Absorção de gases da queima de combustíveis fósseis em torre de recheio estruturado utilizando lama vermelha

A produção de alumina pelo processo Bayer produz de 1 a 3 toneladas de resíduo por tonelada de alumínio. Esse resíduo é denominado lama vermelha, composto de minerais não solúveis em hidróxido de sódio concentrado, como hematita e outros óxidos férreos, quartzo e óxidos de titânio. A lama vermelha possui em sua composição variados teores de NaOH, dependendo especificamente da planta industrial utilizada. A proposta desse trabalho é avaliar o processo de absorção de gases provenientes de uma caldeira em contracorrente com uma suspensão de lama vermelha a 27%, em torre spray e em torre de recheio estruturado. Foram realizados experimentos variando-se o tipo de torre de absorção, temperatura da fase líquida e teor de sólidos na fase líquida para avaliar a redução do teor dos gases de combustão na saída da torre de absorção e a variação do pH de acordo com o tempo de operação, para que fosse possível identificar o tempo necessário para que ocorra a neutralização da lama vermelha, bem como a redução no teor de dióxido de carbono, para isso foram realizadas medições dos teores de gases na entrada e na saída da torre de recheio estruturado, bem como medições de temperatura e pH. A absorção de CO₂ presente no gás de combustão pela suspensão de lama vermelha se dá pelo processo da carbonatação, no qual o gás reage com o NaOH presente na lama vermelha, sendo a água o catalisador. Os resultados obtidos após os experimentos foram satisfatórios, e concluiu-se que o processo realizado nas torres de absorção é eficiente para a diminuição do pH da lama vermelha e a redução do teor de CO₂ liberado para a atmosfera, promovendo um ganho duplo para o meio ambiente.

Balanço de gases de efeito estufa e emissões de CO2 do solo nos sistemas de colheita da cana-de-açúcar manual queimada e mecanizada crua

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação dos níveis de umidificação e aquecimento durante ventilação artificial com a estação de trabalho de anestesia Primus da Dräger com baixo fluxo de gases frescos e permutador de calor e umidade

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comparação da umidade e temperatura dos gases inalados com alto ou baixo fluxo de gases frescos e com ou sem permutador de calor e umidade em anestesia pediátrica

Pós-graduação em Anestesiologia - FMB

Gases de efeito estufa produzidos pela combustão de biomassa

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Redução das emissões de gases efeito estufa no processo de fabricação do sinter

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação de genotoxicidade e estresse oxidativo em profissionais recém-expostos aos resíduos de gases anestésicos

Pós-graduação em Cirurgia Veterinária - FCAV

Processo combinado bacteriano/químico para remoção de H2S de gases

Particularmente de gases industriais, biogás e demais condições que exijam a purificação de gases antes de sua emissão para a atmosfera, visando a remoção de H~ 2~S, através da reação de oxidação deste gás com uma solução de íons Fe^ 3+^ produzidos por células imobilizadas de Acidithiobacillus ferrooxidans, uma bactéria quimioautotrófica e acidofílica, oxidante de ferro e formas reduzidas de enxofre. Como resultado do processo de oxidação do H~ 2~S pelos íons Fe^ 3+^ ocorre a produção de enxofre elementar (elemento recuperável no processo) e de íons Fe^ 2+^, os quais são re-oxidados pela bactéria à íons Fe^ 3+^ . Este reagente retorna então ao sistema para um novo ciclo de oxidação do H~ 2~S.

DNA damage and antioxidant status in medical residents occupationally exposed to waste anesthetic gases

PURPOSE:To investigate the effects of occupational exposure to waste anesthetic gases on genetic material and antioxidant status in professionals during their medical residency. METHODS:The study group consisted of 15 medical residents from Anesthesiology and Surgery areas, of both genders, mainly exposed to isoflurane and to a lesser degree to sevoflurane and nitrous oxide; the control group consisted of 15 young adults not exposed to anesthetics. Blood samples were drawn from professionals during medical residency (eight, 16 and 22 months of exposure to waste anesthetic gases). DNA damage was evaluated by comet assay, and antioxidant defense was assessed by total thiols and the enzymes glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase (CAT). RESULTS:When comparing the two groups, DNA damage was significantly increased at all time points evaluated in the exposed group; plasma thiols increased at 22 months of exposure and GPX was higher at 16 and 22 months of exposure. CONCLUSION:Young professionals exposed to waste anesthetic gases in operating rooms without adequate scavenging system have increased DNA damage and changes in redox status during medical residency. There is a need to minimize exposure to inhalation anesthetics and to provide better work conditions.

Rn-222, Rn-220 and other dissolved gases in mineral waters of southeast Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Emissão de gases de efeito estufa nos sistemas de colheita crua e queimada no estado de São Paulo, Brasil

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Análise da variação da vazão e da concentração do metano presentes nos gases gerados no aterro sanitário de Rio Claro - SP

The study of the generation of landfill gas contributes to the understanding of the relationship between gas production and other parameters, such as time of disposal of waste and moisture (rainfall) and, thus, can subsidize the viability study for energy. This study aims to evaluate the interference of the time of disposal of waste and moisture (rainfall) in the production and composition of biogas generated at the landfill in Rio Claro - SP. As a result it was observed that for the landfill studied, the average percentage of methane in biogas ranged from 49.9% to 54.7%. It was found that moisture (rainfall) and the time of waste disposal are parameters which do not cause significant changes in methane concentration in biogas. However, when analyzed the flow of biogas, which had the maximum average value of 152.86m3/h and minimum average value of 15.47m3/h was observed great interference of moisture (rainfall) and the time of disposal of waste, because well of gas located in newer areas of the landfill showed higher values of flow rate than the areas where the landfill was the beginning of the arrangement. The same way, it was observed that in the dry season flow of biogas decreased in all drains gas analyzed

Avaliação dos gases de efeito estufa a partir do carvão

This paper addresses the context of emissions of Greenhouse Gases (GHG) from activities related to Coal, called fugitive emissions. The survey of factors, development, analysis, and suggestions for controlling emissions are conducted in order to reduce risks to the environment and people around it. The greenhouse gases absorb radiation, emitted by the Earth’s surface, and hinder their escape into space. This process is essential to terrestrial life. Increasing the concentration of those gases in the atmosphere has led to an increase in the terrestrial temperature. A selection of processes that emit gases and the study and development of calculations for measuring fugitive emissions applied in different sources from coal are performed. The greenhouse gases can be released from the extraction, processing, storage, and transportation of fossil fuels to the end consumer. Coal has 4 main fugitive factors: mining, post-mining, oxidation at low temperature, and uncontrolled combustion. The coal formation process produces methane (CH4) and carbon dioxide (CO2), being the methane, the main greenhouse gas from the coal mining and handling. The types of activities and the weight of each in the issuing process are observed. It is also made comparisons between the countries with the highest emissions rates. Are evaluated what has been done and what is needed to decrease emissions, for example the use of gas as an alternative fuel for energy generation

Análise e simulação de modelos matemáticos para a estimativa da geração de gases em bioprocessos de decomposição anaeróbia de resíduos sólidos em aterros sanitários

Brazil faces a complex problem in respect to municipal solid waste, having been in recent years an increase of its generation without the country there be adequate for proper disposal thereof. In many states , the percentage of waste destined improperly , ie , in dumps , landfills, send- outs , among others , is greater than that disposed in landfills , which would be the most correct way to be made. It can be argued that this discrepancy is due to the high cost of implementation and operation of the landfill, and the same need large areas with physical characteristics that suit their operations . When there is a provision in properly constructed landfills , municipal solid waste grounded generate gases with high potential energy through biochemical reactions during the anaerobic decomposition of organic material stored . Such gases can be used for power generation within the landfill or other economic means . To estimate the gas generation will be sufficient for such economic compensation , there are mathematical models that make estimating the amount of gas produced . These models calculate the energy capacity and generation , using parameters obtained based on the characteristics of solid waste , climate of the region where they are grounded and grounding time . Such models have been raised and studied so that it was possible to perform simulations that demonstrate the behavior of biogas generation related to the external conditions of the landfill that interfere with biological reactions within. The results show differences between the values obtained , it shows that the preparation of the models found and used in the simulations were allocated amounts for different parameters that determine this difference in the estimate . Therefore, to rule, the models have difficulty understanding this because there is no clarity in the formulation of the equations , and the definition of variables and parameters would require a detailed study to...

Implementação de um tuboexpansor na refinaria do Planalto Paulista – REPLAN com objetivo do aproveitamento da energia contida nos gases residuais do FCC – Fluid Catalytic Cracking na geração de energia elétrica

The steel type AISI 4130 (ultra-high strength steel) is an alloy of low carbon and its main alloying elements are chromium and molybdenum, which improves the toughness of the weld metal. It has numerous applications, especially where the need for high mechanical strength. It is widely used in equipment used by the aviation industry, such as cradle-tomotor, and this is the motivation for this study. Cots are of fundamental importance, because the engine supports and maintains balance in the fixed landing gear. This equipment is subjected to intense loading cycles, whose fractures caused by fatigue are constantly observed. Will be determined the effects caused by re-welding the structure of aeronautical equipment, and will also study the microstructure of the metal without welding. The studies will be done on materials used in aircraft, which was given to study. The results provide knowledge of microstructure to evaluate any type of fracture that maybe caused by fatigue. Fatigue is a major cause of aircraft accidents and incidents occurred, which makes the study of the microstructure of the metal, weld and re-solder the knowledge essential to the life of the material. The prevention and control of the process of fatigue in aircraft are critical, since the components are subjected to greater responsibility cyclic loading