posted on 2015-12-18, 00:00authored byXabier Erdocia, Raquel Prado, Javier Fernández-Rodríguez, Jalel Labidi
Olive tree pruning was delignified
by organosolv processes (acetosolv,
formosolv, and acetosolv/formosolv) to extract different lignins.
The obtained lignins (acetosolv lignin (AL), formosolv lignin (FL),
and acetosolv/formosolv lignin (AFL)) were depolymerized using three
different solvents (methanol, ethanol, and acetone) under supercritical
conditions in a batch reactor to produce high value-added compounds.
The recovered products (oil, char, and residual lignin) were analyzed
in order to determine their composition and to know the influence
of employed solvent and lignin. Lignin was successfully depolymerized
in all cases, and the molecular weight of residual lignin was significantly
reduced compared to raw lignin. The obtained oil had numerous phenolic
monomers, with syringol and guaiacol being the main products in all
studied cases. Depolymerization of AFL led to maximum yield of oil
(38.04%), and acetone was the best solvent in terms of phenolic monomers
production.