Fuels from biomass (biofuels) are used to mitigate the greenhouse gases produced through the utilization of fossil fuels. Non-edible or waste biomass can be pyrolized to produce bio-oil. The oil (an unstable and low energy product) can be further upgraded through hydrodeoxygenation to produce gas and/or diesel range hydrocarbons and value added chemicals. In this research, the valorization of fast pyrolysis bio-oil from maple sawdust was explored in two steps. Primarily, solvent extraction was carried out to remove water from the bio-oil (35% water, 55% oxygen and a heating value of 21.6 MJ/kg). The solvents explored were benzene, ethanol, and chloroform. Chloroform reduced the amount of high molecular oxygenates from 58 to 30%, increased the amount of hydrocarbons from 20 to 41%, and reduced the moisture content to <0.2%. The modified bio-oil was comprised almost entirely of phenol and phenol derivatives. It possessed 42% oxygen and a heating value of 44.0 MJ/kg. Then, the objective was to remove oxygen while obtaining a high yield of hydrocarbons suitable for use as transportation fuels through hydrodeoxygenation. Hydrodeoxygenation of the modified bio-oil was studied with different metal catalysts impregnated on H-ZSM-5 in a batch reactor. H-ZSM-5 was chosen based on results from model compound testing and its use in industry. 8.5-13% Mo, 1-5% Ni, 2.5-5% Sr, 5-10% W, CoMo and NiMo were loaded onto H-ZSM-5 (average pore size, 0.54 nm). The experiments were carried out over a temperature range of 250-350°C, pressure range of 2-5 MPa, stirring speed of 500 rpm, catalyst loading 2-10wt%, and a tetralin to oil ratio of 2-10:1. Tetralin was added as a hydrogen donor solvent and lignin dilutant to prevent polymerization of the feed. The products were coke/tar, gas, water, and an organic liquid. 2.5% Ni/ZSM-5 proved to be the most effective catalyst with 95% oxygen removal and 89.0% yield of hydrocarbons (20% of which were aliphatic). The least effective was 2.5% Sr/ZSM-5 with 87% oxygen removal and 24.5% hydrocarbon yield. The liquid products obtained via 2.5% Ni had a heating value of 47.0 MJ/kg, a moisture content of 0.07%, and a crystallization point of -81.3°C. The products were fully miscible with diesel fuel. Optimization of the process utilizing statistical design software and 2.5% Ni/ZSM-5 catalyst yielded an experimental hydrocarbon yield of 94.3% (predicted value of 95.3%). The optimum conditions were found to be T=350°C, P=3 MPa, catalyst loading=3.5 g (7 wt%), solvent to oil ratio of 10, rpm=500, and a reaction time of 45 min. The liquid products obtained under optimum conditions contained 22wt% aliphatic hydrocarbons. The physical properties of the liquid product included a high heating value of 47.3 MJ/kg, a low moisture content of 0.07wt%, a close-to-neutral pH of 6.4, and a crystallization temperature of -88.4°C. This data suggests these liquid hydrocarbons could be used as a transportation fuel.

Fuels from biomass (biofuels) are used to mitigate the greenhouse gases produced through the utilization of fossil fuels. Non-edible or waste biomass can be pyrolized to produce bio-oil. The oil (an unstable and low energy product) can be further upgraded through hydrodeoxygenation to produce gas and/or diesel range hydrocarbons and value added chemicals. In this research, the valorization of fast pyrolysis bio-oil from maple sawdust was explored in two steps. Primarily, solvent extraction was carried out to remove water from the bio-oil (35% water, 55% oxygen and a heating value of 21.6 MJ/kg). The solvents explored were benzene, ethanol, and chloroform. Chloroform reduced the amount of high molecular oxygenates from 58 to 30%, increased the amount of hydrocarbons from 20 to 41%, and reduced the moisture content to <0.2%. The modified bio-oil was comprised almost entirely of phenol and phenol derivatives. It possessed 42% oxygen and a heating value of 44.0 MJ/kg. Then, the objective was to remove oxygen while obtaining a high yield of hydrocarbons suitable for use as transportation fuels through hydrodeoxygenation. Hydrodeoxygenation of the modified bio-oil was studied with different metal catalysts impregnated on H-ZSM-5 in a batch reactor. H-ZSM-5 was chosen based on results from model compound testing and its use in industry. 8.5-13% Mo, 1-5% Ni, 2.5-5% Sr, 5-10% W, CoMo and NiMo were loaded onto H-ZSM-5 (average pore size, 0.54 nm). The experiments were carried out over a temperature range of 250-350°C, pressure range of 2-5 MPa, stirring speed of 500 rpm, catalyst loading 2-10wt%, and a tetralin to oil ratio of 2-10:1. Tetralin was added as a hydrogen donor solvent and lignin dilutant to prevent polymerization of the feed. The products were coke/tar, gas, water, and an organic liquid. 2.5% Ni/ZSM-5 proved to be the most effective catalyst with 95% oxygen removal and 89.0% yield of hydrocarbons (20% of which were aliphatic). The least effective was 2.5% Sr/ZSM-5 with 87% oxygen removal and 24.5% hydrocarbon yield. The liquid products obtained via 2.5% Ni had a heating value of 47.0 MJ/kg, a moisture content of 0.07%, and a crystallization point of -81.3°C. The products were fully miscible with diesel fuel. Optimization of the process utilizing statistical design software and 2.5% Ni/ZSM-5 catalyst yielded an experimental hydrocarbon yield of 94.3% (predicted value of 95.3%). The optimum conditions were found to be T=350°C, P=3 MPa, catalyst loading=3.5 g (7 wt%), solvent to oil ratio of 10, rpm=500, and a reaction time of 45 min. The liquid products obtained under optimum conditions contained 22wt% aliphatic hydrocarbons. The physical properties of the liquid product included a high heating value of 47.3 MJ/kg, a low moisture content of 0.07wt%, a close-to-neutral pH of 6.4, and a crystallization temperature of -88.4°C. This data suggests these liquid hydrocarbons could be used as a transportation fuel.

Bio-oil obtained by the fast pyrolysis of biomass has the potential to serve as source of alternative liquid fuel for both power generation and transportation fuel. Bio-oils are comprised of oxygenated compounds, due to the presence of a high percentage of these oxygenated groups bio-oil possesses negative properties such as low heating value, low volatility, thermal instability, corrosiveness, immiscibility with fossil fuels and a tendency to polymerize over time. Bio-oils have been converted to both boiler and transportation fuels in laboratory and demonstration projects. However, the available technologies have not proven commercially viable. Therefore, the main objective of this study is to develop additional, potentially commercializable, technologies to upgrade bio-oils and pretreated bio-oil by hydroprocessing pathways. Previous hydrodeoxygenation studies over nearly three decades have provided considerable information about methods to upgrade bio-oil by this technology. However, rapid catalyst deactivation and low yields continue to be problematic and further research is required to refine current hydrodeoxygenation methods and catalysts. In our study we are applying pretreatment to the bio-oil at ambient temperature and pressure conditions to hydroprocess pretreated bio-oil in a single-stage. An initial pretreatment was performed to convert aldehydes present in the bio-oil into carboxylic acids followed by a single-stage hydroprocessing, that was performed to produce hydrocarbons. Where appropriate, successful products produced from the hydroprocessing treatments were analyzed for acid value, oxygen content, heating value, elemental analysis, FTIR and GC-MS. Statistical analysis was performed by analysis of variance (ANOVA).

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Various distillates are treated with hydrogen gas during hydrotreatment in the presence of catalyst in order to reduce the sulfur and aromatic content of the product. Optimal hydrotreater performance is essential for producing Nynas specialty oils, in order to fulfill the planned production volume and to meet the product specification. Loss of catalyst activity is inevitable during the production. To adjust for the impact of catalyst deactivation, different process variables are manipulated. Different distillates affect the catalyst in different ways due to the variation in distillate composition. Distillates with higher organic nitrogen content and running at a lower temperature tend to deactivate the catalyst more due to the adsorption of nitrogen compounds on the active sites of the catalyst and their slow nature of desorption. In this master thesis, different catalyst deactivation mechanisms with a focus on nitrogen deactivation have been studied. Since nitrogen is not normally measured at Nynas, nitrogen content of different distillates and products and how these values change during operation was not known. Different distillates, blend of distillates and different products were measured to estimate roughly the typical nitrogen value of the distillates and products. The temperature data inside the reactors were analyzed to calculate and plot WABT (weighted average bed temperature) during different product runs and to see whether there is a correlation between the nitrogen content of the feed and operation severity (increase in WABT). Historical process data from hydrotreater unit 2 (mostly from 2013-2014) were analyzed with a view to finding out signs of catalyst deactivation. Similar product runs were also analyzed and compared to see how the catalysts performed at different periods of time. A kinetic model, based on HDS kinetics, has been used for following up two product runs. To do so, sulfur content of the feed and product were measured. Aromatic content of the product was also measured to see whether the product was on specification. .From the calculation and plotting of WABTs, it could be seen that there is an increase in WABT during the product runs operating at lower temperatures and with higher nitrogen content. From the comparison of two P3 product runs at two different time periods, it could be seen that ∆T development over one bed (amount of reaction over the bed) was much lower at one time. This can possibly be a sign of catalyst deactivation since it contributed to lesser amount of reaction over the bed. From the calculations by using the kinetic model, it could be seen that the actual temperatures were higher than the predicted temperatures. The increase in WABTs could also be noticed. These observations can possibly be coupled with nitrogen deactivation of the catalysts.  However, more tests are required to verify whether the temperature differences were significant or not. Other parameters which are also important from product selling point of view such as viscosity, color, flash point, acid number etc. and have not been covered in this degree project need to be taken into consideration before making further conclusions.

La sécurité des procédés est une préoccupation majeure dans l'industrie du raffinage et de pétrochimie. Pour les procédés très exothermiques, l'emballement thermique doit être évité. Ainsi, l'objectif de la thèse est la mise en place d'une méthodologie d'étude de la stabilité thermique dans les réacteurs chimiques qui permet de déterminer les zones opératoires de fonctionnement stable du réacteur. Après le développement d'un modèle dynamique de réacteur, la méthodologie consiste à cartographier les zones de stabilité et d'instabilité du système réactionnel en régime stationnaire et dynamique. Le critère de Van Heerden (régime stationnaire) à été généralisé pour application à des systèmes réactionnels complexes. La méthode de perturbation des états stationnaires (régime dynamique) a aussi été intégrée à la méthodologie avec l'analyse des valeurs propres.Cette méthodologie a été appliquée au procédé d'hydroconversion en lit bouillonnant de charges pétrolières lourdes, ceci à l'échelle pilote et industrielle. Des modèles dynamiques adaptés au procédé pilote et industriel ont été développés. Ils tiennent en compte la complexité de la charge ainsi que le schéma des deux procédés. L'étude de la stabilité stationnaire et dynamique a été réalisée. Des cartographies de stabilité/instabilité en fonction des principaux paramètres du procédé ont été tracées. D'après les résultats obtenus, la plage stable pour réacteur pilote est plus large que pour le réacteur industriel. La variation des paramètres du procédé ont le même effet sur les deux réacteurs. Les cartographies de stabilité obtenues sont un outil indispensable pour l'ingénieur lors du design des procédés ou leur opération. / In refining and petrochemistry process safety is a major issue. For highly exothermic processes it is necessary to ensure in a rigorous way the safe that the process operates in safe conditions, hence avoiding thermal runaway. The objective of this thesis was to develop a methodology to determine the operating conditions of reliable operation of chemical reactors. The methodology relies on stationary and dynamic analysis. The stationary stability analysis based on the Van Heerden criterion was generalized to complex chemical systems. The dynamic analysis applies the perturbation theory to definitely determine if a stationary point is stable according to eigenvalue analysis.The methodology was applied to ebullated-bed technology for residue hydroconversion at pilot and industrial scale. Two comprehensive dynamic models that accurately represent the ebullated-bed pilot plant and industrial process were developed for the study. The models take into account a detailed description of the reactive system and the configuration of the pilot and industrial plants: three phases, kinetics and flow characterization. A stationary and dynamic thermal stability analysis was carried out for both configurations and stable/unstable operating regions were identified. The study showed that the pilot plant reactor can operate in a larger domain of operating conditions compared to the industrial reactor while the parameters have the same effect on both reactors. The resulting reactor operation diagrams are a essential guide for engineers in the reactor design and operation practice.