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Several agricultural wastes, such as the residues of the winemaking industry, have been tested using traditional chemical methods of pulping aimed to obtain bleached pulp, but only low yields and poor fiber quality have been achieved so far. In this work, we evaluate a two-stage chemi-thermomechanical pulping (CTMP) to assess the feasibility to add value to the residues of the wine industry (grape stalks and vine shoots) by obtaining fibers with papermaking and/or cardboard quality. The first stage of the process evaluates different conditions with low chemical charges of Na2SO3and/or NaOH (3 to 5% on wood basis) at different temperatures (130 to 160 °C) for 60 min. The second stage consists of a mechanical refining that converts fiber bundles and shives into pulps. CTMP pulping performed with 5% Na2SO3at 160 °C from grape stalks and vine shoots showed the best combination of fiber quality regarding higher screened pulp yield, lower rejects and fines content, and adequate drainability. Results showed that pulp from waste lignocellulosic of the winery industry can be produced by a green approach (low chemical charge and severity in CTMP pulping) and became an alternative for paper, packaging, fiber additives, or new biobased materials.

Drimys winteriand Nothofagus dombeyi, two native Chilean wood species with high potential for pulp production, were biodegraded by Ganoderma australe. This fungus is known to provoke extensive and selective biodelignification of these wood species in the field. Under laboratory conditions, N. dombeyiunderwent higher weight and component losses than D. winteri. In neither case was the lignin removal selective, because glucan loss was almost simultaneous with lignin degradation. The decayed wood chips became progressively discoloured throughout the biodegradation time. The brightness increase was only partly reversed in thermal reversion assays. Nothofagus dombeysolubility in 1% NaOH increased by 13.7% after 9 weeks of biodegradation, while D. winterisolubility increased by 14.2% in a shorter period (6 weeks). In both cases, the solubility increase was proportional to the liquor absorbance increase at 272 nm, which indicates that the wood solubility in 1% NaOH was dependent of lignin solubilization.