Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
1.
Artigo | IMSEAR | ID: sea-230842

RESUMO

Energy consumption plays a pivotal role in the development of societies. Sustainable Energy Resources are vital inputs for daily life, and energy and industrial products are essential for economic growth (Ministry of Energy and Natural Resources, 2022). Consequently, those responsible for managing a country's energy sector must ensure the uninterrupted, reliable, timely, clean, and affordable supply of energy, as well as diversify energy sources to enhance energy security.The concept of "sustainable development" has emerged in response to the need to prevent irreversible environmental damage caused by conventional energy sources and outdated technologies while ensuring access to energy as a fundamental human right under optimal conditions (Pamir, N 2005). Developed societies have transitioned from planning based solely on energy source acquisition and production to a planning approach that carefully considers the energy-economy-ecology balance (3E) while taking into account resource diversity and geopolitical realities (Energy Policies and Global Developments, emo.org.tr).Turkey remains heavily dependent on energy imports, accounting for approximately 74% of its energy needs (Ministry of Energy and Natural Resources, 2023). The multifaceted nature of Turkey's energy strategy and its energy dependence emphasize the importance of international relations in this field.U.S. energy policies have global ramifications, particularly in areas such as energy resource utilization, energy trade, and energy independence (Ministry of Energy and Natural Resources, 2022). U.S. energy policies play a significant role in international relations, impacting relationships with other countries, especially in matters related to energy exports and imports.In Europe, there is uneven progress towards clean electricity, with both successes and challenges in transitioning to a low-carbon energy system. While the European energy sector has taken significant steps towards decarbonization, there has been limited progress in some countries, and much more progress is needed. Achieving a fully decarbonized energy system in Europe requires united efforts and coordination to address the challenges posed by fossil fuel dependence and climate change.

2.
Artigo | IMSEAR | ID: sea-230180

RESUMO

The provision of energy infrastructure is essential for economic growth, social cohesion, and environmental sustainability. This paper served to evaluate the challenges associated with energy development and transition across the African continent and proffer opportunities for sustainable transition. Extensive use of documents, official data and statistics on different aspects of the African society was employed for this study. Exploratory documentary research materials, extant literature, publications, journals and articles on the current status of energy generation and delivery in Africa, the concept of renewable energy pathways, the need for energy transitions and the major strategies in place in Africa and around the world were important study areas for this work. Exploratory research method and systematic review approach were used to study the energy transition techniques, challenges and opportunities across Africa. Important research points were the concept of renewable energy pathways, the need for energy transitions, the major strategies in place in Africa and around the world to meet with the zero-carbon emission strategies of 2050, the future directions in energy provision—renewable energy development, economic diversification and energy-efficiency in Africa and the effects of energy transition on the social, political, economic and cultural spheres across Africa. Results obtained showed that energy transition in Africa is rapidly growing, though differently across the region, following huge investments made into the renewable energy sector, legislations and policies on the fossil fuel usage and carbon emission and introduction of better and more efficient systems. Nevertheless, the challenges reported in this studying plaguing the African energy transition come in five spheres: social, political, economic, technological and cultural. These challenges seem to be ancient, ubiquitous and multidimensional. Harnessing the opportunities in renewable energy will surely boost the economy of the different case study countries. A willing socio-political disposition towards renewable energy sources, increased investment plan for cleaner energy, reduced emphasis on fossil fuels and private-public sector collaboration will surely be giant steps to tapping into the numerous benefits of renewable energy sources. Energy transition in African countries can only be achieved under the auspices of a strong political will, social drive, cultural motivation and technological inclination towards a sustainable transition to cleaner renewable energy sources and less focus on fossil fuels.

3.
Artigo | IMSEAR | ID: sea-221463

RESUMO

Fossil fuels, such as coal and natural gas are typically used to generate electricity. Fossil fuels are non-renewable resources and harmful to the environment as they release greenhouse gases when burned. With the increased demand of cleaner sources for electricity generation, renewable sources need to be adopted. In India, Tirunelveli District, solar energy has been used in numerous industrial buildings as a source of electricity generation since the country benefits from high solar radiation throughout the year. However, solar energy is still not used in residential buildings despite a wide interest from the sector. This paper identified and assessed the barriers to implementing solar energy in residential buildings from the perspective of homeowners in India, Tirunelveli District. Based on a literature search followed by a ranking and factor analysis of data from a questionnaire survey, key barriers were identified. Ninety-one responses from residents in India, Tirunelveli District were obtained. The questionnaire results showed that the main barriers to adopting solar systems are financial limitations followed by limited solar suppliers in the region and lack of awareness of government incentives. The results of this study could be used to help suppliers and industrial stakeholders in understanding the major barriers and the government to put forward policies to promote solar systems for electricity generation in residential buildings.

4.
Artigo | IMSEAR | ID: sea-218859

RESUMO

Environmental laws and energy laws have always been a topic of debate among policymakers, legal scholars, and environmentalists. While environmental laws aim to protect the environment and natural resources, energy laws are designed to ensure a reliable and secure energy supply. The Indian government has implemented several laws and policies to protect the environment and promote renewable energy in recent years. This paper provides a comparative analysis of environmental laws and energy laws generally as well as in India to understand the effectiveness of the legal framework governing these areas and identify areas where improvements can be made. The Environmental Protection Act, Wildlife Protection Act, and Water (Prevention and Control of Pollution) Act are the major environmental laws in India, while the Electricity Act, National Tariff Policy, and National Electricity Policy govern the energy sector. Despite the efforts made by the government, India still faces several environmental and energy challenges, including air pollution, water pollution, deforestation, high cost of renewable energy, and limited availability of energy storage solutions. The paper highlights the need for the Indian government to take bold steps to enforce environmental laws and promote renewable energy to ensure a sustainable and secure energy future for its citizens while protecting the environment for future generations. The paper concludes that both environmental laws and energy laws are important for ensuring a sustainable future, and that there is a need to strike a balance between the two.

5.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1536165

RESUMO

Debido a que el futuro del petróleo es incierto, en la búsqueda de los combustibles alternativos se ha encontrado que el alcohol es un fuerte candidato como combustible; los alcoholes inferiores más representativos son el metanol y el etanol, los cuales han demostrado en general baja miscibilidad, por lo que pueden generar una separación de fases al ser mezclados después de un cierto tiempo. La única manera de emplearlos en un motor diésel es mezclándolos con biodiésel o con surfactantes. Por el contrario, los alcoholes superiores tienen características más adecuadas para ser mezclados o empleados en el motor diésel. Por su parte, los éteres son una buena opción cuando se trate de combustión piloto en que se considere emplear combustibles gaseosos como el biogás o el syngas en motor diésel dual. En esta investigación se exploran las alternativas que existen para mejorar las características del alcohol, por ejemplo, mezclarlo con biodiésel, biogás, agua o nanopartículas, y también se analizan las emisiones que se producen con las mezclas generadas. El objetivo es indagar las diferencias entre los alcoholes inferiores y los alcoholes superiores de cadena larga, así como las mezclas que se pueden generar para mejorar el rendimiento del motor. Los resultados afirman que los alcoholes de cadena larga tienen mejores propiedades físico-químicas que los alcoholes de cadena corta; el butanol es el único combustible que puede ser transportado y almacenado en las mismas redes de tuberías actuales de los productos petroleros existentes. También se cuenta con la opción de usar el alcohol como combustible piloto en un motor diésel dual; esto puede servir para aplicar una enorme variedad de combustibles tanto líquidos como gaseosos, lo cual hace que las opciones en su aplicación se incrementen. Como conclusión, se recomienda explorar nuevas mezclas analizando sus sinergias con varios combustibles alternativos. La posibilidad de realizar el diesterol-BED genera resultados muy alentadores, por lo que se recomienda seguir haciendo análisis sobre esa línea para encontrar la mezcla óptima.


As the future of oil is uncertain and in the search for alternative fuels, it has been found that alcohol is a strong candidate as a fuel. The most representative lower alcohols are methanol and ethanol, which have generally demonstrated low miscibility so that they can generate phase separation when mixed after a certain period of time. The only way to use them in a diesel engine is to mix them with biodiesel or surfactants. By contrast, higher alcohols have more suitable characteristics to be mixed or used in the diesel engine. In the case of ethers they are a good option when it comes to pilot combustion considering using gaseous fuels such as biogas or syngas in dual diesel engine. This research explores the alternatives that exist to improve the characteristics of alcohol as it can be mixed with biodiesel, biogas, water or nanoparticles and also analyzes the emissions that are generated with the mixtures. The aim of this research is to explore the differences between lower alcohols and long chain upper alcohols, as well as the mixtures that can be generated to improve engine performance. The results of this research claim that long-chain alcohols have better physico-chemical properties than short-chain alcohols, butanol being the only fuel that can be transported and stored in the same current pipeline networks of existing oil products. There is also the option to use alcohol as a pilot fuel in a dual diesel engine. The latter can be used to apply a huge variety of both liquid and gaseous fuels, this makes the options in its application increase. As a conclusion of this work, it is recommended to explore new mixtures analyzing their synergies with various alternative fuels. The possibility of performing diesterol-BED generates very encouraging results, therefore it is recommended to continue to perform analyses on that line to find the optimal mixture.


Na busca por combustíveis alternativos porque o futuro do petróleo é incerto, verificou-se que o álcool é um forte candidato como combustível, onde os álcoois inferiores mais representativos são o metanol e o etanol, que, em geral, demonstraram baixa miscibilidade, de modo que podem gerar separação de fase quando misturadas após um determinado período de tempo, a única forma de as utilizar num motor diesel é misturá-las com biodiesel ou tensioactivos, pelo contrário, os álcoois superiores têm características mais adequadas para serem misturados ou utilizados no motor diesel, no caso dos éteres, são uma boa opção quando se trata de combustão piloto, considerando a utilização de combustíveis gasosos, como biogás ou gás de síntese em motores a diesel duplos, esta pesquisa explora as várias alternativas que existem para melhorar as características do álcool, pois pode ser misturado com biodiesel, biogás, água ou nanopartículas e também analisa as emissões que são geradas com as misturas geradas, O objetivo desta pesquisa é explorar as diferenças entre álcoois inferiores e álcoois superiores de cadeia longa, bem como as misturas que podem ser geradas para melhorar o desempenho do motor. Os resultados desta pesquisa afirmam que os álcoois de cadeia longa têm melhores propriedades físico-químicas do que os álcoois de cadeia curta, sendo o butanol o único combustível que pode ser transportado e armazenado nas mesmas redes de gasodutos atuais que os produtos petrolíferos existentes, há também a opção de usar álcool como combustível piloto em um motor diesel duplo, Este último pode ser usado para aplicar uma enorme variedade de combustíveis líquidos e gasosos, o que aumenta as opções em sua aplicação. Como conclusão deste trabalho recomenda-se explorar novas misturas analisando suas sinergias com vários combustíveis alternativos, a possibilidade de realizar diesterol-BED gera resultados muito encorajadores, portanto, recomenda-se continuar a realizar análises nessa linha para encontrar a mistura ideal.

6.
Artigo em Inglês | WPRIM | ID: wpr-979368

RESUMO

Aims@#The primary aim of this study was to utilize abundant palm oil mill effluent (POME) waste and turn it into a value-added product of biomass fuel with high calorific energy value (CEV) via fermentation and drying process, then simultaneously reduce abundant liquid waste.@*Methodology and results@#POME is available abundantly in Malaysia and only a small portion of it is utilized to produce other value-added products. In this study, fermentation of POME in the presence of bacteria (Lysinibacillus sp.) and fungus (Aspergillus flavus) separately at 37 °C, 180 rpm for 5 days, followed by overnight oven-drying at 85 °C was conducted. Four fermentation medium conditions were performed, viz.: (1) autoclaved POME, (2) autoclaved POME with the addition of Lysinibacillus sp., (3) autoclaved POME with the addition of A. flavus and (4) POME as it is (non-sterile).@*Conclusion, significance and impact of study@#Among all conditions, fermentation utilizing autoclaved POME in the presence of A. flavus evinced the highest CEV of 25.18 MJ/kg. The fermentation in the presence of Lysinibacillus sp. strain revealed high COD and BOD removal efficiency of 59.20% and 320.44 mg/L as well as the highest reduction of oils and grease among other groups with the value of 15.84%. Future research directions are proposed for the elucidation of co-fermentation in the presence of both Lysinibacillus sp. and A. flavus.


Assuntos
Óleo de Palmeira , Biomassa , Biocombustíveis , Eliminação de Resíduos Líquidos
7.
Ciênc. rural (Online) ; 52(2): e20201104, 2022. tab, graf, ilus, mapas
Artigo em Inglês | VETINDEX, LILACS | ID: biblio-1286050

RESUMO

Continued unsustainable exploitation of natural resources promotes environmental degradation and threatens the preservation of dry forests around the world. This situation exposes the fragility and the necessity to study landscape transformations. In addition, it is necessary to consider the biomass quantity and to establish strategies to monitor natural and anthropic disturbances. Thus, this research analyzed the relationship between vegetation index and the estimated biomass using allometric equations in different Brazilian caatinga forest areas from satellite images. This procedure is performed by estimating the biomass from 9 dry tropical forest fragments using allometric equations. Area delimitations were obtained from the Embrapa collection of dendrometric data collected in the period between 2011 and 2012. Spectral variables were obtained from the orthorectified images of the RapidEye satellite. The aboveground biomass ranged from 6.88 to 123.82 Mg.ha-1. SAVI values were L = 1 and L = 0.5, while NDVI and EVI ranged from 0.1835 to 0.4294, 0.2197 to 0.5019, 0.3622 to 0.7584, and 0.0987 to 0.3169, respectively. Relationships among the estimated biomass and the vegetation indexes were moderate, with correlation coefficients (Rs) varying between 0.64 and 0.58. The best adjusted equation was the SAVI equation, for which the coefficient of determination was R² = 0.50, R2aj = 0.49, RMSE = 17.18 Mg.ha-1 and mean absolute error of prediction (MAE) = 14.07 Mg.ha-1, confirming the importance of the Savi index in estimating the caatinga aboveground biomass.


A exploração contínua e insustentável dos recursos naturais promove a degradação ambiental e ameaça a conservação das florestas secas no mundo. Essa situação expõe a fragilidade e a necessidade de estudar as transformações da paisagem. É necessário considerar o quantitativo de biomassa e o estabelecimento de estratégias para monitorar distúrbios naturais e antrópicos. Assim, este trabalho teve como objetivo analisar a relação entre o índice de vegetação e a biomassa estimada por meio de equações alométricas em diferentes áreas da caatinga brasileira a partir de imagens de satélite. Este procedimento é realizado estimando-se a biomassa de nove fragmentos de floresta tropical seca com o uso em equações alométricas. As delimitações das áreas foram obtidas da coleção da Empresa Brasileira de Pesquisa Agropecuária, a partir dos dados dendrométricos coletados no período entre 2011 e 2012. As variáveis espectrais foram obtidas a partir das imagens ortorretificadas do satélite RapidEye. A biomassa acima do solo variou de 6,88 a 123,82 Mg.ha-1. Os valores de SAVI para os coeficientes L = 1 e L = 0,5, NDVI e EVI variaram de 0,1835 a 0,4294, 0,2197 a 0,5019, 0,3622 a 0,7584 e 0,0987 a 0,3169, respectivamente. As relações entre a biomassa estimada e os índices de vegetação foram moderadas, com coeficiente de correlação (rs) variando entre 0,64 e 0,58. A equação mais bem ajustada foi a Equação do SAVI, com coeficiente de determinação foi R² = 0,50, R2aj = 0.49, RMSE = 17.18 Mg.ha-1 e erro médio absoluto de predição (MAE) = 14.07 Mg.ha-1, confirmando a importância do índice SAVI na estimativa da biomassa aérea da Caatinga.


Assuntos
Florestas , Técnicas de Apoio para a Decisão , Biomassa , Energia Renovável , Zona Semiárida , Tecnologia de Sensoriamento Remoto
8.
Braz. arch. biol. technol ; Braz. arch. biol. technol;64(spe): e21200045, 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1278460

RESUMO

Abstract Natural gas steam reforming is commonly used for hydrogen production. However, research has shown that ethanol autothermal reforming can produce cleaner hydrogen gas efficiently. Despite this, there is a lack of studies on the energy self-sufficiency conditions of the ethanol autothermal reform. In this paper, we use simulations and the Response Surface Methodology (RSM) for the multivariate analysis of the energy self-sufficiency conditions in this process. First, we constructed and validated an industrial flowchart. After that, RSM allowed us to assess the process variables effects. The process variables studied were temperature (0 to 1000 ºC), pressure (20 to 30 bar), steam/ethanol ratio (2 to 5 mol/mol) and O2/ethanol ratio (0 to 1.5 mol/mol). We observe that the temperature and steam/ethanol ratio increase have a positive effect on hydrogen production. On the contrary, the O2/ethanol ratio increase has a negative effect, and the pressure increase is not statistically significant on hydrogen production. Therefore, the pressure was used at its minimum level (20 bar) while the temperature and the steam/ethanol ratio at its maximum levels (1000 ºC and 5 mol/mol). We also evaluated the energy consumption for the Autothermal Reactor (ATR). The reactor consumed 477.92 kJ/mol ethanol to produce 5.12 mol H2/mol ethanol when we use 1000 ºC, 20 bar, steam/ethanol 5 mol/mol, and O2/ethanol 0 mol/mol. ATR's energy self-sufficiency is achieved by using 1000 ºC, 20 bar, steam/ethanol 5 mol/mol, and O2/ethanol 0.86 mol/mol. In these conditions, 3.95 mol H2/mol ethanol is produced with 0 kJ/mol ethanol.


Assuntos
Etanol , Gás Natural , Energia Renovável , Hidrogênio , Exercício de Simulação , Modelos Anatômicos
9.
Braz. arch. biol. technol ; Braz. arch. biol. technol;64(spe): e21200734, 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1285561

RESUMO

Abstract The State of Paraná stands out in Brazil for its hydraulic potential for electricity generation. Furthermore, the State also shows potential for the use of other sources of energy, such as solar energy, biogas and biomass. The study traces the profile of electric energy consumption and compiles analysis of the alternative energy potentials of Paraná on the use of solar energy, the biomass of forest residues and agricultural crops, the generation of biogas through the residues of farmed animals and the urban solids residues. The work took account for the estimates, the logistical limitations for the biomass or biogas collection and the real availability of the wastes in terms of viability of exploration through distributed generation plants. The use of the business analytics software Tableau Desktop 2020.3.2® made possible the open data analysis at the municipal level. The paper provides realistic estimates about the feasibility of the use of alternative energy sources in the State of Paraná.


Assuntos
Fontes Geradoras de Energia , Energia Renovável , Brasil , Análise de Dados
10.
Ciênc. rural (Online) ; 51(12): e20200320, 2021. tab, graf
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1339651

RESUMO

ABSTRACT: The generation of wastes in poultry abattoirs has increased considerably in recent years due to the growing demand for chicken meat. This fact, combined with the current need for developing new forms of renewable energy from biomass, and the lack of disposal facilities, motivated this study. We determined the technical feasibility of the barbecue charcoal production using briquettes produced with different blends containing sludge from a poultry abattoir and Pinus spp. shavings. To that end, we have mixed both residues by gradually adding 10 to 90 % of sludge in the blends, which resulted in 9 treatments containing sludge, and 1 containing only shavings. After that, we produced four briquettes of each treatment and charred them by using a heating ramp. After charring, we submitted the charcoal to the analyzes of Moisture Content (MC), Bulk Density (BD), Compressive Resistance (CR), Gross Calorific Value (GCV), and Proximate Analysis (PA). We calculated the Gravimetric Yield (GY) and the Energy Density (ED) by using the results from the other analyzes. Results showed that the CR, the GCV, the Volatile Matter (VM), and the Fixed Carbon Content (FC) of the charcoals decreased by increasing the proportion of sludge in the blends. However, the charcoals' bulk density (BD) increased, which also increased its energy density (ED) and ash content (AC). The best blend to produce charcoal for household use was the one containing 90 % of sludge and 10 % of Pinus spp. shavings.


RESUMO: A geração de efluentes nos abatedouros de aves aumentou consideravelmente nos últimos anos devido à crescente demanda por carne de frango. Esse fato, combinado com a atual necessidade de desenvolvimento de novas formas de energia renovável a partir da biomassa e a falta de instalações de descarte para isso, motivou este estudo. O objetivo foi determinar a viabilidade técnica da produção de carvão para churrasco, usando briquetes produzidos com diferentes misturas contendo lodo de abatedouro de aves e maravalha de Pinus spp. Para determinar a viabilidade técnica, misturou-se os dois resíduos adicionando gradualmente 10-90 % de lodo nas misturas, o que resultou em nove tratamentos contendo lodo e um contendo apenas maravalha. Depois disso, quatro briquetes de cada tratamento foram produzidos e carbonizados. Após a carbonização, os carvões foram submetidos às análises de teor de umidade (MC), densidade a granel (BD), resistência à compressão (CS), poder calorífico superior (GCV) e análise imediata (PA). O Rendimento Gravimétrico (GY) e a Densidade Energética (DE) de cada tratamento foram calculados usando os resultados das outras análises. A resistência à compressão (CR), o poder calorífico superior (GCV), o teor de voláteis (VM) e o teor de carbono fixo (FC) do carvão diminuiu com o aumento da proporção de lodo nas misturas. A densidade aparente (BD), o teor de cinzas (AC) e a densidade energética (ED) aumentaram com o acréscimo de lodo na mistura. A melhor mistura para a produção de carvão de briquetes para uso doméstico foi a que teve 90 % de lodo e 10 % de partículas de Pinus.

11.
Braz. arch. biol. technol ; Braz. arch. biol. technol;64: e21200781, 2021. tab
Artigo em Inglês | LILACS | ID: biblio-1339313

RESUMO

Abstract Fruit juice industry generates massive amount of lignocellulosic by-products annually which are excellent raw materials for bioethanol production. In the current study, bioethanol production from apricot (Prunus armeniaca) pomace by Kluyveromyces marxianus was investigated for the first time. Some key parameters for fermentation such as pretreatment methods, biomass and cellulase loading and time, were optimized. Kluyveromyces marxianus produced 30.09 g/L ethanol in the 20% washed apricot pomace and 120 FPU/g cellulose enzyme loading. The highest theoretical yield and Y P/S values were also observed as 94.7% and 0.50 g/g, respectively, when 15 FPU/g cellulose enzyme was used. These results depict that apricot pomace is a promising feedstock for bioethanol production.


Assuntos
Kluyveromyces , Biocombustíveis , Energia Renovável , Prunus armeniaca
12.
Braz. arch. biol. technol ; Braz. arch. biol. technol;64: e21200100, 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1153289

RESUMO

HIGHLIGHTS Comparative study of the operation of eight real cases of systems installed in Paraná. There is a convergence between the values estimated by the Atlas and the ones calculated. It was possible to identify the cities that presented the greatest figures of merit.


Abstract With the development of renewable energies in the world, there is also an increase in solar photovoltaic systems globally. In Brazil, and in the state of Paraná, there is an exponential growth of this form of energy generation, which causes the necessity to study the performance of the installed systems. Therefore, this article analyzed eight photovoltaic systems installed in the state of Paraná, under the aspect of figures of merit parameters, through calculations of final yield, performance ratio and capacity factor. In addition, the calculated values were compared to the values estimated by the Solar Energy Atlas of the State of Paraná. As a result, the largest average differences in final yield, between the calculations and the Atlas, were found in the cities of Cascavel, while the smallest were observed in Goioerê.


Assuntos
Humanos , Energia Solar/estatística & dados numéricos , Energia Fotovoltaica/métodos , Brasil , Consumo de Energia/estatística & dados numéricos , Energia Fotovoltaica/estatística & dados numéricos , Modelos Teóricos
13.
Artigo | IMSEAR | ID: sea-204838

RESUMO

Climate change is not just a global threat, but an unprecedented public health emergency. Climate change has been characterized by global warming, increased frequency and intensity of precipitation, catastrophic wind events, and extreme weather events, associated with heat waves, flooding disasters, and prolonged droughts. The United Nations Framework Convention on Climate Change (UNFCCC) attributes climate change to anthropogenic or human activities. Globally, the most vulnerable regions, to hazardous impacts of climate change, are the mega-deltas of Africa and Asia, due to high exposure to sea level rise, storm surges, coastal erosion, and river flooding, compounded by increasing human-induced pressures on coastal areas. The vulnerability of the Niger Delta region, is exacerbated by oil spillages, gas flaring. and environmental degradation. This review article highlights, the urgent implementation of mitigation and adaptation as opportunities for full transformation of economies, of the Niger delta region, in line with sustainable developmental goals (SDGs).

14.
Artigo | IMSEAR | ID: sea-204829

RESUMO

Scrutiny and analysis of various energy applications show that the energy conversion to useful work or new products has been systematically inefficient. The global energy’s total effective conversion efficiency is estimated only about 20% and about 80% of the energy has been discharged into the environment. It is this energy that leads to the unbalance of the climate system’s energy budget balance and causes the global warming. This article presents a simple equivalent climate change model to track the past global warming and to predict the future change trend at the global scale. The model comprises of an equivalent climate change surface air boundary layer, an equivalent climate change land surface boundary layer and an equivalent climate change seawaters surface boundary layer. It produces unique definitive relationships between the temperature changes and the heat entered the air, waters and land. The model can also be used to forecast future non-renewable energy consumption needed to keep the temperature rising under Paris Accord. Analysis of currently available data by using this model confirms that temperature changes in air, seawaters and land closely correlate to the amount of heat discharged into the climate system from human activities. NASA and NOAA’s observations of temperature anomalies for the surface air, sea surface and land surface are well consistent with the temperature changes calculated by this model, especially the calculated results at the depth of 70 meters of the surface air boundary layer and NASA’s Lowess Smoothing trend are very close. Flaring intensifies global warming. Reducing use of fossil fuels, nuclear and geothermal energies, developing surface renewable energies and increasing energy’s total effective conversion efficiency and thus reducing the amount of residual/waste energy are the paths to effectively and efficiently control global warming.

15.
Eng. sanit. ambient ; Eng. sanit. ambient;24(5): 861-873, set.-out. 2019. graf
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1056090

RESUMO

RESUMO A falta de água é um problema que afeta muitas regiões do nosso planeta, especialmente ilhas e locais de clima muito seco. Especialistas dizem que essa situação irá se agravar e que, em 2025, cerca de 1,8 bilhão de pessoas sofrerão com essa escassez. Embora métodos tradicionais de dessalinização sejam alternativas bem conhecidas e implantadas para obtenção de água potável, eles não são sustentáveis ambientalmente, porque são geralmente supridos por combustíveis não renováveis, cuja queima intensifica o efeito estufa, trazendo desequilíbrios ao meio ambiente. Outra opção que vem sendo desenvolvida ao longo dos anos é a dessalinização por energia solar. Como se trata de uma forma de energia limpa, abundante e renovável, esse método já é muito indicado em regiões isoladas, de baixa e média demanda. Algumas técnicas são apresentadas neste trabalho, que foca o método de dessalinização por umidificação e desumidificação (DSUD). Essa técnica tem se mostrado a mais eficiente, devido ao seu reaproveitamento de energia. Há ainda muito o que melhorar para viabilizar a sua implantação em grande escala, principalmente em termos de produção de água, energia específica requerida e custo específico de produção de água. Entretanto, a DSUD já se mostrou uma técnica sustentável, promissora, de custo razoável e funcionamento simples. Dessa forma, os autores incentivam maiores investimentos em pesquisas no Brasil na área de dessalinização solar e aproveitamento dos rejeitos do processo, visando à produção de água purificada nas regiões brasileiras que têm deficiência em água potável.


ABSTRACT The lack of water is a problem that affects many regions in our planet, specially in very dry places and isles. Experts say that this situation will worsen, and that by 2025 about 1.8 billion people will suffer with water scarcity. Although traditional desalination methods are well-known and implemented alternatives to obtain fresh drinking water, they are not environmentally sustainable, because they are generally supplied by non-renewable fuels, whose combustion intensifies the greenhouse effect, causing disequilibrium to the environment. Another option that has been developed along the years is the desalination by solar energy. Since it is a clean, abundant and renewable type of energy, it is already a good option to isolated regions, whose demand is low or medium. Some technics are shown in this work, which focuses on the humidification-dehumidification desalination method. This technique has shown to be the most efficient one, due to its energy reuse. There is still a long way to go in order to make it viable in large scale, especially in terms of water production, specific energy requirement and specific cost of water production. However, solar desalination by humidification-dehumidification has proven to be a sustainable, promising technic which is reasonably costly and simple to operate. Therefore, the authors encourage more investments in researches in Brazil in the area of solar desalination and use of its rejects, aiming at the production of fresh water in Brazilian regions lacking it.

16.
Electron. j. biotechnol ; Electron. j. biotechnol;38: 1-9, Mar. 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1051273

RESUMO

BACKGROUND: Microbial oils produced by diverse microorganisms are being considered as alternative sources of triglycerides for biodiesel production. However, the standalone production of biodiesel from microorganisms is not currently economically feasible. In case of yeasts, the use of low-value nutrient sources in microbial production and the implementation of cost-efficient downstream processes could reduce costs and make microbial lipids competitive with other commodity-type oils in biodiesel production. Industrial biodiesel synthesis from oleaginous seeds is currently based on a multistep process. However, a simple process called in situ transesterification (ISTE), which takes place within the biomass without a previous lipid extraction step, is receiving increasing interest. In this work, the optimal conditions for an ISTE process to obtain biodiesel from previously selected oleaginous yeast (Rhodotorula graminis S1/S2) were defined using the response surface methodology (RSM). RESULTS: Using the RSM approach, the optimal conditions for the maximum yield with minimum reaction time included a methanol-to-biomass ratio of 60:1, 0.4 M H2SO4, and incubation at 70°C for 3 h. The optimized in situ process yield was significantly higher (123%) than that obtained with a two-step method in which fatty acids from saponifiable lipids were first extracted and then esterified with methanol. The composition of the fatty acid methyl ester mixture obtained from R. graminis S1/S2 by ISTE met Uruguayan standards for biodiesel. CONCLUSION: The characteristics achieved by the optimized method make microbial oil a potential alternative for biodiesel production from yeast at an industrial scale.


Assuntos
Leveduras/metabolismo , Biocombustíveis , Tempo de Reação , Rhodotorula , Biomassa , Meio Ambiente , Esterificação , Ésteres , Ácidos Graxos , Energia Renovável , Lipídeos , Metilação
17.
Eng. sanit. ambient ; Eng. sanit. ambient;24(1): 143-155, jan.-fev. 2019. tab, graf
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1001938

RESUMO

RESUMO O aproveitamento do biogás gerado a partir da decomposição da matéria orgânica dos resíduos sólidos urbanos (RSU), além de ser uma fonte renovável de energia, também contribui com a redução do lançamento de metano e do dióxido de carbono (CO2) na atmosfera, que são importantes gases de efeito estufa (GEE). No entanto, o biogás é pouco explorado no país e seu potencial continua sendo controverso, principalmente devido às diferentes metodologias de avaliação adotadas. A pesquisa realizada mostra que, entre 2004 e 2015, foram implantadas nos aterros de resíduos do País somente 9 usinas termelétricas, que juntas geram 86,3 MW de energia elétrica, e duas usinas que produzem biometano. Considerando as estimativas existentes, o Brasil explora somente de 7 a 20% do biogás produzido nos aterros de resíduos para fins energéticos.


ABSTRACT The use of biogas generated by the decomposition of organic matter from urban solid waste, besides being a renewable source of energy, also contributes to the reduction of the methane and carbon dioxide's release into the atmosphere, which are significant greenhouse effect gases (GHG). However, biogas is little explored in the country and its potential remains controversial, mainly due to the different adopted methodologies of evaluation. This research shows that, between 2004 and 2015, only nine thermoelectric plants were implanted in waste landfills in the country, which together generated 86.3MW of electricity and two plants that produced biomethane. Considering the existing estimates, Brazil exploits only 7 to 20% of the biogas produced in landfills for energy purposes.

18.
Artigo | IMSEAR | ID: sea-214154

RESUMO

Microbial fuel cells (MFCs) have the potential to convert organic substratesinto electricity thus facilitating the strategies of renewable energy production. In recentyears the exploration for newer energy resources for MFC has widened and in thiscontext, the use of glycerol in bioenergy production was investigated to check itsefficacy in electricity generation. Thus, the power generation of a double-chamberedMFC was observed with glycerol as the substrate and Citrobacter sp. as the bacteriumof interest. Here, the MFC system yielded a power density of 79.42 mW/m² with carboncloth as the electrodes and Nafion as the proton exchange membrane. Further, the MFCsystem was optimized for the ambient temperature, in which the maximum voltage andcurrent were obtained at 35⁰C. In the study, the Citrobacter sp. showed its bestperformance at the optimum temperature of 350C. Likewise, the optimal pH for the MFCsystem in which the electrical output was high was observed in the pH value of 7.4.Moreover, the anodic bacterial biofilm analysis under confocal microscope providedevidence of the presence of live bacteria which were responsible for the efficientcurrent generation of the MFC system.

19.
Braz. arch. biol. technol ; Braz. arch. biol. technol;62(spe): e19190024, 2019. graf
Artigo em Inglês | LILACS | ID: biblio-1132153

RESUMO

Abstract The current reality of the energy market requires generation, control, distribution and consumption to become more efficient. Recent arrangements with electric energy stored in accumulators appear as strategic tools in the environment where the cost of energy supplied by the concessionaires and permission holders has accumulated successive increases, indirectly enabling the control and management of applications of micro or local minigeneration, from renewable sources in general. Systems with energy storage (e.g. batteries) and local demand management (many consumer units) achieve great efficiency by allowing the optimized consumption of the available energy, both by the local power grid and by the accumulated grid. Other advantages are presented for the distributors, allowing the relief of the electricity network, remunerating the investment in reduced intervals of time. Consideration should be given to the possibility of local autonomy, even if partially, by providing energy from the storage to the local loads in eventual failures in the supply of energy by the distribution network or at times where supply has a higher cost.


Assuntos
Autonomia Profissional , Fontes Geradoras de Energia , Abastecimento de Energia/métodos , Energia Renovável
20.
Braz. arch. biol. technol ; Braz. arch. biol. technol;62(spe): e19190003, 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1055428

RESUMO

Abstract The objective of this paper is to evaluate, through the 100-year Life Cycle Analysis, Global Warming Potential (GWP) and Global Temperature Increasing Potential (GTP) impact categories. It is proposed scenario of replacement of the energy matrix for the supply of electricity by Solar Photovoltaic, adopting as consumption base the facilities of Supermarkets, as they contribute to environmental impacts for greenhouse gas emissions such as: intensive use of electricity, occupation large areas such as the main building or parking lot sealing the ground, the movement of customers' vehicles with air and noise pollution and the use of plastic bags. Modifying the energy matrix using electricity from renewable sources enables the reduction of greenhouse gas emissions. According to proposed scenarios for the composition of the energy matrix, based on the emission values of the Concessionaire's matrix, the result of the analysis confirms the premise that the use of renewable sources contributes to the reduction of environmental impacts, and that the substitution of Concessionaire's energy matrix for Photovoltaic Solar Energy represents a reduction in terms of kgCO2-eq, over the 100-year horizon, of 85% for GTP and 86% for GWP.


Assuntos
Meio Ambiente , Energia Fotovoltaica , Aquecimento Global/prevenção & controle , Energia Renovável
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA