Use of Diethanolamine to Obain Cellulosics Pulps from Solid Fraction of Hydrothermal Treatment of Rice Straw

Abstract

We assessed the potential of the solid residue from a
hydrothermal treatment of rice straw as an alternative raw material for obtaining cellulose pulp. To this end, we examined the influence of operational variables in the diethanolamine pulping of this material on the properties of the cellulose pulp obtained and of paper sheets made from it.
Using a central composite factor design and fitting the results to a polynomial model allowed us to establish equations relating the dependent variables to the independent ones with errors less than 8% in all cases except for burst index (27%).
The optimum conditions with a view to saving reagents, heating energy and immobilized capital were found to be a diethanolamine concentration of 70%, a temperature of 162.5 ºC, a cooking time of 60 min and a liquid/solid ratio of 8. These conditions provide paper sheets with physical properties that depart by less than 8% from their optimum values, and a pulp yield and Kappa number differing by less than 14% from their best levels.
We compared the results obtained in the diethanolamine
pulping of the solid fraction from the hydrothermal treatment
of rice straw with those for kraft and diethanolamine
pulp from eucalyptus and pine wood, and found the properties
of the former to fall in between those for the latter two.