Liquid-liquid equilibrium in hydrocarbon+alcohol mixtures : phase behavior and development of additives for miscibility improvement in diesel oil+ethanol mixtures / Equilibrio liquido-liquido em misturas de hidrocarbonetos + alcoois : comportamento de fases e desenvolvimento de aditivos para aumentar a miscibilidade em misturas oleo diesel + etanol

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

The addition of ethanol to diesel oil affects various properties of this fuel mixture, such as miscibility, viscosity, energy content and cetane number (NC). One of the difficulties in using such a mixture is its tendency to phase separation at lower temperatures, forming two liquid phases. Aiming at preventing these problems, the present study was divided in three parts: description of the phase behavior of diesel oil-ethanol mixtures, investigation of additives (or mixtures) capable of increasing their miscibility and examination of their fuel properties, assessed by their cetane numbers. Analyses of the miscibility curves for diesel oil-ethanol mixtures reveal that the phase separation temperatures depend on the content of ethanol, on the composition of the oil samples investigated and on the amount of water present. Addition of certain compounds leads to an increased miscibility, in most cases due to formation of ethanol-in-oil micro-emulsions, as confirmed by light scattering measurements. A series of additives was investigated and the best perfonnances, as measured by the most pronounced decreases in the phase transition temperatures, was shown by mixtures of fatty acids and amines, such as oleic acid and dodecylamine. Ethanol addition also caused a decrease in the cetane number of the mixture, which could be adequately compensated by adding compounds like ethylhexylnitrate.

ASSUNTO(S)

combustiveis diesel diesel oil miscibilidade misturas combustiveis fuel mixtures aditivos miscibility additives

ACESSO AO ARTIGO

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