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A Review of Modelling of the FCC Unit—Part II: The RegeneratorSelalame, Thabang W., Patel, Rajnikant, Mujtaba, Iqbal, John, Yakubu M. 18 March 2022 (has links)
yes / Heavy petroleum industries, including the Fluid Catalytic Cracking (FCC) unit, are among some of the biggest contributors to global greenhouse gas (GHG) emissions. The FCC unit’s regenerator is where these emissions originate mostly, meaning the operation of FCC regenerators has come under scrutiny in recent years due to the global mitigation efforts against climate change, affecting both current operations and the future of the FCC unit. As a result, it is more important than ever to develop models that are accurate and reliable at predicting emissions of various greenhouse gases to keep up with new reporting guidelines that will help optimise the unit for increased coke conversion and lower operating costs. Part 1 of this paper was dedicated to reviewing the riser section of the FCC unit. Part 2 reviews traditional modelling methodologies used in modelling and simulating the FCC regenerator. Hydrodynamics and kinetics of the regenerator are discussed in terms of experimental data and modelling. Modelling of constitutive parts that are important to the FCC unit, such as gas–solid cyclones and catalyst transport lines, are also considered. This review then identifies areas where the current generation of models of the regenerator can be improved for the future. Parts 1 and 2 are such that a comprehensive review of the literature on modelling the FCC unit is presented, showing the guidance and framework followed in building models for the unit.
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A model to evaluate CO2 emission reduction strategies in the USArar, Joseph I. 06 August 2007 (has links)
No description available.
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The (un)sustainability of hotel breakfast buffets : Food and its potential to mitigate greenhouse gas emissions in the context of tourismGube, Marlene January 2016 (has links)
Tourism and food are two sectors that have major impact on the environment, including the amount of global greenhouse gases (GHGs) they emit. The potential of the tourism sector to mitigate greenhouse gases through adaptation strategies of food supply and consumption at breakfast buffets in hotels is the major field of investigation in the current study. This thesis contributes an empirical analysis that uses knowledge from fieldwork in a touristic area in Sweden. The empirical work of this study consists of two steps. First, measuring the (un)sustainability of breakfast buffets in hotels, using the FOODSCALE method, determining potential pathways toward a less greenhouse gas emission intensive food supply and second, to distinguish tourist interest to adopt toward a more climate friendly diet away from home. As food consumption patterns of tourists are considered as critical contributors to greenhouse gas emissions, changes toward a more environmental friendly diet are urgently needed helping substantially in mitigating emissions of GHGs. However, this field has been sparsely explored which made it an interesting and important area for current research in tourism studies. The results and analysis showed that sustainable food consumption patterns of tourists can be encouraged through breakfast buffets. However, this is depending on a couple of determinants which have to be applied and fulfilled by breakfast buffets in hotels. Tourists interest to adapt toward a more climate friendly diet while being on holidays is depending on their eating habits and their interest in environmental sustainability issues. With the help of the 3 identified guest groups it can be determined that the majority of tourists' is willing to give up carbon-intensive eating habits and change their behavior when being on holidays. Hotels can act as role models, promoting more sustainable behaviour through sustainable food offers at breakfast buffets. The idea of hotels acting as role models focuses on encouraging beneficial decision-making, such as adopting food consumption patterns toward a carbon-neutral diet.
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Qualité nutritionnelle et impact carbone des choix alimentaires individuels : le cas FrançaisVieux, Florent 11 December 2012 (has links)
La santé et l'environnement sont, avec l'économie et le social, deux piliers de l'alimentation durable dont la convergence est discutée. On peut les estimer respectivement à travers la qualité nutritionnelle et l'impact carbone. Dans le cadre de ce travail de thèse, nous proposons d'appréhender la problématique de la convergence nutrition-environnement en adoptant deux approches différentes. Tout d'abord, nous avons estimé la conséquence, sur l'impact carbone de l'alimentation, d'une modification de choix alimentaires individuels. Puis, en classant les individus en fonction de la qualité nutritionnelle de leur alimentation, nous avons estimé si l'impact carbone était différent en fonction de cette qualité nutritionnelle. Premièrement, nous avons montré que la modification des choix alimentaires ne peut s'avérer être une stratégie de réduction majeure de l'impact carbone associé à l'alimentation. Deuxièmement, le niveau d'impact carbone ne diffère que très peu en fonction de la qualité nutritionnelle de l'alimentation. Une bonne qualité nutritionnelle semble même associée à un plus fort impact carbone. Les résultats conduisent à remettre en question l'idée communément relevée dans la littérature qu'il existerait une convergence "naturelle" dans le domaine de l'alimentation entre la promotion de la santé publique et la protection de l'environnement. Notre approche est originale, car nous avons pris en compte la variabilité de l'alimentation réelle des individus, et que nous avons estimé avec précision la qualité nutritionnelle de leur alimentation. Cette thématique constitue un vaste champ de recherches qu'il convient de défricher de façon urgente. / Health and environment are, with economy and social concerns, two pillars of food sustainability whose compatibility is discussed. They can be estimated through nutritional quality and carbon footprint respectively. In this thesis, we propose to analyze the convergence between nutrition and environment by adopting two different approaches. First, we have estimated the effect of modifying individual food choices on diet-related carbon footprint. Second, by classifying the individuals based on the nutritional quality of their diet, we compared the diet-related carbon footprint among the classes of individuals. First, we have shown that changes in food choices may not be an efficient strategy for reducing the diet-related carbon footprint. Second, the level of carbon footprint did not differ much according to the nutritional quality of diets. A high quality diet even seems associated with a higher carbon footprint.The results lead to question the idea commonly found in the food and nutrition literature that there is a “natural” convergence between promotion of public health and environmental protection. Our approach is original because we have taken into account the variability of realistic individual food consumptions and we estimated the nutritional quality of diets with precision. This topic is a vast field of researches which has to be explored urgently.
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Investeringsunderlag för värmepump : Investeringsunderlag för ett byte från pelletspanna till värmepump i fastighet på södra GotlandOwen Berghmark, Victor January 2019 (has links)
Inom EU finns mål på att sänka utsläppen med 40% till år 2030. I Sverige står bygg och fastighetssektorn för cirka 21% av Sveriges totala utsläpp. För att lyckas nå EU:s klimatmål måste en konvertering till förnybara uppvärmningskällor ske. Region Gotland ansvarar idag för över 500 000m2 fastigheter. Många använder idag pellets till uppvärmning. Pellets ses som klimatneutralt och släpper därför inte ut mer koldioxid än vad trädet plockat upp. Ett problem som uppstår då pelletspannorna kräver underhåll och leveranser. Flera av Region Gotlands fastigheter ligger flera mil iväg från både leverantör och underhållspersonal vilket ökar kostnader och miljöpåverkan än mer. En av dessa fastigheter, brandstationen i Öja, ligger till grund för denna studie. Då det finns flera fastigheter med liknande förutsättningar kan rapporten användas som underlag för dessa. Studien undersöker ifall en konvertering från pelletspannan till en värmepump kan sänka kostnaderna och bidra till lägre utsläpp. Vid en konvertering till värmepump sänks systemtemperaturerna från 80/60 till 55/45 vilket kan skapa problem för befintliga radiatorer, rör och pumpar. Radiatorernas och rörens kompatibilitet med nya temperaturerna under söks därför i studien men pumpar utelämnas för en framtida studie. Med hjälp av transmissionsberäkningar och en formel baserad på grad dagar och tidigare energiförbrukning beräknades ett värmebehov för fastigheten på 23,8 kW den kallaste dagen på året. Med detta kunde tre värmepumplösningar tas fram. Samtliga lösningar innefattar även en ny ackumulatortank då den nuvarande är över 40 år gammal och har ett flertal brister. Med optimering av uppvärmningssystemet genom att sänka temperaturen i de fläktvärmda rummen till 15 grader kan värmebehovet sänkas med 4kW. En undersökning gällande installation av solfångare har även gjorts, där det inte visade sig lönsamt med dagens tappvarmvattenbehov. Efter de dimensioneringar som gjorts framkommer även att två rörslingor behöver bytas, men att ett eventuellt radiatorbyte lämnas till efter en konvertering för att se om dessa behöver bytas. Undersökningarna visar även att de befintliga fläktvärmarna är överdimensionerade och inte behöver bytas. Utsläppsberäkningar visar att utsläppen kan minskas med 2565 kg CO2 eq per år vid en eventuell konvertering. Payoffmetoden har använts för att visa att de tre lösningarna har en mycket kort återbetalningstid mellan 3,9 år för luft/vattenvärmepumpar från CTC till 4,7 år för Thermias bergvärmelösning. Med hjälp av LCC kalkyler har lösningarna livstidskostnad tagits fram. Ställt mot den be fintliga pelletspannan uppgår besparingen till 879 000kr för Thermias lösning – 966 000kr för CTC:s lösning med en kalkylränta på 1,5%. Slutsatsen är därför att en konvertering till värmepump bör ske för att spara både ekonomiskt men även för att minska utsläppen. / One of EU’s climate goals is to reduce the greenhouse gas emissions by 40% by the year of 2030. In Sweden the “building and real estate sector” stands for 21% of Sweden’s total pollution of greenhouse gas emissions. To reach EU’s goals by 2030 there must be a transformation to renewable sources for use in the heating of real estates. Region Gotland manages over 500 000 m2 of estates. Many of which uses pellet as the source of heating. This heating alternative requires regular deliveries of material and maintenance. Many of the estates in the care of Region Gotland are far away from both the supplier and maintenance team which creates great transport costs and gas emissions. The fire sta- tion in “Öja” is one of them and is the one used in this study. As there are many similar buildings the results here can be used as a foundation for those estates. This study is exploring if a conversion from pellet to a heating pump can lower the expenses and greenhouse gas emissions. By changing to a heat- ing pump from a pellet boiler the temperatures are reduced from 80/60°C to 55/45 °C in the system. This may cause problem with radiators, pumps and pipes. Because of this, radiators and pipes will also be inves- tigated, but pumps will be left out for another study. The heat needed to increase the temperature in the building to 21 °C at a DVUT of -8,7 °C was calculated using transmission losses calculations and a formula based on “graddagar” and earlier energy uses by the estate, to 23,8 kW. Based on the calculated heat, three heating pump solutions were created, all of whom included a new water heater with storage tank. The old storage tank is over 40 years by age and therefore has many short- comings. Using calculations to optimize the heat usage, the heat needed can be re- duced by 4kW at DVUT by lowering the temperature to 15 °C in the fan heated area of the building while still being within the laws of the Swe- dish work environment authority. An investigation was made to see if solar collectors could be used to heat the domestic hot water in the estate. The results showed that in this case it wouldn’t be economically justifiable due to low energy cost with a new heating pump. The calculations done for pipes and radiators showed that two pipes must be replaced but that the radiators are mostly fine with the new tempera- tures. A replacement of the radiators should be left till after the conver- sion. Calculations on the fan heaters showed that there is no need to re- place these. Calculations on greenhouse gas emissions showed that the emissions can be reduce by 2565 kg CO CO2-eq each year if the pellet boiler is replaced by a heating pump. The Pay-off method and LCC calculations was used to show the profita- bility in the three heating pump solutions. The Pay-off time for the solu- tions ranged from CTC’s air to water heating pumps at 3,9 years to 4,7 years for Thermia’s geothermal heating pump. The LCC calculations showed that changing to a heat pump could generate a saving of 879 000 SEK for Thermia’s solution to 966 000 SEK for CTC’s solution. The conclusion is therefore that the pellet boiler should be changed to a heating pump to save money and reduce the greenhouse gas emissions.
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Grazing strategies, animal performance and environmental sustainability in intensive pasture-based milk production systems / Estratégias de pastejo, desempenho animal e sustentabilidade ambiental em sistemas intensivos de produção de leite à pastoBatalha, Camila Delveaux Araujo 06 November 2018 (has links)
In Brazilian livestock, and its diverse ways of production, the management of grazing animals is known as the lowest return on investment on land use opportunities. Nevertheless, among different types of milk production systems, it is noted that the use of pasture grazing is a common feature between them. Thus, to achieve profitability and maintain system sustainability, the identification of the most adequate and efficient pasture management practices, can maximize production per cow and production per unit area. The low efficiency of this method of production, also classifies the national livestock as the major source of environmental pollution due the emission of pollutants, such as greenhouse gases and nitrogen. The adoption of pasture management techniques respecting forage physiological limits and increasing digestibility of nutrients, can reduce the excretion of nutrients and the production of methane per kilo of milk produced on the environment. The objectives of this thesis were to investigate metabolic variables, greenhouse gas emissions and animal performance for dairy cows grazing elephant grass subjected to rotational stocking strategies. Chapter 1: In this study was to evaluate two strategies of grazing management: pre-grazing targets of 95% versus maximum canopy light interception (LI). In intensive pasture-based milk production systems, the management based on LI95% allows lactating cows to have access to pastures with lower proportion of stems, with higher proportions of young leaves better chemical composition and perform an efficient grazing with lower forage losses. Therefore, the LI95% pasture management strategy results in higher energy intake, higher milk production per cow, higher stocking rates of pasture and higher milk yield per area. Also, the strategy allows the decrease of methane emissions per net energy intake when comparing to management based on LIMax. However, dietary N use efficiency did not increase with this management practice. Chapter 2: The objective of the second study was to evaluate the effects of paddock allocation time (a.m. vs. p.m.) on milk production, ruminal variables and efficiency of N use of mid-lactation dairy cows. In intensive pasture-based milk production systems, allocating cows on new paddocks on p.m. time has no effect on forage intake and milk production of grazing mid-lactation cows. However, the higher content of nonstructural carbohydrate of forage from p.m. pastures increases the yield of microbial protein, decreases milk urea nitrogen and tends to increase the yields of milk protein and milk casein compared to a.m. pastures. Throughout this thesis there were an improvement on nutritive value of forage adopting LI95% as a pre- grazing target and forage grazed at p.m. Therefore, the time of allocation on paddock should be used along with LI95% as fine-tune in intensive pasture-based milk production systems. / No Brasil, a produção animal em pastagens é reconhecida por ser uma atividade pouco competitiva frente a outras oportunidades de uso da terra. Embora sejam inúmeros os tipos de sistemas de produção de leite no Brasil, nota-se que a utilização de pastagens é característica comum. Assim, a identificação de práticas adequadas e eficientes de manejo do pastejo contribuirá com aumento da produção por vaca e por unidade de área, além de contribuir para a sustentabilidade do sistema. A baixa eficiência do uso dos recursos naturais tem classificado a pecuária nacional como uma importante fonte de poluição ambiental devido à emissão de poluentes, como gases de efeito estufa e excreção de nitrogênio. A adoção de técnicas de manejo de pastagens respeitando os limites fisiológicos da forrageira e aumentando sua digestibilidade, podem reduzir a produção de metano por quilo de leite produzido no ambiente e a excreção de nutrientes. Os objetivos desta tese foram investigar variáveis metabólicas e desempenho animal de vacas leiteiras em capim-elefante cv. cameroon submetido a estratégias de pastejo rotativo. Capítulo 1: Neste estudo foram avaliadas duas estratégias de manejo de pastejo: meta de pré-pastejo de 95% versus máxima interceptação luminosa (IL). Em sistemas intensivos de produção de leite à pasto, o manejo baseado no IL95% permite que vacas tenham acesso a pastos com maior relação folha: colmo, menores perdas de forragem, resultando em uma forragem com melhor composição química. Os animais pastejando forragem com IL95% tiveram maior consumo de matéria seca e energia, com maior produção de leite por vaca e taxa de lotação resultando em maior produção de leite por área. Além disso, a estratégia permite a diminuição das emissões de metano por consumo de energia líquida quando comparado a máxima IL. No entanto, a eficiência do uso de N não aumentou com essa prática de manejo. Capítulo 2: O objetivo do segundo estudo foi avaliar os efeitos do período de início pastejo (a.m. ou. p.m.) na produção de leite, variáveis ruminais e eficiência de uso de N de vacas leiteiras no terço médio da lactação. Em sistemas intensivos de produção de leite à pasto, o pastejo de novos piquetes no período da tarde não teve efeito sobre o consumo de forragem e produção de leite de vacas no terço médio da lactação. No entanto, o maior teor de carboidratos não fibrosos da forragem ao final do dia possibilitou o aumento da síntese de proteína microbiana, redução do nitrogênio uréico no leite e apresentou tendência para aumento da produção de proteína e caseína do leite em comparação à vacas que iniciaram o pastejo no período da manhã. Ao longo dos estudos desta tese houve uma melhora no valor nutritivo da forragem adotando IL95% e da forragem pastejada no período da tarde. Assim, o pastejo no período da tarde deve ser adotado juntamente com IL95% como ajuste fino em sistemas intensivos de produção de leite à base de pasto.
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Grazing strategies, animal performance and environmental sustainability in intensive pasture-based milk production systems / Estratégias de pastejo, desempenho animal e sustentabilidade ambiental em sistemas intensivos de produção de leite à pastoCamila Delveaux Araujo Batalha 06 November 2018 (has links)
In Brazilian livestock, and its diverse ways of production, the management of grazing animals is known as the lowest return on investment on land use opportunities. Nevertheless, among different types of milk production systems, it is noted that the use of pasture grazing is a common feature between them. Thus, to achieve profitability and maintain system sustainability, the identification of the most adequate and efficient pasture management practices, can maximize production per cow and production per unit area. The low efficiency of this method of production, also classifies the national livestock as the major source of environmental pollution due the emission of pollutants, such as greenhouse gases and nitrogen. The adoption of pasture management techniques respecting forage physiological limits and increasing digestibility of nutrients, can reduce the excretion of nutrients and the production of methane per kilo of milk produced on the environment. The objectives of this thesis were to investigate metabolic variables, greenhouse gas emissions and animal performance for dairy cows grazing elephant grass subjected to rotational stocking strategies. Chapter 1: In this study was to evaluate two strategies of grazing management: pre-grazing targets of 95% versus maximum canopy light interception (LI). In intensive pasture-based milk production systems, the management based on LI95% allows lactating cows to have access to pastures with lower proportion of stems, with higher proportions of young leaves better chemical composition and perform an efficient grazing with lower forage losses. Therefore, the LI95% pasture management strategy results in higher energy intake, higher milk production per cow, higher stocking rates of pasture and higher milk yield per area. Also, the strategy allows the decrease of methane emissions per net energy intake when comparing to management based on LIMax. However, dietary N use efficiency did not increase with this management practice. Chapter 2: The objective of the second study was to evaluate the effects of paddock allocation time (a.m. vs. p.m.) on milk production, ruminal variables and efficiency of N use of mid-lactation dairy cows. In intensive pasture-based milk production systems, allocating cows on new paddocks on p.m. time has no effect on forage intake and milk production of grazing mid-lactation cows. However, the higher content of nonstructural carbohydrate of forage from p.m. pastures increases the yield of microbial protein, decreases milk urea nitrogen and tends to increase the yields of milk protein and milk casein compared to a.m. pastures. Throughout this thesis there were an improvement on nutritive value of forage adopting LI95% as a pre- grazing target and forage grazed at p.m. Therefore, the time of allocation on paddock should be used along with LI95% as fine-tune in intensive pasture-based milk production systems. / No Brasil, a produção animal em pastagens é reconhecida por ser uma atividade pouco competitiva frente a outras oportunidades de uso da terra. Embora sejam inúmeros os tipos de sistemas de produção de leite no Brasil, nota-se que a utilização de pastagens é característica comum. Assim, a identificação de práticas adequadas e eficientes de manejo do pastejo contribuirá com aumento da produção por vaca e por unidade de área, além de contribuir para a sustentabilidade do sistema. A baixa eficiência do uso dos recursos naturais tem classificado a pecuária nacional como uma importante fonte de poluição ambiental devido à emissão de poluentes, como gases de efeito estufa e excreção de nitrogênio. A adoção de técnicas de manejo de pastagens respeitando os limites fisiológicos da forrageira e aumentando sua digestibilidade, podem reduzir a produção de metano por quilo de leite produzido no ambiente e a excreção de nutrientes. Os objetivos desta tese foram investigar variáveis metabólicas e desempenho animal de vacas leiteiras em capim-elefante cv. cameroon submetido a estratégias de pastejo rotativo. Capítulo 1: Neste estudo foram avaliadas duas estratégias de manejo de pastejo: meta de pré-pastejo de 95% versus máxima interceptação luminosa (IL). Em sistemas intensivos de produção de leite à pasto, o manejo baseado no IL95% permite que vacas tenham acesso a pastos com maior relação folha: colmo, menores perdas de forragem, resultando em uma forragem com melhor composição química. Os animais pastejando forragem com IL95% tiveram maior consumo de matéria seca e energia, com maior produção de leite por vaca e taxa de lotação resultando em maior produção de leite por área. Além disso, a estratégia permite a diminuição das emissões de metano por consumo de energia líquida quando comparado a máxima IL. No entanto, a eficiência do uso de N não aumentou com essa prática de manejo. Capítulo 2: O objetivo do segundo estudo foi avaliar os efeitos do período de início pastejo (a.m. ou. p.m.) na produção de leite, variáveis ruminais e eficiência de uso de N de vacas leiteiras no terço médio da lactação. Em sistemas intensivos de produção de leite à pasto, o pastejo de novos piquetes no período da tarde não teve efeito sobre o consumo de forragem e produção de leite de vacas no terço médio da lactação. No entanto, o maior teor de carboidratos não fibrosos da forragem ao final do dia possibilitou o aumento da síntese de proteína microbiana, redução do nitrogênio uréico no leite e apresentou tendência para aumento da produção de proteína e caseína do leite em comparação à vacas que iniciaram o pastejo no período da manhã. Ao longo dos estudos desta tese houve uma melhora no valor nutritivo da forragem adotando IL95% e da forragem pastejada no período da tarde. Assim, o pastejo no período da tarde deve ser adotado juntamente com IL95% como ajuste fino em sistemas intensivos de produção de leite à base de pasto.
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Proposta de diretrizes para capacitação de “verificadores de relatórios de inventário de emissões de GEE”Andrade, Edson Carlos Santos de 01 July 2017 (has links)
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Previous issue date: 2017-07-01 / O Tratado de Kyoto concluiu que as mudanças climáticas têm, nas ações do homem, uma das causas do descontrole do efeito estufa, através das emissões em excesso “Gases de Efeito Estufa (GEE)”. O objetivo é reduzir essas emissões, cuja meta foi estabelecida para 2030, e realizar inventários é monitorar o quanto cada país está emitindo. As empresas fazem os Inventários, providenciam que os mesmos sejam verificados por profissionais de órgãos de terceira parte. Neste contexto, o objetivo desta pesquisa é propor diretrizes para a capacitação desses verificadores. Como metodologia, foi realizada revisão da literatura, que fez abordagem sobre cada etapa do processo. As obras de autores e normas suportam a sistemática necessária para elaboração do inventário e sua verificação. Competências necessárias são enfatizadas, segundo abordagem moderna onde Conhecimento, Habilidade e Atitude (CHA) conceituam o modelo de Competência a ser seguido pelos profissionais envolvidos. A metodologia aplicada na pesquisa também contempla característica descritiva e são utilizadas ferramentas, tais como questionários que fazem uso de métodos qualitativo e quantitativo. Através da pesquisa verificou-se a necessidade de melhoria da capacitação dos Verificadores, pois na visão dos Avaliadores do INMETRO, as não conformidades abertas no processo de avaliação dos organismos, grande parte destas, relacionam-se aos verificadores. Quanto à Habilidade observou-se gaps relacionados à liderança e visão sistêmica e à dimensão Atitude, que é a necessidade do verificador ser aberto a feedbacks. Quanto à diversidade dos segmentos a elaborarem inventários, todos colocaram que interatividade dos verificadores e treinamentos podem minimizar tal dificuldade. Os objetivos foram atingidos e aspectos foram colocados para a melhoria do processo e, consequentemente, com vistas a aumentar a credibilidade dos Inventários de Emissões de GEE / The Kyoto Treaty concluded that climate change have on the actions of man, one of the causes of the lack of control of the greenhouse effect, through excessive emissions "of Greenhouse Gases (GHG). The objective is to reduce these emissions, whose goal was set for 2030 and perform inventories is how to monitor how much each country is sending. Companies make inventories ensure that they are checked by professional third-party organ. In this context, the objective of this research is to propose guidelines for the training of these testers. How methodology literature review was carried out which did approach on each step of the process. The works of authors and systematic support standards required for your verification and inventory. Skills are emphasized, according to modern approach where Knowledge, skill and attitude, conceptualize the competency model to be followed by the professionals involved. The methodology applied in research also includes descriptive feature and are used tools such as questionnaires that make use of qualitative and quantitative methods. Through research it was found the need to improve the training of checkers, because in the view of the evaluators from INMETRO, the non-conformities opened in the evaluation process, a large part of these, relating to checkers. As for the observed Skill gaps related to: leadership and systemic view and the size is the need of the Verifier be open to feedback. As the diversity of segments to draw up inventories, all put to interactivity of the testers and training can minimize such difficulty. The objectives were achieved and aspects were put to improve the process, consequently increasing the credibility of GHG Emission Inventories.
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Modeling Electric Vehicle Energy Demand and Regional Electricity Generation Dispatch for New England and New YorkHowerter, Sarah E 01 January 2019 (has links)
The transportation sector is a largest emitter of greenhouse gases in the U.S., accounting for 28.6% of all 2016 emissions, the majority of which come from the passenger vehicle fleet [1,2]. One major technology that is being investigated by researchers, planners, and policy makers to help lower the emissions from the transportation sector is the plug-in electric vehicle (PEV). The focus of this work is to investigate and model the impacts of increased levels of PEVs on the regional electric power grid and on the net change in CO2 emissions due to the decrease tailpipe emissions and the increase in electricity generation under current emissions caps. The study scope includes all of New England and New York state, modeled as one system of electricity supply and demand, which includes the estimated 2030 baseline demand and the cur- rent generation capacity plus increased renewable capacity to meet state Renewable Portfolio Standard targets for 2030.
The models presented here include fully electric vehicles and plug-in hybrids, public charging infrastructure scenarios, hourly charging demand, solar and wind generation and capacity factors, and real-world travel derived from the 2016-2017 National Household Travel Survey. We make certain assumptions, informed by the literature, with the goal of creating a modeling methodology to improve the estimation of hourly PEV charging demand for input into regional electric sector dispatch models. The methodology included novel stochastic processes, considered seasonal and weekday versus weekend differences in travel, and did not force the PEV battery state-of-charge to be full at any specific time of day.
The results support the need for public charging infrastructure, specifically at workplaces, with the “work” infrastructure scenario shifting more of the unmanaged charging demand to daylight hours when solar generation could be utilized. Workplace charging accounted for 40% of all non-home charging demand in the scenario where charging infrastructure was “universally” available. Under the increased renewable fuel portfolio, the reduction in average CO2 emissions ranged from 90 to 92% for the vehicles converted from ICEV to PEV. The total emissions reduced for 15% PEV penetration and universally available charging infrastructure was 5.85 million metric tons, 5.27% of system-wide emissions.
The results support the premise of plug-in electric vehicles being an important strategy for the reduction of CO2 emissions in our study region. Future investigation into the extent of reductions possible with both the optimization of charging schedules through pricing or other mechanisms and the modeling of grid level energy storage is warranted. Additional model development should include a sensitivity analysis of the PEV charging demand model parameters, and better data on the charging behavior of PEV owners as they continue to penetrate the market at higher rates.
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Subsurface re-injection of carbon dioxide for greenhouse gas control: influence of formation heterogeneity on reservoir performanceFlett, Matthew Alexander January 2008 (has links)
The injection of carbon dioxide (CO2) into saline formations for the purpose of limiting greenhouse gas emissions has been proposed as an alternative to the atmospheric venting of carbon dioxide. In the evaluation process for selecting a potential target saline formation for the disposal of carbon dioxide, flow characterisation of the disposed plume should be undertaken by reservoir simulation of the target formation. The movement of injected carbon dioxide in the saline formation is influenced by many factors including the physics of carbon dioxide at deep formation depths and pressure, physical interactions with formation rock and pore water and variations in the rock flow pathways through changes in formation heterogeneity. This thesis investigates the roles of physical interactions on the disposal of carbon dioxide and the ability to contain the injected gas through evaluation of trapping mechanisms such as dissolution of CO2 in formation water and residual gas trapping through the process of gas-water relative permeability hysteresis. Variable formation heterogeneity is evaluated for its impact on the migration of injected CO2 plume movement and the role of formation heterogeneity in impeding or accelerating the immobilisation of injected carbon dioxide. Multiple reservoir simulation studies were conducted to evaluate, initially, the role of different trapping mechanisms in immobilising the movement of injected carbon dioxide and subsequently, the role of variations in formation rock in the migration and trapping of and injected plume of carbon dioxide. The major simulation study shows that the selection process for identifying appropriate saline formations should not only consider their size and permeability but should also consider their degree of heterogeneity endemic to the formation. / A set of reservoir performance metrics were developed for the CO2 disposal projects. The metrics were applied to compare plume migration of injected CO2 (both vertically and laterally) and containment (through dissolution and residual phase trapping) in these studies. The findings demonstrate how formation heterogeneity has a significant impact on the subsurface behaviour of the carbon dioxide. Formation dip influences the rate of migration, with low formation dipping reservoirs having slower rates of vertical migration. Increasing the tortuousity of the migration flow path by either increasing the shale (non-reservoir) content or lengthening the shale baffles in the formation (corresponding to a gradual decrease in reservoir quality), can progressively inhibit the vertical flow of the plume whilst promoting its lateral flow. The increase in the tortuosity of the CO2 migration pathway delays the migration of CO2 and increases the residence time for the CO2 in the formation. Thus, formation heterogeneity impedes the onset of residual gas trapping through hysteresis effects. Ultimately less carbon dioxide is likely to collect under the seal in heterogeneous formations due to increased reservoir contact and long residence times, thereby reducing the risk of seepage to overlying formations. / Given sufficient permeability for economic injection of CO2, then low to mid net-to-gross heterogeneous saline formations with low formation dip and lengthy intra-bedded shales are desirable for selection for the geological disposal of CO2. Detailed reservoir characterisation of any potential geological disposal saline formations is required in order to accurately predict the range of outcomes in the long term flow characterisation of injected CO2 into those formations.
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