Neste trabalho foi avaliado a seletividade de reações biocatalisadas por fungos basidiomicetos frente a compostos bifuncionalizados com os grupos cetona e seleneto (1-2) ou cetona e sulfeto (3-4). Os compostos 1-4 foram sintetizados de acordo com metodologias descritas na literatura. Na síntese dos padrões racêmicos dos β-hidróxi-selenetos 1a-2a e β-hidróxi-sulfetos 3a-4a observou-se que a redução química utilizando NaBH4 levou a formação preferencial dos estereoisômeros cis-(1a-4a). Enquanto que a redução promovida na utilização dos fungos basidiomicetos levou a formação preferencial do estereoisômero trans-(1a-4a). Desta forma duas metodologias complementares para a preparação de β-hidróxi-selenetos e β-hidróxi-sulfetos foram estabelecidas. Cinco linhagens destes fungos (Irpex lacteus CCB 196, Trametes rigida CCB 285, Pycnoporus sanguineus CCB 501, Trametes byssogenum CCB 203, Trametes versicolor CCB 202 ) foram testadas visando à obtenção de β-hidróxi-selenetos (1a-2a) e β-hidróxi-sulfetos (3a-4a) na forma enantiomericamente pura ou enriquecida. Um estudo qualitativo indicou que o fungo Trametes rigida CCB 285 apresentou alta seletividade frente aos compostos utilizados levando aos produtos cis-(1a-4a) e trans-(1a-4a) com elevados valores de excessos enantioméricos (e.e. 99 %). Posteriormente, um estudo quantitativo permitiu o isolamento dos produtos, a determinação dos rendimentos isolados e também a configuração absoluta para os compostos isolados. Na segunda parte deste trabalho avaliou-se a aplicação de fungos Aspegillus terreus em reações de desmetilação/desalquilação de aminas terciárias. Os resultados obtidos indicam que os estes fungos apresentam grande potencial para reações de desmetilação de aminas terciárias aromáticas, sendo que as reações conduzidas em meio neutro (pH = 7) levaram aos produtos desmetilados com bons valores de conversão. No entanto, não foram observadas reações de desalquilação com grupos etila nas condições utilizadas. / In this work was considered the selectivity of reactions biocatalysted by basidiomycetes fungi with bifuncionalized compounds with ketone and selenide groups (1-2) or ketone and thio groups (3-4). The compounds 1-4 were prepared in according with methodologies from literature. During the synthesis of standard racemic β-hydroxyselenides 1a-4a and β-hydroxysulfides 3a-4a we noticed that chemical reduction using NaBH4 led to the preferential formation of the cis-(1a-4a) isomers. On the other hand, the bioreduction promoted by basidiomycetes fungi led to the preferential formation of trans-(1a-4a) isomers. Therefore, two complementary methodologies for preparation of β-hydroxyselenides and β-hydroxysulfides were established. Five strains of basidiomycetes fungi (Irpex lacteus CCB 196, Trametes rigida CCB 285, Pycnoporus sanguineus CCB 501, Trametes byssogenum CCB 203, Trametes versicolor CCB 202) were examined to aim at the preparation of β-hydroxyselenides and β-hydroxysulfides on the enantiomerically pure form. A qualitative study indicated that cells of T. rigida CCB 285 showed high selectivity led to the products cis-(1a-4a) and trans-(1a-4a) in high enantiomeric excess (ca 99 %). After that, a quantitative study allowed us to determine the isolated yields and the absolute configuration for the compounds cis-(1a-4a) and trans-(1a-4a). In the second part of this work was considered the application of Aspergillus terreus fungi in demethylation/dealkylation reactions by tertiary amines. The results indicated that those fungi showed a big potencial for demethylation reaction of aromatic tertiary amines. The reaction done on the pH = 7 led to the demethylated products with good values of conversion. Dealkylation reactions were not observed.

The cycling of biogenic volatile sulfur compounds (VSCs) within marine and terrestrial ecosystems has been shown to play an integral role in atmospheric chemistry; by influencing global climate change through the creation of cloud condensation nuclei and controlling acid-base chemistry; as well as influencing sediment chemistry including the interactions with trace metals, particularly regarding iron sulfide formation. Despite this, the examination of VSCs within Australian coastal acid sulfate soils (ASS) is an unexplored area of research. As ASS in Australia occupy an area in excess of 9 M ha, there is a clear need for a greater understanding of the cycling of these compounds within such systems. This thesis looks at the concentrations of several VSCs within agricultural and undisturbed ASS on the east coast of Australia. Initial measurements of sulfur dioxide (SO2) were made using passive diffusion samplers, which were followed by two detailed field-based studies looking at the concentrations and fluxes of both SO2 and hydrogen sulfide (H2S) using flux-gradient micrometeorological techniques. These novel results indicated that this agricultural ASS was a substantial source of atmospheric H2S (0.036-0.056 gSm-2yr-1), and SO2 (0.095-0.31 gSm-2yr-1), with flux values equating to many other salt- and freshwater marshes and swamps. The flux data also suggested that the ASS could be a continual source of H2S which is photo-oxidised during the daytime to SO2. Measurements of both compounds showed separate, inverse correlations to temperature and moisture meteorological parameters indicating possible contributing and / or causal release factors. Further identification of these and other VSCs within ASS samplers was undertaken in the laboratory using gas chromatography in combination with solid-phase microextraction. Although SO2 and H2S were not discovered within the headspace samples, two other VSCs important in atmospheric sulfur cycling and trace metal geochemistry were quantified; dimethylsulfide (DMS; &gt 300??g/L) and ethanethiol (ESH &gt 4??g/L). The measurements of H2S, DMS and ESH are the first quantifications with Australian ASS, and they may be important for refining regional or local atmospheric sulfur budgets, as well as interpreting previous SO2 emissions from ASS. Ultimately this thesis further enhances our understanding of the cycling of VSCs within acid sulfate systems.

The cycling of biogenic volatile sulfur compounds (VSCs) within marine and terrestrial ecosystems has been shown to play an integral role in atmospheric chemistry; by influencing global climate change through the creation of cloud condensation nuclei and controlling acid-base chemistry; as well as influencing sediment chemistry including the interactions with trace metals, particularly regarding iron sulfide formation. Despite this, the examination of VSCs within Australian coastal acid sulfate soils (ASS) is an unexplored area of research. As ASS in Australia occupy an area in excess of 9 M ha, there is a clear need for a greater understanding of the cycling of these compounds within such systems. This thesis looks at the concentrations of several VSCs within agricultural and undisturbed ASS on the east coast of Australia. Initial measurements of sulfur dioxide (SO2) were made using passive diffusion samplers, which were followed by two detailed field-based studies looking at the concentrations and fluxes of both SO2 and hydrogen sulfide (H2S) using flux-gradient micrometeorological techniques. These novel results indicated that this agricultural ASS was a substantial source of atmospheric H2S (0.036-0.056 gSm-2yr-1), and SO2 (0.095-0.31 gSm-2yr-1), with flux values equating to many other salt- and freshwater marshes and swamps. The flux data also suggested that the ASS could be a continual source of H2S which is photo-oxidised during the daytime to SO2. Measurements of both compounds showed separate, inverse correlations to temperature and moisture meteorological parameters indicating possible contributing and / or causal release factors. Further identification of these and other VSCs within ASS samplers was undertaken in the laboratory using gas chromatography in combination with solid-phase microextraction. Although SO2 and H2S were not discovered within the headspace samples, two other VSCs important in atmospheric sulfur cycling and trace metal geochemistry were quantified; dimethylsulfide (DMS; &gt 300??g/L) and ethanethiol (ESH &gt 4??g/L). The measurements of H2S, DMS and ESH are the first quantifications with Australian ASS, and they may be important for refining regional or local atmospheric sulfur budgets, as well as interpreting previous SO2 emissions from ASS. Ultimately this thesis further enhances our understanding of the cycling of VSCs within acid sulfate systems.

Heating milk to high temperatures such as 140 ºC, as used in ultra high temperature (UHT) processing, causes physical and chemical changes in the milk. The production of a cooked flavour is a major change which reduces consumer acceptance of the UHT milk. It has been correlated with the formation of volatile sulphur compounds (VSCs) that result from milk proteins, principally the whey proteins β-lactoglobulin, containing the the sulphur amino acids cystine, cysteine and methionine. The VSCs in milk, whose concentrations are in the parts per billion to parts per million range, are highly reactive, easily oxidised, and sensitive to heat during thermal processing and analysis; this makes them a challenge to analyse. A sensitive method based on gas chromatography with pulsed flame photometric detection coupled with headspace sampling by solid phase microextraction (SPME/GC/PFPD) was developed to detect these compounds in commercial UHT milk and to investigate their production and disappearance during heating and storage. The SPME/GC/PFPD procedure was optimised using different extraction time (15 min, 30 min, & 60 min) – temperature (30 oC, 45 oC & 60 oC) combinations with CAR/PDMS fibre to obtain maximum sensitivity. A short extraction time (15 min) at low temperature (30 oC) was chosen to provide high sensitivity for detecting all VSCs in UHT milk without introducing artefactual VSCs. The extraction method and GC run time (16 min) make this method simple and fast. Nine VSCs were detected in commercial indirectly processed UHT milk, skim and whole. These are hydrogen sulphide (H2S), carbonyl sulphide (COS), methanethiol (MeSH), dimethyl sulphide (DMS), carbon disulphide (CS2), dimethyl disulphide (DMDS), dimethyl sulphoxide (DMSO), dimethyl sulphone (Me2SO2) and dimethyl trisulphide (DMTS). An additional unknown compound was detected but could not be identified by GC/MS because its concentration was below the detection limit of the MS detector. The concentrations of H2S, DMS and DMTS were higher than their threshold values indicating their importance in milk flavour, especially cooked flavour. Several attempts have been made to reduce the cooked flavour in UHT milk. In the current research, the use of hydrogen peroxide (H2O2) to oxidise the VSCs and thereby reduce cooked flavour was investigated. H2O2 is used as a milk preservative and is generally recognised as safe (GRAS) in USA. Several concentrations of H2O2 (0.001%, 0.005%, 0.01%, 0.02% & 0.03%) were added to milk to assess its effects on VSCs and on whey proteins denaturation in UHT milk. H2O2 effectively reduced the concentration of all VSCs, except DMDS which was increased, presumably by oxidation of MeSH. H2S was completely oxidised or reduced below its threshold value. Low concentrations of H2O2 (0.001% & 0.005%) had no effect on, or decreased, the extent of denaturation of β-lactoglobulin when added after or before processing, respectively. Some UHT plants use severe heating conditions, leading to high levels of denaturation of whey proteins, particularly β-Lg, the main source of the VSCs in milk. Correlations between heat severity, β-Lg denaturation and individual VSC generation were investigated in milk batch-heated at 80 oC and 90 oC, and UHT milk processed at 120-150 oC. In accordance with previous reports, β-Lg was more heat-sensitive than α-La. Only five VSCs were detected. The concentrations of H2S and MeSH correlated well with denaturation of β-Lg and α-La. DMS concentration correlated well with β-Lg in UHT milk but not in the batch-heated milk. CS2 did not show a good correlation with heat intensity and appeared to plateau out after a certain level of heating. Conversely, COS and MeSH seemed to require a certain minimum amount of heat before generation commenced; this corresponded to denaturation of β-Lg above 49% and 89% respectively at 80 oC. The higher concentrations of DMS and H2S in UHT milk compared with batch-heated samples having similar degrees of denaturation suggested other possible sources for their production and the importance of the heat severity in generating them. For example, at high heat intensity, S-methylmethionine and thiamine could be sources of DMS and H2S respectively. Furthermore, in whole milk as used in this work, milk fat globule membrane proteins are another source of VSCs. The outcome of this study will help UHT manufacturers to understand the production and disappearance of the VSCs in commercial UHT milk and how to adjust the processing conditions to avoid generation of cooked flavour. Additionally, the promising results of using low concentrations of H2O2 to oxidise the VSCs will provide the industry with another means of reducing cooked flavour. Before H2O2 use is implemented in UHT processing, future studies are required to evaluate all of its effects, including sporicidal effects. Overall, this study makes a contribution to finding a solution to the cooked flavour problem in UHT milk, thereby increasing market share of this milk in countries such as Australia, the UK and North America where cooked flavour is the main barrier to its consumer acceptance.

Neste trabalho foi avaliado a seletividade de reações biocatalisadas por fungos basidiomicetos frente a compostos bifuncionalizados com os grupos cetona e seleneto (1-2) ou cetona e sulfeto (3-4). Os compostos 1-4 foram sintetizados de acordo com metodologias descritas na literatura. Na síntese dos padrões racêmicos dos β-hidróxi-selenetos 1a-2a e β-hidróxi-sulfetos 3a-4a observou-se que a redução química utilizando NaBH4 levou a formação preferencial dos estereoisômeros cis-(1a-4a). Enquanto que a redução promovida na utilização dos fungos basidiomicetos levou a formação preferencial do estereoisômero trans-(1a-4a). Desta forma duas metodologias complementares para a preparação de β-hidróxi-selenetos e β-hidróxi-sulfetos foram estabelecidas. Cinco linhagens destes fungos (Irpex lacteus CCB 196, Trametes rigida CCB 285, Pycnoporus sanguineus CCB 501, Trametes byssogenum CCB 203, Trametes versicolor CCB 202 ) foram testadas visando à obtenção de β-hidróxi-selenetos (1a-2a) e β-hidróxi-sulfetos (3a-4a) na forma enantiomericamente pura ou enriquecida. Um estudo qualitativo indicou que o fungo Trametes rigida CCB 285 apresentou alta seletividade frente aos compostos utilizados levando aos produtos cis-(1a-4a) e trans-(1a-4a) com elevados valores de excessos enantioméricos (e.e. 99 %). Posteriormente, um estudo quantitativo permitiu o isolamento dos produtos, a determinação dos rendimentos isolados e também a configuração absoluta para os compostos isolados. Na segunda parte deste trabalho avaliou-se a aplicação de fungos Aspegillus terreus em reações de desmetilação/desalquilação de aminas terciárias. Os resultados obtidos indicam que os estes fungos apresentam grande potencial para reações de desmetilação de aminas terciárias aromáticas, sendo que as reações conduzidas em meio neutro (pH = 7) levaram aos produtos desmetilados com bons valores de conversão. No entanto, não foram observadas reações de desalquilação com grupos etila nas condições utilizadas. / In this work was considered the selectivity of reactions biocatalysted by basidiomycetes fungi with bifuncionalized compounds with ketone and selenide groups (1-2) or ketone and thio groups (3-4). The compounds 1-4 were prepared in according with methodologies from literature. During the synthesis of standard racemic β-hydroxyselenides 1a-4a and β-hydroxysulfides 3a-4a we noticed that chemical reduction using NaBH4 led to the preferential formation of the cis-(1a-4a) isomers. On the other hand, the bioreduction promoted by basidiomycetes fungi led to the preferential formation of trans-(1a-4a) isomers. Therefore, two complementary methodologies for preparation of β-hydroxyselenides and β-hydroxysulfides were established. Five strains of basidiomycetes fungi (Irpex lacteus CCB 196, Trametes rigida CCB 285, Pycnoporus sanguineus CCB 501, Trametes byssogenum CCB 203, Trametes versicolor CCB 202) were examined to aim at the preparation of β-hydroxyselenides and β-hydroxysulfides on the enantiomerically pure form. A qualitative study indicated that cells of T. rigida CCB 285 showed high selectivity led to the products cis-(1a-4a) and trans-(1a-4a) in high enantiomeric excess (ca 99 %). After that, a quantitative study allowed us to determine the isolated yields and the absolute configuration for the compounds cis-(1a-4a) and trans-(1a-4a). In the second part of this work was considered the application of Aspergillus terreus fungi in demethylation/dealkylation reactions by tertiary amines. The results indicated that those fungi showed a big potencial for demethylation reaction of aromatic tertiary amines. The reaction done on the pH = 7 led to the demethylated products with good values of conversion. Dealkylation reactions were not observed.

Heightened concerns for cleaner air and increasingly more stringent regulations on sulphur content in transportation fuels will make desulphurization more and more important. The sulphur problem is becoming more serious in general, particularly for diesel fuels as the regulated sulphur content is getting an order of magnitude lower, while the sulphur contents of crude oils are becoming higher. This thesis aimed to develop a desulphurisation process (based on oxidation followed by extraction) with high efficiency, selectivity and minimum energy consumption leading to minimum environmental impact via laboratory batch experiments, mathematical modelling and optimisation. Deep desulphurization of model sulphur compounds (di-n-butyl sulphide, dimethyl sulfoxide and dibenzothiophene) and heavy gas oils (HGO) derived from Libyan crude oil were conducted. A series of batch experiments were carried out using a small reactor operating at various temperatures (40 ¿ 100 0C) with hydrogen peroxide (H2O2) as oxidant and formic acid (HCOOH) as catalyst. Kinetic models for the oxidation process are then developed based on `total sulphur approach¿. Extraction of unoxidised and oxidised gas oils was also investigated using methanol, dimethylformamide (DMF) and N-methyl pyrolidone (NMP) as solvents. For each solvent, the `measures¿ such as: the partition coefficient (KP), effectiveness factor (Kf) and extractor factor (Ef) are used to select the best/effective solvent and to find the effective heavy gas oil/solvent ratios. A CSTR model is then developed for the process for evaluating viability of the large scale operation. It is noted that while the energy consumption and recovery issues could be ignored for batch experiments these could not be ignored for large scale operation. Large amount of heating is necessary even to carry out the reaction at 30-40 0C, the recovery of which is very important for maximising the profitability of operation and also to minimise environmental impact by reducing net CO2 release. Here the heat integration of the oxidation process is considered to recover most of the external energy input. However, this leads to putting a number of heat exchangers in the oxidation process requiring capital investment. Optimisation problem is formulated using gPROMS modelling tool to optimise some of the design and operating parameters (such as reaction temperature, residence time and splitter ratio) of integrated process while minimising an objective function which is a coupled function of capital and operating costs involving design and operating parameters. Two cases are studied: where (i) HGO and catalyst are fed as one feed stream and (ii) HGO and catalyst are treated as two feed streams. A liquid-liquid extraction model is then developed for the extraction of sulphur compounds from the oxidised heavy gas oil. With the experimentally determined KP multi stage liquid-liquid extraction process is modelled using gPROMS software and the process is simulated for three different solvents at different oil/solvent ratios to select the best solvent, and to obtain the best heavy gas oil to solvent ratio and number of extraction stages to reduce the sulphur content to less than 10 ppm. Finally, an integrated oxidation and extraction steps of ODS process is developed based on the batch experiments and modelling. The recovery of oxidant, catalyst and solvent are considered and preliminary economic analysis for the integrated ODS process is presented.

<p>The global oil refining industry with its present shift inproduct distribution towards fuels such as gasoline and dieselwill most likely hold the fort for many years to come. However,times will change and survival will very much depend onprocessing flexibility and being at the frontiers of refiningtechnology, a technology where catalysts play leading roles.Today oil refiners are faced with the challenge to producefuels that meet increasingly tight environmentalspecifications, in particular with respect to maximum sulphurcontent. At the same time, the quality of crude oil is becomingworse with higher amounts of polyaromatics, heteroatoms(sulphur and nitrogen) and heavy metals. In order to staycompetitive, it is desirable to upgrade dense streams withinthe refinery to value-added products. For example, upgradingthe fluid catalytic cracking (FCC) by-product light cycle oil(LCO) into a high quality diesel blending component is a veryattractive route and might involve a two-step catalyticprocess. In the first step the LCO is hydrotreated andheteroatoms are removed and polyaromatics are saturated, in thesecond step naphthenic rings are selectively opened to improvethe cetane number of the final product.</p><p>The present research is devoted to the second catalytic stepof LCO upgrading and was carried out within the framework of aEuropean Union project entitled RESCATS.</p><p>From the patent literature it is evident that iridium-basedcatalysts seem to be good candidates for ring-opening purposes.A literature survey covering ring opening of naphthenicmolecules shows the need for extending investigations toheavier model substances, more representative of the dieselfraction than model compounds such as alkylated mono C5 and C6-naphthenic rings frequently employed in academic studies.</p><p>Ring-opening catalysts, mainly Pt-Ir based, were synthesisedat KTH by two different methods: the microemulsion and theincipient wetness methods. Characterization of the catalystswas performed using a number of techniques including TPR,TEM-EDX, AFM and XPS etc. Catalytic screening at atmosphericpressure using pure indan as model substance was utilized todetect ring-opening activity and the magnitude of selectivityto desired cetane-boosting products. The development of suchring-opening catalysts is the topic of Paper I.</p><p>When designing a catalytic system aimed at refiningpetroleum, it is crucial to monitor the evolution of thesulphur distribution throughout the different stages of theprocess so that catalyst properties and reaction parameters canbe optimised. The final section of this thesis and Paper II arethus devoted to high-resolution sulphur distribution analysisby means of a sulphur chemiluminescence detector (SCD).</p><p><b>Keywords:</b>ring opening, naphthenes, cetane numberimprovement, indan, light cycle oil (LCO), Pt-Ir catalyst,catalyst characterization, aromatic sulphur compounds, GC-SCD,distribution, analysis.</p>

Le secteur industriel du traitement des déchets génère des émissions gazeuses induisant des nuisances odorantes auprès des populations riveraines des installations. Ces effluents gazeux contiennent une grande diversité de composés volatils : oxygénés (acides gras volatils, cétones, aldéhydes, alcools), azotés et soufrés (hydrogène sulfuré (H2S), diméthylsulfure (DMS), diméthyldisulfure (DMDS) et méthanethiol (MT)). Ces effluents gazeux sont traités par un dispositif approprié que sont les bioprocédés. Néanmoins, les seuils de perception des composés odorants et plus particulièrement ceux des composés soufrés, très bas, obligent à atteindre des efficacités d’abattement particulièrement élevées, faute de quoi le résiduel de concentration peut être à l’origine d’un impact notable sur les populations riveraines. L’objectif de cette étude est donc d’améliorer les performances de ces procédés biologiques par la mise en oeuvre de filières de traitement. L’originalité de ce travail est d’évaluer les performances d’épuration d’un mélange de composés soufrés par la mise en oeuvre du couplage de deux procédés biologiques que sont le lit percolateur et le biofiltre.Le premier résultat de ce travail de thèse a consisté à évaluer l’impact du pH sur l’activité de dégradation de composés soufrés en mélange (H2S, DMS et DMDS) en mettant en oeuvre des microcosmes. La valeur du pH de la phase aqueuse a une influence sur l’efficacité d’élimination des DMS et DMDS. Une élimination complète de ces derniers est observée pour une gamme de pH comprise entre 5 et 7. Les performances de ce couplage ont été comparées avec celles observées dans le cas de biofiltres seuls (dupliquats). Après une phase d’acclimatation, un fonctionnement stable est maintenu en conditions opératoires stationnaires. Les potentialités du couplage ont été mises en évidence, les niveaux d’abattement des DMS et DMDS étant supérieurs (de l’ordre de 20%) pour le couplage de bioprocédés. La composante microbiologique a fait l’objet d’une attention particulière en évaluant les densités de deux populations connues pour dégrader ces composés soufrés (Hyphomicrobium et Thiobacillus thioparus) par q-PCR au sein du biofiltre couplé au filtre percolateur et des biofiltres de référence. Les résultats obtenus mettent en évidence la présence de ces deux populations à des taux élevés (104 copies du gène ADNr-16S/ng ADN extrait pour Thiobacillus thioparus et 104-106 copies du gène ADNr-16S/ng ADN extrait pour Hyphomicrobium). La répartition de ces deux populations est similaire dans les deux cas (couplage et biofiltres seuls).Face à des perturbations représentatives de celles observées sur site, la robustesse du couplage a pu être mise en évidence, les niveaux d’efficacité d’avant les chocs sont récupérés dans un délai inférieur ou égal à 72 heures après l’arrêt de la perturbation. Enfin, une application sur site (équarrissage) a été conduite sur une période de trois mois et a permis de valider les résultats de laboratoire et de montrer l’adaptabilité d’un tel système face à la variabilité d’un effluent réel. / Waste treatment industries generate gaseous emissions that may induce odor annoyance to the surrounding populations. These gaseous effluents contain a large variety of volatile compounds such as oxygenated (volatile fatty acids, ketones, aldehydes and alcohols), nitrogen and sulphur compounds (hydrogen sulphide (H2S), dimethylsulphide (DMS), dimethyldisulfide (DMDS) and methanethiol (MT). These gaseous emissions are controlled by using an adequate system such as biotechniques. Nevertheless, because of their very low odor thresholds, complete elimination of sulphur compounds has to be assessed, as the residual concentration can induce an odorous impact on neighbourhood populations. The aim of this study is to improve these bioprocesses performances by carrying out an adequate system strategy. The originality of this work is to evaluate the removal efficiency of a mixture of sulphur compounds by implementing a combination of two bioprocesses and more precisely a biotrickling filter and biofilter.The first step of this PhD. work consisted of evaluating the pH impact on the biodegradation activity of a mixture of sulphur compounds (H2S, DMS and DMDS) by using microcosms. The pH has an impact on the removal efficiency of DMS and DMDS. The total removal of these compounds is observed for a pH range between 5 and 7. The performances of the coupling have been compared with those reached by implementing control biofilters (duplicated). After an acclimatization period, stable performances are maintained under constant operating conditions. The efficiency of the coupling have been highlighted, the DMS and DMDS abatement levels are superior (around 20%) for the bioprocesses combination.The microbiological component has been investigated within all biofilters by estimating the densities of two populations involved in the biodegradation of sulphur compounds (Hyphomicrobium and Thiobacillus thioparus), by using qPCR. The obtained results highlighted the presence of both populations at high level (104 copies of DNAr-16S gene/ng extracted DNA for Thiobacillus thioparus and 104-106 copies of DNAr-16S gene/ng extracted DNA for Hyphomicrobium). The repartition of these two bacterial populations is similar in both cases (coupling system and reference biofilters). Under transient shock load conditions, the robustness of the coupling has been revealed. The efficiency levels before the shock load are recovered 48 hours after the perturbation off. Finally, the monitoring of an on- site pilot (rendering facility) has been carried out during three months. The laboratory results have been confirmed and the suitability of such a system has been showed under industrial gas variability.

Les émissions odorantes constituent un enjeu environnemental dont l'importance n'a cessé de croître dans les zones urbaines et industrielles. Les émissions anthropogéniques de composés soufrés contribuent à une concentration locale excédant fortement le seuil de perception. Afin de satisfaire des contraintes règlementaires de plus en plus strictes, les procédés biologiques dont la biofiltration sont une alternative intéressante car respectueuse de l'environnement et de moindre coût. Les seuils de perception des composés soufrés, très bas (µg. m-3), obligent à atteindre des efficacités d'abattement particulièrement élevées, le résiduel de concentration pouvant être à l'origine d'un impact notable sur les populations riveraines. L'étude a donc consisté à améliorer les performances des biofiltres concernant l'élimination des composés soufrés i) en ajustant certains paramètres opératoires clefs tels que le sens de circulation de l'effluent gazeux, le pH et l'ensemencement du matériau support, ii) en considérant le dimensionnement des biofiltres mis en œuvre (unités pilotes de laboratoire et semi-industrielles) et iii) la complexité du gaz à traiter (mono-polluant et mélange de composés à traiter). / Odorous emissions are a serious concern whose importance became higher in urban and industrial areas. Anthropogenic emissions of sulphur compounds lead to local concentration that exceeds strongly the odour threshold of human nose. In order to fulfil legal requirements that have become stricter in recent years, biological processes and biofiltration more accurately are an interesting alternative as biofilters provide an expanding variety of opportunities for economical and environmentally friendly solutions for many waste gas emissions. The odour thresholds of sulphur compounds are very low (µg.m3 air) and then require that biofilters provide high removal efficiency as the residual concentration can induce an odorous impact on neighbourhood populations.Hence, the study consisted in improving biofilters performances concerning sulphur compounds treatment i) by upgrading important operating parameters such as air flow distribution, pH and inoculation of packing material, ii) by considering biofilters design (laboratory and semi-industrial pilot units) and iii) the gaseous effluent complexity (only one pollutant and mixture of different compounds).

The global oil refining industry with its present shift inproduct distribution towards fuels such as gasoline and dieselwill most likely hold the fort for many years to come. However,times will change and survival will very much depend onprocessing flexibility and being at the frontiers of refiningtechnology, a technology where catalysts play leading roles.Today oil refiners are faced with the challenge to producefuels that meet increasingly tight environmentalspecifications, in particular with respect to maximum sulphurcontent. At the same time, the quality of crude oil is becomingworse with higher amounts of polyaromatics, heteroatoms(sulphur and nitrogen) and heavy metals. In order to staycompetitive, it is desirable to upgrade dense streams withinthe refinery to value-added products. For example, upgradingthe fluid catalytic cracking (FCC) by-product light cycle oil(LCO) into a high quality diesel blending component is a veryattractive route and might involve a two-step catalyticprocess. In the first step the LCO is hydrotreated andheteroatoms are removed and polyaromatics are saturated, in thesecond step naphthenic rings are selectively opened to improvethe cetane number of the final product. The present research is devoted to the second catalytic stepof LCO upgrading and was carried out within the framework of aEuropean Union project entitled RESCATS. From the patent literature it is evident that iridium-basedcatalysts seem to be good candidates for ring-opening purposes.A literature survey covering ring opening of naphthenicmolecules shows the need for extending investigations toheavier model substances, more representative of the dieselfraction than model compounds such as alkylated mono C5 and C6-naphthenic rings frequently employed in academic studies. Ring-opening catalysts, mainly Pt-Ir based, were synthesisedat KTH by two different methods: the microemulsion and theincipient wetness methods. Characterization of the catalystswas performed using a number of techniques including TPR,TEM-EDX, AFM and XPS etc. Catalytic screening at atmosphericpressure using pure indan as model substance was utilized todetect ring-opening activity and the magnitude of selectivityto desired cetane-boosting products. The development of suchring-opening catalysts is the topic of Paper I. When designing a catalytic system aimed at refiningpetroleum, it is crucial to monitor the evolution of thesulphur distribution throughout the different stages of theprocess so that catalyst properties and reaction parameters canbe optimised. The final section of this thesis and Paper II arethus devoted to high-resolution sulphur distribution analysisby means of a sulphur chemiluminescence detector (SCD). Keywords:ring opening, naphthenes, cetane numberimprovement, indan, light cycle oil (LCO), Pt-Ir catalyst,catalyst characterization, aromatic sulphur compounds, GC-SCD,distribution, analysis.