Aplicación de métodos hidrotérmicos y Lacasa-Mediador en procesos de biorrefinería de Eucalyptus Globulus

Abstract

Sustainable development and the renewability of resources goes through the search/use of new sources of resources and chemical and consumer products where lignocellulosic forest biomass and in particular the high production capacity is revealed as a necessary source of raw materials. The aim of this Doctoral Thesis work was the Application of Stages of Autohydrolysis and Enzymatic Oxidative delignification th!'ough Lacease-Mediator System in Biorefinel'y Processes of Eucalyptus globulus globulus in a "Biorefinery" framework. The evaluation is carried of a process of obtaining cellulose pulp and paper, through by means of processes of conventional delignification (soda-antraquinone, ethanol soda and kraft) and its comparison with that same process, but carrying out a previous stage of extraction of hemicelluloses (autohydrolysis) and an enzymatic treatment with the Lacease-Mediator System. The works ofthis Doctoral Thesis have been carried out in 5 blocks that are summarized below: Selecting the pre-hydrolysis conditions for eucalyptus wood in a fractional exploitation biorefining scheme: The operating conditions for the autohydrolysis of eucalyptus wood were optimized with a view to maximizing hemicellulose extraction while preserving the integrity of glucan. Autohydrolysis of the raw material at a liquid/solid ratio of 8 kg water/kg material at l 80ºC for 30 min was found to provide a commercially useful liquid phase containing most ofthe starting hemicellulose. Optimization ofthe paste process to the soda-AQ from Eucalyptus globulus wood after the selective extraction of hemicelluloses: This study investigates the operating conditions used in the soda anthraquinone pulping of Eucalyptus globulus wood after autohydrolysis pretreatment on the yield, kappa number, and brightness of the resulting unbleached pulp. Moreover, strength-related properties of the resulting handsheets was examined to identify the best pulping co11ditio11s and compare the outcome with that of a conventional soda-anthraquino11e pulping process. Application of an enzymatic delignification stage by means of a lacease/mediator (HBT) system after autohydrolysis and prior to conventional delignification of soda-anthraquinone of Eucalyptus globulus: In a biorefinery framework, a lacease/mediator system treatme11t followi11g autohydrolysis was carried out for eucalyptus wood prior to soda-anthraquinone pulping. The enzymatic and autohydrolysis co11ditions with a view to maximizing extraction of hemicelluloses while preserving the integrity of glucan were optimized. Application of an enzymatic delignification stage by means of a lacease/mediator (syringaldehyde) system after antohydrolysis and prior to conventional delignification of organosolv with ethanol soda of Eucalyptus globulus: Two previous treatme11ts have been applied to the ethanol-soda paste process 011 Eucalyptus globulus wood to evaluate its i11flue11ce 011 the properties of the obtained cellulose pulps. The treatments consisted of a first optimized stage of autohydrolysis (temperature: 180ºC, time: 30 min), followed by enzymatic oxidative delignification by a lacease / mediator system (syringaldehyde). Évaluation of the extraction of hemicelluloses by means of autohydrolysis in an altemative variety of eucalyptus wood (Eucalyptus urograndis) and its influence on the development of properties of the paper: This work provides an assessment on the compatibility between autohydrolysis and kraft pulping of Eucalyptus urograndis wood with a vision of utilizing left over streams for manufacturing value added products. The best kraft pulps obtained from autohydrolyzed solids were subjected to an optimized bleaching sequence involving double alkaline oxygen and pressurized H202 processing (0-D- EP-D) and beating processing to assess a conceptual approach to the "Biomass Refinery" concept.