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Gasification is a flexible technology which is applied in industry for electricity generation, hydrogen production, steam raising and liquid fuels production. Furthermore, it can utilize one or more feedstocks such as coal, biomass, municipal waste and petroleum coke. This versatility, in addition to being adaptable to various emissions control technologies (including carbon capture) renders it an attractive option for years to come. One of the most common gasifier types is the entrained-flow slagging gasifier. The behaviour of inorganic fuel components in these gasifiers is still ill-understood even though it can be the determining factor in their design and operation. A literature review of inorganic matter transformation sub-models for entrained-flow slagging gasifiers is provided. Slag viscosity was identified as a critical property in the sub-models. Slag viscosity models are only applicable to a limited range of slag compositions and conditions, and their performance is not easily assessed. An artificial neural network model was developed to predict slag viscosity over a broad range of temperatures and slag compositions. Furthermore, a toolbox was developed to assist slag viscosity model users in the selection of the best model for given slag compositions and conditions, and to help users determine how well the best model will perform. The slag viscosities of coal, petroleum coke and coal/petroleum coke blends were measured in the temperature range of 1175-1650ºC. Interaction of vanadium-rich slags with various materials was investigated. The results from the first two parts of a three-part research program which involves fuel characterization, testing in a 1 MWth gasifier, and computational fluid dynamics (CFD) modeling for entrained-flow slagging gasification are presented. The end goal is to develop a CFD model which includes inorganic matter transformations. Fuel properties were determined with prioritization based on their application; screening of potential fuels, ensuring proper gasifier operation, gasifier design and/or CFD modeling. Using CanmetENERGY’s 1 MWth gasifier, five gasification tests were completed with the characterized coals. Solid samples from the refractory liners, in-situ gas sampling probe sheaths and impingers, the slag tap, the slag pot, quench discharge water and scrubber water were collected and characterized.

The British Gas Lurgi slagging gasifier is a counter-current fixed bed gasifier operating at high pressure. Coal descending the gasifier is pyrolysed to form coke which is then gasified. Properties of such coke affect the gasifier in its efficiency of operation. This thesis describes a) the carbonisation of cokes from coal under simulated gasifier conditions, b) the characterisation of the resultant cokes in terms of structure and physical properties and, c) the formulation of relationships between coal thermoplasticity and coke properties. Three high-volatile bituminous coals Manvers Barnburgh NCB 702, and Gedling (Manton NCB 502, NCB 802) were carbonised in an autoclave under a range of pressures (0.5- 8.0 MPa), using two different heating regimes, shock heating to 700 °c and slow heating to 700 °c at 5 °C/min. Physical characterisation of the resultant cokes was carried out using optical and mechanical techniques. Optical anisotropy and image analysis were used to determine coke structure and porosity respectively. Tensile strength, microstrength and abrasion resistance were measured to establish the cokes' resistance to various forms of breakage. High pressure dilatometry and plastometry were used to measure the effects of pressure and heating rate on coal thermoplastic properties. Relationships between coal thermoplastic properties and coke properties are very complex. This work has shown that these relationships are highly dependent on carbonisation conditions with heating rate rather than pressure being the more dominant parameter.

Dans le procédé de gazéification, la biomasse est transformée à haute température dans des conditions catalytiques, en produits gazeux qui peuvent avoir différentes utilisations : la production de gaz de synthèse (Syngas), la production de chaleur ou d'électricité, la synthèse de biocarburants, etc. Ce procédé est cependant générateur de goudrons et de particules, de part la matière première d'origine végétale. Il est donc nécessaire de connaître et d'optimiser les conditions de gazéification afin de minimiser la production de goudron. Les études ont porté sur l'optimisation des conditions opératoires dans un réacteur à lit fluidisé sur des coques d'amandes et des granules de miscanthus x giganteus. L'efficacité du lit a été évaluée en utilisant des systèmes catalytiques tels olivine, Ni olivine, Fe-olivine complétés par un système secondaire de bougies filtrantes à activité catalytiques. Au final, l'association d'un lit catalytique (Fe-olivine) et bougies catalytiques permet d'améliorer la conversion de la biomasse. Afin de suivre l'efficacité de la conversion des composés aromatiques, chaque composant des goudrons a été dosé par CLHP. En parallèle, d'autres approches ont été validées : elles permettent d'effectuer un suivi en ligne de la formation des goudrons lors de la gazéification. L'intérêt de la chromatographie sur couche mince a permis un dosage des composés aromatiques totaux par ajouts doses. Une analyse semi-quantitative est également possible après séparation par famille de composés aromatiques en fonction du nombre de noyaux et du degré de condensation, ces développements sont totalement originaux pour le suivi des goudrons issus de la biomasse / Gasification could be defined as a group of processes that converts solid or liquid fuels into a combustible gas. Therefore, biomass gasification can be employed to meet different market needs. Among the different gasification technologies available, fluidized bed gasifiers are very attractive because they take the advantage of the excellent mixing characteristics and high reaction rates of gas-solid mixtures. Miscanthus x giganteus (mxg) pellets and crushed and sieved almond shells have been used as biomass feedstock. Comparing the results obtained using the two biomasses at analogous operating conditions, no significant differences concerning the gas yield, gas composition and tar content could be observed. During the work, innovative catalytic hot gas filters for in-situ tar and particulate abatement, as well as two interesting Ni and Fe based catalyst have were tested in real gasification conditions. Further improvements have been obtained by combining the synergic catalytic effect of Fe-olivine and the catalytic filter candle, resulting in a efficient Tar abatement (-92% in the producer gas), and a consequently increase of gas yield by 72%. Also, the use of catalytic filter allows efficient particle separation so that the final result is a hot and clean fuel gas made available right at the exit of the gasifier reactor. The composition of tar was followed by HPLC as reference method. Other methods like HPTLC allow the separation of aromatic compounds according their number of aromatic rings. Quantification without separation was validated in order to control on line the production of tar during the gasification process

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<p>The term biofuel is referred to as liquid or gasous fuels for the transport sector that are produced from biomass. Producing biofuels from cellulose- rich materials are considered as relevant technology nowadays.</p><p>There is a research and technological development project for years at Malardalens Högskola about bioethanol and biogas production, and the university joined to the Vaxtkraft project in Vasteras, Sweden, aims to produce biogas out of ley crop and organic waste.</p><p>The purpose of my study was to analyse the efficiency of producing transportation fuels, spezifyed ethanol and biogas from straw.</p><p>Extraction of sugar from straw under different conditions with respect to pH, temperature and extraction time were studied. Thereafter biogasification with bacteria to form CH4 and ethanol fermentation with Saccharomyces was performed and the gas production measured.</p><p>The extractions were carried out separately at 121 °C and 140-145 °C, with 20, 40, 60, 120 minutes extraction time. The pH during the processes was set to 5 and 3 with buffer solution. To consider the extraction rate, the better conditions are lower pH, higher temperature and longer extraction time.</p><p>The results show the optimal extraction is performed at 140-145 °C for 120 minutes with pH 3.</p><p>The gasification was carried out at 37 °C with using Baker’s yeast. The results indicate that in contrast to the extraction, the gasification is better with the samples which extraction was carried out at lower temperature and higher pH. The best gasification was achieved by the samples with 121°C and pH 5 extraction irrespectively of the extraction time, although they had the worst extraction rate results.</p><p>More research and detailed quality analysis are needed to determine the reason of this seeming contradiction</p>

Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 111-114). Also available on the World Wide Web.

The term biofuel is referred to as liquid or gasous fuels for the transport sector that are produced from biomass. Producing biofuels from cellulose- rich materials are considered as relevant technology nowadays. There is a research and technological development project for years at Malardalens Högskola about bioethanol and biogas production, and the university joined to the Vaxtkraft project in Vasteras, Sweden, aims to produce biogas out of ley crop and organic waste. The purpose of my study was to analyse the efficiency of producing transportation fuels, spezifyed ethanol and biogas from straw. Extraction of sugar from straw under different conditions with respect to pH, temperature and extraction time were studied. Thereafter biogasification with bacteria to form CH4 and ethanol fermentation with Saccharomyces was performed and the gas production measured. The extractions were carried out separately at 121 °C and 140-145 °C, with 20, 40, 60, 120 minutes extraction time. The pH during the processes was set to 5 and 3 with buffer solution. To consider the extraction rate, the better conditions are lower pH, higher temperature and longer extraction time. The results show the optimal extraction is performed at 140-145 °C for 120 minutes with pH 3. The gasification was carried out at 37 °C with using Baker’s yeast. The results indicate that in contrast to the extraction, the gasification is better with the samples which extraction was carried out at lower temperature and higher pH. The best gasification was achieved by the samples with 121°C and pH 5 extraction irrespectively of the extraction time, although they had the worst extraction rate results. More research and detailed quality analysis are needed to determine the reason of this seeming contradiction