Bio fuels are made from an extensive selection of fuels derived from biomass, including wood waste, agricultural wastes, and alcohol fuels. As a result of increased energy requirements, raised oil prices, and concern over greenhouse gas emissions from fossil fuels, bio fuels are acquiring increased public and scientific attention. The ethanol industry is booming and during the past several years, there has been an increase in demand for fuel ethanol and use of its co-products. To increase potential revenues from ethanol processing and its utilization, extensive research is proceeding in this field. In Western Canada, wheat is the primary raw material used in the production of ethanol by fermentation and distillers dried grains with solubles (DDGS) are one of the major co-products produced during this process. At present, the DDGS are generally sold as animal feed stock but with some alteration they could be used in other useful areas.<p> Densification of biomass and use of it for fuel like wood pellets, hay briquettes, etc. have been studied for many years and have also been commercialized. In this thesis, pellets made from distillers dried grains have been investigated. DDGS were obtained from Noramera Bioenergy Corp. and Terra Grain Fuels Ltd. Before transforming them into pellets, they were characterized on the basis of physical and chemical properties. A California pilot-scale mill (with and without steam conditioning) was used for pelleting the distillers grains with solubles.<p> A full factorial design with two levels of moisture content (i.e., 14 and 15.5% (w.b.)), hammer mill screen size (i.e., 3.2 and 4.8 mm) and temperature (i.e., 90 and 100°C) was used to determine the effects of these three factors on the pellet properties made from Noramera Bioenergy Corp., without steam conditioning. Different levels of moisture content were used for the pellets made from Terra Grain Fuels Ltd. (i.e., 11.5 and 13.09% (w.b.)), with steam conditioning. The initial moisture contents of the DDGS were 12.5 and 13.75% (w.b.) from Noramera and Terra Grain, respectively. The moisture content of DDGS grinds ranged from 11.6 to 12.03% (w.b.) for the Noramera samples, and from 11.5 to 13.09% (w.b.) for Terra Grain DDGS. The moisture content decreased with a decrease in the hammer mill screen size.<p> The use of a smaller screen size achieved an increase in both the bulk and particle densities of the DDGS. The coefficient of internal friction was almost the same for both samples but cohesion was higher in Noramera samples (8.534 kPa). The DDGS obtained from Noramera Bioenergy Corp. contained dry matter (91.40%), crude fibre (4.98%), crude protein (37.41%), cellulose (10.75%), hemi-cellulose (21.04%), lignin (10.50%), starch (3.84%), fat (4.52%) and ash (5.16%); whereas the samples obtained from Terra Grain Fuels contained dry matter (87.69%), crude fibre (7.33%), crude protein (32.43%), cellulose (10.81%), hemi-cellulose (27.45%), lignin (4.37%), starch (4.18%), fat (6.37%) and ash (4.50%).<p> The combustion energy of the Noramera samples was 19.45 MJ/kg at a moisture content of 8.6% (w.b.) whereas the combustion energy of Terra Grain samples was 18.54 MJ/kg at 12.31% (w.b.) moisture content.<p> The durability of the pellets increased as the screen size decreased which is likely due to the fact that a smaller screen size produces more fine particles. This fill voids in the pellets and, hence, makes them more durable.<p> The length of the pellets produced from Noramera DDGS increased with a decrease in moisture content possibly because pellets formed at higher moisture content absorb less moisture. Therefore, the length does not increase as much. Lateral expansion occurred most with higher temperature and lower moisture content and with lower temperature and higher moisture content. The length to diameter ratio of the pellets followed the same trend as the change in pellet length. The length of the pellets produced from Terra Grain also increased with a decrease in moisture content. The lateral expansion increased with increase in screen size and moisture content and also, with decrease in moisture content and increase in temperature. The length to diameter ratio increased with decrease in screen size and moisture content, similar to the change in pellet length. The highest bulk density of Noramera pellets resulted from smaller screen size and lower moisture. The particle density increased with a decrease in screen size and an increase in moisture content. The highest bulk density of Terra Grain pellets occurred with an increase in temperature and decrease in moisture content. The highest particle density occurred with an increase in temperature and decrease in screen size.<p> The pellet hardness increased with a decrease in moisture content and screen size did not have any significant effect. The Terra Grain pellets were harder because they were subjected to steam conditioning. Steam conditioning helps to increase the hardness.<p> The pellet durability increased with a decrease in screen size and increase in moisture content. The steam conditioning also caused the higher durability in the Terra Grain pellets. In terms of moisture absorption, the only significant factor was moisture content. Pellets with lower moisture content absorbed more moisture.<p> The ash content values of pellets were higher in Noramera samples than in Terra Grain samples because of high moisture content in Noramera samples. The combustion energy of the Noramera pellets was higher than the Terra Grain pellets because of the high percentage of dry matter and lignin present in Noramera samples. The emission results for both the sample pellets were similar. When the DDGS pellets were compared to wood pellets, emission of nitrous oxide was lower for wood whereas, carbon dioxide was higher.

No description available.

Activated carbon is widely used in the gold processing industry as an adsorbent for the gold cyanide complex, [Au(CN)(subscript)2]. However, many other processing reagents are also adsorbed (termed fouling), which compete with the gold cyanide complex for active sites on the carbon. So far the only way of assessing the amount of fouling due to organic compounds that has adsorbed on the carbon is through the use of thermogravimetry (TG). Unfortunately, thermogravimetry only gives the percentage total of organic fouling agents adsorbed and no information can be obtained on the identity of the individual organic fouling agents. Thus this current work reports the development of analytical methods capable of identifying specific fouling agents.In this thesis the identification of two types of common organic fouling agents adsorbed on activated carbon during gold processing has been established using three thermal analysis techniques, namely thermal desorption-pyrolysis-gas chromatography-mass spectrometry (TD-py-GC-MS), thermogravimetry-mass spectrometry (TG-MS), and thermogravimetry-Fourier transform infrared (TG-FTIR) spectroscopy. TD-py-GC-MS was used to identify the individual decomposition gases of each sample. TG-MS and TG-FTIR were used to obtain the decomposition temperatures of the fouling agents, and to identify/monitor the gases evolved as a function of temperature. All analyses were performed in an inert atmosphere.The organic fouling agents studied were xanthates and frothing agents, which are used as flotation reagents. The xanthates studied were sodium ethyl xanthate (SEX), sodium isobutyl xanthate (SiBX), potassium ethyl xanthate (PEX), and potassium amyl xanthate (PAX). The frothing agents studied were polypropylene glycol (PPG), polypropylene glycol methyl ether (PPGME), alpha-terpineol, and methyl isobutyl carbinol (MiBC). The thermal decomposition of ++ / each pure reagent was studied, and then the reagents were individually adsorbed on an activated carbon (Haycarb, -45 mu m) and their thermal decomposition reinvestigated. These pure systems were then compared to the thermal decomposition of activated carbon samples taken from two gold processing plants.Between seven and sixteen gases were identified via TD-py-GC-MS for the decomposition of each xanthate. Common gases and types of gases identified included carbonyl sulfide, carbon disulfide, thiols, alcohols, carbonates, sulfides, disulfides, and carbonothioic acid, O,S, dialkyl esters. The thermogravimetric curve of each xanthate displayed two mass losses. The mass losses and their corresponding temperatures were dependent on the alkyl chain and alkali cation of the xanthate. TG-MS and TG-FTIR showed carbonyl sulfide and carbon disulfide were the most significant gases evolved from the decomposition of each xanthate.Each xanthate was adsorbed on activated carbon, and its thermal decomposition characteristics reinvestigated. On heating, similar gases were evolved to those detected for the xanthate alone. However, the TG curves displayed three mass losses compared to two with the xanthates not adsorbed on activated carbon. The first mass loss of each sample was attributed to a hydrolysis reaction between water retained in the activated carbon and the xanthate. TG-MS and TG-FTIR analyses showed carbon disulfide and carbonyl sulfide were the most significant gases evolved during the first mass loss and second mass losses respectively, and consequently these gases could be used as indicators of xanthate fouling on plant samples.The TD-Py-GC-MS, TG-MS, and TG-FTIR analyses of the frothing agents showed these compounds mainly boiled with little indication of thermal decomposition. The thermogravimetric curve of each frother displayed one mass loss. Upon reinvestigation of ++ / the frothing agents individually adsorbed on activated carbon, a number of different gases were identified by the TD-py-GC-MS analyses. For all adsorbed frothing agents (except MiBC) these included propanal, 2-ethyl-4-methyl1,3-dioxolane, 3,3-oxybis-2-butanol, and dioxanes. Each TG curve displayed one mass loss due to the decomposition of the frothing agent. The TG-MS and TG-FTIR analyses showed propanal was the most significant gas evolved for the PPG and PPGME. For alpha-terpineol, propene was also a significant gas, although this gas was not detected by TG-FTIR. The TD-py-GC-MS and TG-FTIR analyses of the MiBC showed it mainly boiled off the carbon without significant alteration.Four activated carbon samples were obtained from different parts of the process circuit in the Three Mile Hill plant in Western Australia. Nine to twelve gases were identified by TD-py-GC-MS analysis of each sample. Common gases included butene, 2-methyl-I-butene, and butanol. The TG curve of each sample displayed one mass loss due to the presence of fouling agents. TG-MS analyses showed butene was the most significant gas evolved for this mass loss. TG-FTIR analyses showed that carbonyl sulfide had also evolved during this mass loss. Thus it was concluded from the detection of carbonyl sulfide and its temperature of evolution, that fouling of the activated carbon by a xanthate had occurred.Five activated carbon samples were obtained from the Salsigne plant in France. Nine to fourteen gases were identified by TD-py-GC-MS analysis of each sample. Common gases included cyclopropane, butene, propanal, isobutanol, isoarnyl alcohol, and 2,5 and 2,6-dimethyl dioxene. The TG curve of each sample displayed one mass loss due to the decomposition of fouling agents, in the same temperature region as the Three Mile Hill samples. TG-MS analyses showed cyclopropane was the most significant gas evolved ++ / for this mass loss. TG-FTIR analyses showed that carbonyl sulfide had also evolved during this mass loss. Thus it was concluded from the detection of propanal, carbonyl sulfide, and their temperatures of evolution that fouling of the activated carbon by a xanthate and a frothing agent had occurred respectively.A comparison of the techniques showed that TD-py-GC-MS analysis was essential for unambiguous identification of the complex gas mixture obtained from decomposition of organic fouling agents. Unfortunately TD-py-GC-MS provided no information on mass losses or temperatures of gas evolution. TG-MS permitted the monitoring of evolved gases versus temperature via their molecular ions. However the molecular ion signals were affected by overlapping fragment and/or isotope ion signals. The TG-FTIR was most useful when the evolved gases gave an infrared adsorption that was very characteristic of the molecule, as for the identification of carbonyl sulfide and carbon disulfide. This work was successful as a combination of the analytical techniques enabled identification of fouling agents adsorbed on plant samples.

Made available in DSpace on 2014-10-09T12:28:22Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:28Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:28:22Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:28Z (GMT). No. of bitstreams: 0 / Neste trabalho, é apresentada uma variação da técnica de espectroscopia por cavidade ressonante tipo ring-down CRDS (do acrônimo em inglês Cavity Ring-Down Spectroscopy) para a obtenção simultânea do espectro de absorção de multicomponentes numa faixa espectral larga do visível. Esta nova técnica se resume no uso do espectro supercontinuum (resultante da irradiação de meios não lineares através de lasers de femtossegundo, ou simplesmente gerada por fontes compactas) como fonte de luz para iluminar a cavidade. Neste contexto são descritas as características dos módulos para a montagem de um MC-SC-CRDS (Multicomponent Supercontinuum Cavity Ring-Down Spectroscopy): os pares de espelhos altamente refletivos, a cavidade ressonante e o sistema de detecção. Alguns problemas relacionados à excitação de multimodos, à luz difusa, ao uso efetivo do intervalo dinâmico de detecção, à baixa resolução do instrumento em resolver linhas estreitas de absorção são situados. Apresentamos os espectros de absorção de H2O (políades 4nu, 4nu + delta ) e O2 (transições proibidas de spin b-X) simultaneamente medidos por essa técnica na faixa do visível, e uma comparação com as linhas de absorção baseadas do banco de dados HITRAN é feita para demonstrar a funcionalidade deste método. / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Little is known of tissue carbon monoxide (CO) changes after acute exposure because tissue levels are in the order of picomoles per milligram and the technology to measure such low concentrations has only become available relatively recently. This study tested three hypotheses: That tissue CO levels (1) vary among tissues after acute poisoning; (2) change over time; but (3) cannot be predicted by measuring carboxyhaemoglobin (COHb) levels. Twenty four healthy male Sprague-Dawley rats were exposed to 2500 ppm CO in air for 45 min. This non-lethal exposure achieved reproducible COHb values of 66 to 72%. Animals were allowed to recover breathing air and were sacrificed at 30 minute intervals for 150 minutes. An additional nine male animals served as unexposed controls. Accurate measurements of tissue CO levels were made in blood, brain, heart, and skeletal muscle samples. All samples were prepared using the validated technique described by Vreman et al., and Reduction Gas Analysis was used to determine the pmol CO per wet weight tissue. Co-oximetry and gas chromatography were performed on all blood samples. Predictably, blood CO content dropped following exposure, but tissue CO content did not follow the same trend in all tissues. This study supports the hypothesis of (1) tissue and (2) time-related variability of CO concentration in three body tissues after exposure and (3) documents lack of utility of COHb for predicting tissue CO tissue values. / Dissertation (MSc)--University of Pretoria, 2007. / Nuclear Medicine / Unrestricted

Nowadays, plastic waste poses one of the greatest risks to the environment. Plastics affect the environment at all stages of their life cycle. Bioplastics have become widely used as a substitute for conventional plastics, without detailed examination of their behavior in real environmental conditions. As a result, it is assumed that they can accumulate in the environment and the question arose as to how to identify them. The main goal of this thesis is to develop a method based on sample pyrolysis that is suitable for the identification and determination of the amount of PLA microplastics in soil and other solid matrices. Three types of soils and sludge were used for analysis. These matrices were spiked to obtain concentration ranges 0,2% - 5,0%. The pyrolysis resulted in evolution of gases with the signals m/z 29, 43 and 44, witch originated from PLA and are suitable for qualitative and quantitative analysis. Analysis of PLA in sludge was more complicated due to similarity of gases evolved from pure matrices. We tested three approaches based on analysis of signal´s peak areas, intensities and temperatures of gas evolution. While the first approach failed, the last two approaches appeared to be promising for qualitative and quantitative analysis of PLA in the sludge. Several methods suitable for qualitative and quantitative analysis of even very small amounts of PLA in soils and sludge have also been designed/developed. These methods were based on analysis of the composition and dynamics of the released gases and the characterisctic degradation temperatures.

The main purpose of the AOD-converter is to lower the carbon content in stainless steel production. The carbon content can be estimated by static theoretical models. It can also be estimated through dynamic models based on analysis of the exhaust gases from the converter. This master thesis is a study on an extended use of exhaust gas analysis data on the AOD-converter at Outokumpu’s stainless steel plant in Avesta, Sweden. There are two main methods of predicting the carbon content based on exhaust gas analysis, mass balance and a linear regression between decarburization rate and carbon content. This master thesis mainly focuses on the development of the linear regression model for steel grades ASTM 304L, 316L, S32101 and S32205 for the last step of the decarburization, as well as ASTM S32205 and S30815 for the second last step of the decarburization. The results showed that the linear regression model can predict the carbon content at the last step of decarburization with a standard deviation between 0,00626 %C and 0,0109 %C for the different steel grades. An equation for carbon prediction dependent on the steel composition was also developed in the master thesis, making it theoretically possible to use for all steel grades, it has however not yet been tested on other steel grades. The CRE measured from the exhaust gases was also studied to find out if it is possibleto use as basis for step changes during the decarburization, but the resultswere inconclusive. / Huvudsyftet med AOD-konvertern är att sänka kolhalten i produktionen av rostfritt stål. Kolhalten kan uppskattas av statiska teoretiska modeller. Den kan också uppskattas av dynamiska modeller baserade på analys av avgaserna från konvertern. Det här examensarbetet handlar om utvidgning av användandet av avgasanalysdata på AOD-konvertern på Outokumpus stålverk i Avesta, Sverige. Det finns i huvudsak två metoder för att bestämma kolhalten med hjälp av avgasanalys, massbalans och en linjär regression mellan kolfärskningshastigheten och kolhalten. Det här examensarbetet fokuserar i huvudsak på utvecklingen av den linjära modellen för stålsorterna ASTM 304L, 316L, S32101 och S32205 för sista steget i kolfärskningen. Samt stålsorterna ASTM S32205 och S30815 för näst sista steget i kolfärskningen. Resultaten visade att den linjära modellen kunde uppskatta kolhalten i sista steget av kolfärskningen med en standardavvikelse mellan 0,00626 %C och 0,0109 %C för de fyra olika stålsorterna. En ekvation som anger sambandet mellan sammansättningen på stålet under kolfärskningen och ekvationen för den linjära regressionen togs också fram i examensarbetet. Teoretiskt kan ekvationen användas för alla stålsorter men den har inte än blivit testad på andra stålsorter. CRE uppmätt med hjälp av avgasanalys undersöktes också för att ta reda på om CRE kan användas för att bestämma när stegbytena ska ske, det gick dock inte att utgöra från resultaten.

<p>This thesis describes some new methods for analysis oforganic trace components from air and water by gaschromatography. The work is particularly focused on thedevelopment of new technologies for analyte enrichment, usingsorbent-based concepts. Short lengths of open tubular columnswere examined for their potential use as denuders.Polydimethylsiloxane-based stationary phases as well as anadsorbent-based column were evaluated in an equilibrium mode oftrapping. For the analytes selected, detection levels in theppb range were obtained (Paper I).</p><p>A new, fully automated set-up for analysis of organic tracecomponents in aqueous samples has been developed (Paper II).The work combines specific advantages of the solid phase microextraction (SPME) technology and stir bar sorptive extractionconcept. Ultra trace components, down to 0.1 ppt could bedetected. Finally a simple method for preparation a new type ofultra thick film open tubular trap is described (Paper III).The traps are characterized by an irregular coating, and it wasdemonstrated that the performance characteristics of thesetraps were practically as good as of traps with a smooth,regular coating. The technology can be utilized in many areas,e.g. environmental monitoring, process analysis and otherfields dealing with analysis of trace organic volatiles ingaseous samples.</p><p><b>Keywords:</b>Organic trace components, volatiles, denuders,sorbent trapping, thick film trapping, open tubular traps,SPME, automation, water analysis, gas analysis, environmentalanalysis.</p>

No description available.