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.

Made available in DSpace on 2016-06-02T19:55:20Z (GMT). No. of bitstreams: 1 TeseJS.pdf: 2519378 bytes, checksum: 7360d56b23a635a75d18e60253999a1a (MD5) Previous issue date: 2007-02-28 / Universidade Federal de Sao Carlos / The increase in the air pollution in the last decades is causing a strong increase in the monitoring and control of emissions of particulate matter in the atmosphere, in order to minimize the problems caused to the environment and to the human health. Particularly, the behavior nanometric particles in the air needs special attention. The fiber filters, one of the oldest methods of particle removal, are, in principle, capable to operate in this size range, but data on their performance are still scarce. In this work, the behavior of an industrial filter of polyester and of a high efficiency (HEPA) filter was studied with the intention of evaluating their performance operating in the removal of nanometric particles from aerosols. The polyester filter had a porosity of 0.884, a thickness of 4.5 mm and diameter of fiber of 16 m and the HEPA filter the porosity of 0.920, thickness of 0.4 mm and diameter of fibers between 0.075 and 2.35 µm. The test aerosol was composed by monodispersed NaCl particles, obtained from the Electrospray Aerosol Generator, model 3480, from TSI, using salt solutions in concentrations from 0.5 to 5.0 g/L. The size of the generated particles varied from 8.4 to 94.8 nm. To determine this diameter, images in an Electronic Transmission Microscope were obtained and analyzed in the image analyzer Image Pro Plus, 3.0. The filtration device was built in acrylic with a filtration area of 40 cm2. The performance of the filters was evaluated through the analysis of the collection efficiency of the nanometric particles, by counting the particles before and after the filter, using a TSI Condensation Nuclei Particle Counter , model 3007. The filter of polyester showed a maximum collection efficiency of 0.990. The HEPA filter demonstrated its capacity to collect particles in this size range, obtaining larger efficiencies than 0.99994. The increase of the filtration velocity, as well as the increase of the diameter of the particles resulted in smaller efficiencies in both filters, typical behavior of filters operating in the range of predominance of the diffusional mechanism. When compared to theoretical models form the literature, it was verified poor fitting. Therefore, it is suggested an adjustment to the LIU and RUBOW (1990) model, and an effective increase in the mechanism of direct interception caused by the Brownian motion was introduced. In the case of the HEPA filters, considering the observed discrepancy between theory and experiment, an approach that took into account the fiber size distribution of the filter was proposed. In both cases a sensitive improvement was verified in the adjustment of the theoretical prediction to the experimental data / A crescente escalada da poluição do ar nas últimas décadas vem causando um sensível aumento no monitoramento e no controle de emissões de material particulado na atmosfera, visando minimizar os problemas causados ao meio ambiente e à saúde humana. Particularmente, o comportamento de partículas nanométricas no ar necessita atenção especial. Os filtros de fibras, um dos métodos mais antigos de remoção de material particulado, são, em princípio, capazes de atuar nessa faixa de tamanho, mas dados sobre seu desempenho são ainda escassos. Neste trabalho estudou-se o comportamento de um filtro industrial de poliéster e de um filtro de alta eficiência (HEPA) com o intuito de avaliar o desempenho dos mesmos operando na remoção de partículas nanométricas de aerossóis. O filtro de poliéster tinha porosidade de 0,884, espessura de 4,5 mm e diâmetro de fibra de 16µm e o filtro HEPA uma porosidade de 0,920, espessura de 0,4 mm e diâmetro de fibras entre 0,075 e 2,35 µm. O aerossol de teste era composto por partículas monodispersas de NaCl, que foram obtidas a partir de um gerador de partículas Electrospray Aerosol Generator, modelo 3480, da TSI, utilizando soluções de sal nas concentrações de 0,5 a 5,0 g/L. O tamanho das partículas geradas variou de 8,4 a 94,8 nm. Para determinar este diâmetro foram obtidas imagens do Microscópio Eletrônico de Transmissão e analisadas no Programa Image Pro Plus, 3.0. O dispositivo de filtração foi construído em acrílico com área de filtração de 40 cm2. O desempenho dos filtros foi avaliado através da análise da eficiência de remoção das partículas nanométricas, através da contagem de partículas, utilizando um contador de partículas, da TSI, modelo 3007. O filtro de poliéster apresentou eficiência de coleta máxima de 0,990. O filtro HEPA demonstrou possui uma grande capacidade de coletar partículas nesta faixa de tamanho, obtendo eficiências maiores que 0,99994. O aumento da velocidade de filtração, bem como o aumento do diâmetro das partículas proporcionou queda na eficiência em ambos os filtros, comportamento típico de filtros operando na região de predominância do mecanismo difusional. Quando avaliados os modelos presentes na literatura, verificou-se que os mesmos não se ajustaram aos dados experimentais. Portanto, propôs-se um ajuste ao modelo de LIU & RUBOW (1990), considerando um aumento efetivo no mecanismo de interceptação direta causado pelo movimento Browniano. No caso dos filtros HEPA, frente à observada discrepância entre teoria e experimentos, foi proposto um equacionamento que levou em conta a distribuição de tamanho das fibras do filtro. Em ambos os casos verificou-se uma sensível melhora no ajuste da previsão teórica aos dados experimentais

Made available in DSpace on 2016-06-02T19:55:38Z (GMT). No. of bitstreams: 1 TeseAPRAR.pdf: 1123678 bytes, checksum: 08006e46754054a6402b0499737e23ca (MD5) Previous issue date: 2005-04-04 / Universidade Federal de Sao Carlos / This work had for objective to study the influence of the variables liquid flow, throat length, number of orifices and gas velocity in the throat in the collection efficiency of a Venturi scrubber. As particulate matter to be removed from the gas, a phosphate concentrate of density 2.9 g/cm3 was used, fed at a mass flow rate of 3.16 g/min. The experimental system used in this work consisted of a Venturi scrubber of rectangular geometry operating horizontally, with liquid injection through 1 to 5 orifices with 1 diameter mm each, distributed in the scrubber throat. For the experiments, two experimental planning were used, with three factors in three different levels. In the first planning was studied the influence of the variables liquid flow in the range from 300 to 900 cm3/min, throat length in the range from 6.5 to 18.5 cm and number of orifices in the range from 1 to 5 holes; the gas velocity in the throat was kept constant at value of 69.33 m/s. In the second planning was studied the influence of the variable gas velocity in the throat in the range from 58.66 to 69.33 m/s, with the liquid injected by a single orifice. It was verified that the overall collection efficiency of the Venturi scrubber varied within the range from 50 to 91%, for the studied conditions in the first planning. A tendency of increase of the efficiency was observed with the increase of the liquid flow and of the throat length. As for the number of orifices, a better performance of the scrubber was verified when only 1 orifice was used. It was verified that the overall collection efficiency of the Venturi scrubber varied within the range from 52 to 93%, for the studied conditions in the second planning. Was observed that the increase in the gas velocity in the throat resulted in an increase in the overall collection efficiency. The predictions of the classical equations for collection efficiency of Johnstone et al. (1954), Calvert et al. (1972) and Leith and Cooper (1980) were compared to the experimental values. It was observed that both for the experimental results and for the models that the global efficiency increases with the increase of the liquid flow. However, it was verified that the models of Johnstone et al. and Calvert et al. underestimated the values of global efficiency obtained experimentally while the model of Leith and Cooper overestimated them. Therefore, it became necessary to adjust a model to the experimental points. It was taken as departure point the model of Calvert et al., for being a classic model and because it is widely used industrially. An adjustment equation for the empiric factor f using the experimental data was then performed. As it was verified in previous tests that the variable throat length is relevant in the collection efficiency and the same does not appear in the equation proposed by Calvert et al., it was decided to adjust an equation of f in function as a function of LG as f= 3005 , 0 . 5161 , 0 G L . The validity of the adjustment was verified by the good agreement of the experimental values of efficiency observed experimentally with the predicted values by the modified Calvert model. / Este trabalho teve por objetivo estudar a influência das variáveis vazão de líquido, comprimento da garganta, número de orifícios e velocidade do gás na garganta na eficiência de coleta de um lavador Venturi. Como material particulado a ser removido de uma corrente gasosa utilizou-se um concentrado fosfático de densidade 2,9 g/cm3 na vazão mássica de 3,16 g/min . O sistema experimental utilizado neste trabalho consistiu de um lavador Venturi de geometria retangular operando horizontalmente e com injeção de líquido através de 1 a 5 orifícios de 1 mm de diâmetro distribuídos na garganta do mesmo. Para a realização dos experimentos utilizou-se dois planejamentos experimentais do tipo completo, com três fatores em três diferentes níveis. No primeiro planejamento foi estudada a influência das variáveis vazão de líquido na faixa de 300 a 900 cm3/min, comprimento da garganta na faixa de 6,5 a 18,5 cm e número de orifícios na faixa de 1 a 5 orifícios, mantendo-se constante a velocidade do gás na garganta com um valor de 69,33 m/s. No segundo planejamento foi estudada a influência da variável velocidade do gás na garganta na faixa de 58,66 a 69,33 m/s, utilizando-se apenas 1 orifício para injeção de líquido. Verificou-se que os percentuais de eficiência de coleta no lavador Venturi ficaram na faixa de 50 a 91% para o primeiro planejamento. Observou-se uma tendência de aumento da eficiência de remoção de partículas com o aumento da vazão de líquido e do comprimento da garganta. Quanto ao fator número de orifícios verificou-se um melhor desempenho do lavador quando utilizou-se apenas 1 orifício. Verificou-se que os percentuais de eficiência de coleta no lavador Venturi ficaram na faixa de 52 a 93% para o segundo planejamento. Observou-se que o aumento da velocidade do gás na garganta provocou um aumento na eficiência de coleta. Comparou-se as predições das clássicas equações de eficiência de Johnstone et al. (1954), Calvert et. al. (1972) e Leith e Cooper (1980) com os valores experimentais. Observou-se que para os resultados experimentais e para os modelos avaliados que a eficiência global é crescente com o aumento da vazão de líquido. No entanto, verificou-se que os modelos de Johnstone et al. e Calvert et al. subestimaram os valores de eficiência global obtidos experimentalmente enquanto o modelo de Leith e Cooper superestimou os mesmos. Com isso, tornou-se necessário ter um modelo para ajustar aos pontos experimentais. Tomou-se como base o modelo de Calvert et al. por ser um modelo clássico e ser amplamente utilizado na indústria. Propôs-se então uma equação de ajuste para o fator empírico f utilizando os dados experimentais. Como verificou-se em testes anteriores que a variável comprimento de garganta é relevante na eficiência de coleta e a mesma não aparece na equação proposta por Calvert et al., decidiuse ajustar uma equação de f em função de LG da forma f= 3005 , 0 . 5161 , 0 G L . Verificou-se a validade do ajuste pela boa concordância dos valores experimentais de eficiência observados experimentalmente com os valores estimados pelo modelo de Calvert modificado.

Research of conditions when sulphure dioxide is absorbed from flue gas, is the main objective of this master's thesis. Efficiency of this flue gas cleaning was measured on an experimental device, which consist of an absorption column filled with structured packing’s, and another component so-called "O-element". Further, a possibility of upgrade this "O-element" to tread more flue gas is presented.

This master's thesis deals with current situation of medical waste management in the Czech Republic and it also analyzes the quality of existing units for thermal treatment of the medical waste. In the second part of the thesis, available off-gas cleaning methods were described as well as the emission limits for waste incineration, which correspond to the legislative regulations effective in the Czech Republic. These emission limits are considered as input data for off-gas cleaning system design. In the main part of this thesis, two technological solutions of off-gas cleaning methods for Up-to-Date medical waste incineration unit were designed. The unit is designed for energy utilization of 1400 tons of medical waste accumulated during one year in a regional hospital of model region. From given input parameters, two appropriate apparatus concepts were created. After that, both concepts were evaluated either form energetic point of view as well as from material one. From these evaluations, key apparatuses of both concepts were designed which provided necessary design dimensions for further investment price estimation of each individual key apparatus. In the conclusion of this thesis, the best solution of an off-gas cleaning method was picked according to the comparison of operating and investment costs.

This diploma thesis deals with selected abatement techniques of nitrogen oxides (NOx) developed for large combustion plants. The first part describes selected NOx, their properties and explains the formation during combustion. Furthermore, there is an analysis of current legal legislation regulating the issue of emission limits. The third part presents selected primary and secondary measures that are widely used. The emphasis is placed on the description of selective catalytic (SCR) and non-catalytic reduction (SNCR). Finally, the basic design of these technologies for model combustion equipment is performed. The consumption of reducing medium and the volume of the catalyst for the mentioned techniques are calculated here. The estimate of selected operating and investment costs is a part of the basic scheme.

Thermal processing of wastes is a metod, when during combustion occur reduction of wastes till 10% previous volume. The main advantage of this method is possibility to heat utilization for heat and electric production. Through thermic process develops range of pollutants (NOx, CO, SO2, HCl, HF, PCDD/F) that had to be remove from off-gas or reduced to enviromental values in agreement with laws in force [16]. For this purpose are combustion units equip with range of devices for removing this pollutans. The main task of this diploma thesis is selectoin of ctirical device in term of pressure drops. The value of pressure drop stands significant part in proposition of efficiecy off-gas fan. In increase or decrease total pressure drop consumption of electrical energy of off-gas fan is rising or going down. Change of consumption in total classification is projecting in energy utilization rate of waste where is determinate if it stands of energy utilizatoin or just incineration. In first part of diploma thesis are described in detail availability methods of off-gas cleaning where is described their principle, advanteges, disadvatages and comparison of effectivity. In second part of diploma thesis is made example model about influnce technology on value of total pressure drop. There were chosen two technologies for removing dioxins (technology of catalytic filtration REMEDIA and DeNox/DeDiox). For both technologies were made detailed analysis of pressure drops single components of these technologies. Attainment results were compared and rated with one another. For analysis these two methods were designed mathematical process in software Maple 9.5.

The topic of the diplome thesis is draft of the waste-to-energy plant for municipal waste with cogeneration of heat. Basic specification of project: Waste-to-Energy plant is facilitated by two rotary kilns of type operating in parallel. Further flue gas leaving the post-combustor enters a multicyclone unit to separate substatial portion of fly-ash. Heat of flue gas at the temperature of 1000°C generates superheated steam in a Heat Recovery Steam Generator (HRSG). Dry sorption process is appllied for flue gas treatment. Specifically sodium bi-carbonate is used for it. Products of reactions and remnants of dust are separated by a baghouse. Superheated steam, generated by two HRSG, presents the inlet stream of a condensing steam turbine with steam extraction. The diploma thesis contains calculation of major devices and basic economical and financial statement of project.

The main theme of this master’s thesis is to acquaint with flue gas cleaning problems. Also modernization of experimental device called “O-element”, installed in laboratory at Institute of process and environmental engineering, is involved in this master’s thesis. “Oelement is used for cleaning acid elements from flue gas. Further there are results of experimental measuring on this device, and their estimation.

The aim of this thesis is the design of municipal waste incinerator using the generated steam for power generation and distribution of heat. At the beginning is engaged in development of waste issues and the current state of waste management. The next section describes the options of waste treatment and possible solutions to the current state of waste issues. The concept of waste incineration plants: For waste incineration is used line for burning 100,000 tons of municipal waste per year.Combustion takes place in a grate boiler. Its advantage is the versatility and flexibility to waste. Electricity generation is dealt with condensing turbine with controlled consumption. The flue gas cleaning is designed to semi-wet method. The final stage involves the calculation of the balance, the calculation of electric energyand basic economic evaluation.