To reduce the greenhouse effect, the use of renewable fuel has to be increased. As renewable fuel has different characteristics compared to fossil fuel regarding content of trace metals, alkali, chlorine and sulphur, the corrosion characteristics in high temperature energy processes have to be evaluated. This thesis concerns high temperature corrosion in the superheater region of a boiler and the syngas cooler area of a gasifier. For the superheater region, laboratory exposures were performed. The methods included a salt dip exposure, where samples were dipped in an equimolar solution of ZnCl2 and KCl, and two salt bed exposures with different chlorine concentrations, 10 and 20 wt%. Ranking of the materials showed that a Ni content above 10 wt% and Cr above 20 wt% reduced corrosion rates in the salt dip and in the 10% Cl salt bed exposure. For exposure in the 20% Cl bed, even higher alloying was needed. An alumina forming austenitic steel showed future potential in sulphidising-chlorinating environments. For the gasifier region, the effect of HCl in a simulated gasifier atmosphere was studied and also samples exposed in the syngas section of a biomass gasifier were investigated. Metal loss was low for all exposures and it was observed that chlorine had minor influence. For the plant exposed samples, a difference compared to that reported for coal gasifiers was the absence of FeS for the lowest alloyed steel. Instead, a deposit with pronounced content of Zn, Ca, S and O was present on the surface. Zinc was suggested to mitigate corrosion. Thermodynamic modelling was used to explain phases present and to predict the nitridation behaviour of an alumina forming austenitic steel. Equilibrium and kinetic modelling of the nitridation showed good coherence with the observed microstructures. However, the kinetic modelling resulted in larger nitridation depths than observed experimentally which was attributed to the presence of a thin oxide layer on the surface of the samples. / <p>QC 20160510</p>

Le but de cette thèse est de développer une méthodologie permettant d’évaluer les performances et la durabilité des systèmes de production d’électricité par gazéification de biomasse en milieu rural en pays en développement. Cette thèse propose un cadre méthodologique général qui décrit les démarches visant: (1) à définir les critères d’évaluation de performance, (2) à choisir les méthodes ou modèles d’évaluation des critères et (3) à choisir la méthode permettant d’analyser la fiabilité de l’évaluation. A partir de ce cadre méthodologique, une méthodologie d’évaluation des systèmes de production d’électricité par gazéification de biomasse en Afrique de l’Ouest est développée. Quatorze (14) critères d’évaluation sont définis en prenant en compte les quatre dimensions de la durabilité (technique, économique, environnemental, social). Des modèles sont élaborés pour l’estimation de chacun des critères considérés. Le modèle d’évaluation global est appliqué sur un projet de système de production d’électricité par gazéification de biomasse au Burkina Faso. Douze (12) configurations de système sont évaluées pour satisfaire les mêmes profils de charge. Les résultats de simulation ont permis d’identifier d’un point de vue de l’opérateur et des consommateurs, la configuration qui permet de valoriser au mieux la ressource en biomasse locale disponible avec un coût d’électricité abordable et qui offre à l’opérateur une flexibilité relative pour s’adapter aux évolutions de la demande en énergie électrique / This thesis aims to develop a performance assessment methodology of power generation systems based on biomass gasification in a rural area case in developing countries. The general methodological framework of this thesis is described in the approaches as follow: (i) defining performance assessment criteria, (ii) selecting methods or models for assessing the criteria, and (iii) choosing the method of analyzing the reliability of the assessment. Based on this methodological framework, a methodology for the assessment of electricity generation by biomass gasification systems in West Africa is developed. Fourteen assessment criteria are defined by taking in account technical, economic, environmental and social aspects. Models are developed for the calculation of each criterion considered. The models are then applied to carry out a performance assessment of the electricity generation by biomass gasification project in Burkina Faso. Twelve (12) system configurations are studied to satisfy the same load profiles. Simulation results allowed identifying from the point of view of the operator and the consumers the configurations which give better valorization of biomass available with an affordable electricity cost and which offer to operator a relative flexibility to adapt to changes in electricity demand.

Liquid transportation fuels can be produced by gasification of carbon containing biomass to syngas( a gaseous mixture of CO and H2) with subsequent conversion of the syngas to fuels. One possible process is the so called mixed alcohols synthesis, which produces a mixture of ethanol and higher alcohols. Another possible process is the reaction of syngas to Fischer-Tropsch liquids, mainly diesel fuel. This study examines the economics of syngas, ethanol and diesel fuel production from lignocellulosic biomass (southern pine residues). The process is modeled with Aspen Plus, a process simulation software package. The process is simulated for plant sizes between 715 and 2205 dry tons/day. The feedstock moisture content is varied between 20% and 50% and the feedstock costs are varied between $30/dry ton and $80/dry ton. The influences of the examined variables on the minimum product selling price are determined. The economic effects of an integration of the mixed alcohols and the FT diesel process with a kraft mill are also evaluated.

A indústria calçadista gera uma significativa quantidade de resíduos, sendo uma alternativa para destino destes o tratamento térmico, que reduz o volume e estabiliza componentes perigosos. Por conseguinte, isto vai ao encontro dos novos desafios na busca de fontes de energias alternativas pelo fato da combustão destes resíduos ser bastante convidativa em função do seu alto poder calorífico. Este estudo está focado na análise de uma planta piloto para o processamento de resíduos sólidos da indústria calçadista (biomassa) e posterior aproveitamento térmico na geração de energia elétrica. A planta é constituída basicamente de um sistema de gaseificação e combustão combinadas e um sistema de controle de poluição do ar. O detalhamento do comportamento do gaseificador é fundamental para a maximização da eficiência do processo, sendo assim, abordado neste estudo. Para análise do gaseificador, foi desenvolvida a sua modelagem matemática. Entretanto, sabe-se da indisponibilidade, muitas vezes, do maior ou menor detalhamento de dados experimentais (geometria do sistema, identificação de espécies intermediárias, etc.) para a simulação numérica satisfatória do processo. Neste sentido, são apresentados neste trabalho, dois modelos matemáticos: um modelo rigoroso e um modelo simplificado, com diferentes abordagens e detalhamento de dados a serem informados. O modelo rigoroso considera a cinética química e os fenômenos de transferência envolvidos; já o modelo simplificado, limita-se a um modelo de equilíbrio químico e termodinâmico do sistema. Os modelos foram implementados no simulador de processos genéricos baseado em equações, EMSO. Depois de validados com dados de literatura, os modelos foram aplicados para simulações de condições reais de operação da planta e análise de sensibilidade frente a parâmetros de operação. Ambos modelos conseguiram representar razoavelmente bem o sistema experimental, dentro das limitações de cada abordagem, o que foi possível identificar condições teóricos ideais para operação a fim de se conseguir a máxima eficiência da planta. / The footwear industries generate an expressive amount of solid wastes. So that the thermal treatment technologies are an alternative destination to these wastes, once their filled volume are reduced and dangerous components are stabilized. Consequently, it can be related to new challenge on alternative energy resources due to combustion of these wastes is attractive in reason of their high calorific value. This study is focalized in the analysis of a pilot plant to process solid wastes (biomass) of footwear industries and using of its thermal capacity to generate electrical energy. The pilot unit is basically formed of one combined gasifier-combustor and one air pollution control system. The analysis of gasifier operation is fundamental to improve the process performance, so that evaluated here. To this task, the mathematical modeling of gasification system was developed. However it is well-known that practical data (geometric measures, identification of intermediary compounds, etc.) are oftentimes available on high or low detailed levels to satisfactory process simulation. In this sense, two mathematical models are presented: one rigorous model and one simplified model based on the level of details and input data. The rigorous model takes into account the chemical kinetics and the involved transfer phenomena; on the other hand the simplified model is limited to thermochemical equilibrium of the system. The models were implemented in an equation-based simulator of generic processes, EMSO. After validation with data from literature, the models were applied for simulation of actual operating conditions of pilot plant and sensitivity analyses regarding to operating parameters. Both models compare reasonably well with experimental system, inside of limitations of each approach. This makes possible to predict the ideal operating conditions in order to reach the maximum efficiency of the pilot plant.

A indústria calçadista gera uma significativa quantidade de resíduos, sendo uma alternativa para destino destes o tratamento térmico, que reduz o volume e estabiliza componentes perigosos. Por conseguinte, isto vai ao encontro dos novos desafios na busca de fontes de energias alternativas pelo fato da combustão destes resíduos ser bastante convidativa em função do seu alto poder calorífico. Este estudo está focado na análise de uma planta piloto para o processamento de resíduos sólidos da indústria calçadista (biomassa) e posterior aproveitamento térmico na geração de energia elétrica. A planta é constituída basicamente de um sistema de gaseificação e combustão combinadas e um sistema de controle de poluição do ar. O detalhamento do comportamento do gaseificador é fundamental para a maximização da eficiência do processo, sendo assim, abordado neste estudo. Para análise do gaseificador, foi desenvolvida a sua modelagem matemática. Entretanto, sabe-se da indisponibilidade, muitas vezes, do maior ou menor detalhamento de dados experimentais (geometria do sistema, identificação de espécies intermediárias, etc.) para a simulação numérica satisfatória do processo. Neste sentido, são apresentados neste trabalho, dois modelos matemáticos: um modelo rigoroso e um modelo simplificado, com diferentes abordagens e detalhamento de dados a serem informados. O modelo rigoroso considera a cinética química e os fenômenos de transferência envolvidos; já o modelo simplificado, limita-se a um modelo de equilíbrio químico e termodinâmico do sistema. Os modelos foram implementados no simulador de processos genéricos baseado em equações, EMSO. Depois de validados com dados de literatura, os modelos foram aplicados para simulações de condições reais de operação da planta e análise de sensibilidade frente a parâmetros de operação. Ambos modelos conseguiram representar razoavelmente bem o sistema experimental, dentro das limitações de cada abordagem, o que foi possível identificar condições teóricos ideais para operação a fim de se conseguir a máxima eficiência da planta. / The footwear industries generate an expressive amount of solid wastes. So that the thermal treatment technologies are an alternative destination to these wastes, once their filled volume are reduced and dangerous components are stabilized. Consequently, it can be related to new challenge on alternative energy resources due to combustion of these wastes is attractive in reason of their high calorific value. This study is focalized in the analysis of a pilot plant to process solid wastes (biomass) of footwear industries and using of its thermal capacity to generate electrical energy. The pilot unit is basically formed of one combined gasifier-combustor and one air pollution control system. The analysis of gasifier operation is fundamental to improve the process performance, so that evaluated here. To this task, the mathematical modeling of gasification system was developed. However it is well-known that practical data (geometric measures, identification of intermediary compounds, etc.) are oftentimes available on high or low detailed levels to satisfactory process simulation. In this sense, two mathematical models are presented: one rigorous model and one simplified model based on the level of details and input data. The rigorous model takes into account the chemical kinetics and the involved transfer phenomena; on the other hand the simplified model is limited to thermochemical equilibrium of the system. The models were implemented in an equation-based simulator of generic processes, EMSO. After validation with data from literature, the models were applied for simulation of actual operating conditions of pilot plant and sensitivity analyses regarding to operating parameters. Both models compare reasonably well with experimental system, inside of limitations of each approach. This makes possible to predict the ideal operating conditions in order to reach the maximum efficiency of the pilot plant.

A indústria calçadista gera uma significativa quantidade de resíduos, sendo uma alternativa para destino destes o tratamento térmico, que reduz o volume e estabiliza componentes perigosos. Por conseguinte, isto vai ao encontro dos novos desafios na busca de fontes de energias alternativas pelo fato da combustão destes resíduos ser bastante convidativa em função do seu alto poder calorífico. Este estudo está focado na análise de uma planta piloto para o processamento de resíduos sólidos da indústria calçadista (biomassa) e posterior aproveitamento térmico na geração de energia elétrica. A planta é constituída basicamente de um sistema de gaseificação e combustão combinadas e um sistema de controle de poluição do ar. O detalhamento do comportamento do gaseificador é fundamental para a maximização da eficiência do processo, sendo assim, abordado neste estudo. Para análise do gaseificador, foi desenvolvida a sua modelagem matemática. Entretanto, sabe-se da indisponibilidade, muitas vezes, do maior ou menor detalhamento de dados experimentais (geometria do sistema, identificação de espécies intermediárias, etc.) para a simulação numérica satisfatória do processo. Neste sentido, são apresentados neste trabalho, dois modelos matemáticos: um modelo rigoroso e um modelo simplificado, com diferentes abordagens e detalhamento de dados a serem informados. O modelo rigoroso considera a cinética química e os fenômenos de transferência envolvidos; já o modelo simplificado, limita-se a um modelo de equilíbrio químico e termodinâmico do sistema. Os modelos foram implementados no simulador de processos genéricos baseado em equações, EMSO. Depois de validados com dados de literatura, os modelos foram aplicados para simulações de condições reais de operação da planta e análise de sensibilidade frente a parâmetros de operação. Ambos modelos conseguiram representar razoavelmente bem o sistema experimental, dentro das limitações de cada abordagem, o que foi possível identificar condições teóricos ideais para operação a fim de se conseguir a máxima eficiência da planta. / The footwear industries generate an expressive amount of solid wastes. So that the thermal treatment technologies are an alternative destination to these wastes, once their filled volume are reduced and dangerous components are stabilized. Consequently, it can be related to new challenge on alternative energy resources due to combustion of these wastes is attractive in reason of their high calorific value. This study is focalized in the analysis of a pilot plant to process solid wastes (biomass) of footwear industries and using of its thermal capacity to generate electrical energy. The pilot unit is basically formed of one combined gasifier-combustor and one air pollution control system. The analysis of gasifier operation is fundamental to improve the process performance, so that evaluated here. To this task, the mathematical modeling of gasification system was developed. However it is well-known that practical data (geometric measures, identification of intermediary compounds, etc.) are oftentimes available on high or low detailed levels to satisfactory process simulation. In this sense, two mathematical models are presented: one rigorous model and one simplified model based on the level of details and input data. The rigorous model takes into account the chemical kinetics and the involved transfer phenomena; on the other hand the simplified model is limited to thermochemical equilibrium of the system. The models were implemented in an equation-based simulator of generic processes, EMSO. After validation with data from literature, the models were applied for simulation of actual operating conditions of pilot plant and sensitivity analyses regarding to operating parameters. Both models compare reasonably well with experimental system, inside of limitations of each approach. This makes possible to predict the ideal operating conditions in order to reach the maximum efficiency of the pilot plant.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第17560号 / 工博第3719号 / 新制||工||1566(附属図書館) / 30326 / 京都大学大学院工学研究科航空宇宙工学専攻 / (主査)教授 吉田 英生, 教授 中部 主敬, 准教授 松本 充弘 / 学位規則第4条第1項該当

The topic of master´s thesis is atmosferic gasification of biomass by the addition of oxygen and steam. The theoretical part is devoted to the description of biomass, process of gasification, kinds of gasification reactor and product gas. Further experiments are devised depending on the gasification medium and output temperature. In this case, the key aspect is the steam addition control. In the practical part, these experiments are performed in a fluidized bed reactor. Resulting values from samples of gas and tar are subsequently processed and evaluated.

Due to the continuous growth of energy consumption it is required that development in the energy sector is focused on renewable energy sources. Another possibility how to reduce the consumption of primary energy resources is also searching for new and non-traditional fuels. The biomass is the best and potentially expandable renewable energy source in geographic conditions in the Czech Republic. The energy usage of biomass has experienced a significant increase in recent years, however, even in the big energy power plant. This increase in consumption made mainly from wood biomass a shortage fuel, and it began to raise its price. The consumers of biomass fuel are starting to look for a different type of fuel at this time. Stalk and slightly contaminated biomass are representatives of these non-traditional fuels. Stalks are mostly annual plants grown primarily for subsistence. Waste parts of these plants can be utilized for production of energy. The characteristic temperatures of stalk ash have relatively low values. Sintering of ash in a device is one of the obstacles for energy usage of stalk. Sintering of ash brings a number of operational problems at power facilities. Therefore, the part of a research is dedicated to the melting of ash. The thermal gasification is one of the possibilities how to use biomass efficiently. Gasification can be understood as the thermo-chemical conversion of solid fuel into a different state, in this case the gaseous state. The combustion process is generally more manageable for gaseous fuels. Due to this process ower emissions of undesirable compounds at the output of the combustion device can be achieved. Thermal gasification process takes place under stochiometric access of oxidant. The gas with low heating value is on the outlet from gasification process. The main components of produced gas are hydrogen, carbon monoxide and methane. The final gas contains also a lot of undesirable constituents, which make this gas disadvantaged in energy. These constituents are neutral components that dilute gas only, and pollutants as dust, tar and compounds of sulfur and chlorine. These pollutants complicate further use of the generated gas. The tar compounds together with dust causing build-up on the conveyor pipe and also on the combustion equipment, which are using this generated gas. The quality of produced gas is increases by another reprocessing and cleaning. The purified gas can be used for cogeneration of energy and burn it in internal combustion engines or gas turbines. Other possibility is typical usage for heating according to the needs of technology. The atmospheric fluidized bed gasification reactor Biofluid 100th was built for experimental purposes in the laboratories of the Energy Institute. The thesis is focused on thermal gasification of stalk and other non-traditional fuels in Biofluid device. The aim is to achieve a stable gasification process of stalk and thereby verify the possibility of stalk use as fuel for technology Biofluid. Subsequent aim is design of methods for cleaning the raw gas from the tar compounds. The research is focused on the secondary gas cleaning methods due to the requirements of high purity of the resulting gas.

Without a doubt, there is a consensus around the international community which suggests that our current way of life is unsustainable for a healthy planet, society and economy. One focal point that should be taken deeply into consideration is the steel industry as, globally, it accounts for 8% of global emissions. Thus, there is a dire need to incorporate drastic measures, if one wishes to reach net-zero emissions by 2050, in accordance with the Paris Agreement of 2015. Electric Arc Furnaces are seeing a rapid implementation in the steel industry. However, at 0.5 tonnes of CO2 emitted per tonne of liquid steel produced, this emissions rating is still significant considering the amount of steel being produced annually. Additionally, these furnaces emit off-gases which must be treated from the dust. This leaves operators with a conundrum as the dust content compromises the use of waste heat recovery boilers for energy recovery, due to constant breakdowns. Therefore, this study aims to analyse the feasibility of using bioenergy and carbon capture and utilisation (CCU) concepts to capitalise on the high off-gas energy and emissions content to remedy the dust issue, whilst producing higher value products. The proposed concept evaluates the effectiveness of using the off-gas as the energy carrier and feed-stock for a biogasificaiton unit. Three different cases based on different EAF off-gas compositions have been investigated. Case 1 suggested that the off-gas composition is very CO2-heavy, whichled to investigating the option of adopting a CO2 biogasification concept to directly use the CO2. Case 1 performed the best in terms of CO2 utilisation efficiency; being 0.293. The system energy utilisation also noted that 49.3% of the inlet streams energy was transferred to the desired product. On a broader picture, this means that around 11% of the total energy coming out of the EAF would be utilised in producing a value-added product in the form of syngas. This contrasts with allowing around 33% of the energy in the EAF either being completely dissipated to the environment or converting it into electricity via waste heat recovery. The following two cases, Case 2 and 3, indicate EAF off-gas composition containing 72% and 40% nitrogen respectively. For Cases 2 and 3, a steam biogasification process was integrated which did not yield positive results for CO2 utilisation, since is a more promising gasifying agent. In addition, significant energy from EAF off-gas is used in raising the temperature of steam to the design temperature of the gasifier. However, although the CO2 was not directly used in this part of the process, it allows for other opportunities of process integration, for example the reverse water-gas shift step.