Optimization of acid hydrolysis from the hemicellulosic fraction of Eucalyptus grandis residue using response surface methodology.
Biotechnological conversion of biomass into fuels and chemicals requires hydrolysis of the polysaccharide fraction into monomeric sugars. Hydrolysis can be performed enzymatically and with dilute or concentrate mineral acids. The present study used dilute sulfuric acid as a catalyst for hydrolysis of Eucalyptus grandis residue. The purpose of this paper was to optimize the hydrolysis process in a 1.4 l pilot-scale reactor and investigate the effects of the acid concentration, temperature and residue/acid solution ratio on the hemicellulose removal and consequently on the production of sugars (xylose, glucose and arabinose) as well as on the formation of by-products (furfural, 5-hydroxymethylfurfural and acetic acid). This study was based on a model composition corresponding to a 2(3) orthogonal factorial design and employed the response surface methodology (RSM) to optimize the hydrolysis conditions, aiming to attain maximum xylose extraction from hemicellulose of residue. The considered optimum conditions were: H(2)SO(4) concentration of 0.65%, temperature of 157 degrees C and residue/acid solution ratio of 1/8.6 with a reaction time of 20 min. Under these conditions, 79.6% of the total xylose was removed and the hydrolysate contained 1.65 g/l glucose, 13.65 g/l xylose, 1.55 g/l arabinose, 3.10 g/l acetic acid, 1.23 g/l furfural and 0.20 g/l 5-hydroxymethylfurfural.
Department of Energy, Engineering Faculty of Guaratinguetá - FEG/UNESP, Av. Ariberto Pereira da Cunha, 333, Pedregulho, Guaratinguetá 12516-410, SP, Brazil.
Eliana Vieira
EV
Canettieri
George Jackson
GJ
de Moraes Rocha
João Andrade
JA
de Carvalho
João Batista
JB
de Almeida e Silva
D019149:Bioreactors; D002241:Carbohydrates / Q000737:chemistry; D005052:Eucalyptus / Q000737:chemistry*; D006868:Hydrolysis; D024301:Plant Bark; D018515:Plant Leaves / Q000737:chemistry; D018520:Plant Shoots / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry*
D002241:Carbohydrates; D011134:Polysaccharides; C007916:hemicellulose