid mass of concrete

Análise teórico-experimental do coeficiente de perfomance (COP) de um sistema de refrigeração por jato-compressão

The use of waste heat of energy conversion equipment to produce a cooling effect, consists currently in a very interesting way of efficiency improvement of energy systems. The present research has as intention the theoretical and experimental study of a new intermittent refrigeration system ejector cycle characteristics, with use of waste heat. Initially, was doing a bibliographical survey about the vapor ejector refrigeration system technology. In the following stage was doing a simulation of the corresponding thermodynamic cycle, with preliminarily intention to evaluate the performance of the system for different refrigerants fluids. On the basis of the results of the simulation were selected the refrigerant fluid and developed an experimental group of benches of the refrigeration system considered, where pressure and temperature sensory had been inserted in strategical points of the refrigeration archetype and connected to a computerized data acquisition system for measure the refrigerant fluid properties in the thermodynamic cycle. The test results obtained show good agreement with the literature

Performance comparativa entre R290/R600a (50:50) e R134a para drop-in em refrigerador doméstico

This research this based on the seminar on Use of Natural Fluids in Refrigeration and Air-Conditioning Systems conducted in 2007 in Sao Paulo. The event was inserted in the National Plan for Elimination of CFCs, coordinated by the Ministry of Environment and implemented by the United Nations Development Programme (UNDP). The objective of this research is analyze the performance of the hydrocarbons application as zeotropic mixtures in domestic refrigerator and validate the application of technical standards for pull down and cycling (on-off) tests to the mixture R290/R600a (50:50) in domestic refrigerator. It was first developed an computational analysis of R290/R600a (50:50) compared to R134a and other mass fractions of the hydrocarbons mixtures in the standard ASHRAE refrigeration cycle in order to compare the operational characteristics and thermodynamic properties of fluids based on the software REFPROP 6.0. The characteristics of the Lorenz cycle is presented as an application directed to zeotropic mixtures. Standardized pull down and cycling (on-off) tests were conducted to evaluate the performance of the hydrocarbons mixture R290/R600a (50:50) as a drop-in alternative to R134a in domestic refrigerator of 219 L. The results showed that the use of R290/R600a (50:50) with a charge of refrigerant reduced at 53% compared to R134a presents reduced energy performance than R134a. The COP obtained with hydrocarbon mixture was about 13% lower compared to R134a. Pull down times in the refrigerator compartments for fluids analyzed were quite close, having been found a 4,7% reduction in pull down time for the R290/R600a compared to R134a, in the freezer compartment. The data indicated a higher consumption of electric current from the refrigerator when operating with the R290/R600a. The values were higher than about 3% compared to R134a. The charge of 40 g of R290/R600a proved very low for the equipment analyzed

Remoção de hidrocarbonetos do gás natural visando o ajuste do índice de metano

The use of the natural gas is growing year after year in the whole world and also in Brazil. It is verified that in the last five years the profile of natural gas consumption reached a great advance and investments had been carried through in this area. In the oil industry, the use of the natural gas for fuel in the drive of engines is usual for a long date. It is also used to put into motion equipment, or still, to generate electric power. Such engines are based on the motor cycle of combustion Otto, who requires a natural gas with well definite specification, conferring characteristic anti-detonating necessary to the equipment performance for projects based on this cycle. In this work, process routes and thermodynamic conditions had been selected and evaluated. Based on simulation assays carried out in commercial simulators the content of the methane index of the effluent gas were evaluated at various ranges of pressure, temperature, flowrate, molecular weight and chemical nature and composition of the absorbent. As final result, it was established a route based on process efficiency, optimized consumption of energy and absorbent. Thereby, it serves as base for the compact equipment conception to be used in locu into the industry for the removal of hydrocarbon from the natural gas produced

Avaliação da temperatura de cristalização da parafina em sistemas: parafina, solvente e tensoativo

The formation of paraffin deposits is common in the petroleum industry during production, transport and treatment stages. It happens due to modifications in the thermodynamic variables that alter the solubility of alkanes fractions present in petroleum. The deposition of paraffin can provoke significant and growing petroleum losses, arriving to block the flow, hindering to the production. This process is associated with the phases equilibrium L-S and the stages and nucleation, growth and agglomeration the crystals. That process is function of petroleum intrinsic characteristics and temperature and pressure variations, during production. Several preventive and corrective methods are used to control the paraffin crystallization, such as: use of chemical inhibitors, hot solvents injection, use of termochemistry reactions, and mechanical removal. But for offshore exploration this expensive problem needs more investigation. Many studies have been carried through Wax Appearance Temperature (WAT) of paraffin; therefore the formed crystals are responsible for the modification of the reologics properties of the oil, causing a lot off operational problems. From the determination of the WAT of a system it is possible to affirm if oil presents or not trend to the formation of organic deposits, making possible to foresee and to prevent problems of wax crystallization. The solvent n-paraffin has been widely used as fluid of perforation, raising the production costs when it is used in the removal paraffin deposits, needing an operational substitute. This study aims to determine the WAT of paraffin and the interference off additives in its reduction, being developed system paraffin/solvent/surfactant that propitiates the wax solubilization. Crystallization temperatures in varied paraffin concentrations and different solvents were established in the first stage of the experiments. In the second stage, using the methodology of variation of the photoelectric signal had been determined the temperature of crystallization of the systems and evaluated the interferences of additives to reduction of the WAT. The experimental results are expressed in function of the variations of the photoelectric signals during controlled cooling, innovating and validating this new methodology to determine WAT, relatively simple with relation the other applied that involve specific equipments and of high cost. Through the curves you differentiate of the results had been also identified to the critical stages of growth and agglomeration of the crystals that represent to the saturation of the system, indicating difficulties of flow due to the increase of the density

Determinação experimental e modelagem termodinâmica do ponto de turbidez de sistemas aquosos com tensoativos nonilfenolpolietoxilados

The nonionic surfactants are composed of substances whose molecules in solution, does not ionize. The solubility of these surfactants in water due to the presence of functional groups that have strong affinity for water. When these surfactants are heated is the formation of two liquid phases, evidenced by the phenomenon of turbidity. This study was aimed to determine the experimental temperature and turbidity nonilfenolpoliethoxyled subsequently perform a thermodynamic modeling, considering the models of Flory-Huggins and the empirical solid-liquid equilibrium (SLE). The method used for determining the turbidity point was the visual method (Inoue et al., 2008). The experimental methodology consisted of preparing synthetic solutions of 0,25%, 0,5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12,5%, 15%, 17% and 20% by weight of surfactant. The nonionic surfactants used according to their degree of ethoxylation (9.5, 10, 11, 12 and 13). During the experiments the solutions were homogenized and the bath temperature was gradually increased while the turbidity of the solution temperature was checked visually Inoue et al. (2003). These temperature data of turbidity were used to feed the models evaluated and obtain thermodynamic parameters for systems of surfactants nonilfenolpoliethoxyled. Then the models can be used in phase separation processes, facilitating the extraction of organic solvents, therefore serve as quantitative and qualitative parameters. It was observed that the solidliquid equilibrium model (ESL) was best represented the experimental data.

Determinação de dados de equilíbrio líquido-vapor a altas pressões para sistemas de hidrocarbonetos assimétricos

Crude oil is a complex liquid mixture of organic and inorganic compounds that are dominated by hydrocarbons. It is a mixture of alkanes from the simplest to more complex aromatic compounds that are present derivatives such as gasoline, diesel, alcohol, kerosene, naphtha, etc.. These derivatives are extracted from any oil, however, only with a very high quality, in other words, when the content of hydrocarbons of low molecular weight is high means that production of these compounds is feasible. The American Petroleum Institute (API) developed a classification system for the various types of oil. In Brazil, the quality of most of the oil taken from wells is very low, so it is necessary to generate new technology to develop best practices for refining in order to produce petroleum products of higher commercial value. Therefore, it is necessary to study the thermodynamic equilibrium properties of its derivative compounds of interest. This dissertation aims to determine vapor-liquid equilibrium (VLE) data for the systems Phenilcyclohexane - CO2, and Cyclohexane - Phenilcyclohexane - CO2 at high pressure and temperatures between 30 to 70oC. Furthermore, comparisons between measured VLE experimental data from this work and from the literature in relation to the Peng- Robinson molecular thermodynamic model, using a simulation program SPECS IVCSEP v5.60 and two adjustable interaction parameters, have been performed for modeling and simulation purposes. Finally, the developed apparatus for determination of phase equilibrium data at high pressures is presented

Inferência do ponto de orvalho em amostras de gás natural processado

This dissertation aims to assess the representativeness of the manual chilled mirror analyzer (model II Chanscope 13-1200-CN-2) used for the determination of condensed hydrocarbons of natural gas compared to the indirect methods, based on thermodynamic models equation of state. Additionally, it has been implemented in this study a model for calculating the dew point of natural gas. The proposed model is a modification of the equation of state of Peng-Robinson admits that the groups contribution as a strategy to calculate the binary interaction parameters kij (T) temperature dependence. Experimental data of the work of Brown et al. (2007) were used to compare the responses of the dew point of natural gas with thermodynamic models contained in the UniSim process simulator and the methodology implemented in this study. Then two natural gas compositions were studied, the first being a standard gas mixture gravimetrically synthesized and, second, a mixture of processed natural gas. These experimental data were also compared with the results presented by UniSim process simulator and the thermodynamic model implemented. However, data from the manual analysis results indicated significant differences in temperature, these differences were attributed to the formation of dew point of water, as we observed the appearance of moisture on the mirror surface cooling equipment

Extração do corante reactive blue 19 utilizando tensoativo não iônico

The generation of effluent from the finishing process in textile industry is a serious environmental problem and turned into an object of study in several scientific papers. Contamination with dyes and the presences of substances that are toxic to the environment characterize this difficult treatment effluent. Several processes have already been evaluated to remove and even degrade such pollutants are examples: coagulation-flocculation, biological treatment and advanced oxidative processes, but not yet sufficient to enable the recovery of dye or at least of the recovery agent. An alternative to this problem is the cloud point extraction that involves the application of nonionic surfactants at temperatures above the cloud point, making the water a weak solvent to the surfactant, providing the agglomeration of those molecules around the dyes molecules by affinity with the organic phase. After that, the formation of two phases occurred: the diluted one, poor in dye and surfactant, and the other one, coacervate, with higher concentrations of dye and surfactants than the other one. The later use of the coacervate as a dye and surfactant recycle shows the technical and economic viability of this process. In this paper, the cloud point extraction is used to remove the dye Reactive Blue from the water, using nonionic surfactant nonyl phenol with 9,5 etoxilations. The aim is to solubilize the dye molecules in surfactant, varying the concentration and temperature to study its effects. Evaluating the dye concentration in dilute phase after extraction, it is possible to analyze thermodynamic variables, build Langmuir isotherms, determine the behavior of the coacervate volume for a surfactant concentration and temperature, the distribution coefficient and the dye removal efficiency. The concentration of surfactant proved itself to be crucial to the success of the treatment. The results of removal efficiency reached values of 91,38%, 90,69%, 89,58%, 87,22% and 84,18% to temperatures of 65,0, 67,5, 70,0, 72,5 and 75,0°C, respectively, showing that the cloud point extraction is an efficient alternative for the treatment of wastewater containing Reactive Blue

Estudo do equilíbrio líquido-vapor do sistema água+etanol+líquido iônico visando a separação do álcool anidro

Anhydrous ethanol is used in chemical, pharmaceutical and fuel industries. However, current processes for obtaining it involve high cost, high energy demand and use of toxic and pollutant solvents. This problem occurs due to the formation of an azeotropic mixture of ethanol + water, which does not allow the complete separation by conventional methods such as simple distillation. As an alternative to currently used processes, this study proposes the use of ionic liquids as solvents in extractive distillation. These are organic salts which are liquids at low temperatures (under 373,15 K). They exhibit characteristics such as low volatility (almost zero/ low vapor ), thermal stability and low corrosiveness, which make them interesting for applications such as catalysts and as entrainers. In this work, experimental data for the vapor pressure of pure ethanol and water in the pressure range of 20 to 101 kPa were obtained as well as for vapor-liquid equilibrium (VLE) of the system ethanol + water at atmospheric pressure; and equilibrium data of ethanol + water + 2-HDEAA (2- hydroxydiethanolamine acetate) at strategic points in the diagram. The device used for these experiments was the Fischer ebulliometer, together with density measurements to determine phase compositions. The experimental data were consistent with literature data and presented thermodynamic consistency, thus the methodology was properly validated. The results were favorable, with the increase of ethanol concentration in the vapor phase, but the increase was not shown to be pronounced. The predictive model COSMO-SAC (COnductor-like Screening MOdels Segment Activity Coefficient) proposed by Lin & Sandler (2002) was studied for calculations to predict vapor-liquid equilibrium of systems ethanol + water + ionic liquids at atmospheric pressure. This is an alternative for predicting phase equilibrium, especially for substances of recent interest, such as ionic liquids. This is so because no experimental data nor any parameters of functional groups (as in the UNIFAC method) are needed

Equilíbrio líquido-líquido para o sistema biodiesel de óleo de semente de melão (Cucumis melo l.) + metanol + glicerina

Rio Grande do Norte, northeast state from Brazil, it is the greatest producer and exporter of yellow melon, well known as Spanish melon. Despite the consumption of this fruit to be mainly its pulp, melon seeds are an important source of lipids considered an industrial residue it has been discharge product. The use of oilseeds in order to produce biodiesel establishes an important raw material and the increase of its production promotes the national development of the agriculture. In this background, the aim of this work has been to use oil from seeds of yellow melon to produce biodiesel and to accomplish a study of the phase equilibrium of the system evolving biodiesel, methanol and glycerin. The biodiesel was obtained by oil transesterification through methylic route with molar ratio 1:9.7 (oil:alcohol) and with a mass of NaOH of 0.5% from the oil mass; the reaction time was 73 minutes at 55 °C. A yield of 84.94% in biodiesel was achieved. The equilibria data present a well-characterized behavior with a great region of two phases. The tie lines indicate that methanol has a best solubility in the phase that is rich in glycerin. Consistency of the experimental data was made based on Othmer-Tobias and Hand correlations which values above 0.99 were found to correlation coefficients, this fact confers a good thermodynamic consistency to the experimental data. NRTL and UNIQUAC models were employed to predict liquid-liquid equilibrium of this system. It was observed a better concordance of the results when NRTL was applied (standard deviation 1.25%) although the UNIQUAC model has presented a quite satisfactory result either (standard deviation 2.70%). The NRTL and UNIQUAC models were also used to evaluate the effect of temperature in the range of 328 K to 358 K, in which a little change in solubility with respect to the data obtained at 298 K was observed, thus being considered negligible the effect of temperature

Determinação de dados de equilíbrio de fases para sistemas aquosos com eletrólitos

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 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