Results
Title

Oxidation in Acidic Medium of Lignins from Agricultural Residues.

Authors

Gisele Labat; Adilson Gonçalves

Abstract

Abstract  Agricultural residues as sugarcane straw and bagasse are burned in boilers for generation of energy in sugar and alcohol industries. However, excess of those by-products could be used to obtain products with higher value. Pulping process generates cellulosic pulps and lignin. The lignin could be oxidized and applied in effluent treatments for heavy metal removal. Oxidized lignin presents very strong chelating properties. Lignins from sugarcane straw and bagasse were obtained by ethanol–water pulping. Oxidation of lignins was carried out using acetic acid and Co/Mn/Br catalytical system at 50, 80, and 115 °C for 5 h. Kinetics of the reaction was accomplished by measuring the UV-visible region. Activation energy was calculated for lignins from sugarcane straw and bagasse (34.2 and 23.4 kJ mol−1, respectively). The first value indicates higher cross-linked formation. Fourier-transformed infrared spectroscopy data of samples collected during oxidation are very similar. Principal component analysis applied to spectra shows only slight structure modifications in lignins after oxidation reaction.

Subjects

BAGASSE; OXIDATION; AGRICULTURE; POWER resources; BIOMASS energy

Publication

Applied Biochemistry & Biotechnology, 2008, Vol 148, Issue 1-3, p151

ISSN

0273-2289

Publication type

Academic Journal

DOI

10.1007/s12010-007-8120-0