Bamboo as a non-traditional lignocellulosic resource for the nanocellulose production: Guadua trinii and Guadua angustifolia.

PRADO GÁRATE, A.E.R.; VALLEJOS, M.E.; FELISSIA, F.E.; SUIREZS, T.

Conferencia; XXV TECNICELPA ? International Forest, Pulp and Paper Conference and XI CIADICYP ? Iberoamerican Congress on Pulp and Paper Research; 2021

TECNICELPA -RIADICYP

High-valueproducts can be obtained from non-traditional lignocellulosic resources such asbamboo, taking full advantage of these materials through efficient, economicand low-pollution fractionation processes. Bamboo is a fibrous resource ofrapid growth and great regional interest, and currently, this is a greatinterest to know its potential to produce high-value products. This studyanalyzes the aptitude of two species of Bamboo (G. angustifolia and G. trinii)as a lignocellulosic resource to obtain nanocellulose based on the biorefineryconcept. The physical, morphological, and chemical characterization werecarried out for both bamboo species. Four different kinds of unbleached soda-AQpulps: two produced from G. angustifolia and G.trinii hydrothermal treated(PGaT and PGtT), and two without treatment before of pulping (PGa and PGt). Thehydrothermal treatment was carried out to remove hemicelluloses at 180°C for 30minutes, using a solid:liquid ratio 1:3. The soda-AQ pulping conditions usedwere 18% NaOH and 0.1% anthraquinone (AQ), 170°C for 60 minutes, a solid:liquidratio 1:4.Soda-AQpulps were characterized by yield, WRV, kappa number, degree of polymerizationand α, β and γ cellulose contents. Nanocellulose were produced from these pulpsby TEMPO oxidation treatment (10% NaBr, 1.6% TEMPO, 5 mmol NaClO, pH 10 for 1hour) followed by mechanical treatment (colloid mill, 1% consistency, 10times). Nanocellulose was characterized by the viscosity of the suspensions.The woody structure of G. trinii was denser than G. angustifolia (0.53 g/cm3and 0.47 g/cm3, respectively), whereas the average fiber length of G. trinii(1.044 mm) was significantly lower than G. angustifolia (1.441 mm), and theaverage wall thickness were of 3.78 µm and 2.01 µm, respectively. The G. triniichemical composition was: 8.66% extractives, 4.05% ash, 23.9% total lignin and65.6% structural carbohydrates, whereas for G. angustifolia it was: 9.55%extractives, 4.58% ash, 25.2% total lignin and 63.8% structural carbohydrates.Yields of PGtT and PGaT were similar (36.5% and 37.3%, respectively), however,the kappa numbers were significantly different (19.8 and 37.2, respectively).PGt yield was slight than PGaT (47.3% and 44.8%, respectively) with kappanumber of 21.8 and 29.3, respectively. This shows that G. trinii has optimalaptitudes compared to G. angustifolia for the pulping process in the pulp andpaper industry. WRVs were similar for the studied pulps, whereas the degree ofpolymerization and α, β and γ cellulose contents were significantly lower for treatedpulps. The carboxylic group contents in treated pulps after TEMPO treatmentwere lower for hydrothermal treated pulps. It was determined that there is asignificant direct correlation between the carboxylic group content and theviscosity of suspensions, which can be related to the aspect ratio ofnanofibers. The aspect ratio of the nanofibrils obtained from hydrothermaltreated pulps was lower (< hemicelluloses content).