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1
King, Nathan D. "Chemical and physical modification of petroleum, coal-tar, and coal-extract pitches by air-blowing." Morgantown, W. Va. : [West Virginia University Libraries], 2004. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=3561.
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Thesis (M.S.)--West Virginia University, 2004.Title from document title page. Document formatted into pages; contains viii, 181 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 107-112).
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Griffin, Thomas Paul. "Intrapartical secondary reactions of tar during bituminous coal pyrolysis." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/14189.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1989.GRSN 408655
Science hard copy bound in 2 v.
Includes bibliographical references (leaves 255-261).
by Thomas Paul Griffin.
Ph.D.
3
Kong, Lingjun. "Characterization of Mineral Oil, Coal Tar and Soil Properties and Investigation of Mechanisms That Affect Coal Tar Entrapment in and Removal from Porous Media." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5093.
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Mineral oils and coal tars are complex nonaqueous phase liquids (NAPLs), which can serve as long-term sources of ground water contamination. Very limited data are available on mineral oil and coal tar entrapment in and removal from porous media. Thus, the objectives of this research were to evaluate the behavior of these NAPLs in porous media, and investigate the mechanisms governing NAPL entrapment in and recovery from porous media.
Quantification of properties of three commercial mineral oils and six MGP coal tars reveals that mineral oils are slightly viscous LNAPLs (density: ~0.88 g/cm3; viscosity: 10-20 cP), whereas coal tars are highly viscous DNAPLs (density: 1.052-1.104 g/cm3; viscosity: 32-425 cP). Measured oil (tar)-water interfacial tensions (IFT) were lower than that of pure NAPLs. Properties of 16 field soil samples (soil particle size distribution, specific surface area, total carbon content, cationic exchange capacity and soil moisture release curves) were characterized. Correlations between residual NAPL saturation and NAPL and soil properties were developed, and show that the entrapment of NAPL dependent upon soil particle size distribution, total carbon content, NAPL viscosity and NAPL-water IFT.
Aqueous pH and ionic strength were found to influence the interfacial properties in tar-water-silica systems. At pHs greater than 7.0, observed reduction in contact angle were attributed to the repulsive electrostatic force between coal tar and solid surface. When pH less than 4, hydration forces played a role on the contact angle decrease. The IFT reduction was resulted from the accumulation of surface-active molecules at the tar-water interface. The effect of ionic strength on interfacial properties was not significant below 0.5 M.
The effects of temperature and surfactant or surfactant/polymer addition on coal tar removal was investigated by conducting coal tar displacement experiments at three different temperatures (22, 35, and 50??with sequential flushing of water, surfactant and surfactant/polymer. Coal tar removal from porous media was enhanced by elevating temperature and surfactant flushing due to the viscosity and IFT reduction, respectively. Xanthan gum was used as the polymer to increase the viscosity of the displacing fluid. In summary, these results provide tools for the prediction of NAPL entrapment in porous media, and for the selection of remediation strategies for coal tar contaminated source zone.
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Twigg, Anthony Nicholas. "The characterisation and modification of binders used in the manufacture of carbon anodes." Thesis, University of Wolverhampton, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329130.
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King, Mark William George. "Migration and natural fate of a coal tar creosote plume." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq21360.pdf.
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Chang, Cliff Cheng-Shiou. "Thermal reactions of freshly generated coal tar over calcium oxide." Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/15046.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1986.MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE.
Bibliography: leaves 351-363.
by Cliff Cheng-Shiou Chang.
Ph.D.
7
Behrouzi, Mahtab. "Petroleum asphaltenes and coal tar pitch : a structural and interfacial study." Thesis, Imperial College London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.436342.
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Takekawa, T. "Chemistry of mesophase formation." Thesis, University of Newcastle Upon Tyne, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379323.
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Kithinji, Jacob P. "Extraction and chromatography of supercritical fluids." Thesis, University of Leeds, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329092.
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O'Brien, Robert John. "Tar production in coal pyrolysis : the effect of catalysts, pressure and extraction." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/47459.
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Matzinos, Panagiotis D. "Coal-tar pitch as the matrix carbon precursor in carbon-carbon composites." Thesis, Loughborough University, 1995. https://dspace.lboro.ac.uk/2134/28083.
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Coal-tar pitch is a promising carbon matrix precursor for carbon-carbon composites. It has a suitable viscosity, high carbon yield, and it forms graphitic structures. In addition, pitch is a relatively cheap raw material. This thesis is a study on the use of coal-tar pitch as carbon matrix precursor in carbon–carbon composites.
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Pironi, Paolo. "Smouldering combustion of organic liquids in porous media for remediating NAPL-contaminated soils." Thesis, University of Edinburgh, 2010. http://hdl.handle.net/1842/3222.
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This research investigated the potential of smouldering combustion to be employed as a remediation approach for soil contaminated by non-aqueous phase liquids (NAPLs). Small-scale (~15 cm), proof-of-concept experiments were the first to demonstrate that organic liquids embedded within an inert soil matrix can be successfully smouldered. Intermediate-scale (~30 cm) column experiments examined in detail the behaviour of the combustion process including its relationship to mass and energy balance and the evolution of temperature profiles. In addition, detailed evaluations of environmental parameters (e.g., soil concentrations, gas emissions) were conducted. For the first time, it was demonstrated that NAPL smouldering combustion can be self-sustaining (i.e., propagation of the smouldering front after termination of the igniter) and self-terminating (i.e., natural extinction of the reaction after all of the NAPL is destroyed). More than 30 column sensitivity experiments quantified the broad range of process parameters - including contaminant type, contaminant mass, soil type, and oxidizer flow rates - within which the process was self-sustaining and essentially complete remediation was achieved (i.e. contaminant mass removal in excess of 99.5%). Maximum burning temperatures were observed in the range 600-1100 C. Average propagation velocities varied between 0.7e-4 and 1.2e-4 m/s. Intensity and velocity of the process were shown to be controlled by the rate at which oxidizer is delivered. Contaminant type and mass was observed to affect peak temperatures and propagation velocity by influencing the energy balance at the reaction front. Moreover, mass and energy balance models were demonstrated to provide reasonable predictions of the observed propagation velocities. Overall, this research introduced an entirely new approach to the remediation of NAPL-contaminated soils and, further, advanced the understanding of the mechanisms that control the underlying process of smouldering combustion of liquids.
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Forsey, Steven. "In situ Chemical Oxidation of Creosote/Coal Tar Residuals: Experimental and Numerical Investigation." Thesis, University of Waterloo, 2004. http://hdl.handle.net/10012/1275.
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Coal tar, coal tar creosote and oily wastes are often present as subsurface contaminants that may migrate below the water table, leaving a widely distributed residual source of contaminants leaching to the ground water. In situ chemical oxidation is a potentially viable technology for the remediation of aquifers contaminated with creosote and coal tars. The oxidant of choice would be flushed through the contaminated area to oxidize aqueous contaminants and enhance the mass transfer of contaminants from the oil phase. A series of batch and column experiments were performed to assess the ability of a chemical oxidizing reagent to oxidize creosote compounds and to increase mass transfer rates. Results from the column experiments were then simulated using a reactive transport model that considered 12 different creosote compounds undergoing dissolution, oxidation and advective-dispersive transport. Three strong chemical oxidizing reagents, Fenton's Reagent, potassium persulfate with ferrous ions, and potassium permanganate were tested with batch experiments to determine their reactivity towards creosote compounds. All three reagents successfully decomposed aqueous creosote compounds and were able to reduce the mass of the monitored creosote compounds within the oil phase. However, both the Fenton's and persulfate reagents required large molar ratios of iron and peroxide because the precipitation of iron continually removed the iron catalyst from the aqueous phase. Fenton's and persulfate reagents could be used in systems that are allowed to become acidic to solubilize the iron, but the cost of adjusting the pH, potential impact on aquifer geochemistry and the short lived free radical reaction make these reagents less practical than KMnO4. KMnO4 oxidizes a wide variety of creosote compound, can be used at very high concentrations, and its concentration will not be reduced significantly as it moves through the zone of contamination. The feasibility of using potassium permanganate as an oxidizing reagent for in situ treatment of creosote residuals was investigated using batch column experiments. Column experiments were conducted at a neutral pH in a carbonate rich sand matrix with creosote at 8 % saturation. The columns were treated intermittently with simulated ground water or KMnO4 dissolved in simulated ground water (8 g/L) for 172 days. Under these experimental conditions the KMnO4 decreased the initial mass of the monitored creosote compounds by 36. 5%, whereas in the control column (no oxidizer) only 3. 9% was removed. To remove all of the monitored creosote compounds from the columns it was calculated that the volume needed would be 40 times less for the KMnO4 solution, compared to flushing alone with simulated ground water. To evaluate the potential effectiveness of in situ chemical oxidation at field sites, numerical model simulations need to incorporate relevant chemical oxidation rates to assess system performance and to provide design guidance. In-depth kinetic studies were performed to determine rate constants and to gain insight into the oxidation of creosote compounds with KMnO4. The study examined the kinetics of the oxidative treatment of a selected group of creosote/coal tar compounds in water using excess potassium permanganate and investigated the correlation between reactivity and physical/chemical properties of the organic pollutants. The oxidation of naphthalene, phenanthrene, chrysene, pyrene, 1-methylnapthalene, 2-methylnaphthalene, acenaphthene, fluorene, carbazole, isopropylbenzene, ethylbenzene and methylbenzene closely followed first-order reaction kinetics, enabling calculation of second-order rate constants. Fluoranthene was only partially oxidized by permanganate and the oxidation of anthracene was too fast to be measured. Biphenyl, dibenzofuran, benzene and tert-butylbenzene failed to react in this study. Comprehensive column experiments complemented by numerical modeling revealed an unequal enhancement of the removal of creosote compounds from the oil phase. For the more readily oxidizable compounds such as pyrene and naphthalene, a significant increase in the mass transfer rates was observed in the oxidation columns, compared to the oxidant free column. For non-oxidizable compounds such as biphenyl and dibenzofuran, an increase in the rate of mass removal was also observed in the oxidation columns, even though their aqueous concentrations were not reduced in the column. This was due to the rapid removal of the more readily oxidizable compounds from the oil, which increases the mole fraction of the non-oxidizable compounds. Thus according to Raoult's Law, the concentration in the aqueous phase becomes closer to its pure phase liquid solubility and its aqueous concentration increases. The most significant result of the experiments is the observed increase in the rate of removal of those compounds that have low aqueous solubilities and are readily oxidized, such as pyrene and fluorene. Compounds that have low aqueous solubilities and are not readily oxidizable, such as chrysene, may still take a long period of time to be removed, but the removal time is greatly reduced with oxidation compared to flushing the area with water alone.
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Iravani, Mohammad Ali. "Monitoring the remediation of coal tar in contaminated soil using electro-geophysical methods." Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS330.
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Au cours des deux dernières décennies, la dépollution et la surveillance des sites pollués sont devenus une question sociétale importante. Les techniques classiques de surveillance par piézomètres et piézairs ne suffisent pas pour suivre les changements caractéristiques dans le sous-sol de ces sites en raison de leur caractère ponctuel. Ainsi l’interprétation de données géophysiques acquises lors de la surveillance de tels sites est un outil pour la dépollution de leurs sols. Les propriétés géophysiques sont des paramètres clés dans la validation des méthodes de dépollution des sols contaminés par des produits chimiques organiques et industriels, comme les hydrocarbures lourds, DNAPL (‘Dense Non-Aqueous Phase Liquids’ en anglais). Parmi les techniques géophysiques pouvant être utilisées pour suivre les propriétés physiques des sites contaminés, les méthodes électriques et électromagnétiques se sont révélées être des techniques de surveillance fiables fournissant des informations sur la résistivité électrique et la permittivité diélectrique reliées aux propriétés physiques et hydrodynamiques du milieu. L’objectif principal de cette thèse est d’évaluer la capacité des méthodes électromagnétiques afin de suivre le processus de dépollution dans des sols contaminés par des DNAPL, via l’utilisation en laboratoire des méthodes de SIP (‘Spectral Induced Polarization’ en anglais, polarisation provoquée spectrale ou dans le domaine fréquentiel en français) et TDR (‘Time Domain Reflectometry’ en anglais) dans des milieux poreux contaminés, ces méthodes mesurant ces propriétés électromagnétiquesDuring the past two decades, the remediating and monitoring of polluted sites have become an important issue. Among all geophysical techniques, electrical methods showed their ability to monitor clean-up programs in these sites. Spectral induced polarization (SIP) technique is a method in near surface geophysics to measure complex electrical resistivity of a medium in the frequency domain. The other geophysical method was used is time domain reflectometry (TDR) that has been developed to measure relative dielectric permittivity, water content and temperature in homogeneous or heterogeneous porous media. This thesis is a challenge to evaluate efficiency and potential of SIP and TDR for a long-term monitoring of dense non-aqueous phase liquids (DNAPLs) recovery in contaminated porous media in the laboratory. Different sets of experiments designed to study the impacts of temperature and saturation changes on electrical complex resistivity and relative permittivity of saturated porous media on isothermal and non-isothermal conditions were examined in different 1D columns. The measurements were made with different couples of pollutants and fluids (i.e. coal tar/water, chlorinated solvent/water and canola oil/salty ethanol) in porous media simulated with glass beads of 1 mm diameter.Our findings concerning to temperature and saturation change show that experimental data of relative permittivity and complex resistivity obey empirical models validating our experimental setup and protocol. The results from the laboratory measurements will be used in the real conditions in field measurements in a remediation program
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Blom, Maria. "Förekomst och urlakning av PAH längs med väg 805, Jokkmokks kommun." Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-144314.
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The purpose of this study was to determine if any amount of PAH (Polycyclic aromatic hydrocarbons) was leaching from the paved road surface of road 805 in Jokkmokk municipality. The study was also meant to determine which factors affected the leaching of PAH in the studied area.The surveyed road was divided into eight sections. Groundwater pipes were inserted into drilled holes, three in each section. Samples from soil, water and asphalt were collected from each section and analyzed for its content of PAH. The groundwater level was measured before each sampling. Some soil samples were analyzed for TOC (total organic carbon) and all the water samples for DOC (dissolved organic carbon). The results showed that PAH was leaching in very different amounts. There was a similarity in the amount of coal tar in the road surface and the amount of PAH in most sections. Although in one section the asphalt sample showed low amount of coal tar but high amount of PAH in the soil- and water samples. This anomaly could not be explained - the assumption was that the sampling had been incorrectly handled. The pollution in the surveyed area is assumed to be caused by the road surface and tire wear. Further studies are necessary to determine with certainty how PAH is leaching in different conditions and with different road pavements.
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Thorns, Leisha Jane. "A novel polymeric approach to the cold cure briquetting of anthracite/breeze fines." Thesis, University of Strathclyde, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366909.
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Maier, Matthias. "The mobilisation of polycyclic aromatic hydrocarbons from the coal tar lining of water pipes." Thesis, University of Surrey, 1998. http://epubs.surrey.ac.uk/842793/.
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Coal-tar was commonly used as an internal lining for corrosion protection of water pipes from the 19th century up to the present. It is reported that these coatings can lead to elevated concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) in the distributed drinking water. The aim of the project was to investigate the processes and mechanisms responsible for the occurrence of these substances in drinking water distribution systems. The results presented in this project showed that the occurrence of PAHs in a distribution system was linked to the presence of the disinfectants chlorine and chlorine dioxide. This dependence could be shown in the laboratory, in a pilot-scale pipe rig as well as in field investigations in a real distribution system. Generally, hostile environmental conditions for microbiological activity such as stagnation periods and anaerobic conditions could be identified as the most important factors to favour the occurrence of PAHs in the drinking water. It was clearly shown that disturbances in the hydraulic regime such as water hammers, operation of valves and rapid increases in flow velocity can result in enhanced PAH concentrations. Immediately after stagnation periods PAH concentrations increased to levels which exceeded the prescribed concentrations of the EC-guideline of 200 ng/l. In laboratory experiments it was demonstrated that the coal-tar is a substrate for the growth of biofilms. Batch experiments and reactor experiments showed that the removal of biofilm resulted in a higher leaching rate of the PAHs into the water. Experiments concerning the potential for the formation of chlorinated PAHs as disinfection by-products from the PAHs prevalent in water distributed through coal-tar lined pipes showed that their occurrence is very unlikely under conditions prevalent in water distribution systems. A theory is presented which indicates that particles adhering to the pipe walls which can be sometimes embedded in the biofilm matrix represent a major factor in the process of the mobilisation of PAHs. The destabilisation of the biofilm matrix by hostile environmental conditions (disinfectants, aerobic conditions, oxygen limitation during stagnation periods) or enhanced shear forces on the biofilm, results in the release of particles highly contaminated with PAHs.
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MacKay, Allison Ann. "Groundwater fate of aromatic hydrocarbons at industrial sites : a coal tar site case study." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/49984.
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Ogden, Gary N. "The quality of binder-filler interfaces in carbon electrodes." Thesis, Loughborough University, 1995. https://dspace.lboro.ac.uk/2134/7049.
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The aims of this research project were to identify and classify the binder-filler interfaces formed in carbon electrodes and to determine the effects of the interfacial quality on important electrode properties. The effects of raw materials and some fabrication process variables on interfacial characteristics and quality of laboratory produced test electrodes were also studied, and the development of binder-filler interfaces during the carbonisation process followed. Electrode quality was assessed by measurement of density, electrical resistivity and tensile strength. Pore structural data were also obtained by using a computerised image analysis system allied to an optical microscope. Interface quality data were obtained by examining etched surfaces in a scanning electron microscope and classifying the binder-filler interface observed into one of five categories. The category depending on the extent of contact between the binder and filler. Accordingly, test electrodes were produced from combinations of four filler carbons, comprising three grades of calcined petroleum coke and an electro-calcined anthracite, and four coal-tar binder pitches which varied in the type and quantity of insoluble matter content. Examination of these test electrodes showed that the nature of the filler carbon used had a dominant influence on the quality of the interface formed, as assessed by this technique. A combination of one filler carbon and one binder pitch was used to study the effects of some fabrication process variables. These were pitch content and, mixing time and temperature. Of these process variables, pitch content and mixing temperature were found to have the major effects on the binder-filler interface and electrode quality. Investigation of the development of the binder-filler interfaces during the carbonisation process showed three distinct zones of interface development and transformation. These zones were associated with three temperature dependent mechanisms; thermal stress relaxation between 200-350 degrees C, volatile gas evolution from coal-tar pitch decompositionb etween3 50-600 degrees C and stresses induced by thermal contraction of the binder phase between 600-1000 degrees C.
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Anderson, Joshua. "Polycyclic Aromatic Hydrocarbon Release from Pavement Rejuvenators Due to Rolling Wheel Contact: An Investigation Using a Model Mobile Load Simulator." Digital WPI, 2019. https://digitalcommons.wpi.edu/etd-theses/1293.
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Polycyclic aromatic hydrocarbon (PAH) compounds, which are common to coal tar and coal-tar-based products, are ubiquitous environmental contaminates with carcinogenic effects to human health and aquatic life. Transport of PAHs via solid phase particulate motion, gaseous phase volatilization, and aqueous phase dissolution into urban waterbodies of PAH compounds from coal-tar-based pavement sealant products has been studied. Pavement rejuvenators are products applied to increase the usable life of pavement. Coal-tar-based rejuvenators contain a significantly larger mass fraction of coal-tar with respect to coal-tar-based sealants, but pavement rejuvenators have not been as extensively studied as pavement sealants. Chemical analysis of detached pavement material treated with coal-tar-bases, asphalt-based, and bio-based rejuvenators was conducted with gas chromatography – mass spectrometry (GC/MS) analysis for 16 PAH compounds and two aromatic heterocyclic organic compounds following extraction with methylene chloride. Detached pavement material was collected from 19 simulated asphalt surface abrasion experiments that used a model mobile load simulator (MMLS) test apparatus that replicated surface challenges from vehicular traffic. The MMLS test apparatus configuration allowed asphalt disc samples treated with different rejuvenation products, to be tested and for detached material to be collected and quantified prior to GC/MS analysis. Test cases evaluated the influence of rejuvenation product type and cure time, as well as the effect of sand application (simulating sand application during slippery winter storm conditions) had on detached particulate and ultimate PAH compound loading. The average mass of particulate detachment from samples following a 48 hour cure time, for the asphalt-based and coal-tar-based rejuvenator products were 0.347 g and 0.480 g, respectively. This mass of detached material was lower than that from pavement treated with bio-based rejuvenator and the control (not treated), which had 4.858 g and 2.567 g of detached particulate material, respectively. When the product cure time was increased to three weeks, which was significantly long enough to capture effects of compound volatilization, average particulate detachment increased to 0.882 g for the coal-tar-based rejuvenator and decreased for the bio-based rejuvenator to 2.600 g. Six tests performed with a single application of winter storm sand after a 48 hour product cure time showed an increase in average particulate detachment to 1.450 g and 0.617 g for pavement treated with the asphalt-based and coal-tar-based rejuvenators, respectively. Conversely, under the same conditions, a reduction in average detached particulate to 3.749 g was observed for the bio-based product. Detached particulate material quantities for each test case were used with the respective cumulative concentration of 16 PAH compounds quantified to make an assessment on the potential PAH compound contamination via solid phase particle transport. The average PAH compound concentration in particulate detached from pavement treated with a coal-tar-based rejuvenator was 3062.8 mg PAH per kg of particulate. This was an order of magnitude higher than the average PAH concentration measured in particulate detached from the two control pavement samples and the two asphalt-based samples after a 48 hour cure time, which were 322.1 and 508.1 mg PAH per kg detached particulate, respectively. PAH compound concentrations were also normalized by the surface area of pavement treated with a rejuvenator to determine the potential PAH compound contamination per unit area. Normalized results for each rejuvenator type were averaged to make an overall evaluation of the potential rejuvenator specific PAH compound loading. The coal-tar-based, bio-based, and asphalt-based rejuvenators had a normalized cumulative solid-phase PAH compound release of 2.35, 0.88, and 0.17 mg PAH per square foot of pavement rejuvenated, respectively. In addition, carbazole was quantified in all pavement samples treated with the coal-tar-based rejuvenator at an average concentration of 125.6 mg carbazole per kg detached particulate. Acridine was quantified in detached particulate from five of seven coal-tar-based test performed at an average concentration (excluding non-detection samples) of 42.1 mg acridine per kg detached particulate.
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Gallacher, Christopher. "Environmental forensics of coal tar using two dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOFMS)." Thesis, University of Strathclyde, 2016. http://digitool.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=27887.
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Coal tars are complex mixtures of inorganic and organic compounds, which are dominated by PAHs and were produced as a by-product of the former manufactured gas industry. Forensic analysis of coal tar samples was carried out using two dimensional gas chromatography coupled with time-of-flight mass spectrometry (GCxGC-TOFMS). This thesis first presents the application of existing multivariate statistical models developed using UK tar samples to tar samples from the USA as well as identifying 947 individual compounds present within the tars. This has important implications as this study demonstrated that statistical methods developed using UK tar samples can be successfully applied to non-UK tars. The thesis then presents the application of post extraction derivitisation to a creosote samples allowing for the detection of 255 compounds, the majority of which would not be detected without derivitisation. The analysis also detected 1505 individual compounds within the Creosote and provides the most comprehensive list of compounds detected within Creosote that has been produced. The analysis was also able to suggest the production process for the tar from which the Creosote was distilled. The use of both derivitisation and GCxGC were vital in providing this forensic information. The thesis then presents the analysis of 16 tar samples using GCxGC and post extraction derivitisation and the production of a database of 2373 individual compounds detected within the tar samples. The study showed that 163 individual compounds were present within all tar samples regardless of the production processused. This has important implications as environmental assessment usually focuses on a limited number of compounds, which could be expanded using the database presented within this thesis. Finally the thesis presented a study that analysed a sample of Pintsch Gas tar, which has never previously been analysed using a mass spectrometer and produced a unique dataset.
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Smith, Catherine Claire. "The mouse tail model in dermatology : a histological study on the effects of crude coal tar and isoquinoline." Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236062.
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This study involves a morphological and histological investigation of normal mouse tail skin and its response to crude coal tar and isoquinoline (a major constituent of coal tar). Mouse tail skin is unusual in that it undergoes both parakeratotic and orthokeratotic keratinization in adjacent sites. The former develops without a granular layer and resembles psoriasis, while the latter, with a granular layer, resembles normal human skin. Based on this property, mouse tail skin has frequently been used as a model for psoriasis but in spite of this, an integrated, detailed picture of its structure has not previously been described. This was achieved in this study by using a range of complementary techniques: light microscopy of embedded and frozen material, scanning and transmission electron microscopy, quantitative image analysis and autoradiography. Such a study may help to elucidate the mechanism of both orthokeratotic and parakeratotic keratinization. Coal tar has been used extensively in the treatment of psoriasis and is safe and effective. However, it is cosmetically unappealing, its mechanism of action is unknown and its efficacy varies with its composition which is extremely heterogeneous. Isoquinoline may significantly contribute to its anti-psoriatic properties. The mode of action of these substances as modifiers of the keratinization process may be clarified by studying their effects on the model. Both substances induced granular layer formation in previously parakeratotic areas, with concommitant development of an orthokeratotic stratum corneum, a desirable property in a potential anti-psoriatic. However, they also induced epidermal thickening and hyperkeratosis. The effects on the pilosebaceous unit were strikingly different: coal tar caused metaplasia of sebaceous glands with follicular hyperkeratosis and hair loss while isoquinoline caused sebaceous gland hypertrophy. Isoquinoline also caused far more epidermal irritation than coal tar, and caused damage to the basal lamina and dermal collagen. The irritant effects were modified to some extent by hydrocortisone cream but this also reduced granular layer induction. These studies suggest that isoquinoline may act on parakeratotic epidermis in a similar way to coal tar. It has the advantages of being a cleaner substance, with a more consistent action. However, its usefulness may be limited by its irritancy.
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Groher, Daniel. "An investigation of factors affecting the concentrations of polycyclic aromatic hydrocarbons in groundwater at coal tar waste sites." Thesis, Massachusetts Institute of Technology, 1990. http://hdl.handle.net/1721.1/14055.
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Lewis, Aaron D. "Gasification of Biomass, Coal, and Petroleum Coke at High Heating Rates and Elevated Pressure." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/4373.
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Gasification is a process used to convert any carbonaceous species through heterogeneous reaction to obtain the desired gaseous products of H2 and CO which are used to make chemicals, liquid transportation fuels, and power. Both pyrolysis and heterogeneous gasification occur in commercial entrained-flow gasifiers at pressures from 4 to 65 atm with local gas temperatures as high as 2000 °C. Many gasification studies have been performed at moderate temperatures, heating rates, and pressures. In this work, both pyrolysis and char gasification experiments were performed on coal, petroleum coke, and biomass at conditions pertinent to commercial entrained-flow gasifiers. Rapid biomass pyrolysis experiments were performed at atmospheric pressure in an entrained-flow reactor for sawdust, switchgrass, corn stover, and straw mostly using a peak gas temperature of 1163 K at particle residence times ranging from 34 to 113 ms. Biomass pyrolysis was modeled using the Chemical Percolation Devolatilization model assuming that biomass pyrolysis occurs as a weighted average of its individual components (cellulose, hemicellulose, and lignin). Thermal cracking of biomass tar into light gas was included using a first-order model with kinetic parameters regressed in the current study. Char gasification rates were measured for biomass, petroleum coke, and coal in a pressurized entrained-flow reactor at high heating-rate conditions at total pressures between 10 and 15 atm. Peak centerline gas temperatures were between 1611 and 1879 K. The range of particle residence times used in the gasification experiments was 42 to 275 ms. The CO2 gasification rates of biomass and petroleum coke chars were measured at conditions where the reaction environment consisted of approximately 40 and 90 mol% CO2. Steam gasification rates of coal char were measured at conditions where the maximum H2O concentration was 8.6 mol%. Measured data was used to regress apparent kinetic parameters for a first-order model that describes char conversion. The measured char gasification rates were far from the film-diffusion limit, and are pertinent for pulverized particles where no internal particle temperature gradients are important. The modeling and measured data of char gasification rates in this research will aid in the design and efficient operation of commercial entrained-flow gasifiers, as well as provide validation for both existing and future models at a wide range of temperatures and pressures at high heating-rate conditions.
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Bommarito, Thomas. "TOXICITY OF SEDIMENTS CONTAINING COAL-TAR PAVEMENT SEALANTS TO NOTOPHTHALMUS VIRIDESCENS AND AMBYSTOMA MACULATUM, SURROGATE SPECIES FOR EURYCEA SOSORUM." Available to subscribers only, 2009. http://proquest.umi.com/pqdweb?did=1796420441&sid=6&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Pieltain, Francoise Joelle Marie. "The effect of different rainfall regimes and drainage conditions on the mobility of PAHs from soil contaminated with coal tar." Thesis, King's College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261887.
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Ed, Maria. "Miljöteknisk undersökning enligt MIFO : en studie på fastigheten Bodsjölandet 1:14 avseende den nedlagda tjärfabriken i Grötingen." Thesis, Uppsala University, Department of Earth Sciences, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-88819.
Full textAbstract:
During 40 years of industrial production, from the end of the 1890’s until the end of 1930’s, coal and wood distillation products were manufactured in AB Carbo’s tar factory along the River Gimån in Grötingen, in the county of Jämtland, Sweden. In accordance with the Swedish Environmental Protection Agency’s Methods for Inventories of contaminated sites, MIFO, the site in Grötingen has been identified as a potentially contaminated site. In order to determine whether toxic substances pose a threat to human health and ecological systems in the area, there was a need to investigate the presence of contaminants, their levels and potential for migration. Sensitivity and protection value regarding exposure of man and the environment at the site is high, since people live next to the site and River Gimån is a part of the Natura 2000 network.
The initial phase of the MIFO method includes a preliminary survey. Information regarding AB Carbo’s activities and production has been obtained by studying map and archive material, as well as by interviews and site inspections. Potential point sources have been identified around the factory forge, storage cellar, distillation building and the wooden channel for the discharge of tar and other condensates into the River Gimån.
Guided by the information gathered in MIFO phase 1, a preliminary site investigation was carried out at the site. It included sampling of soil, sediment, groundwater and surface water together with sample analysis of heavy metals and organic pollutants. The result of the analysis shows that very high levels of the contaminants PAH, aromatics and lead are found in both soil and groundwater. The sediment contamination level is high while that of surface water is very low. The distribution of contamination levels among the samples indicates a likely point source close to the distillation building due to very high contamination levels in soil and groundwater close to that point. The point source may represent a larger spillage or dumped waste products.
Two of the contaminants present at the site, phenantrene and phenol, were studied by using the model CHEMFLO-2000. The analysis focussed on mobility in unsaturated soils under conditions that prevail at the site in Grötingen. The adsorption of phenantrene is significantly higher in comparison to that of phenol.
Comprehensive assessment and risk classification results in risk class 2 for the site in Grötingen, which implies a need for further investigations and measurements. The risk of human exposure could be reduced by removing contaminated soil around the factory forge. Additional studies should focus on finding the location of the point source around the distillation building as well as contaminant migration from the wooden channel and the geographical spreading of heavy metal contamination.
Från slutet av 1890-talet och fram till slutet av 1930-talet tillverkades träkol och trädestillationsprodukter vid AB Carbos kolugnsanläggning i Grötingen, Jämtlands län. En undersökning enligt MIFO-modellen motsvarande fas 1 och fas 2 har genomförts på området med syfte att fastställa vilka föroreningar som förekommer på området, föroreningsnivå, spridningsförutsättningar och sammanfattningsvis bedöma föroreningssituationen på området utifrån de miljö- samt hälsorisker som området ger eller kan ge upphov till. Objektsområdet har hög känslighet och högt skyddsvärde då människor bor permanent alldeles intill objektsområdet samt att det intilliggande vattendraget Gimån ingår i Natura 2000-nätverket.
Genom de orienterande studier som genomfördes i MIFO fas 1 har kart- och arkivstudier samt intervjuer resulterat i information om kolugnsanläggningens verksamhet samt tillverkade produkter. På fabriksområdet identifierades potentiella punktkällor vid fabrikens smedja, källare, reningsverk samt vid den träränna varigenom spilltjära släpptes ut till Gimån.
Utifrån den information som erhölls i den orienterande fasen genomfördes en riktad provtagning enligt MIFO fas 2 i såväl mark och sediment som grund- och ytvatten. Bedömning av uppmätta föroreningshalter baseras på riktvärden och skattas från mindre allvarliga till mycket allvarliga. Analysresultaten påvisar allvarliga till mycket allvarliga halter av PAH, aromater och bly i jorden och grundvattnet. Andra föroreningar som påvisas i högre halter på området är alifater och koppar. Föroreningsnivån med avseende på PAH i sedimenten bedöms som allvarlig medan analysresultaten från ytvattenprovtagningen påvisar mycket låga föroreningsnivåer. Provtagningsresultaten påvisar ett mycket förorenat grundvattenflöde från reningsverket, där en punktkälla i form av större spill eller nedgrävda förvaringskärl kan vara lokaliserad. Eventuell spridning av föroreningar från trärännan går inte att fastställa då föroreningsspridning även kan ske från det intilliggande området där kolugnar och kondenseringshus har varit lokaliserade.
Föroreningarna fenantren och fenol studerades genom modellering i CHEMFLO-2000 med avseende på deras rörlighet i omättad jord under de geohydrologiska förhållanden som råder på objektsområdet i Grötingen. Resultatet visar att fenantren adsorberas i marken i betydligt större grad än fenol. Koncentrationen fenantren i porvattnet minskar nästan lika mycket som den totala koncentrationen fenantren i marken, vilket tyder på att fenantren binds starkt genom adsorbtion i marken.
Den samlade riskbedömningen av objektet resulterar i att objektet bedöms tillhöra riskklass 2, vilket innebär att objektet ger upphov till en stor risk för människa och miljön. Fortsatta undersökningar på området i Grötingen bör fokusera på att hitta den punktkälla vid reningsverket som bedöms vara orsaken till de höga föroreningsnivåer som uppmättes i grundvattenrör V1. Den geografiska utbredningen av de ytliga föroreningarna som påträffades där smedjan har stått bör också utredas vidare och eventuellt avlägsna förorenad jord eller vidta åtgärder för att minska exponeringen. Vidare undersökningar bör även klarlägga spridningen från trärännan samt orsakerna till de höga föroreningsnivåer av bly som uppmättes på området.
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Van, der Merwe Cornelius Johannes. "Evaluation of thermal desorption as an alternative technique for the measurement of coal tar pitch volatiles / Cornelius Johannes van der Merwe." Thesis, North-West University, 2011. http://hdl.handle.net/10394/8080.
Full textAbstract:
Motivation: The accurate and reliable measurement of the concentration of coal tar pitch
volatiles (CTPVs) in ambient air has proved to be a challenge for occupational hygienists. The
challenge must however be confronted due to, amongst others, the carcinogenic properties of
some poly–aromatic hydrocarbons (PAHs) contained in CTPVs.
Aim: To determine the feasibility of a thermal desorption (TD) technique based method as an
alternative method to be used for the measurement of the concentration of CTPVs in ambient
air by assessing it along criteria such as ease of use, cost, accuracy and precision by
comparing it to NIOSH’s Method 5515 and OSHA’s Method 58 and to determine the level of
exposure to CTPVs on the anode paste floor of an electric furnace, used for the smelting of
platinum group metals (PGMs) concentrate.
Methodology: To satisfy the research objective, two accepted methods the National Institute
of Occupational Safety and Health’s (NIOSH) method 5515 and the Occupational Safety and
Health Administration’s (OSHA) method 58 were used for the measurement of the
concentration of CTPVs with a TD technique based method used as a third, alternative method.
All three methods were used concurrently to measure the concentration of CTPVs in ambient
air, at the anode paste floor of a platinum group metals (PGMs) concentrate smelter.
Results and conclusions: The NIOSH method proved to be the most precise method while the
TD technique based method proved to be the most accurate. The TD technique based method
proved to measure the widest range of individual CTPVs and were able to measure the highest
concentration of Benzo(a)pyrene, an individual CTPV that is classified as a Group 1
(carcinogenic to humans) chemical substance by the International Agency for Research on
Cancer (IARC). The OSHA method measured on average almost four times less total CTPVs
than either the NIOSH or the TD technique based method and failed to readily measure
individual CTPVs with a molecular weight lower than that of Phenanthrene.Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2012.
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Klebingat, Stefan [Verfasser], Rafig Akademischer Betreuer] Azzam, and Peter [Akademischer Betreuer] [Quicker. "Development, validation and scenario analyses of two Underground Coal Gasification (UCG) model approaches focussing on gas quality-tar production control and tar pollutant-water solubility risk prognoses / Stefan Klebingat ; Rafig Azzam, Peter Georg Quicker." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1157122434/34.
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Hattingh, Barend Burgert. "Product evaluation and reaction modelling for the devolatilization of large coal particles / Barend Burgert Hattingh." Thesis, North-West University, 2012. http://hdl.handle.net/10394/8739.
Full textAbstract:
A fundamental understanding of the process of devolatilization requires extensive knowledge of
not only the intrinsic properties of the parent coal and its subsequent formed products (tars,
gases and chars), but also its characteristic reaction rate behaviour. Devolatilization behaviour
has been extensively addressed in literature with the use of powdered coal samples, which
normally do not adhere to particle size constraints of coal conversion processes utilizing lump
coal. The aim of this investigation was therefore to assess the devolatilization behaviour (with
respect to product yield and -quality; and reaction rate modelling) of four typical South African
coals (UMZ, INY, G#5 and TSH) confined to the large particle regime. All four coals were found
to be bituminous in rank, with vitrinite contents ranging between 24.4 vol.% and 69.2 vol.%
(mineral matter free basis). Two were inertinite-rich coals (UMZ and INY) and the other two
were vitrinite-rich coals (G#5 and TSH). From thermoplasticity measurements it was evident that
only coal TSH displayed extensive thermoplastic behaviour, while a comparison between
molecular properties confirmed the higher abundance of poly-condensed aromatic structures
(aromaticity of 81%) present in this coal.
Product evolution was evaluated under atmospheric conditions in a self-constructed, large
particle, fixed-bed reactor, on two particle sizes (5 mm and 20 mm) at two isothermal reactor
temperatures (450°C and 750°C) using a combination of both GC and MS techniques for gas
species measurement, while standard gravimetric methods were used to quantify tar- and char
yield respectively. Elucidation of tar- and char structural features involved the use of both
conventional- and advanced analytical techniques. From the results it could be concluded that
temperature was the dominating factor controlling product yield- and quality, with significant
increases in both volatile- and gas yield observed for an increase in temperature. Tar yields
ranged between 3.6 wt.% and 10.1 wt.% and increased in the order UMZ < INY < TSH < G#5,
with higher tar yields obtained for coal G#5, being ascribed to larger abundances of vitrinite and
liptinite present in this coal. For coal TSH, lower tar yields could mainly be attributed to the
higher aromaticity and extensive swelling nature of this coal. Evolved gases were found to be
mainly composed of H2, CH4, CO and CO2, low molecular weight olefins and paraffins; and
some C4 homologues. Advanced analytical techniques (NMR, SEC, GC-MS, XRD, etc.)
revealed the progressive increase of the aromatic nature of both tars and chars with increasing
temperature; as well as subsequent differences in tar composition between the different parent coals. In all cases, an increase in devolatilization temperature led to the evolution of larger
amounts of aromatic compounds such as alkyl-naphthalenes and PAHs, while significant
decreases in the amount of aliphatics and mixed compounds could be observed. From 13C
NMR, HRTEM and XRD carbon crystallite results it was clear that an increase in temperature
led to the formation of progressively larger, more aromatic and structurally orientated polycondensed
carbon structures.
Reaction rate studies involved the use of non-isothermal (5-40 K/min) and isothermal (350-
900°C) thermogravimetry of both powdered (-200 μm) and large particle samples (20 mm) in
order to assess intrinsic kinetics and large particle rate behaviour, respectively. Evaluation of
the intrinsic kinetic parameters of each coal involved the numerical regression of non-isothermal
rate data in MATLAB® 7.1.1 according to a pseudo-component modelling philosophy. Modelling
results indicated that the intrinsic devolatilization behaviour of each coal could be adequately
described by using a total number of eight pseudo-components, while reported activation
energies were found to range between 22.3 kJ/mol and 244.3 kJ/mol. Description of the rate of
large particle devolatilization involved the evaluation of a novel, comprehensive rate model
accounting for derived kinetics, heat and mass transport effects, as well as physical changes
due to particle swelling/shrinkage. Evaluation of the proposed model with the aid of the
COMSOL Multiphysics 4.3 simulation software provided a suitable fit to the experimental data of
all four coals, while simulation studies highlighted the relevant importance of not only the effect
of particle size, but also the importance of including terms affecting for heat losses due to
particle swelling/shrinkage, transport of volatile products through the porous char structure, heat
of reaction and heat of vaporization of water.Thesis (PhD (Chemical Engineering))--North-West University, Potchefstroom Campus, 2013
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Di, Corleto Ross. "Biological monitoring of occupational exposure to polycyclic aromatic hydrocarbons in prebake smelting." Thesis, Queensland University of Technology, 2010. https://eprints.qut.edu.au/37639/1/Ross_Di_Corleto_Thesis.pdf.
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In 1984, the International Agency for Research on Cancer determined that working in the primary aluminium production process was associated with exposure to certain polycyclic aromatic hydrocarbons (PAHs) that are probably carcinogenic to humans. Key sources of PAH exposure within the occupational environment of a prebake aluminium smelter are processes associated with use of coal-tar pitch. Despite the potential for exposure via inhalation, ingestion and dermal adsorption, to date occupational exposure limits exist only for airborne contaminants.
This study, based at a prebake aluminium smelter in Queensland, Australia, compares exposures of workers who came in contact with PAHs from coal-tar pitch in the smelter’s anode plant (n = 69) and cell-reconstruction area (n = 28), and a non-production control group (n = 17). Literature relevant to PAH exposures in industry and methods of monitoring and assessing occupational hazards associated with these compounds are reviewed, and methods relevant to PAH exposure are discussed in the context of the study site.
The study utilises air monitoring of PAHs to quantify exposure via the inhalation route and biological monitoring of 1-hydroxypyrene (1-OHP) in urine of workers to assess total body burden from all routes of entry. Exposures determined for similar exposure groups, sampled over three years, are compared with published occupational PAH exposure limits and/or guidelines.
Results of paired personal air monitoring samples and samples collected for 1-OHP in urine monitoring do not correlate. Predictive ability of the benzene-soluble fraction (BSF) in personal air monitoring in relation to the 1-OHP levels in urine is poor (adjusted R2 < 1%) even after adjustment for potential confounders of smoking status and use of personal protective equipment.
For static air BSF levels in the anode plant, the median was 0.023 mg/m3 (range 0.002–0.250), almost twice as high as in the cell-reconstruction area (median = 0.013 mg/m3, range 0.003–0.154). In contrast, median BSF personal exposure in the anode plant was 0.036 mg/m3 (range 0.003–0.563), significantly lower than the median measured in the reconstruction area (0.054 mg/m3, range 0.003–0.371) (p = 0.041). The observation that median 1-OHP levels in urine were significantly higher in the anode plant than in the reconstruction area (6.62 µmol/mol creatinine, range 0.09–33.44 and 0.17 µmol/mol creatinine, range 0.001–2.47, respectively) parallels the static air measurements of BSF rather than the personal air monitoring results (p < 0.001). Results of air measurements and biological monitoring show that tasks associated with paste mixing and anode forming in the forming area of the anode plant resulted in higher PAH exposure than tasks in the non-forming areas; median 1-OHP levels in urine from workers in the forming area (14.20 µmol/mol creatinine, range 2.02–33.44) were almost four times higher than those obtained from workers in the non-forming area (4.11 µmol/mol creatinine, range 0.09–26.99; p < 0.001). Results justify use of biological monitoring as an important adjunct to existing measures of PAH exposure in the aluminium industry. Although monitoring of 1-OHP in urine may not be an accurate measure of biological effect on an individual, it is a better indicator of total PAH exposure than BSF in air.
In January 2005, interim study results prompted a plant management decision to modify control measures to reduce skin exposure. Comparison of 1-OHP in urine from workers pre- and post-modifications showed substantial downward trends. Exposure via the dermal route was identified as a contributor to overall dose. Reduction in 1-OHP urine concentrations achieved by reducing skin exposure demonstrate the importance of exposure via this alternative pathway.
Finally, control measures are recommended to ameliorate risk associated with PAH exposure in the primary aluminium production process, and suggestions for future research include development of methods capable of more specifically monitoring carcinogenic constituents of PAH mixtures, such as benzo[a]pyrene.
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Hanser, Ogier. "La matière organique dissoute issue de sols contaminés par des goudrons de houille : vers une meilleure compréhension de sa nature et de sa réactivité." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0019/document.
Full textAbstract:
De nombreuses friches héritées d’activités industrielles révolues présentent des pollutions organiques persistantes (charbon, goudron…). Alors que la réglementation impose un une évaluation du degré de contamination de ces sites, elle ne prend pas en compte les sous-produits de transformation tels que les composés polaires, peu considérés. Pourtant ils se solubilisent dans la phase aqueuse par percolation des eaux météoriques à travers ces surfaces contaminées. Bien que la littérature ciblant la matière organique dissoute (MOD) d’origine naturelle soit abondante, elle n’est pas directement transposable à la MOD issues des friches contaminées, qui reste à définir pour une meilleure compréhension du devenir de la pollution dans ces sites anthropisés. Une approche multi-techniques a été appliquée pour appréhender le plus précisément possible la MOD issue de terres d’anciennes cokeries et usines à gaz, par le biais d’expériences en laboratoire et des dispositifs de terrain (lysimètres). L’étude de ces derniers montre qu’ils contiennent une forte teneur en MOD aromatique, dont les composés aromatiques polycycliques ne représentent qu’une faible proportion de la MOD totale. Des expériences complémentaires ciblant l’influence de certains paramètres (pH et hydrophobicité) suggèrent un lien fort entre le pH et l’organisation spatiale de la MOD, ainsi qu’une diminution de la masse moléculaire apparente avec l’augmentation de l’hydrophobicité. Des expériences de vieillissement artificiel ont montré un enrichissement en produits polaires condensés entraînant leur forte mobilisation par l’eauA large amount of wastelands inherited from former industrial activities contains persistent organic contamination (coal, coal tar…). While the regulation requires an evaluation of the contamination degree of these soils, it doesn’t take into account the transformation by-products such as polar compounds, poorly studied. Yet they solubilize in aqueous phase by percolation of meteoric waters through these contaminated sites. Despite the fact that literature targeting the fresh DOM is abundant, it is not directly transposable to the anthropogenic DOM coming from wastelands, which still need to be more precisely defined to improve our knowledge of this specific DOM and its evolution over time. A multi-technical approach was developed to comprehend the anthropogenic DOM coming from former coking and gas plant soils, thanks to a combination of laboratory experiments (under controlled conditions) and on field devices (lysimeters). Their study show that they contained high polycyclic aromatic compound (PAC) contents, whose proportions in polar PACs exceed the ones in soil measurements. However, these PACs only consist of a low proportion of the total DOM. Complementary experiences targeting the influence of some parameters (pH, hydrophobicity) show a major hydrophobic characteristic and suggest a strong link between the pH and the spatial DOM organization. Artificial aging experiences show an enrichment in polar compounds leading to their water mobilization
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Guajioty, Eric. "Etude du ressuage en recuisson d'électrodes de carbone imprégnées au brai." Grenoble INPG, 1989. http://www.theses.fr/1989INPG0074.
Full textAbstract:
La recuisson a 333#oc d'electrodes en carbones impregnees au brai de houille conduit a une importante perte d'impregnant (exsudat: 36%). Le moteur principal de l'ecoulement est constitue par les gaz formes en cours de recuisson dont l'origine est double: (i) thermodecomposition et (ii) reaction du brai avec les groupes oxygenes superficiels du substrat. Leur destruction par prechauffage des electrodes a 800#oc sous azote avant impregnation diminue d'un tiers le ressuage, ameliorant ainsi les caracteristiques de produits apres graphitation
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Filsinger, Markus. "PAK-Freisetzung aus tauchgeteerten Rohren unter Berücksichtigung verschiedener Wasserqualitäten." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2004. http://nbn-resolving.de/urn:nbn:de:swb:14-1103360121437-66347.
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Der Einfluss des Biofilms, der Inkrustation, der Fließgeschwindigkeit und der Wasserqualität auf die Freisetzung von PAK wurde in Batch-, Drehkolbenreaktorversuchen und an einem Rohrleitungssystem untersucht. Chlorung von tauchgeteerten Edelstahlcoupons mit Biofilm führten zu einer fast vollständigen Ablösung des Biofilms und einer Zunahme der Freisetzung von Fluoren, Phenanthren und Fluoranthen. Die PAK-Freisetzung von tauchgeteerten Edelstahlcou-pons in einer Lösung von Trinkwasser mit 0,1% Natriumazid als Hemmstoff der Atmungskette, der den Biofilm nicht ablöst, führten zu einer Zunahme aller untersuchten PAK in der gleichen Größenordnung wie ohne Bio-film. In chloriertem Teerleachat wurden unter der teilweisen Anwendung einer einfachen Methode der kontinu-ierlichen Extraktion folgende PAK-Derivate analysiert: Chloracenaphthen, 1-Chlorpyren, 9-Fluorenon, Anthron. Da Reaktionsprodukte von Phenanthren und Fluoranthen nicht gefunden werden konnten, wird eine Weiterreaktion zu 9-Fluorenon vorgeschlagen, die durch die Pechoberfläche katalysiert wird. Instationäre Korrosion und nicht vorhandener aerober Abbau sind die Gründe für eine PAK-Zunahme während StagnationphasenThe influence of biofilm, encrustation, flow velocity and water quality on the release of PAHs was investigated in batch, continuously flown reactor experiments and in a pipe rig system. Chlorination of coal-tar coated stainless steel slides with biofilm resulted in an almost complete removal of the biofilm and an increase of the release of fluorene, phenanthrene and fluoranthene. PAH release of coal-tar coated stainless steel slides exposed to a solution of drinking water with 0,1% sodium azide as an inhibitor of the respiratory chain which did not remove the biofilm led to an increase of all observed PAHs up to the same magnitude as without biofilm. In chlorinated coal-tar leachate the following derivatives were detected while partly utilizing an easy method for a continuously extrac-tion: chloroacenaphthene, 1-chloropyrene, 9-fluorenone, anthrone. While reaction products of phenanthrene and fluoranthene could not be found a further reaction to 9-fluorenone catalysed by the coal-tar surface is proposed. Instationary corrosion and no aerobic degradation are the reasons for PAH increase during stagnation periods
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Sung, Hsueh-Chang, and 宋學昌. "Remove of Coal Tar Base by Solid Acids." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/47637158475813582941.
Full textAbstract:
碩士國立臺灣大學
化學工程學系研究所
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The products from coal tar usually contains small amount of t ar bases,such as quinoline (QN) and iso-quinoline (IQN).These impurities may d owngrade the products because of stinking odor and undesired color. The profit s can be significantly increased if tar bases can be reduced in the products. This study proposed a method which used solid acids to remove tar bases throug h adsorption process. Solid acids have similar acidity to liquid acid,while th ey can be regenerated so that they are enviormenetal frdly. Five solid acids,S iO2-Al2O3,HY,NH4-Mordenite,IR-120 and IRC-50S were used in these study. Wash o il (from China Steel Chemical Corp.) contained near 3.5% of QN/IQN was treated by solid acid with the wash oil/solid acid ratio of 2 at 25℃ for 24 hours. Q N and IQN were completely removed by IR-120, while near 50% reduction were fou nd by using other four solid acids. The other coal tar product, refined naphth alene, contained near 300 ppm of QN and IQN. QN and IQN were completely remove d by SiO2-Al2O3 with e naphthalene/solid acid ratio of 5 at 90℃ in one-hour a dsorption. The adsorption capability of SiO2-Al2O3 for wash oil was maintained even after four cycles of regeneration at 650℃ in air. For the refined napht halene product, the regeneration of solid acid could comprise two stages. Afte r QN/IQN adsorption, part of naphthalene could be recovered from solid acid by desorption at 200℃ in the first stage. Then, SiO2-Al2O3 was totally regenera ted at 600℃ in air. SiO2-Al2O3 could still be suitable for adsorion operation even after three cycles of regeneration, the results indicated that the adsor ption by solid acids was an effective method to reduce tar bases in the produc ts of coal tar. The economic analysis showed that the capital investment of re fined naphthalene process could be fully recovered within half year, based on the production capacity of China Steel Chemical Corp.
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Fraser, Michelle J. "Long-Term Fate of an Emplaced Coal Tar Creosote Source." Thesis, 2007. http://hdl.handle.net/10012/3399.
Full textAbstract:
An emplaced source of coal tar creosote within the sandy Borden research aquifer has provided an opportunity to document the long term (5140 days) natural attenuation for this complex mixture. Plumes of dissolved chemicals were produced by the essentially horizontal groundwater flowing at about 9 cm/day. Eleven chemicals were extensively sampled seven times using a monitoring network of ~280 14-point multilevel samplers.
A model of source dissolution using Raoult’s Law adequately predicted the dissolution of nine of eleven compounds analysed. Mass transformation has limited the extent of the plumes as groundwater flowed more than 500 m yet the plumes are no longer than 50 m. Phenol and xylenes were removed and naphthalene was attenuated from its maximum extent on day 1357. Some compound plumes reached an apparent steady state and the plumes of other compounds (dibenzofuran and phenanthrene) are expected to continue to expand due to an increasing mass flux and limited degradation potential.
Biotransformation is the major process controlling natural attenuation at the site. The greatest organic mass loss is associated with the high solubility compounds. However, the majority of the mass loss for most compounds has occurred in the source zone. Oxygen is the main electron acceptor yet the amount of organics lost cannot be accounted for by aerobic mineralization or partial mineralization alone.
After 10 years the source zone was treated with permanganate in situ to reduce the flux of contaminants into the dissolved plume and to permit natural attenuation to further reduce the plume extent. A sufficient mass of permanganate was injected to oxidize ~10% of the residual source. Laboratory experiments demonstrated that eight of ten of the study compounds were readily oxidized by permanganate. Once treated oxidized compounds displayed a reduced plume mass and mass discharge while they migrated through the monitoring network. Once beyond the monitoring network the mass discharge and plume mass of these compounds returned to pre-treatment trends. Non-reactive compounds displayed no significant decrease in mass discharge or plume mass. Overall the partial in situ chemical oxidation of the coal tar creosote source produced no long-term effect on the dissolved plumes emanating from the source.
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Weng, Ying-Pei, and 翁熒珮. "Elimination of odors emitted from hot melting of coal tar." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/17224287897634867246.
Full textAbstract:
碩士國立中山大學
環境工程研究所
103
Coal tar is a brown or black liquid of extremely high viscosity. Coal tars are complex and variable mixtures of phenols, naphthalene, polycyclic aromatic hydrocarbons (PAHs), and heterocylic compounds. Coal-tar creosote is the most widely used wood and bamboo preservative today; both industrially, processed into wood and bamboo using pressure methods such as &;quot;full-cell process&;quot; or &;quot;empty-cell process,&;quot; and more commonly applied to the materials through brushing. Commercial creosote contains mainly of phenols, cresols, xylenols, naphthalene, and anthracene. In the wood-preservative operations, phenolic and naphthalenic smells emit from the work place and the smell can be a nuisance for the nearby residents. In addition, coal-tar creosote is carcinogenic and harmful to the human health. In this study, an oxidation-reduction in-series scrubbing process was used to test its feasibility to remove gas-borne odorous compounds emitted from heated coal-tar creosote. An aqueous sodium hypochlorite solution with an available chlorine of 350 mg/L adjusted to a pH of 6.5 was tested to be feasible to oxidize the gaseous phenolic and naphthalenic compounds. The followed 3,500 mg/L H2O2 solution adjusted to a pH of approximately 12 was able to reduce the gaseous chlorine emitted from the oxidative scrubbing liquid to a value of around 0.2 ppm. The two-stage scrubbing process could achieve a non-methane hydrocarbon (NMHC) removal of 62-81%. Results indicate that with the conditions, for treating 1,000 m3 of the vented gas, it needs 0.33 kg of 12% NaOCl solution and 0.00115 kg of 30% H2O2 solution. The total chemical cost is 2.32 NTD with costs of 12% NaOCl solution at NTD 6.5/kg and 30% H2O2 solution at NTD 15/kg. Key words: coal-tar creosote, odor control, sodium hypochlorite, chemical scrubbing
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Divya, Sree V. "Impact of Dispersion of Gases from Combustion of Coal Tar." Thesis, 2015. http://ethesis.nitrkl.ac.in/7932/1/639.pdf.
Full textAbstract:
This project ‘Impact of Dispersion of gases from combustion of Coal tar’ deals with gases released during combustion of Coal tar and the area affected by these gases. This depends on many parameters. This is solved by using the software “ANSYS”. For modeling, the parameters which affect the flow of gases are need to be known. In general, wind flow, presence of obstacles and temperature may affect the flow.
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SHEN, CHIN-WEI, and 沈晉煒. "Domestic Coal-tar Pitch and Carbon Composite for Lithium Ion Batteries." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/9bcuk6.
Full textAbstract:
博士逢甲大學
材料科學與工程學系
107
This study uses the coal-tar pitch (R692B-BPR) produced by China Steel Chemical Corporation (CSCC) that applied to the following items: 1. Use pitch in nitrogen and change different variables (temperatures and times) to making the mesophase pitch, then was analyzed size and quantity by polarizing optical microscope, softening point test, differential thermal analysis (DTA), benzene insoluble (B.I.) component and quinoline insoluble (Q.I.) component. With the above analysis to assess the spinning ability of domestic coal-tar pitch. Put the samples into a simple spinning device (Spinning port D=0.4 mm, L/D=3, Nitrogen pressure 2~4 kg/cm2, 290~350 ℃) to extrude the fibers. As the quinoline insoluble component is improved, the carbon fiber’s crystallinity is also better. 2. The negative electrode of a lithium-ion battery should have the characteristics of large charge capacity, excellent charge and discharge cycle, steady discharge voltage, low irreversible charge capacity, and stable electrolyte. Natural graphite and mesocarbon microbeads (MCMB) are the most common materials used for the negative electrodes of such batteries. This study examines the effect of the use of homemade non-modified MCMB (HMM), modified MCMB (HMMQ), and natural graphite (NG) to produce electrodes on the batteries' high current charge–discharge behavior. In this experiment, the charge–discharge results showed that the voltage plateaus of HMM and HMMQ sloped due to short-range structural order, which enabled the intercalation and deintercalation of lithium ions to occur at different voltages. When HMMQ was charging and discharging high current at a rate of 2 C, the battery's charge capacity reached 160 mAh•g−1 and the coulometric efficiency exceeded 96%. Following the start of charging and discharging, a stable solid electrolyte interface (SEI) layer formed on HMMQ. The charge capacity of HMMQ was approximately 167 mAh•g−1 after 100 charge–discharge cycles at 1 C, and the cycles were stable. According to FTIR analysis, the content of the SEI layer produced within HMMQ consisted of Li2CO3 and (CH2OCOLi)2, and was stable, non-soluble, and passive. Negative electrodes made using modified material displayed good stability throughout many cycles when charging and discharging at a high current. 3. High–capacity electrode materials are critical for developing portable electronic equipment that requires high–energy lithium–ion batteries (LIBs). Diverse materials and fabrication methods have been developed for this purpose. In this study, carbon composite paper (CCP) containing recovered silicon powder was tested as the current collecting plate and electrode for LIBs, after stabilization process at 250 ℃ in air followed by carbonization at 1000 ℃ in N2. In long cycle tests, the discharge capacities of electrodes with 2.5, 5, and 10 wt.% silicon were increased to 94%, 129%, and 41% that of the silicon-free electrode, respectively.
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Makgato, Seshibe Stanford. "Investigating the effect of substituting fractions of imported coals with coke oven tar on coke quality: pilot plant study." Thesis, 2015. http://hdl.handle.net/10539/16732.
Full textAbstract:
In this study, coke oven tar addition over a range of 0 – 8 wt.% was evaluated as a possible
substitute for imported coals fractions. Coke oven tar used was collected from coke oven tar
decanters of the by-products section of the coke making plant. Moisture content in coke oven
tar varied depending on the residence time and water carryover from coke oven tar separators
to storage tanks. Therefore, various moisture ranges were considered in order to observe its
effect on coal blend, carbonization and coke properties. The optimum moisture content in
coke oven tar was found to be 3% with a coke oven tar addition of 6 wt.% in the coal blend.
At the same coke oven tar addition of 6 wt.% in the coal blend but with 6% moisture content
in coke oven tar, coke properties improved, coke yield showed up to 4% decrease. On the
other hand, with 1% moisture content in coke oven tar of 6 wt.% in the coal blend, coke
yield increased by 1% and low coke properties such as I40 of 42.9 and Stability of 50.3 were
achieved. The latter process was characterized by excessive increased in wall pressure and
pushing energy. Both wall pressure and pushing energy increase are less desirable due to
their detrimental effect on the physical condition of the oven walls. Furthermore, addition of
coke oven tar with 1% moisture content to coal blend can be prohibited by its high viscosity.
At 3% moisture content in coke oven tar addition of 6 wt.% in the coal blend, coke properties
improved. When the amount of coke oven tar was increased to 8 wt.% at the optimum coke
oven addition, coke yield was not affected but low CSR of 57.8 against a target of ³60 was
achieved as opposed to CSR of 65.4 at 6 wt.%. Also, coke stability of 52.2 at 8 wt.% as
opposed to 56.1 at 6 wt.% was achieved. Moreover, the highest I40 of 50.9 was achieved at 6
wt.% whereas with 8 wt.% coke oven tar, I40 of 47.9 was achieved. However, up to 2%
decrease in coke yield was observed. Despite this 2% decrease in coke yield, coke oven tar
addition is a positive and viable option based upon economic factors (i.e. this reduces the
quantity and cost of imported coals and still achieves improved coke quality which result in
improved blast furnace operation and better hot metal quality).
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Chen, Yung-chuan, and 陳永川. "Studies of High Temperature Sulfidation Corrosion in a Coal Tar Distillation Process." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/57647526167770836136.
Full textAbstract:
碩士國立高雄第一科技大學
環境與安全衛生工程所
91
This study is based the observation of corrosion on a circulation loop system at the coal tar distillation plant over a period of several years. Leakage of the pipeline and major facility was damaged as well. Seventeen emergency shut off had been occurred for this reason from 1997 to 2002. Fire alerts were also occurred due to autoignition of FeS, product in the corrosion reaction, which has drew the attention of the safety concerns. Corrosions of the equipment, frequencies of emergency shut down, and the cost of the inspection is relatively higher than the expected. This potential industrial hazardous of the distillation plant was not well studied in the past. Changing the corroded pipeline and adding corrosion inhibitor might be beneficial of preventing corrosion of the system. However, the improvements of using these methods are limited. Based on the literature search regarding the corrosion mechanism, corrosion in this case was believed to be triggered under the presence of trace amount of sulfide in the fluid at a high operation temperature. Either H2S or naphthenic acid is not able to initiate the reaction as we originally expected. It was generally believed that there will be no corrosion reactions over the equipment if the sulfide content in the mixture stream is lower than 0.6%. Nevertheless, it is not true upon completion of this study. Corrosion protection strategies have been studied by knowing the various reasons triggering the corrosion reaction over the equipment. Changing the equipment pipeline will be the best remedy under the economical and safety concerns. Suggestions of using different plumbing materials under different operation condition were made in this study, which may reduce the potential industrial hazard under the operation condition. The suggestions may also be beneficial of enhancing the public safety concerns.
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Chao, Jung-Chi, and 趙榮麒. "Processing of Mesophase Coal-Tar Pitch to be used in Lithium Secondary Batteries." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/873cf2.
Full textAbstract:
碩士逢甲大學
材料科學所
91
In this study electrochemical characteristics of various carbon electrodes made from mesophase coal-tar pitch, used as the anode of the lithium ion batteries have been investigated. The relationship between the capacity of lithium ion batteries and the microstructure and properties of carbon anodes were carefully examined. The X-ray diffraction and Raman spectra were used to examined the structures of mesophase pitch carbon. Elemental analysis to determine the compositions after different heat treatments, the BET method for analyzing the surface area and the density of this carbon material was also measured. Moreover, charge-discharge cyclic tests and cyclic voltammograms were employed to get the electrochemical properties of the batteries and correlated to the different parameters of carbon materials. Discharge capacity of carbons were found to be influenced by the values of Lc, La and BET specific surface area of materials. Synthesizing graphite from mesophase coal-tar pitch was performed by different heating rate during the graphitization process. To study the charge-discharge capacity and reversibility between the carbonized and graphitized mesophase pitch, the mixture of coke and graphite produced from mesophase coal-tar pitch were also used. Different ratios of the carbon materials for the electrode affect the electrochemical behavior of the battery. The mixture of coke and graphite with weight ratio of 5:5 gave to a remarkable change in reducing irreversible electrical capacity to about 165mAh/g, and mentained a high reversible capacity of about 354 mAh/g, with a cyclic efficience of about 68.21%, and a slow decay in discharge capacity. The hysteresis in the voltage profile of mixture was also decreased. Therefore, mixture of coke and graphite material with good electrochemical properties may will be the future material for anodes in the lithium ion batteries.
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Lin, Chun-Han, and 林君翰. "Fabrication of mesophase pitch using a mixture of coal tar pitch and petroleum pitch." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/77996730589143845560.
Full textAbstract:
碩士國防大學理工學院
材料科學與工程碩士班
100
The fabrication of the mesophase pitch precursor of carbon fiber with the mixture of coal tar pitch (RBP) and petroleum pitch (A240) was studied. The blends were prepared from different RBP/(A240+RBP) ratio ranging from 20 to 80%. The heat-treatment process was manipulated to develop the precursor of the carbon fiber in the nitrogen flow of 300 sccm under the normal atmosphere pressure and the heating temperature of 420℃ and 430℃ for 2 hr at the raising rate of 3℃min 1 . After the mesophase pitch preparation , the Element Analysis (EA) was used to analyze the variation of H/C in the mesophase pitches, the softening point test was used to evaluate the flow-ability and softening point, and the polarized optical microscope was used to observe the growth of mesophase pitch from the RBP/A240 blends with different ratio. The pyrolysis temperature of the blends were evaluated with thermal gravimetric analysis (TGA). The influence of the RBP/(A240+RBP) ratio on the mesophase pitch growth at the same heat treatment condition was studied with all the aforementioned characterization accompanying the toluene insoluble (TI) test.
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Łamacz, Agata. "Study of catalytic removal of NOx from coal combustion flue gases and tar from coal gasification on CeZrO2 supported metal catalysts." Rozprawa doktorska, 2013. https://repolis.bg.polsl.pl/dlibra/docmetadata?showContent=true&id=64282.
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Łamacz, Agata. "Study of catalytic removal of NOx from coal combustion flue gases and tar from coal gasification on CeZrO2 supported metal catalysts." Rozprawa doktorska, 2013. https://delibra.bg.polsl.pl/dlibra/docmetadata?showContent=true&id=64282.
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Makgatho, Michael. "Coal tar pitch volatiles exposure in a petrochemical refinery plant: a task based exposure assessment." Thesis, 2009. http://hdl.handle.net/10539/6772.
Full textAbstract:
This study describes tripper car operators’ exposure to coal tar pitch volatiles at an operation at Coal Distribution Steam Plant that involves the use of coal tar mix to feed as fuel the steam generating boilers. A cross-sectional task-based exposure assessment approached was used. The objectives of this study were to monitor tripper car operators’ exposures to coal tar pitch volatiles as benzene soluble fraction and to then compare the measured concentrations with the occupational exposure limit. The general aim of the study was to accumulate data about employee exposure to coal tar pitch volatiles in South African Petrochemical Refineries.
A total of 56 samples was collected and analyzed for coal tar pitch volatiles – benzene soluble fraction. Of the 56 samples, 41 were personal samples collected on the breathing zones of the workers and 15 samples were field blank samples. The method used for the collection of the samples was the United States Department of Labor, Occupational Safety & Health Administration Method 58.
In South Africa the available occupational exposure limit for coal tar pitch volatiles is the time weighted average occupational exposure limit – recommended limit for cyclohexane soluble fraction which is 0.14 mg/m3. For the evaluation of personal exposure to compare with the occupational exposure limit, the UK Health & Safety Executive Method for the Determination of Hazardous Substances (MDHS) 68 was adopted in the past to monitor workplace air. This method was since withdrawn by the Health & Safety Executive after research conducted by the Health & Safety Laboratory revealed that unacceptable variability were introduced into the method due to the small mass changes involved and the difficulty in accurately weighing the filters before and after the cyclohexane extraction. Due to the unavailability of a suitable and acceptable method to assess workers’ exposure to coal tar pitch volatiles – cyclohexane soluble fraction to compare to the South African occupational exposure limit, the Occupational Safety & Health Administration Method Number 58 was used during this study for the collection of the samples. This is a validated method. This method follows a similar approach as the MDHS 68 however benzene is used instead of cyclohexane during sample extraction.
The Occupational Safety and Health Administration have the permissible exposure limit of 0.2 mg/m3 for coal tar pitch volatiles – benzene soluble fraction to use when assessing worker exposure. This limit was used during this study for assessing tripper car exposure to coal tar pitch volatiles.
No coal tar pitch volatiles were detected on the samples collected during the study. The results revealed concentrations below detection limit of the test laboratory analytical method. The detection limit used thereof was 0.1 mg per sample. The tripper car operators were therefore exposed to coal tar pitch volatiles at concentrations that complied with the permissible exposure limit 0.2 mg/m3.
The hypothesis of this study was that the tripper car operators at Coal Distribution Steam Plant are over exposed to coal tar pitch volatiles – benzene soluble fraction. This hypothesis is therefore rejected.
Based on the results derived from this study it is recommended that further research studies be conducted specifically with focus on different methods of exposure assessment to workers exposed to coal tar pitch volatiles in South African Petrochemical Refinery Plants.
- ii -
Since the method used was limited to the particulate phase of the contaminant exposure, with the gaseous phase of exposure to coal tar pitch volatiles only looked at when the PEL is exceeded. A method that can measure both the gaseous and particulate phase of the contaminant must be investigated.
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邱毅文. "A Study on the Manufacturing Water-Resistance Membrane of Moisture-Cured PU/Coal Tar Pitch." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/69274860109767432237.
Full textAbstract:
碩士逢甲大學
紡織工程研究所
83
This study combined the advantages of moisture-cured PU and coal tar pitch to manufacture the water-resis-tance membrane. The experiment changed three difference NCO/OH ratio (1.5, 1.8, 2.0), three difference Diol/Triol (10, 15, 20), four difference Pitch/PU ratio (10, 20, 30, 40)and adds to three difference silane (A-187, A-189, A-1100), then adds to plasticizer (DOP) and slovent (toluene) modify their viscosity and processly. And to study the mix ratio to have the best physical propetry, The result shows found that at the NCO/OH ratio at 1.8, the Diol/Triol ratio at 15, adds to 0.1% oxazolidin moisture scavenger to synthesize the PU preppolymer, then biends coal tar pitch and adds to silane, at the Pitch/PU ratio at about 30%, adds to silane (A187), at 1%, the DOP at 80% and toluene at 15% can reach the best physical property. After the test of the watr-proof, the ultraviolet rays, the chemical medicine, their tensile strength and ultimate elongation can maintarn good number. And the test of the climate-proof, because at long time incur the effect of sunlight and rain in a cycle, the sample become brittle and stiff and their surface lose original glossy. The test of mechanical property can find to reduce the elongation of sample, because the sample become brittle and stiff. Their mechanical property can also maintain good number. When th Pitch/PU wather-resistance membrane coated on the concrete surface, it can thoroughly seal the vacancy of pentrated by the water and air. So we can appropri-ate manufacture the high performance of water-resistance membrane of Pitch/PU.
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Ramjee, Shatish. "Rheological Behaviour and Characterisation of Pitch-Based Carbon Precursors." Thesis, 2015. http://hdl.handle.net/2263/46244.
Full textAbstract:
Pitch material is an important precursor in the production of carbon bre, carbon composites
and synthetic graphite. It has a complex transformation during pyrolysis which
incorporates the separation of a liquid crystalline phase, known as mesophase. This thesis
attempts to enhance the understanding of this change in composition, structure and its
resultant behaviour.
In this study, two pitches, a coal-tar pitch (MP110) and a (SASOL) Lurgi-gasi er
pitch, are pyrolised to produce material at di erent stages of mesophase development.
These pitches produce mesophase of di erent mosaic type and therefore also resultant
coke.
The MP110 was thermally treated up to a temperature of 437 and produced
anisotropic pitch (which still contains signi cant particulate matter). The nucleated
mesophase spheres did not coalesce to produce domains; this behaviour being attributed
to the particulate material. The SASOL pitch produced a di erent type of mesophase
material. The mesophase produced was of ne mosaic domains; a sample with continuous
mesophase regions was also produced with a mesophase content of approximately 60%
(by volume).
The aromatic starting material of MP110 produced higher quinolone and toluene
insoluble (QI and TI) compounds after pyrolysis. This was also observed in the increase
of C/H (molar ratio of carbon to hydrogen). The more aliphatic SASOL starting pitch
showed similar trends to its MP110 counterparts with respect to QI (quinoline insolubles),
TI (toluene insolubles) and C/H. The glass transition and associated temperatures of
the pitches were analysed via thermal mechanical analysis (TMA), dynamic scanning
calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The techniques
showed consistency between instruments, with TMA providing the likeliest re
ection of
the true thermodynamic glass transition temperature. The loss of volatile components
was accompanied by an increase in glass transition temperature (observed in conjunction with C/H and mesophase content). For anisotropic MP110 pitches, two relaxations were
observed, one for the isotropic fraction, the other for the mesophase. No such behaviour
was easily observed for the SASOL pitches.
Rheological measurements were obtained to understand the behaviour of the pitches.
Measurements were limited to a speci c viscosity range. The measurements of the samples
were therefore made at di erent temperatures. The relation of the measurement
temperature to the glass transition temperature is thus of extreme importance. The
temperature governs the state of the structure; whether it be suspension, emulsion or gel.
Oscillatory shear experiments were undertaken for the pitch material. Predominantly
isotropic material showed transition from viscoelastic solid to viscoelastic liquid as previously
observed in pitch material.
The anisotropic MP110 pitches did not allow for the production of mastercurves due
to non-linear viscoelastic e ects caused by the softening of mesophase. This being the
transition from a suspension of hard spheres to an emulsion of deformable droplets (depending
on temperature).
For the higher mesophase content anisotropic SASOL pitches, mastercurves were produced;
it had a similar shape to the isotropic pitches (at temperatures closer to the
glass transition), but signi cantly increased elasticity was observed at higher temperatures.
This phenomenon supported the hypothesis of a strong interaction between the
components and phases of the pitch, and thus the possibility of gelled systems.
Rotational shear-rheometry was also utilised and showed that isotropic pitch material
behaves as a predominantly isoviscous
uid.
The anisotropic MP110 pitches of approximately 30% mesophase showed high- and
low-shear viscosity plateau
uid behaviour. This being caused by the breakup of agglomerated
mesophase spheres. This was tested by the implementation of the Krieger-
Dougherty suspension model. The possibility of droplet deformation was investigated
for these samples by utilising a Krieger-Douherty based emulsion analogue, which con-
rmed suspension like behaviour (at the measured temperatures). MP110 samples with
more mesophase were measured at higher temperatures. Their behaviour is more akin to
Power-law shear-thinning behaviour. Being further away from the continuous isotropic
phase glass transition temperature, the behaviour observed is similar to that of emulsions.
SASOL anisotropic pitches showed signi cant yielding upon shear, which is attributed
to structure breakdown. This behaviour is appropriately described by a yield stress, shearthinning
model such as Herschel-Bulkley. Measurements of viscosity for these samples
were made at temperatures signi cantly further from the glass transition temperature as
compared to that of the MP110 pitches. This corroborates strong interaction between
its components. The observed shapes of the curve, at temperatures of measurement,
support the notion of a gel structure. This behaviour is rst proposed via the complex
structure observed (clusters of ne mosaic mesophase domains) and supported by strong interaction of the components inferred from obtained rheological properties.Thesis (PhD)--University of Pretoria, 2015.
tm2015
Chemical Engineering
PhD
Unrestricted
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Wong, Ka-Wai, and 黃家維. "Coal Tar Pitch Coated Natural Graphite as Anode Materials of Lithium Ion Batteries for Electrochemical Effect." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/13093084468663619191.
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Liao, Ni-Ko, and 廖尼軻. "The Study on Thermal Characterization of Mesophase in Coal Tar Pitch and Manufacture of Silicon Carbide." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/69506522033224564398.
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