Separação e caracterização de oleos provenientes da liquefação direta do bagaço de cana

AUTOR(ES)

Andre Ribeiro Cotrim

DATA DE PUBLICAÇÃO

1986

RESUMO

In this work we describe our attempts to separate the heavy oil, obtained in the direct liquefaction of sugar cane bagasse with sodium formate/water/argon, using liquid chromatography, distllation and liquid-liquid extraction. Both, the crude oil and the resulting fractions were characterized by Infrared, nuclear magnetic resonance and mass spectrometry, gas chromatography, gas chromatography/mass spectrometry and microanalysils. ln our attempt to fractionate the crude oil by liquid chromatography, we found that the apoIar components can be separated on neutral silica gel columns, from which they are easily eluted in the first fractions. On the other hand, the separation of the phenolic and acidic compounds was inefficient and needs to be improved. Vacuum distillation of the crude oil at 120°C produced a fraction of volatiles with a20 % yield, which contained acetic acid, hydroxyacetone, methylfurane toluene, phenol, dimethylfurane, cresols, cyclohexenones, ethylphenol, guaiacol, substituted guaiacols and dimethoxyphenol. The separation, identification and quantitative determination of these products were performed by high resolution gas chromatography/mass spectrometry and by high resolution low voltage mass spectrometry. The solvent extraction allowed the separation of the residual oils into acidic components (extracted with NaOH solution), basic compounds (extracted with HCl solutio) and neutral components (soluble in hexane). We obtained a yield of ca. 30 % of acidic compounds (mainly acrboxylic acids, mono and polyphenols). The quantity of basic components present is smaller than 1%, justifyed by the low N and S content in the oils obtained from lignocellulosic materials. The neutral compounds represent ca. 10% of the oil and are mistures of alcohols, aliphatic ketones and aromatic hydrocarbons. The precipitated and the insoloble components are substances of high molecular weight, such as oligomerized polyphenols, which make-up the remaining 30% of the this oil.

ASSUNTO(S)

cana-de-açucar - derivados bagaço de cana

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