AVALIAÇÃO DO EFEITO DAS VARIÁVEIS DE PROCESSO NO BRANQUEAMENTO DE POLPA CELULÓSICA COM PERÓXIDO DE HIDROGÊNIO - (2018)

Acessos: 33

Camila Juliane Marcondes, Gustavo Ventorim, Rafael dos Santos, Felipo Augusto Pereira

Volume: 28 - Issue: 3

Resumo. The bleached pulp market has been working to provide brightness levels at values of 92% ISO respecting, however, environmental standards and seeking for less aggressive processes. Then, the additional chlorine dioxide that would be necessary to lift brightness ​​has been replaced by hydrogen peroxide. The present study aimed to evaluate the influence of hydrogen peroxide charge, pressure and temperature variation in the bleaching sequence D0(E+P)D1(P+O). It was used industrial kraft pulp, from hybrid of Eucalyptus urophylla X Eucalyptus grandis, oxygen-delignified, whose initial characteristics were: brightness 61.8% ISO, viscosity 36.9 cP and kappa number 8.9. The last stage (P+O) was performed varying the hydrogen peroxide charge (3 kg/t and 6 kg/t), temperature (95°C and 105°C) and pressure (0 atm and 5 atm). To evaluate the effect of such variations over cellulosic pulp, viscosity, brightness and brightness reversion tests were carried out according to TAPPI standards. In general, increase of hydrogen peroxide charge (from 3 kg/t to 6 kg/t) caused a small increasing on brightness values and a small viscosity decreasing on the cellulosic pulp. The increase of 10°C in temperature had a positive effect on brightness parameter, increasing the respective values, on the other hand, for the viscosity analysis the achieved values showed a reduction tendency. For the variation of oxygen pressure it was also observed brightness increasing and viscosity decreasing.

Idioma: Portuguese

Registro: 2024-10-19 22:32:15

http://www.redalyc.org/articulo.oa?id=53458112026

10.5902/1980509833463