Ednildo Andrade Torres

Biodiesel: an overview

The importance of biodiesel production was analyzed based on scientific articles and patents. A critical analysis was presented on the most used oil sources, the catalysts and the methods to verify the transesterification yields. Also analyzed were the comparative studies on emissions from pure fossil diesel and mixtures with biodiesel in variable proportions. Finally some challenges and considerations focused on technological, agronomic and infrastructure aspects of biodiesel production were indicated.

Cadeia do biodiesel da bancada à indústria: uma visão geral com prospecção de tarefas e oportunidades para P&D&I

Contextualized overview of the Biodiesel Production Chain, from the lab bench to the industry, with critical evaluation of state-of-art and technological development through scientific articles and patents, focusing on feedstock, reaction/production, first and second generation processes, specification and quality, transport, storage, co-products (effluents and sub-products), and emissions. Challenges are identified and solutions are proposed based on the Brazilian feedstock, edaphoclimatic conditions, process monitoring in remote regions, state policy, and environment preservation, among others. Forecasts are made based on the technology assessment, identifying future trends and opportunities for R&D&I.

Recovery of different waste vegetable oils for biodiesel production: a pilot experience in Bahia State, Brazil.

In Brazil, and mainly in the State of Bahia, crude vegetable oils are widely used in the preparation of food. Street stalls, restaurants and canteens make a great use of palm oil and soybean oil. There is also some use of castor oil, which is widely cultivated in the Sertão Region (within the State of Bahia), and widely applied in industry. This massive use in food preparation leads to a huge amount of waste oil of different types, which needs either to be properly disposed of, or recovered. At the Laboratorio Energia e Gas-LEN (Energy & Gas lab.) of the Universidade Federal da Bahia, a cycle of experiments were carried out to evaluate the recovery of waste oils for biodiesel production. The experiences were carried out on a laboratory scale and, in a semi-industrial pilot plant using waste oils of different qualities. In the transesterification process, applied waste vegetable oils were reacted with methanol with the support of a basic catalyst, such as NaOH or KOH. The conversion rate settled at between 81% and 85% (in weight). The most suitable molar ratio of waste oils to alcohol was 1:6, and the amount of catalyst required was 0.5% (of the weight of the incoming oil), in the case of NaOH, and 1%, in case of KOH. The quality of the biodiesel produced was tested to determine the final product quality. The parameters analyzed were the acid value, kinematic viscosity, monoglycerides, diglycerides, triglycerides, free glycerine, total glycerine, clearness; the conversion yield of the process was also evaluated.

Exergetic evaluation of a cogeneration system in a petrochemical complex

The purpose of this paper is the study of a real cogeneration system existing in a petrochemical complex. The total capacity of the plant is 200 MW of electrical power and 2100 t/h of steam for processes. This work presents the mass and energy balances of this cogeneration system. Exergy of each involved stream is calculated and the exergetic balance of each subsystem is presented, as well as of the global system, identifying where and why losses and irreversibility occur. Efficiencies based on the second law of thermodynamics are calculated for each subsystem and compared. Some conclusions regarding operational strategies are presented.

Critical evaluation of the oxygen-enhanced combustion in gas burners for industrial applications and heating systems

O conceito de eficiencia energetica em equipamentos esta cada vez mais em pauta com os desdobramentos do aquecimento global e, dentre os equipamentos industriais, os queimadores possuem um dos maiores impactos nesta discussao por se tratar de um equipamento de combustao industrial. A procura por queimadores mais eficientes energeticamente e imprescindivel para o adequado uso de combustiveis fosseis durante a fase de transicao entre esta fonte de energia para as energias alternativas, a qual pode durar mais de cinquenta anos. O presente trabalho traz uma avaliacao do uso da tecnica de combustao enriquecida com oxigenio (OEC), identificando importantes pontos, especialmente na transferencia de calor e na emissao de poluentes, para a aplicacao desta tecnica na industria de petroleo e sua cadeia, na qual a utilizacao da OEC e raramente usada. Nao foi identificada na literatura uma revisao critica do uso da OEC e as implicacoes do seu uso na industria de petroleo e gas. The concept of energetic efficiency in equipments is highlighted nowadays, due to its implication with the global warming issues. Amongst industrial equipments, burners have one of the greatest impacts on this discussion, since they are large scale combustion devices. The search for more efficient burners is of paramount importance, toward a more adequate use of the fossil fuels, during the transition phase between this energy source and new alternatives, which may last more than fifty years. The present work brings an evaluation of the Oxygen Enhanced Combustion technique (OEC), identifying important issues, especially those related with the heat transfer and emission of pollutants, and discussing its application in the oil industry and its supply chain, where the OEC is barely used. As far as the authors could search in the literature, there are no published critical reviews regarding the use of OEC and its implications in the oil and gas industry.

Biodiesel Production from Microalgae: A Mapping of Articles and Patents

Global concern about climate change and the increasing demand for energy have drawn the attention of scientists, policymakers, and various other stakeholders to look for alternative sources of clean and renewable energy, especially transportation fuel. Biodiesel currently produced from vegetable oils and animal fats has been found to be an ideal blending material and replacement for diesel as it is compatible with existing diesel engines, reduces tailpipe emissions, and is biodegradable. However, the increasing conversion of food crops for the biofuel production has caused a food versus fuel debate. One solution suggested has been the use of microalgae because they can accumulate large amount of lipids inside their cells and have high biomass productivity. A typical algal culture system can generate 150–400 barrels of oil per acre per year which is 30 times more than traditional oil seed crops. Algae have several advantages. They can be grown on abandoned or unproductive land using sea water, brackish, or waste water. Furthermore, it is environmentally friendly as it alleviates acidification of the ocean and can be cultivated on a large scale. In recent years, a large number of algal species have been screened and studied for their potential as feedstock for biodiesel production. Some microalgal species such as Botryococcus braunii, Chlorella sp., Scenedesmus sp., and Chlorococcum sp. have shown great potential for biodiesel production. A large number of papers have been published, and several patents have been filed in the field of algal biodiesel production. This chapter analyzes the past developments and current status of research in biodiesel production from microalgae. It aims to evaluate the perspectives of the research related to algal biodiesel, analyzing the patents and scientific articles published in this field. For this study, we used VantagePoint v7, a powerful text-mining tool, to extract results from patent databases and academic publications which will be very useful for further study.

Hydroelectric production from Brazil's São Francisco River could cease due to climate change and inter-annual variability

By the end of this century higher temperatures and significantly reduced rainfall are projected for the Brazilian North and Northeast (NE) regions due to Global Warming. This study examines the impact of these long-term rainfall changes on the Brazilian Northeasts hydroelectric production. Various studies that use different IPCC models are examined in order to determine the average rainfall reduction by the year 2100 in comparison to baseline data from the end of the 20th century. It was found that average annual rainfall in the NE region could decrease by approximately 25-50% depending on the emissions scenario. Analysis of historical rainfall data in the São Francisco basin during the last 57years already shows a decline of more than 25% from the 1961-90 long-term average. Moreover, average annual rainfall in the basin has been below its long-term average every year bar one since 1992. If this declining trend continues, rainfall reduction in the basin could be even more severe than the most pessimistic model projections. That is, the marked drop in average rainfall projected for 2100, based on the IPCC high emissions scenario, could actually eventuate before 2050. Due to the elasticity factor between rainfall and streamflow and because of increased amounts of irrigation in the São Francisco basin, the reduction in the NEs average hydroelectric production in the coming decades could be double the predicted decline in rainfall. Conversely, it is estimated that wind power potential in the Brazilian NE will increase substantially by 2100. Therefore both wind and solar power will need to be significantly exploited in order for the NE region to sustainably replace lost hydroelectric production.

Evaluation of Formaldehyde and Acetaldehyde Emission Rates in Natural Gas Confined Flames with OEC

This study evaluates experimentally the technique of oxygen enhanced combustion – OEC – and its interaction with emission rates of both formaldehyde and acetaldehyde – precursors for the production of tropospheric ozone and other atmospheric pollutants – in natural gas confined flames. The experiment analyzed low enrichment with oxygen, which does not require significant existing equipment changes. The emission rates were verified by analysis in liquid chromatography. Through the use of oxidizer enrichment of 2 and 4%, the emission rates of formaldehyde and acetaldehyde were reduced with OEC in comparison with the use of atmospheric air as oxidant. The formaldehyde/acetaldehyde ratio on the tested conditions indicates a likely preferential reduction of formaldehyde emissions.

Development and Evaluation of Analytical Method for Micronutrients (Na, K, Ca and Mg) Determination in natura Propolis Samples by HR-CS FAAS

Propolis e uma mistura complexa de substâncias colhidas por abelhas presentes em exsudados de plantas, cera e polen. O objetivo deste trabalho foi o desenvolvimento e validacao de um metodo analitico para determinacao de micronutrientes em amostras de propoles in natura empregando HR–CS FAAS apos digestao assistida por radiacao micro-ondas. A exatidao do metodo foi demonstrada atraves do uso de material de referencia certificado, ensaio de recuperacao e comparacao dos resultados obtidos com ICP OES. O teste t apresentou concordância a um nivel de 95% para os resultados com material de referencia certificado. O procedimento otimizado propiciou recuperacao na faixa de 86 a 110% dos analitos. O procedimento analitico otimizado foi aplicado em 48 amostras coletadas no estado da Bahia (Brasil).

MAPEAMENTO TECNOLÓGICO DE PATENTES E ARTIGOS COM O TEMA AVALIAÇÃO DO CICLO DE VIDA

O objetivo deste trabalho e fornecer um mapeamento das pesquisas ja desenvolvidas com o tema Avaliacao do Ciclo de Vida (ACV), nas bases de dados de patentes e artigos. A ACV e uma ferramenta da area ambiental que estuda os potenciais impactos de um processo produtivo ou produto, considerando desde a retirada das materias-primas ate a disposicao final dos residuos. A metodologia empregada na pesquisa das patentes foi a base de dados do Escritorio Europeu de Patentes – Espacenet, com o codigo de classificacao internacional associado a anterioridade e palavras-chave, e para os artigos a base da Web of Science. As patentes publicadas com a tematica ACV resultou num numero baixo, apenas sete documentos foram encontrados. Quanto aos artigos, existe uma evolucao crescente de publicacoes com o passar dos anos, em 2012 foram 1444, mostrando que o conhecimento da ACV esta sendo difundido no meio academico.