SciELO - Scientific Electronic Library Online

 
vol.35 issue4Wasps venoms of the genus Parachartergus sp. and Polybia sp (Vespidae: Polistinae) in Costa Rica: a biological potential to explore author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Journal

Article

Indicators

Related links

  • Have no similar articlesSimilars in SciELO

Share


Revista Tecnología en Marcha

On-line version ISSN 0379-3982Print version ISSN 0379-3982

Abstract

ALBARRAN-MOLINA, Eyra Maria  and  RANGEL, Jesus. Optimal determination in the extraction of hemicelluloses of high quality from Eucalyptus sp. sawdust, through hydrothermal treatment. Tecnología en Marcha [online]. 2022, vol.35, n.4, pp.3-17. ISSN 0379-3982.  http://dx.doi.org/10.18845/tm.v35i4.5822.

Eucalyptus sp chips are one of the most important residues or by-products obtained from primary wood processing in the various regions worldwide (12). Its main use is the production of energy (13). When subjected to hydrothermal treatment conditions for the extraction of the hemicelluloses can extract the substances soluble in wáter (17), leaving a solid fraction of cellulose and lignin that will follow other processes of separation and use (11). The waste material used was a mixture of Eucalyptusrostrata, E. grandis and E. Saligna with ages between 12 and 50 years, obtained in one of the sawmills of the region. The sample that was used in the experimental runs comprises the fraction that passes through the 20 mesh and is retained in 80 mesh inside a Zonytest manual sieve. Initially, a factorial design was applied to verify the influence of time (30, 45 and 60 min), temperature (120, 150 and 180 ° C) and liquid / solid ratio (5, 10, 15). This last variable was not significant. Afterwards, an optimization design was applied to the composite centered in the faces, varying the time (20, 30 and 40 min) and temperature (170, 180 and 190 ° C). The treatments were carried out in 200mL digesters in a glycerin bath. The best point obtained was validated with a scale change in a 4.6 L digester, with a heating jacket and a special stirring system. Temperature proved to be the most influential factor in the pretreatment of autohydrolysis of sawdust. The highest extraction of hemicelluloses (89% of initial hemicelluloses) was obtained at 190 ° C and 20 min, however to minimize the generation of furfural by optimizing multiple responses, the best condition was 180 ° C and 20 min. The response surface shows that similar results could be achieved at 170 ° C if the treatment time is extended to 50 min.

Keywords : Eucalyptus; biorefinery; fractionation; autohydrolysis; hemicelluloses.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )