Exploring the effects of treatments with carbohydrases to obtain a high-cellulose-content pulp from a non-wood alkaline pulp

In this work, treatments with a xylanase (X) and carbohydrases mixture (Cx) were 19 applied on a TCF bleached sisal pulp in order to obtain high-cellulose content fibers 20 applicable on a wide range of uses. A limit of ˜12% w/w final content in hemicelluloses 21 was found regardless of the enzymatic treatment assessed. An extraction with 4% and 22 9% w/v NaOH was performed for further hemicelluloses removal. We found that NaOH dose could be strongly reduced if combined with Cx or Cx+X treatments. Also, if necessary, a stronger reduction could be obtained with 9% w/v NaOH, which was found to be boosted in a 14% if performed after a treatment with Cx. An end-product with a low content in xylans (˜2.9% w/w) and in HexA (5.8 µmol/odp) was obtained. Pulp Fock solubility was also increased (˜30%) by enzymatic treatments. HPLC analysis of effluents provided useful information of enzymatic catalytic mechanisms
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