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Valorization of wood and plastic waste by pyro-gasification and syngas cleaning / Valorisation de déchets de bois et matières plastiques par pyrogazéification et épuration des gazEphraim, Augustina 30 November 2016 (has links)
Les déchets de bois et de plastiques sont des ressources prometteuses pour la production du gaz de synthèse (syngaz) par la pyro-gazéification grâce à leurs disponibilités et leurs caractéristiques énergétiques. Cependant, le syngaz issu de ces déchets peut contenir des teneurs élevées en chlorure d’hydrogène (HCl) qui est corrosif et toxique et qui doit donc être éliminé. Premièrement, les expériences de pyrolyse des mélanges de bois de peuplier et de plastiques ont mis en évidence l’influence des plastiques sur les produits obtenus. En effet, le HDPE et PS augmentent respectivement le pouvoir calorifique du syngaz et le rendement en huiles, tandis que le PVC augmente le rendement en char et le HCl dans le syngaz. Ensuite, les expériences de pyro-gazéification à l’échelle pilote ont montré que l’ajout de 1 % en masse de PVC dans un déchet de bois augmente la teneur en goudrons et HCl dans le syngaz par un facteur respectivement de 2 et 5,5, tandis que la concentration de chlore dans le char résiduel est 16 fois plus élevée. En parallèle, un model CFD a été développé pour simuler la pyro-gazéification du déchet de bois en couplant les phénomènes d’écoulement de fluides, transfert de masse et de chaleur, et les réactions chimiques. Ce modèle se compose des sous-modèles de séchage, pyrolyse, oxydation et gazéification du char. Les résultats de simulation sont en bon accord avec les données expérimentales obtenues par des expériences dans un gazéifieur à l’échelle pilote. En outre, les analyses de sensibilités du sous-modèle de la gazéification de char ont été réalisées. Finalement, une étude expérimentale a été conduite sur le traitement de HCl dans le syngaz. L’étude se concentre sur la valorisation de deux résidus solides industriels issus de la production de bicarbonate et carbonate de sodium. Leurs réactivités sont comparées avec celles de deux adsorbants commerciaux, NaHCO3 et Ca(OH)2. L’effet de la matrice gazeuse sur la performance des adsorbants est également examiné. Les résidus industriels ont un potentiel intéressant par rapport aux adsorbants commerciaux. Les résultats obtenus montrent des nouvelles approches pour la purification du syngaz généré par la gazéification des déchets de bois et de plastiques. / Wood and plastic waste are interesting feedstock for the production of syngas via pyro- gasification, mainly due to their abundant supply and good fuel properties. However, syngas derived from waste may contain significant amounts of hydrogen chloride (HCl), which is corrosive and toxic and must therefore be removed. In this work, co-pyrolysis experiments were first conducted in order to study the influence of mixing different plastics with wood samples on the pyrolysis products. It was found that HDPE and PS significantly increase the heating value and HCl content of the gas product respectively, while PVC increases the yield of char and HCl. Next, pilot-scale experiments were performed, which revealed that adding 1 wt% PVC to wood waste raises the content of tar and HCl in syngas by factors of 2 and 5,5 respectively, and also elevates the chlorine concentration in the char residue 16 time over the value obtained in the absence of PVC. In parallel, a CFD model was developed to simulate the pyro-gasification of wood waste by coupling fluid flow, heat and mass transfer, and chemical reactions. This model consists of drying, pyrolysis, oxidation and char gasification sub-models. The simulation results were in good agreement with experimental data obtained from the pilot-scale experiments. Furthermore, sensibility analyses on the char gasification sub-model were performed. Finally, an experimental study was conducted on the removal of HCl from syngas. The study focused on valorizing two industrial solid wastes generated from the process of sodium carbonate and sodium bicarbonate manufacture. Their HCl adsorption performance were compared to those of the commercial sorbents, NaHCO3 et Ca(OH)2. Moreover, the effect of gas matrix on their performance was studied. The industrial wastes showed potential for treating acid gas as compared to the commercial sorbents used. This opens up new approaches to the purification of syngas generated by the pyro-gasification of wood and plastic waste. Read more
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Providing Sustainable Life-solutions with a Hybrid Micro-Power Plant in Developing Countries: an Assessment of Potential ApplicationsÖncel, Melih, Marion, Gonzalo January 2013 (has links)
Today, energy access is a significant challenge all over the world, particularly in African countries. At the same time, providing energy access is generally accepted as a way to promote sustainable development. In countries such as Uganda, lack of energy access is evident. In this country only 9% of households have access to electricity. About 87% of these households are located in rural and remote areas. Thus, off-grid rural electrification solutions are required to supply electricity services to a significant part of the population.The ultimate objective of this thesis is to propose a specific solution to cover basic energy needs of the rural population considering environmental, social and economic benefits. How can sustainable life solutions be provided in rural areas, by using the energy surplus from a decentralized small-scale biomass gasification power plant? The analysis used as a starting point the Green Plant Concept, which considers the design of a sustainable off-grid platform that produces energy to provide life solutions and also to excite local entrepreneurship in the rural sites where it is implemented. The concept implies participation of the private sector – a telecommunication company – which is a unique feature in the context of rural energization.To develop our analysis, a field trip has been conducted in Uganda, Africa, to answer sub-questions such as How to reach a cost-effective system? How to adapt a business oriented approach to the community’s life-style in order to be well accepted? How to foster the development of the area by having a positive socio-economic impact on society? How to create an environmental friendly solution? How to achieve the maximum efficiency in terms of reusing waste? Tools such as Multi Criteria Analysis (MCA) and SWOT analysis were used to interpret collected information and identify impacts of the suggested solutions.The research has shown the great potential of the Green Plan Concept. We conclude by selecting three applications that can enhance the provision of basic energy needs while creating benefits for the stakeholders involved in the process: i) Mini-Grid solutions, ii) Battery Charging Stations and iii) Heat Pipe Exchangers. We also highlighted the relevance of bringing, in addition to appropriated technologies, different stakeholders together, considering their common interests.The research is finalized by estimating the payback period based on the current and expected energy consumption and the capital investment related to the suggested applications. It is important to highlight that the payback time estimations do not include the participation of the telecom companies. This means that the estimated payback period of 7 years could be significantly reduced by the inclusion of this stakeholder. Read more
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Assessment of Power Production Possibilities in Two Sawmills in La Palma, CubaFuglesang, Malin January 2012 (has links)
The Cuban power sector with its heavy dependency on foreign oil is in much need of investment and development. In the past decade, the Cuban government launched an ‘energy revolution,’ the Revolución energética, which aims at generating electricity from renewable sources. As part of this effort, the country looks toward tapping into its biofuels which mainly consist of bagasse from the sugar industry and wood residues from the forest industry. Against this background, the thesis is a case study of how to use the wood residues from two Cuban sawmills in order to generate electricity. The focus is on electricity generation as the mills have no current need for heat. The mills belonging to the state owned company EFI La Palma located in western Cuba are small, with a yearly production of 8400 m3 and 12 500 m3 sawn timber. The wood residues; sawdust, slabs, wood chips and bark, are currently simply dumped in two large deposits near the mills and represent a wasted resource which pollutes the local environment. Three electricity generating alternatives are initially investigated in the literature review: a steam cycle, gasification connected to an internal combustion engine and a Stirling engine using heat from biomass combustion. The gasification alternative is deemed most suitable and the thesis evaluates how two downdraft wood gasifiers would perform if connected to the two currently unused diesel generators of 276 kW and 504 kW which are in place in each of the mills. The specific gasifier models examined are the Indian company Ankur’s WBG 250 and WBG 400 and the fuel preparation necessary to use these gasifiers is investigated. The electricity consumption of the mills is compared with the potential electricity generation. It is found that the smaller mill could produce a yearly amount of 1,5 MWh of electricity for the grid and the larger mill could export 3,2 MWh. As the engines must be run in dual mode, the net present value of the gasification system is dependent on the level of replacement diesel which according to Ankur will be between 50 and 75 %. In the smaller mill the investment in the gasifier system is profitable at replacement levels greater than 65,4 % and in the larger mill, the investment becomes profitable at replacement levels above 63,8 %. Moreover, the profitability of the investment is highly dependent on the Cuban electricity price which currently is strongly subsidized. The reduction in CO2 emissions are also dependent on the replacement level and at 75 % replacement level they are found to be 665 tons in the smaller mill and 1272 tons in the larger mill. / Actualmente, el sector energético cubano depende fuertemente de petróleo importado y se encuentra en necesitad de inversiones para su desarrollo y modernización. Durante la década pasada, el gobierno cubano inició la ‘Revolución energética’ que tiene como objetivo incluir en la generación de electricidad fuentes renovables. Una parte de este programa es la utilización de los biocombustibles del país, que consisten principalmente del bagazo de la industria azucarera y de los residuos de madera provenientes de la industria forestal. En este contexto, la tesis presenta un estudio de caso de cómo utilizar los residuos de madera de dos aserraderos cubanos para generar electricidad. Hoy en día, los aserraderos no necesitan calefacción y por lo tanto el enfoque es la generación de electricidad. Los aserraderos pertenecen a EFI La Palma, una empresa estatal, y están ubicados en Pinar del Rio, la provincia más occidental de Cuba. Producen 8400 m3 y 12 500 m3 de madera aserrada por año. Actualmente los residuos de madera; aserrín, cortezas y astillas, son dejados en depósitos localizados cerca de cada aserradero. Esos residuos no solo representan un desperdicio de recursos, además, son una fuente de contaminación local. Inicialmente, tres alternativas de generación de electricidad son investigadas en la revisión de la literatura: el ciclo de vapor, la gasificación conectada a un motor de combustión interna y finalmente la combustión de biomasa conectada con un motor de Stirling. La alternativa de gasificación fue considerada la más adecuada. La tesis evalúa cuanto el rendimiento de dos gasificadores de madera con fluje descendente conectados a dos generadores de diesel de 276 kW y de 504 kW que actualmente existen en los dos aserraderos. Los modelos de motor examinados son: WBG 250 y WBG 400 de la empresa india Ankur. La preparación de la biomasa también es investigada con el fin de usarla con los motores mencionados. El consumo de electricidad se comparó con la generación de electricidad potencial de los aserraderos. Los resultados muestran que el aserradero más pequeño podría generar 1,5 MWh de electricidad por año para vender a la red mientras en el aserradero más grande, 3,2 MWh de electricidad por año. Como los motores deben funcionar en modo dual, el valor neto presente del sistema de gasificación depende del nivel de sustitución de diesel que según Ankur sería entre 50 y 75%. En el aserradero más pequeño, la inversión en el sistema de gasificador es rentable a niveles de reemplazo de más de 65,4% y en el aserradero más grande, la inversión se vuelve rentable a niveles de reemplazo por encima de 63,8%. Además, la rentabilidad de la inversión depende fuertemente del precio de electricidad cubano, un precio que actualmente es considerablemente subsidiado. La reducción de las emisiones de CO2 depende igualmente del nivel de sustitución, a un nivel de 75% los dos aserraderos tienen una disminución de emisiones de 665 toneladas y de 1272 toneladas, respectivamente. Read more
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Etudes numérique et expérimentale de la synthèse de biogaz : vers la transformation thermochimique solaire de copeaux de bois / Numerical and experimental studies of biogas synthesis : toward a thermochemical conversion of wood chipsLorreyte, Clarisse 15 December 2017 (has links)
La gazéification de biomasse lignocellulosique en biogaz fait partie des technologies attractives permettant de s’affranchir des énergies fossiles et de valoriser les déchets agricoles ou forestiers. Néanmoins, le développement de cette technologie est freiné par son rendement énergétique faible et la production de polluants (CO2, NOx…). La pyrolyse/gazéification par voie solaire permettrait alors de pallier certains de ces inconvénients (énergie propre et gratuite, process à haute température produisant moins de polluants). Dans ce contexte, l’objectif de cette thèse est de développer une approche expérimentale et numérique afin de maîtriser les procédés de pyrolyse/gazéification de copeaux de bois pour mieux appréhender le développement de la gazéification solaire. D’abord, un travail détaillé de caractérisation des copeaux de bois a été réalisé, alliant diverses analyses des échantillons mais aussi des analyses basées sur l’utilisation d’images tomographiques au rayon X pour déterminer les propriétés morphologiques et, par simulation numérique, les propriétés effectives de transport des copeaux de bois. Ensuite, des essais avec un four-réacteur à échelle laboratoire ont été réalisés pour étudier le séchage, la pyrolyse et la gazéification des copeaux de bois. Ces essais nous ont permis d’étudier l’influence de paramètres comme la température en séchage et en pyrolyse ou le débit de vapeur d’eau en gazéification. En parallèle, un modèle multi-physique pour la simulation de la pyrolyse a été développé. Cet outil a permis une étude détaillé des phénomènes mis en jeu et, in fine, permettrait d’optimiser le système. Enfin, le design d’un gazéifieur solaire a été réalisé. / Thermochemical conversion of lignocellulosic biomass belongs to attractive technologies which are viable routes to reduce reliance on fossil energy and to enhance carbon conversion efficiency. Nevertheless, classical gasification process via autothermal combustion of biomass presents severe drawbacks as bad yield and produced important pollutants. Solar concentrated energy enables high temperature reactions with reduced contaminating gas and higher yield. In this context, this thesis aims at developing experimental and numerical approaches to study detailed mechanism of pyrolysis and gasification processes of wood chips packed bed which are key step toward designing efficient solar gasifier. In a first time, inner properties of wood (initial composition and thermal decomposition) were studied via ultimate and proximate analyzes. Structural and morphological properties of wood chips were computed using image analysis. Effective mass and heat transport properties of the packed bed were assessed via direct numerical simulation combined with X-ray tomographic images. Then a laboratory scale device enabling to characterize pyrolysis and gasification kinetics and gas production was developed. The aim of this experimental work was to understand the impact of parameters such as drying and pyrolysis temperatures, and the steam flow rate during gasification. A multiphysical model of pyrolysis of wood chips packed bed was also developed. It allowed to perform detailed study of pyrolysis physics and in fine it will allow optimizing the pyrolysis/gasification process. Finally, a first design for a solar gasifier was reported and constitutes the basis of further studies. Read more
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Čištění energoplynu z biomasy v katalytickém vysokoteplotním filtru / Syngas Cleaning in Hot Catalytic FilterLisý, Martin January 2009 (has links)
Disertation thesis deals with development of hot dolomite filter for the purposes of cleaning of gas polluted by biomass and waste gasification with ash and tar as well as sulphur and chlorine compounds as main pollutants. Gas is then cleaned so that it can be utilized in cogeneration units with combustion engines. This supports advancement of gasification techniques using decentralized power and heat generation especially for design of small scale units. Concrete aims of this thesis are stated in chapter 2. Experimental fluid gasification stend Biofluid 100 has been in operations at Brno University of Technology (BUT) since 2000 and it helps research of biomass and waste gasification. Development of the filter initially utilized needs and experience with the utility during cooperation of BUT and ATEKO Hradec Králové. Water scrubber was used for gas cleaning, however, this method proved to be ineffective. Alternative solutions were considered. Based on literature search, natural catalysts with limestone basis were opted. First part of the thesis presents literature search of this issue. Historic development and description of gasification process are briefly discussed as well as elementary classification of gasification generators. This part is followed by chapters dealing with gas pollutants. Tar – the most significant pollutant – is discussed in a separate chapter which presents tar formation, its classification, characteristics and methods for its removal. Brief summary of requirements on gas properties with respect to its utilization in various applications (especially in cogeneration units) follows. Other part of the literature search part focuses on methods of removal of tar from gas, especially on catalyst methods. Dolomite characteristics, description of dolomite calcination as well as simplified kinetic model of tar cracking using dolomite are presented. Based on literature search, laboratory and verification equipment was designed for the purposes of dolomite properties testing. Equipment description as well as description of experimental stend Biofluid 100 where the experimental tests were carried out can be found in introduction of the experimental part. This is followed by a complete description of pilot equipment design of hot dolomite filter with general description of experimental work process, brief characteristics of the fuel and catalytic material used. Final part of the work comprises of experiment results that were carried out on the pilot equipment. Focus is on efficiency of tar removal in connection with operation temperature, amount of catalytist and material used. Influence of these parameters on gas composition and energy intensity of the whole process under these conditions is mentioned as well. Possibility of autonomous unit operations without electricity heating is briefly outlined. Summary of the most significant results including the potential of future hot dolomite filter development is stated the final part of the thesis. Read more
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Návrh metod čištění plynu při zplyňování stébelnin / Design of Methods for Cleaning of Gas at Gasification of StalkMoskalík, Jiří January 2013 (has links)
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. Read more
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[pt] MODELAGEM TERMODINÂMICA DA GASEIFICAÇÃO DE BIOMASSA: OTIMIZAÇÃO DAS CONDIÇÕES OPERACIONAIS NA CO-GASEIFICAÇÃO DE RESÍDUOS SÓLIDOS URBANOS / [en] THERMODYNAMIC MODELING OF BIOMASS GASIFICATION: OPTIMIZATION OF OPERATING CONDITIONS IN THE CO-GASIFICATION OF URBAN SOLID WASTEROBERTO VINICIUS GRANHA FIUZA 10 August 2021 (has links)
[pt] Devido aos efeitos nocivos dos combustíveis de origem fóssil, cresceu o interesse no uso de fontes sustentáveis de energia, em particular os derivados da biomassa. O presente trabalho consiste no desenvolvimento de uma ferramenta de modelagem computacional da composição da mistura gasosa, chamado gás de síntese ou syngas resultante da gaseificação, baseado no equilíbrio termodinâmico. Assim, são avaliadas a flexibilidade, a confiabilidade e a estabilidade computacional das abordagens de equilíbrio estequiométrico e de minimização da energia livre de Gibbs para determinação das composições do syngas formado no processo. São investigados a influência da umidade relativa da biomassa (0, 20 e 40 por cento em base mássica), da temperatura de gaseificação (800, 1100 e 1400 K), da razão ar combustível em relação a estequiometria (0,2, 0,3 e 0,4) e da quantidade de oxigênio no agente de gaseificação (oxigênio puro, ar ou mistura equimolar dos dois) na composição do syngas, bem como nas eficiências energética e exergética, para biomassas compostas de carbono, oxigênio e hidrogênio. O melhor modelo é usado para otimizar a concentração de agente oxidante e de temperatura que maximizem a eficiência energética para biomassas com 20 por cento de umidade relativa no ar. Esses dados, estão usados para desenvolver modelos matemáticos preditivos usando o conceito de análise de misturas, cuja robusteza é avaliada por análise de variância (ANOVA). Esses resultados estão comparados com as simulações realizadas em um modelo teórico considerando a cinética das reações. Observou-se que o método usando a minimização da energia livre de Gibbs apresentou os melhores resultados para uma aproximação inicial, se tornando uma boa ferramenta para a fase de projeto. No entanto, é necessário desenvolvimento de outros modelos como cinético, CFD ou RNA para análises precisas da gaseificação. / [en] Due to the harmful effects of fossil fuels, interest in the use of sustainable energy sources, in particular those derived from biomass, has grown. The present work consists in the development of a computational modeling tool for the composition of the gas mixture, called synthesis gas or syngas resulting from gasification, based on thermodynamic equilibrium. Thus, the flexibility, reliability and computational stability of the stoichiometric equilibrium and Gibbs free energy minimization approaches are evaluated to determine the compositions of the syngas formed in the process. The influence of biomass relative humidity (0, 20 and 40 percent on mass basis), gasification temperature (800, 1100 and 1400 K), fuel air ratio related to stoichiometry (0.2, 0.3, 0.4) and the amount of oxygen in the gasification agent (pure oxygen, air or equimolar mixture of the two) are investigated in the composition of the syngas, as well as in the energy and exergy efficiencies, for biomasses composed of carbon, oxygen and hydrogen. The best model is used to optimize the oxidizing agent concentration and temperature that maximize energy efficiency for biomass with 20 percent relative humidity in the air. These data are used to develop predictive mathematical models using the concept of analysis of mixtures, whose robustness is assessed by analysis of variance (ANOVA). These results are compared with simulations performed in a theoretical model considering the reaction kinetics. the method using Gibbs free energy minimization presented the best results for an initial approximation, becoming a good tool for a design phase. However, it is necessary to develop other models such as kinetic, CFD or RNA for accurate gasification analysis. Read more
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Integrating CO2 Utilisation and Biomass Gasification with Steel-making Electric Arc Furnaces (EAF) / Integrering av koldioxid utnyttjande och förgasning av biomassa i elektriska ljusbågsugnar för ståltillverkningMokhtari, Adel January 2022 (has links)
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. Read more
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Environmental and economic potential of rice husk use in An Giang province, VietnamPham, Thi Mai Thao 07 January 2019 (has links)
To evaluate CO2 emission mitigation potential and cost effectiveness of rice husk utilization, Life Cycle Analysis was conducted for 9 scenarios. The results showed that, gasification is the most efficient CO2 mitigation. From cost analysis, the cost mitigation can be achieved by replacing the current fossil fuels in cooking scenarios. Among the power generation scenarios, it was found that 30MW combustion and 5MW gasification power generations were the most economically-efficient scenarios. The briquette combustion power generation appeared less cost-competitive than direct combustion, whilst the large-scale gasification scenarios and the pyrolysis scenarios give the increase in cost from the baseline. From the viewpoints of both CO2 and cost, it was indicated that the
win-win scenarios can be the rice husk use for cooking, for large-scale combustion power generation, and for small-scale gasification. / Để đánh giá tiềm năng giảm thiểu phát thải CO2 và hiệu quả chi phí của việc sử dụng trấu, phương pháp đánh giá vòng đời sản phẩm đã được thực hiện cho 9 kịch bản. Kết quả cho thấy, khí hóa trấu để sản xuất điện có tiềm năng giảm phát sinh khí CO2 nhiều nhất. Kết quả phân tích chi phí cho thấy việc giảm thiểu chi phí có thể đạt được khi thay thế sử dụng nhiên liệu hóa thạch trong kịch bản dùng trấu cho nấu ăn. Giữa các kịch bản về sản xuất điện, hiệu quả kinh tế cao nhất trong trường hợp đốt trực tiếp trấu để sản xuất điện ở quy mô công xuất lớn (30MW) và khí hóa ở quy mô trung bình (5MW). Trường hợp dùng củi trấu không mang lại hiệu quả kinh tế so với dùng trực tiếp trấu để phát điện. Hai trường hợp dùng trấu để sản xuất dầu sinh học và khí hóa gas công suất lớn
(30MW) cho thấy chi phí tăng cao so với điều kiện biên. Kịch bản cho kết quả khả thi về hiệu quả kinh tế và giảm phát thải CO2 là dùng trấu để nấu ăn, đốt trực tiếp để phát điện công suất lớn và khí hóa công suất trung bình. Read more
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The Performance of Planar Solid Oxide Fuel Cells using Hydrogen-depleted Coal SyngasBurnette, David D. January 2007 (has links)
No description available.
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