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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Characterization of Volatile Organic Compounds (VOC) in wet-white and metal-free leathers

Naviglio, Biagio, Caracciolo, D., Florio, Claudia, Gambicorti, T., Aveta, R., Girardi, V., Scotti, M. 26 June 2019 (has links)
Content: As it is known in the tanning sector, in recent times, the so-called wet-white and/or metal-free concepts have had a certain increase. For example, in the automotive sector, the wet-white tanning system, carried out with glutaraldehyde and tannins, has been widely diffused. In fact, car manufacturers offer, for interior furnishings, leather not only for high-end cars but increasingly also in the lower segments. The components on which the leather upholstery is applied are mainly steering wheel, seats, dashboard and panels. Therefore, the use of leather also in this context must be able to meet both the aesthetic/performance criteria and the environmental ones; environmental criteria should also consider the air quality of the interior of a motor vehicle. In practice, the interior furniture consisting of finished leather must be able to release a few volatile substances and, at the same time, provide a typical smell of leather. Considering, therefore, the diffusion of alternative chrome tanning systems for the different uses, in this work, wet-white (glutaraldehyde and tannins) will be investigated, both from the point of view of the performance characteristics and from the ecotoxicological ones. and leathers deriving from the latest generation of metal-free tanning. For the characterization of Volatile Organic Compounds (VOC) the GC-MS will be used coupled with the 'Purge and Trap' technique with the aim of obtaining information on the new substances used in the wetwhite / metal free production process and then avoiding undesired effects during use (eg bad smell, SVHC substances, etc.) Take-Away: metal-free automotive VOC
142

Zařízení pro zneškodňování odpadních plynů katalytickou oxidací / Equipment for Disposal of Waste Gases of Catalytic Oxidation

Brummer, Vladimír January 2017 (has links)
This thesis deals with the design of the equipment and documentation for the design of equipment for the removal of volatile organic compounds (VOC) and carbon monoxide (CO) by catalytic oxidation and the selection of appropriate technological conditions for this technology. Introduction is devoted to familiarization with the field of the catalytic oxidation, used catalysts, catalyst supports and their active components. Advantages and disadvantages of the use of catalytic oxidation versus thermal incineration are outlined and currently applicable legislative terms for VOC and CO emissions are listed. In the next part of the thesis the fundamental mathematical tools and research findings available for catalytic reactor model designed primarily for monolithic catalysts are summarized. Presented kinetic model considers continuous reactor with plug flow of gas and adiabatic heating by oxidation reactions corrected for the heat loss of the reactor. The next chapter discusses the design of the new prototype of the catalytic oxidation pilot plant (i.e. the reactor incl. peripherals) primarily intended for monolithic catalysts and bulk catalysts in the form of the fixed bed. The basis for the design and sizing are material and energy balances in the ChemCAD for different intended use of the unit, from which boundary conditions of the unit operating parameters arises. Pilot plant has been designed and built, functionality tests was scheduled also with consecutive obtaining of experimental data not only for the reactor kinetic model. Results of the model for the catalytic combustion were in good agreement with measured data. The next part includes two industrial case studies of the catalytic oxidation process usage for the chemical industry. In particular it was dealt with a replacement of the non-catalytic combustion for the catalytic for VOC abatement from chemical production plants off-gas streams of the company Momentive Specialty Chemicals in Sokolov and German city Leuna. These case studies have brought many valuable experimental and technological knowledge from long-term pilot tests and also verification of design concept, thanks to which it was later possible to design a pilot unit for removal of pollutants in premises of NETME Centre and among other to economically evaluate the usage of catalytic oxidation for the off gas cleaning, in comparison with traditional combustion, in two completely different individual cases. This information was valuable and necessary for the verification of theoretical assumptions of the thesis on specific conditions of two different industrial productions. Based on acquired practical experience and theoretical background, guidelines for designing of devices for VOC and CO removal in the industry were developed.
143

Charakterisierung der Rezeptoreigenschaften ausgewählter Clathratbildner für die Detektion flüchtiger organischer Verbindungen in einem thermochemischen Sensor

Schröpfer, Michaela 16 November 1999 (has links)
In der Arbeit wurde erstmals die Eignung von Silizium-Bauelementen mit monolithisch integrierten Thermosäulen als Wärmeleistungstransducer für thermochemische Sensoren zur Detektion flüchtiger organischer Verbindungen (VOC) untersucht. Dabei wurden bereits in massensensitiven und kapazitiven Sensoren bewährte Polymerschichten als chemisch sensitive Rezeptoren verwendet. Als Kriterien für die Bewertung des Sensors dienten Empfindlichkeit, Signal-Rausch-Verhältnis, Reproduzierbarkeit und Signaldynamik. Weiterhin konnte die für die Anwendung der Silizium-Thermosäulen entwickelte Methodik zur Charakterisierung neuer organischer Clathratbildner als potentielle Rezeptormaterialien genutzt werden. Für die untersuchten Clathratbildner wurden die Empfindlichkeiten und die Signaldynamik gegenüber einer Auswahl typischer organischer Lösungsmittel gemessen. Es konnte festgestellt werden, dass die Empfindlichkeitsrelationen deutlich von den Eigenschaften der Rezeptorschichten bestimmt werden und damit eine Mustererkennung in entsprechend konfigurierten Sensorarrays möglich sein sollte. Entgegen den Erwartungen spielt jedoch für die Selektivität der Rezeptorschichten der stereoselektive Effekt der Clathratbildung keine Rolle, da entsprechende Phasenumwandlungen erst oberhalb sensorrelevanter Partialdrücke auftreten und der Messeffekt lediglich durch Adsorption erzeugt wird.
144

En utvärdering av reduceringstekniker för VOC på Beckers Group / An evaluation of VOC abatement at Beckers Group

Hultin, Carl January 2015 (has links)
Denna rapport är en studie där tre olika reningstekniker för att reducera utsläppen av VOC, (volatile organic compounds) på färgföretaget Beckers Group, jämförs och utvärderas. De reduceringsmetoder Beckers använder sig av i dagsläget vilka ska jämföras är på anläggningen i Sverige en uppkoncentrering med en zeolitrotor följt av katalytisk förbränning. Anläggningarna i Kina har ett skrubbertorn med diesel följt av en aktiv kolbädd som polersteg. Anläggningarna i USA har en katalytisk förbränningsmetod kallad Oxidizer. Teknikerna jämförs och utvärderas utifrån teknik, miljö och ekonomi i rapporten. Rapporten inleds med att teori gällande färgtillverkning, lösningsmedel och reningsteknikerna redogörs. Därefter görs en utförlig beskrivning för respektive anläggning utifrån teknik, miljö och ekonomi. Denna information ligger sedan till grund för jämförelse och utvärdering av metoderna. Rapporten kompletteras med beräkningsredskap för att uppskatta vilken av de ovan nämnda teknikerna som kan anses vara lämplig för en given utsläppssituation samt för att uppskatta kapitalet för denna teknik. Det framgår i rapporten att uppkoncentrering med en zeolitrotor följt av katalytisk förbränning är den miljömässigt bästa reningstekniken då den kräver mindre energi, har hög reningsgrad samt att den genererar väldigt lite avfall. Sämst ur miljösynpunkt är skrubbertorn med diesel följt av en aktiv kolbädd eftersom den har en lägre reningsgrad samt att stora mängder avfall erhålls. Ur miljösynpunkt kan denna metod förbättras om omhändertagandet sker med stor försiktighet samt om avfallet återanvänds. Oxidizern hamnar där emellan då den har bra reningsgrad och genererar mycket lite avfall men metoden kräver stödbrännare för att driva processen vilket ökar energikonsumtionen. Ekonomiskt är investeringskapitalet avsevärt lägre för skrubbertornet med diesel följt av en bädd med aktivt kol och dyrast är uppkoncentrering med en zeolitrotor följt av katalytisk förbränning. Ökar luftflödet ut från anläggningen kommer det att löna sig att installera en rotor före förbränningen då denna kommer återbetalas tack vare insparande av energikostnader. Investeringskapitalet för Oxidizern liknar metoden i Sverige bortsett från själva kapitalet för rotorn. De rörliga kostnaderna för skrubbertorn med diesel följt av aktivt kol är beroende av om kol och diesel kan åeranvändas, gör det inte det blir kostnaderna mycket höga för detta och stiger med den mängd VOC som måste renas. / This work is a study where three different reduction techniques regarding VOC (volatile organic compounds) abatement, at the paint and coating company Beckers Group, is compared and evaluated. The reduction techniques that Beckers Group is using are a rotor technique to concentrate up the VOC-concentration before a catalytic combustion in Sweden, a Catalytic combustion technique called Oxidizer in USA and a scrubber technique with diesel followed by active carbon in China. The techniques are evaluated regarding technique, environment and economic aspects. The report starts with a theoretical background of paint manufacturing, solvent and the reduction techniques. Then the three different techniques are described in detail regarding the technical, environmental and economic aspects. This information will provide the ground for the comparison and evaluation of the system. The report is complemented with some tools to estimate which of the techniques that would be the most appropriate for a given situation and also for estimating the investment capital of the technique. It appears, in the report, that the rotor technique followed by a catalytic combustion is the best technique according to the environmental aspect since it has low energy consumption and is not generating a lot of waste. The worst technique in an environmental aspect is the scrubber technique with diesel followed by active carbon because of the lower VOC-reduction value and a big amount of waste that is obtained. Out of an environmental aspect this technique can be improved by taking care of the waste with great caution by reusing or recycling. The Oxidizer end up in between because it has good reduction rate and generate very little waste, but the method requires support burner to drive the process, which increases the energy consumption. The investment in capital is much lower for the scrubber with diesel followed by active carbon than the catalytic combustion of VOC. If the air flow is big it will pay off with a rotor for concentrating up the VOC-concentration thanks to lower energy consumption. Investment capital for Oxidizern is similar to the method used in Sweden except from the cost of the rotor. The cost for the scrubber is depending on whether the diesel and carbon can be reused or recycled. If not the diesel and carbon is being reused or recycled the cost will increase with the amount of VOC treated.
145

Sustainable production of bio-energy products in the sawmill industry

Vidlund, Anna January 2004 (has links)
One of the great challenges facing society is to convert theglobal energy system to a sustainable process. Currently, 80%of the world´s energy is supplied through the combustionof fossil fuels. Not only are the fossil resources limited, theutilisation also increases the level of greenhouse gases in theatmosphere. The convertion to a sustainable energy system isproblematic since the technology needed to exploit mostnon-fossil energy sources is not yet fully developed, e.g.solar energy. Biofuel is an available renewable energy sourcewhich is already widely used in many countries. If an effectiveswitch-over from fossil fuels to biofuels is to be realised,biofuels must be viewed as a limited resource. Consequently, itis important that the handling, upgrading and utilisationprocesses involving biofuels are efficient so that itspotential can be fully exploited. This thesis considers efficient biofuel utilisation andupgrading within the sawmill industry. The goal has been toanalyse not only the technical opportunities for energy savingsin the sawmill industry, but also to analyse the costeffectiveness and environmental impact of studied measures. Theheat demand of the sawmill industry is almost completelycovered by its own by-products; primarily bark, sawdust andwood chips. The increased demand and improved economic value ofwoody biofuels on the market is thus an incentive for thesawmill industry to place more focus on energy issues. Thesawmill industry also has a more or less constant heat loadover the year, which is a beneficial factor for integrationwith district heating networks, biofuel upgrading plants andcombined heat and power plants. The conclusion of the study is that a variety of energyproducts such as heat, unrefined biofuel, pellets andelectricity can be efficiently produced in the sawmill industryand sold for profit to external customers. The payback periodsfor the proposed investments are moderate and both theemissions of volatile organic compounds and global CO2 aredecreased. Should the proposed measures be fully implemented atSwedish sawmills, about 2.8 TWh of biofuel could be savedannually, 0.5 TWh of waste heat could be sold as districtheating and 0.8 TWh of green electricity could be produced.Language: English Keywords:Sawmill industry, energy efficiency, heatrecovery, integration, biofuel, upgrading, district heating,fuel pellets, CHP, VOC, CO2
146

Analys av miljöpåverkan av resursanvändning hos industriföretag : Kartläggning av VOC och livscykelanalys för färgprodukter / Analysis of the environmental impact of resource use in industrial companies : Mapping of VOCs and life cycle analysis for paint products

Ottosson, Therese, Hjalmarsson, Amanda January 2021 (has links)
Miljöförändringar har resulterat i att växthusgaser (GHG) har studerats. Från flertalet studier anses nyckelindikatorerna för klimatförändringarna vara de förändrade koncentrationerna av GHG, särskilt koldioxid (CO2). Utsläpp av flyktiga organiska ämnen (VOC), är ett annat ämne som studerats. VOC kan i närvaro av kväveoxider (NOx) och solljus bidra till bildandet av marknära ozon. VOC kan också ha en direkt negativ hälsoeffekt hos människan vid långvarig exponering. Syftet med studien är att redogöra för hur företag/industrier kan bidra till att uppnå det globala målet som innefattar effektivare resursanvändning genom att analysera ett industriföretags resursanvändning. För att analysera utsläpp av VOC kartläggs användningen av kemikalier, specifikt från förrådet hos företaget Volvo CE i Braås. För att genomföra livscykelanalysen skapas ett scenario för färgprodukterna som används i detaljmåleriet. Scenariot används för att ställa upp systemgränser för vad som ska täckas av analysen. Resultatet visar att det är vid användningen av färgprodukterna som mest utsläpp av CO2e förekommer.
147

Analyse dynamique en champ proche de la contribution des sources de composés organiques volatils, en région urbaine sous influence industrielle / New-field dynamic analysis of the contribution of Volatile Organic Compounds sources, in urban region under industrial influence

Xiang, Yang 14 December 2011 (has links)
À ce jour, l'identification des sources de Composés Organiques Volatils (COV) a fait l'objet de nombreuses études, afin de déterminer leur contribution à la pollution atmosphérique. Néanmoins, le comportement dynamique de l'atmosphère, dans sa dimension micro-météorologique, n'a jamais été pris en compte dans une approche sources-récepteur. Celui-ci est pourtant essentiel dans l'interprétation des mesures physico-chimiques de la pollution de l'air en champ proche, dans une région urbaine sous influence industrielle. La complexité de ces zones d'études provient non seulement des différents modes d'émissions et de la variété des activités industrielles, mais aussi des phénomènes météorologiques à multi-échelles, qui influent la dispersion et le transport à petite échelle spatiale (typiquement quelques kilomètres). En nous appuyant sur la mesure de 85 COV (dont 23 COV oxygénés) sur une durée de plusieurs mois, nous avons développé une méthodologie novatrice, associant lors de l'analyse des résultats d'un modèle sources-récepteur PMF (Positive Matrix Factorization) des grandeurs météorologiques, pour identifier des sources et comprendre leur comportement dynamique. En introduisant la turbulence verticale, pour la première fois dans ce type d'analyse, la température et le rayonnement solaire, comme paramètre d'analyse des facteurs de comportements ont pu être différenciés, permettant de distinguer les modes d'émissions diffuses et canalisées. Ainsi, nous avons pu classer les sources des COV par nature et par mode d'émissions, et également mettre en évidence des masses d'air âgées contenant des espèces secondaires. / Recently, sources apportionment of Volatile Organic Compounds (VOC) has been the subject of a great numbers of studies, in order to determine their contributions to atmospheric pollution. However, the dynamical behavior of atmosphere, within its micro-meteorological scale, has never been taken into account in the sources-receptor approach, yet it is the main factor to interpret near-field physic-chemical measurements of air pollution, in an urban area under industrial influences. The complexity of such a study area results from not only the emission modes and the various industrial activities, but also the meteorological phenomenon in multi-scale, which influences the dispersion and transport in a small scale (tipically several kilometers). With measurements of 85 VOC (including 23 oxygenated VOC) during several months, we have developed an innovative methodology, associating the results of the PMF (Positive Matrix Factorization) modeling and the meteorological parameters, in order to identify the sources and to understand their dynamical behaviors. By introducing the vertical turbulence for the first time in this kind of analysis, the temperature and the solar radiation, as parameters of factor analyses, two behaviors have been distinguished, leading to identify the emissions near ground and in the upper part of surface layer. In this way, we have labeled the sources according to their nature as well as their emission mode, and we have highlighted the aged air mass containing secondary pollutants.
148

Analysis Of Complex Volatile Organic Compound Mixtures Using Active Spme-Gc-Ms

Famiyeh, Lord 09 May 2015 (has links)
The ultimate goal of this research is to develop an efficient, reproducible and low cost method for analysis of VOCs in complex mixtures such as those in exhaled breath and in headspace of fungi cultures. In Chapter I; analytical methods for volatile biomarkers identification is reviewed In Chapter II, active SPME GCMS was employed to analyze VOCs in the breath of a single healthy male and a single female. The goal was to determine the extent of intra-individual variations in the VOC profiles. In Chapter III, a preliminary study was carried out in a greenhouse to determine the pathogenicity of different isolates of M. phaseolina on soybeans. This will allow, in future studies, the matching of VOC profiles of different isolates of M. phaseolina with their relative pathogenicity. This is a key step towards the development of an early warning system for the detection of pathogenic M. phaseolina fungus contaminations.
149

Quantification Of Emissions From Lawn And Garden Equipment In Central Florida

Crum, Megan Leigh 01 January 2007 (has links)
The objective of this study was to evaluate the practical limits of EPA's NONROAD 2005 to accurately simulate Central Florida conditions, especially with regard to lawn and garden equipment. In particular we investigated a NONROAD emission inventory using default inputs and then created a locally specific emission inventory. These emission inventories were prepared for Orange, Osceola, and Seminole county and focused only on the VOC and NOx emissions caused by lawn and garden equipment. The model was manipulated to assess its ability to represent this specific category of nonroad equipment for a given airshed first by running a base case scenario using default data and then by developing a locally-specific scenario through administration of a survey. The primary purpose of the survey was to evaluate local values for equipment population, equipment characteristics, activity estimates, and other relevant information. To develop these local input estimates, data were collected concerning population and usage statistics in the Central Florida area and were combined with emission factors, load factors, allocation factors, and other needed values that have been previously established by the U.S. EPA. The results of the NONROAD model were compared with the resulting emission estimates calculated from locally derived inputs, and as a result of the analysis an accurate emission estimate was calculated. In addition, several possible air quality action steps were further assessed according to feasibility, cost, and predicted emission benefit. These potential management projects were further investigated by assessing the success of other similar projects in other cities in an effort to establish specific costs and emission benefits as they relate to the tri-county area.
150

Methods and Observations for the Influence of Temperature on Volatile Loss from Wine Fermentation

Goldfarb, David Martin 01 February 2015 (has links) (PDF)
Background and Aims: Volatile loss of carbon dioxide, ethanol, esters and other compounds occurs during wine fermentation. When collected nondestructively, valuable ethanol and aroma compounds can be preserved for various uses while mitigating production restrictions and regulations regarding volatile organic compound (VOC) loss from wine production. Knowledge of the volume of volatiles lost during wine fermentation contributes to a better understanding of the magnitude of possibilities for resource recovery/aroma recovery, the implications of volatile loss on wine composition as well as a more clear understanding of the possible effect of alcoholic fermentation on air quality. The aim of this study was to contribute to a better understanding of how the loss of volatiles from wine fermentation varies with temperature. Methods and Results: Temperature controlled microscale fermenters were developed and infrared detection technology was adapted to study the effect of temperature on volatile loss. Results are presented for the rates and volumes of volatile loss from the fermentation of California Syrah at constant temperatures (17, 23, 27, 33˚C) in 1.9L containers. Observed volatile losses are compared to theoretical losses based on kinetic and stoichiometric principals. Each ferment started with 1200g of fruit and was adjusted to 23.5˚B. Following Brix adjustment, final volumes ranged from 1129.16mL to 1160.10mL. Conclusion: The loss of VOC from fermentation increases exponentially with temperature. Total VOC and CO2 loss appears to be slightly less than theory predicts. Significance of the Study: A significant loss of compounds occurs during wine fermentation. Commercial and environmental benefits may be achieved if efforts are made to recover and make use of these otherwise wasted compounds. Funding provided by the Agricultural Research Initiative, California State University.

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