Authors: Héctor A Ruiz Denise S Ruzene Daniel P Silva Fernando F Macieira da Silva António A Vicente José A Teixeira
Publish Date: 2011/01/28
Volume: 164, Issue: 5, Pages: 629-641
Abstract
The present work describes the delignification of wheat straw through an environmentally friendly process resulting from sequential application of autohydrolysis and organosolv processes Wheat straw autohydrolysis was performed at 180°C during 30 min with a liquid–solid ratio of 10 v/w under these conditions a solubilization of 44 of the original xylan with 78 of sugars as xylooligosaccharides of the sum of sugars solubilized in the autohydrolysis liquors generated by the hemicellulose fraction hydrolysis The corresponding solid fraction enrichment with 637 of glucan and 755 of residual xylan was treated with a 40 ethanol and 01 NaOH aqueous solution at a liquid–solid ratio of 10 v/w with the best results obtained at 180°C during 20 min The highest lignin recovery measured by acid precipitation of the extracted lignin was 325 g/100 ml The lignin obtained by precipitation was characterized by FTIR and the crystallinity indexes from the native cellulose the cellulose recovered after autohydrolysis and the cellulose obtained after applying the organosolv process were obtained by Xray diffraction returning values of 2132 5517 and 5359 respectively Visualization of the fibers was done for all the processing steps using scanning electron microscopy
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