Low Capital Bleaching of Chemical Pulp
AssigneeEcolab USA Inc.
InventorsPrasad Y. Duggirala, Sergey M. Shevchenko
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Abstract
Bleaching methods and formulations for bleaching/delignification processes for chemical pulp are provided. The bleaching methods utilize peroxide and an organomanganese complex under aqueous caustic conditions, increasing bleaching efficiency of the overall bleaching/delignification process. Chemical pulp having increased brightness can be obtained at decreased temperatures and with reduced stage time, resulting in reduced chemical consumption and improved energy efficiency.
Claims20
A method of bleaching alkali oxidized chemical pulp comprising:
- treating alkali oxidized chemical pulp with peroxide and an organomanganese complex under aqueous caustic conditions subsequent to an acidic oxidative bleaching stage to form an enhanced chemical pulp.
A method of enhancing chemical pulp comprising:
- treating chemical pulp under acidic oxidative conditions to form an acidic oxidized chemical pulp;
- washing the acidic oxidized chemical pulp with aqueous caustic solution to form an alkali oxidized chemical pulp;
- and
- treating the alkali oxidized chemical pulp with peroxide and an organomanganese complex to form an enhanced chemical pulp.
A thermally stable aqueous formulation for bleaching of a chemical pulp comprising an organomanganese complex and water, wherein the aqueous formulation has a pH of from about 3 to about 7 and the organomanganese complex is at a concentration of from about 0.0001% to about 3% by weight based on weight of the aqueous formulation.
Dependencies are inferred from the claim text.