89 resultados para Greenhouse Gas Emission Saving
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The objective of this work was to quantify methane (CH4) emission using the sulfur hexafluoride (SF6) tracer technique, by dairy cattle on pasture in Brazilian tropical field conditions. Measurements were performed in the rainy season, with Holstein and Holstein x Zebu crossbred, from lactating and dry cows and heifers grazing fertilized Tobiatã grass, and heifers grazing unfertilized Brachiaria grass. Methane and SF6 concentrations were determined by gas chromatograph. Methane emissions by lactating cows varied from 13.8 to 16.8 g/hour, by dry cows from 11.6 to 12.3 g/hour, by heifers grazing fertilized grass was 9.5 g/hour and by heifers grazing unfertilized grass varied from 7.6 to 8.3 g/hour or 66 to 72 kg/head/year. Methane emission per digestive dry matter intake (DMDI) varied from 42 to 69 g/kg DMDI for lactating cows, 46 to 56 g/kg for dry cows, 45 to 58 g/kg for heifers grazing fertilized grass and 58 to 62 g/kg for heifers in unfertilized grass pasture. The CH4 emission measured on dairy cattle feeding tropical grasses was higher than that observed for temperate climate conditions.
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This paper aims to highlight the state of the art of obtaining carbon credits through the use of electric vehicles. This is one of the solutions to significantly reduce the emission of GHG (Greenhouse Gas) emissions in the case of CO 2, NOx, SOx, and CH 4 (thermochemical reactions arising from the combustion of gasoline with ethanol) in motor vehicles. For this quantitative study was done based on the survey of bibliographic data available and the development of basic calculations considering the car fleet of the Country of Brazil and the CO 2 emissions generated by the same. Thus explaining the considerable gain in air quality and reduction of vectors of greenhouse gases in the case of replacing the current fleet of vehicles combustion of hydrocarbon aliphatic chain, for an eco-efficient fleet consists of electric vehicles and/or hybrids.
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Soil tillage and other methods of soil management may influence CO 2 emissions because they accelerate the mineralization of organic carbon in the soil. This study aimed to quantify the CO2 emissions under conventional tillage (CT), minimum tillage (MT) and reduced tillage (RT) during the renovation of sugarcane fields in southern Brazil. The experiment was performed on an Oxisol in the sugarcane-planting area with mechanical harvesting. An undisturbed or no-till (NT) plot was left as a control treatment. The CO2 emissions results indicated a significant interaction (p < 0.001) between tillage method and time after tillage. By quantifying the accumulated emissions over the 44 days after soil tillage, we observed that tillage-induced emissions were higher after the CT system than the RT and MT systems, reaching 350.09 g m-2 of CO2 in CT, and 51.7 and 5.5 g m-2 of CO2 in RT and MT respectively. The amount of C lost in the form of CO2 due to soil tillage practices was significant and comparable to the estimated value of potential annual C accumulation resulting from changes in the harvesting system in Brazil from burning of plant residues to the adoption of green cane harvesting. The CO 2 emissions in the CT system could respond to a loss of 80% of the potential soil C accumulated over one year as result of the adoption of mechanized sugarcane harvesting. Meanwhile, soil tillage during the renewal of the sugar plantation using RT and MT methods would result in low impact, with losses of 12% and 2% of the C that could potentially be accumulated during a one year period. © 2013 IOP Publishing Ltd.
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Pós-graduação em Agronomia (Energia na Agricultura) - FCA
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The aim of this study was to evaluate CO2 emission, canopy characteristics and herbage accumulation in pastures of pensacola bahiagrass under frequencies of defoliation. The experiment was conducted at the Universidade Estadual Paulista Julio de Mesquita Filho, Faculty of Agrarian Sciences and Veterinary of UNESP, Jaboticabal, São Paulo, Brasil. The experimental period was from May 3rd to July 26th 2012. The experimental area comprised 28 m² of pensacola bahiagrass (Paspalum notatum Flügge), divided into 10 plots for allocation of treatment (frequencies of defoliation = 2 or 4 weeks). The following variables were studied: canopy height, light interception, leaf area index, herbage accumulation, tiller density, CO2 emissions, soil temperature and moisture. The frequencies of defoliation in the months of May, June and July slightly affect pensacola bahiagrass characteristics. CO2, soil temperature and moisture are more associated to environmental conditions (months of evaluation) than to the frequencies of defoliation imposed to the canopies.
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Pós-graduação em Agronomia (Produção Vegetal) - FCAV
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The process of steel production emits a large quantity of greenhouse gases, specifically carbon dioxide (CO2), and the reduction of such emissions is one of the main challenges for the industry in the 21st. Century. To quantify these emissions, the Worldsteel Association (association of the 170 large steel manufacturers of the world) published a methodology (CO2 Emission Data Collection) for calculation and comparison of CO2 emissions among its members. After that, in 2010, this methodology became an ISO (International Organization for Standardization) norm. Today, the calculation of the CO2 emissions in steel making companies follow the ISO 14404-1 for units with blast furnaces and the ISO 14404-2 for units with electric furnaces. In the last years, new technologies were and continue to be developed for the steel making sector aiming at energetic improvements and greenhouse gas reductions (mainly CO2) by the several processes involved in the production of steel. This work had the objective of producing a tool to calculate the CO2 emissions for the steel making sector. An Excel spreadsheet was developed to calculate the emission intensities of CO2 of a steel plant, the Usina Presidente Vargas, of the Companhia Siderúrgica Nacional (CSN). The spreadsheet furnishes results of CO2 emissions and energetic fluxes, and simulates the benefits that some of the new technologies can give to the company. The spreadsheet calculates the emissions in two ways: a) based on the carbon fluxes that enter the unit, and b) based on the emissions of each specific process within the unit (coking, sinterization, blast furnace, among others)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)