Title
Biorefining of Leucaena leucocephala. Energy optimization of black liquor and polysaccharide fractions
Authors
FRANCISCO LÓPEZ JAVIER M. FERIA JUAN CARLOS GARCÍA M. TRINIDAD GARCÍA and M. JESUS DÍAZ

Received October 6, 2014
Published Volume 50 Issue 9-10 October-December
Keywords soda–anthraquinone process, energy, black liquor, autohydrolysis, Leucaena leucocephala, pulp

Abstract
A Leucaena leucocephala variety was pulped with the soda–anthraquinone process to obtain a liquid fraction for use as an energy source. To this end, the raw material was subjected to a two-stage fractionation process in order to optimize the black liquor and polysaccharide fractions for energy production. This aim was accomplished by using a hydrolysis treatment before pulping. Both the pretreatment and the pulping process were optimized with a view to obtaining the best possible pulp properties and renewable energy from the black liquor, and the results were compared with those obtained in the absence of prior hydrolysis. Alkaline (soda–anthraquinone) cooking of the hydrolysis solid residue provided cellulose pulp and energy from black liquor at least as efficiently as without autohydrolysis and with the added advantage of using milder delignification conditions. Up to 46.6% of hemicellulose in the raw material was extracted as xylooligomers, xylose and furfural into the liquid phase.