Análise do processo de combustão e emissões em motores de ignição por compressão utilizando misturas de farneseno e diesel comercial e d-limoneno como aditivo
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Data
2021-09-01
Autores
Ribeiro, Filipe Neves Braga Soares
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Universidade Estadual Paulista (Unesp)
Resumo
O estudo e desenvolvimento de combustíveis renováveis se mostra crucial no atual cenário mundial. Na área de motores a combustão interna de ignição por compressão o uso de ésteres de óleos vegetais (biodiesel) está aumentando ano após ano no Brasil, especialmente devido à exigência legal de mistura ao óleo diesel fóssil comercializado. Biocombustíveis avançados têm sido estudados como substitutos ao diesel fóssil. O farneseno é um hidrocarboneto obtido através de um micro-organismo geneticamente modificado, desenvolvido pela Amyris, do qual pouco se conhece sobre sua aplicabilidade como combustível. A possibilidade de utilizar biomassa para aditivar combustíveis pode ser a resposta para adequar melhor as características físico-químicas das misturas de forma a obter melhores desempenhos e menores emissões de gases tóxicos. O d-limoneno é um terpeno monocíclico obtido da casca da laranja, faz parte dos rejeitos da produção cítrica e recentemente tem sido estudado como componente/aditivo de combustíveis para motores de combustão interna. Neste trabalho foi realizada, de forma inédita, a aplicação de farneseno como componente de uma mistura contendo diesel e biodiesel (diesel comercial brasileiro), bem como um estudo dos efeitos do uso de d-limoneno como aditivo à mistura. Foi utilizado um motor monocilíndrico de ignição por compressão, e os combustíveis foram testados de acordo com suas emissões de O2, CO2, CO, HC, NOx e fumaça. Foram estudadas misturas com 0, 5, 10 e 15% em volume de farneseno misturado ao diesel, posteriormente d-limoneno foi adicionado em concentrações de 10, 15 e 20% nas misturas para avaliar sua influência como aditivo. Foram obtidas as curvas de pressão, taxa de liberação de calor, fração de combustível queimado e atraso de ignição para todas as misturas, e foram analisadas as emissões geradas pelo motor para cada ensaio. Os resultados apontam que a adição de até 15% de farneseno gerou uma combustão de qualidade comparável ao diesel S-10 utilizado. A presença do d-limoneno elevou o pico de liberação de calor, o qual demora mais para ser atingido devido à menor velocidade de queima inicial. As variações notadas nas emissões de gases são uma tendência de menor emissão de fumaça, menor quantidade de NOx e CO2 para as amostras contendo os compostos renováveis, com ligeira desvantagem para estes quanto à emissão de CO.
The study and development of renewable fuels are crucial in the current world scenario. In the area of CI engines, the use of vegetable oils esters (biodiesel) is increasing every year in Brazil, due to the legal requirement to blend it in diesel oil. Advanced biofuels have been studied as substitutes for fossil diesel. Farnesene is a hydrocarbon obtained from a genetically modified yeast, developed by Amyris, about which applicability as a fuel is still unknown. The possibility of blending more biofuel to diesel fuel may be the way to achieve better physicochemical characteristics of the mixtures to obtain better performance and lower emissions of toxic gases. D-limonene is a monocyclic terpene obtained from orange peel, a waste from citrus production that has recently been studied as a fuel additive for internal combustion engines. In this work, an unprecedented application of farnesene as a component of a blend containing diesel and biodiesel (Brazilian commercial diesel) was carried out, as well as a study of the effects of using d-limonene as an additive to this blend. A single-cylinder CI engine was used to evaluate the fuel blends according to their emissions of O2, CO2, CO, HC, NOX and smoke. Mixtures with 0, 5, 10 and 15% by volume of farnesene blends with diesel were studied, then d-limonene was added at concentrations of 10, 15 and 20% in new blends to evaluate its influence as an additive. The in-cylinder pressure curves, heat release rate curves, mass fraction burned curves and ignition delay were evaluated for each prepared fuel mixture. The emissions generated by the engine in each test were also analyzed. The results show that the addition of up to 15% Farnesene showed a good combustion, with comparable quality to the S-10 diesel used. The presence of d-limonene tends to increase the heat release peak, which takes longer to reach. It was observed that the burning speed at the beginning of combustion was lower for the samples containing d-limonene. Gas emissions presented lower smoke emission, lower amounts of NOx and CO2 for all samples containing renewable fuel, with a slight disadvantage for these in relation to CO emission.
The study and development of renewable fuels are crucial in the current world scenario. In the area of CI engines, the use of vegetable oils esters (biodiesel) is increasing every year in Brazil, due to the legal requirement to blend it in diesel oil. Advanced biofuels have been studied as substitutes for fossil diesel. Farnesene is a hydrocarbon obtained from a genetically modified yeast, developed by Amyris, about which applicability as a fuel is still unknown. The possibility of blending more biofuel to diesel fuel may be the way to achieve better physicochemical characteristics of the mixtures to obtain better performance and lower emissions of toxic gases. D-limonene is a monocyclic terpene obtained from orange peel, a waste from citrus production that has recently been studied as a fuel additive for internal combustion engines. In this work, an unprecedented application of farnesene as a component of a blend containing diesel and biodiesel (Brazilian commercial diesel) was carried out, as well as a study of the effects of using d-limonene as an additive to this blend. A single-cylinder CI engine was used to evaluate the fuel blends according to their emissions of O2, CO2, CO, HC, NOX and smoke. Mixtures with 0, 5, 10 and 15% by volume of farnesene blends with diesel were studied, then d-limonene was added at concentrations of 10, 15 and 20% in new blends to evaluate its influence as an additive. The in-cylinder pressure curves, heat release rate curves, mass fraction burned curves and ignition delay were evaluated for each prepared fuel mixture. The emissions generated by the engine in each test were also analyzed. The results show that the addition of up to 15% Farnesene showed a good combustion, with comparable quality to the S-10 diesel used. The presence of d-limonene tends to increase the heat release peak, which takes longer to reach. It was observed that the burning speed at the beginning of combustion was lower for the samples containing d-limonene. Gas emissions presented lower smoke emission, lower amounts of NOx and CO2 for all samples containing renewable fuel, with a slight disadvantage for these in relation to CO emission.
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Biocombustíveis, Farneseno, D-limoneno, Biodiesel, Aditivos, Biofuels, Farnesene, D-limonene, Additives