Formic acid-peroxyformic acid pulping of Aspen wood:: An optimization study

Populus tremula*Populus tremuloides wood samples were subjected to three-stage pulping in formic acid media with hydrogen peroxide addition, according to the Miler process. By means of three incomplete, second-order, centered, factorial designs, the effects of selected operational variables on the composition and technical properties of pulps were assessed for optimization purposes. Under the best conditions assayed, a pulp with 2.30 % lignin, 87.0 % cellulose and 3.25 % xylan was obtained at 53.2 % pulp yield. Good SCAN viscosity (826 ml/g), reduced Kappa number (9.0) and satisfactory alkaline resistance (R-10 = 89.0; R-18 = 91.0) proved the potentiality of the selected pulp for dissolving pulp production.