PEROXIDE BLEACHING OF PULPS FROM AGRICULTURAL RESIDUES .1. PEROXIDE BLEACHING OF KRAFT BAGASSE PULP

Semi-bleached qualities with pulp whiteness values in the range of 60- 65% per cent were obtained by using one stage alkaline hydrogen peroxi de of kraft bagasse pulp, with lignin content of 4.8 per cent. The inf luence factors in pulp bleaching processes were studied, e.g., pH of b leaching liquor, 2-14; peroxide dose, 1-5 per cent (based on pulp); li quor ratio, 2-7:1 (bleaching liquor:pulp); bleaching temperature, 45-7 0-degrees-C and bleaching time 30-180 minutes. Analysis of the produce d pulps for lignin, hemicelluloses contents and degree of polymerizati on (DP) were determined. In addition, effect of adding some stablizers salts, such as sodium silicate (1%), epsom salt (0.1 %) (based on pul p) and mixture of both, on the mentioned pulps properties were evaluat ed. On the other hand, the kinetic phenomena during the peroxide bleac hing was taken on consideration. It was found that, the order of perox ide bleaching of kraft bagasse pulp is first and the activation energy is 47.2 Kj/mole.