RESUMO
Fourteen ionic liquids (ILs) were obtained and characterized by nuclear magnetic resonance and infra-red spectroscopy. One of these liquids, n-butylammonium acetate, was used in the treatment of coir fiber prior to acid hydrolysis. For this purpose, the fiber was pulped with 8% (w/w) sodium hydroxide for 6h under 2.5 atm pressure at 137°C and then treated with IL for 2h at 90°C. The samples were hydrolyzed in acetic acid at different concentrations and temperatures. The reducing sugar concentrations were determined in all samples, and the optimal hydrolysis conditions were established (32.2% acetic acid at 122.4°C). The reaction time was also studied, and the conversion was maximized at 3h. Under the best hydrolysis conditions, crude fiber, pulping fiber, and IL-treated fiber were hydrolyzed to yield 8.53%, 47.58%, and 89.75% of reducing sugars, respectively.
