Oil storage tanks and their pipelines are mostly constructed under the ground. If the leaches are occurred, the soil pollution and the contamination of groundwater quality will influenced seriously. The soil of oil polluted sites is usually containing the huge amounts of volatile organic compounds (VOCs) and other organics. These VOCs is uncomfortable on physical body when they spread into atmosphere not only to cause the harm of human health but also to react into photochemical smog. Besides, the VOCs are probably reacting with nitrogen oxides into the problems of high concentrations of ozone. In this study, we used a regenerative catalytic oxidizer (RCO) to deal with VOCs in soil of the oil polluted sites. The RCO system was packed with self-made catalyst of 20 wt%CuMn/£^-Al2O3. Experimental results revealed 90¡Ó5% of the influent VOCs (C0=450-10,000 ppm) was thermally destruction with no catalyst in beds operated with a valve shifting time (ts) of 2 min, superficial gas velocities (Ug) of 0.37 m/s (evaluated at an influent air temperature of around 30¢J) and present maximum destruction temperature (TS) of 800-900¢J. With the catalyst packings and operation conditions of Ug=0.37 m/s and C0=450~10,000 ppm, the destruction efficiency of 93.35 and 96.5% were observed, respectively in average at TS of 600 and 650¢J. When Ug=1.11 m/s and C0=450-10,000 ppm, the destruction efficiency of 87.51 and 93.75% were observed, respectively in average at TS of 600 and 650¢J. The destruction efficiency of RCO is high at higher influent concentration of VOCs and low gas velocities at TS=600-650¢J.

No description available.

Abstract Isopropyl alcohol¡]IPA¡^and toluene are extensively used in industry as solvents. They are all highly toxic to animals and humans. Accordingly, IPA and toluene are strongly associated with problems of VOCs. In first step catalytic incineration was adopted to decompose IPA and toluene in laboratory, and the second step for a pilot-scale regenerative catalytic oxidizer ¡]RCO¡^were adopted to decompose mixture VOCs in real soil herein. The screening test of catalytic activity and the influences of the operational parameters on IPA and toluene removal efficiencies were widely discussed through catalytic incinerations of IPA and toluene in laboratory. The more effective and cheaper catalysts through above discussions of catalytic incineration were selected. And they were utilized in an pilot scale RCO as follows to investigate their performance in VOCs oxidation and RCO operations in THC removal of contamination soils. The achievements of this study are summarized as follows: ¡]1¡^Cu/Mn and Cu/Co gravel catalytic incinerations of isopropyl alcohol The results demonstrated that 10 wt% Cu0.6Co0.4 catalyst was the most effective because the CO2 yield reached 95 % under the following operating conditions; a temperature of 425oC, an inlet IPA concentration of 2500 ppm, an oxygen concentration of 21%, and a space velocity of 13500 hr-1. Additionally, the stability test results indicated that the 10 wt% Cu0.6Co0.4 catalyst exhibited excellent stability at both low and high conversion of IPA. ¡]2¡^20% Cu/Mn aluminum oxide catalytic incinerations of toluene The conversion for toluene reached 95% when the Cu/Mn catalyst was used with a metal ratio of 1:1 and 20% loading at 350¢XC, an influent toluene concentration of 1000 ppm, oxygen concentration of 21%, a space velocity of 12000 hr-1, and relative humidity of 26%. The long-term test was proceeded for seven days at a constant influent toluene concentration of 1000 ppm, constant oxygen concentration of 21%, constant space velocity of 12000 hr-1 and constant relative humidity of 26%. The SEM results indicated the Cu/Mn catalyst was quite stable at 350¢J. ¡]3¡^RCO testing for a copper/manganese catalyst of gaseous toluene The Cu/Mn (20wt%) catalyst was selected as the best one, because it converted 95% of the toluene at 400¢J. The results also indicating that the Cu/Mn catalyst was quite stable at 400¢J. (4) RTO treatment of VOCs with SVE system The conversion for VOCs reached 80% at 900¢XC, an influent VOCs concentration of 450-2000 ppm and a gas flow rate of 0.5 m3/min.The Thermal Recovery Efficiency¡]TRE¡^was approximately 86-90% in a RTO operated at 800-900¢J. (5)RCO treatment of VOCs with SVE system¡]10 wt% Cu0.6Co0.4 gravel catalyst¡^ The 10 wt% Cu0.6Co0.4 gravel catalyst was the poverty active, because it converted 65% of the VOCs by SVE system operated at 650¢J. (6)RCO treatment of VOCs with SVE system¡]20% Cu/Mn aluminum oxide catalytst¡^ The 20% Cu/Mn aluminum oxide catalytic was the best choice, because it converted 95% of the VOCs at 650¢J, an influent VOCs concentration of 450-10000 ppm and a gas flow rate of 0.5-1.5 m3/min. The SEM results indicated that the conversion of VOCs decay did not clearly vary at 650¢J, also indicating that the Cu/Mn catalyst selected was quite stable. The TRE was approximately 90% in a RCO¡]20% Cu/Mn aluminum oxide catalytic¡^operated at 650¢J. (7)RCO treatment of VOCs with SVE system¡]20% Cu/Mn gravel catalytst¡^ The 20% Cu/Mn gravel catalytst was the best selection , because it converted 95% of the VOCs at 600¢J, an influent VOCs concentration of 450-10000 ppm and a gas flow rate of 0.5-1.5 m3/min. The SEM results indicated that the conversion of VOCs decay did not clearly vary at 600¢J, also indicating that the Cu/Mn catalyst selected was quite stable. The TRE was approximately 90% in a RCO¡]20% Cu/Mn gravel catalytic¡^operated at 600¢J.

No description available.

[pt] O presente trabalho descreve o desenvolvimento de um sistema de dessorção térmica aplicável a remediação de solos contaminados por compostos orgânicos. O sistema consiste de um bastonete térmico capaz de aquecer o solo através de um fluxo radial e de um oxidador térmico destinado ao tratamento das emissões gasosas. Fazem parte do sistema, como equipamentos acessórios, controladores de temperatura do tipo rampa patamar, isolantes térmicos de fibra cerâmica, membranas plásticas e amostradores de água e de gases. Estes últimos são utilizados para averiguar a eficiência do oxidador térmico. O sistema desenvolvido atingiu aos objetivos de projeto. O bastonete térmico foi capaz de aplicar temperaturas de até 600 ºC seguindo trajetórias de temperatura programadas. O mesmo pode-se afirmar do sistema de tratamento das emissões gasosas. O programa experimental realizado em um solo residual de gnaisse, obtido de um talude rodoviário da Rodovia Washington Luís, contaminado por óleo queimado, revelou que o sistema desenvolvido é capaz de reduzir a concentração de compostos orgânicos a um valor mínimo, bem abaixo dos limites estabelecido pelos órgãos ambientais nacionais e estrangeiros. O programa expôs a importância da aeração da matriz porosa durante o tratamento para impedir a formação de coque. As determinações analíticas revelaram que as emissões gasosas resultantes do aquecimento do solo residual contaminado com óleo queimado tratam-se de parafinas de olefinas. A duração do ensaio bem como o projeto do arranjo espacial da distribuição dos bastonetes em um sistema in situ de remediação pode ser determinada através do emprego da formulação de propagação de calor formulada por Stegemeier (1998). / [en] This dissertation refers to the development of an in situ system devised to remediate soils contaminated with organic compounds. The system consists basically of a thermal probe capable of heating the soil matrix through radial flow and a thermal oxidizer that treats the resulting gases emissions. The system clearly reached the design aims. The thermal probe consistently programed temperatures up to 6000C to the soil matrix following applied thermal paths. The thermal oxidizer was capable to heat gases emissions up to 9000C under prolonged exposure. The experimental program was carried out using a residual soil from gnaiss taken from a slope at Washington Luiz Roadway. This soil was contaminated with used oil and submitted to a series of tests in order to assess the efficiency of the system developed herein. The results suggest that thermal desorption was able to reduce the degree of contamination to levels well below the limits established by National and International Environmental Agencies. The results also revealed the importance of aeration during the process to avoid the formation of coke. Fingerprinting tests carried out on gases emissions revealed that they were composed mainly by olefins and paraffins. The design of an in situ system as well as the termination criteria for in situ thermal desorption treatment might well be accomplished using the heat propagation theory developed by Stegemeier (1998).

The development of innovative propulsion systems requires testing in suitable facilities that reveal the efficacy of design models and allow for design refinement. The qualification process starts from ground tests and ends in vacuum chambers. The aim of this project is to design a versatile space propulsion facility capable of hosting different rocket engine architectures and providing an adequate supply line for different types of oxidizers and fuels in gaseous form. Identifying the key and critical components and implementing such components for the development of the facility and study the state of the art on safety standards and good practices for rocket engine testing. The test bed should be designed to withstand the structural stresses generated by the engine during static tests, while the supply line system should provide the mass flow required by the engine to deliver the design thrust (maximum thrust of 5kN). In this project, different types of rocket engines and their testing, fuel and oxidizers feed supply, risks involved and safety precautions in working of rocket test facilities are studied. A list of components for the development of such a rocket test facility and design of a logical layout plan consisting of various critical components for the propellant and oxidizer feed system is carried out. A total budget for the rocket test facility by evaluating the costs of various high quality and reliable components involved is produced. By accommodating different rocket architectures to withstand a maximum load of 5kN, an efficient design of the rocket test bed was realized and a static structural analysis of the same was performed that suffice for the objectives of the project.

Rocket propulsion using the hybrid-propellant scheme is a technology that offers much promise in applications where high-performance liquid rocket engines are deemed too complex and solid rocket motors are considered to lack performance or safety. However, despite extensive research, there is still a lack of knowledge in the theoretical aspects of hybrid rocketry, especially in the area of fuel-oxidizer mixing and fuel regression rate. This lack of a good theoretical model makes the implementation of good, practical solutions and mature, well-functioning designs more diffcult. This disadvantages the hybrid rocket engine when compared to liquid rocket engines or solid rocket motors.In this study, a hybrid rocket engine burning polymethyl methacrylate (PMMA) with compressed air has been designed to the point of a preliminary design defnition. PMMA is a transparent material, and this has been utilized to create a transparent-chamber rocket engine where engine processes can be studied with various optical methods withoutinterrupting or disturbing the operation of the engine. The function of hybrid rocket engines, the technological solutions involved in designing working hybrid rocket engines and the constituent parts of hybrid rocket engines have been studied. The nature of the trade-offs between performance and simplicity that occur when designing a rocket engine are also studied, with a focus on maximizing simplicity, safety and minimizing expenses, while still designing an engine that fulfills basic requirements. The results include a design defnition with a preliminary user’s guide, a feasibility study, and a summary of the results of the hybrid rocket performance model that was used to determine appropriate design parameters.

<div>Since as early as the 1920s, dinitrogen tetroxide (N2O4) has been regarded as a promising oxidizer in rocket propulsion systems. In more recent times, its predecessor, mixed oxides of nitrogen (MON), remains a top contender among oxidizers, due to its unique characteristics such as low freezing temperature and compatibility with common spacecraft materials. Today, these N2O4-based oxidizers are the preferred choice in many upper stages, launch escape systems, reaction control systems, liquid apogee engines, and in-space primary propulsion systems. N2O4-based oxidizers are a key factor in rocket propulsion, and thoroughly understanding their history, development, characteristics, synthesis, and composition analysis are crucial for space exploration today and into the future.<br><br></div><div>To fully understand and predict the physical properties of a MON sample, it is important to measure and quantify its chemical composition. The recommended method for MON composition analysis, as prescribed by the Department of Defense’s Defense Specification (MIL-SPEC) document on N2O4, involves the oxidation of NO and dinitrogen trioxide (N2O3) in the MON sample to determine their amounts. An equation unofficially called the “MIL-SPEC equation” is then used to determine the amount of NO needed to mix with N2O4 to synthesize that particular MON sample. However, no explanation is given as to how the equation was derived, or its significance.<br><br></div><div>This thesis aims to collect and organize key information on the synthesis, handling, and composition analysis of MON propellant. First, the history of development of N2O4-based oxidizers was researched, and current and future uses of N2O4 and MON propellants were identified. Then a method for synthesis and composition analysis was devised and tested. Water contamination was expected of skewing the results, so the process of water contamination was examined analytically. Then a detailed derivation of the MIL-SPEC equation was conducted, to fully understand its mechanics. An attempt was then made to reverse-engineer an unexplained numerical value in the equation, labeled by the author as the “solubility factor”. Several derivations were provided with varying degrees of complexity, producing alternative solubility factors of varying accuracies. Finally, experimental data was applied to these derived, hypothetical solubility factors and the MIL-SPEC solubility factor, with the intent of determining whether improvements could be made to the MON composition determination process.<br><br></div><div>The results suggest that the MIL-SPEC equation is sufficient for providing a relatively accurate measurement of the composition of a MON sample, while also being easy to implement, both in taking the necessary measurements and in conducting the numerical calculation. However, some minor adjustments to the equation could produce consistently more accurate composition measurements without adding any more difficulty or complication.</div>

A spin-cast silicone membrane has been successfully bonded between two injection-molded microstructured plastic discs. This sandwich structure creates a useful platform for mass production of microfluidic systems, provided that the bonds are leakproof. The bonds were achieved by a silicon dioxide coating deposited on the plastic discs by evaporation. This investigation is concerned with the process and the result only, no theory is discussed.