SISTEMA E PROCESSO PARA REDUCAO DO CONSUMO DE OXIGENIO NA OXIDACAO DO LICOR NEGRO

摘要

High heat recovery and minimized oxygen requirement for oxidation of sulfur compounds in black liquor is obtained by integrating the oxidation into the multiple effect evaporation system of the pulp mill recovery sequence. The oxidation step is carried out at an intermediate stage in the multiple effect concentration of weak black liquor in counterflow to the external heat input, and the thus oxidized liquor is then further concentrated by flow through the remaining effects of the system co-currently with the direction of heat flow.