A process for delignifying pulp with organic peroxyacid in the presence of phosphonic acids and their salts
AssigneeSolvay Interox (Societe Anonyme)
InventorJohan Devenyns
Life of this patent
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Abstract
Process for improving the selectivity of the delignification of a chemical paper pulp by employing a peroxyacid, in which the unbleached pulp originating from the cooking operation is treated with an aqueous solution of this organic peroxyacid in the presence of at least one stabilizer selected from phosphonic acids and their salts.
Claims12
A process for improving the selectivity of the delignification of a chemical paper pulp by means of an organic peroxyacid, comprising the step of:
- treating an unbleached pulp originating from a cooking operation with an aqueous solution of the organic peroxyacid containing at least 10% by weight of peroxyacid in the presence of a stabilizer for the peroxyacid, said stabilizer comprising at least one compound selected from the group consisting of phosphonic acids and their salts, wherein the organic peroxyacid is fed in an amount sufficient to delignify the unbleached pulp and produce a delignified chemical pulp.
A process for improving the selectivity of the delignification of a kraft paper pulp by means of an organic peroxyacid, comprising the step of:
- treating an unbleached pulp originating from a cooking operation with an aqueous solution of the organic peroxyacid containing at least 10% by weight of peroxyacid in the presence of a stabiliser for the peroxyacid, said stabiliser comprising at least one compound selected from the group consisting of phosphonic acids and their salts, wherein the organic peroxyacid is fed in an amount sufficient to delignify the unbleached pulp and produce a delignified kraft paper pulp.
A process for improving the selectivity of the delignification of a sulphite paper pulp by means of an organic peroxyacid, comprising the step of treating an unbleached pulp originating from a cooking operation with an aqueous solution of the organic peroxyacid containing at least 10% by weight of peroxyacid in the presence of a stabiliser for the peroxyacid, said stabiliser comprising at least one compound selected from the group consisting of phosphonic acids and their salts, wherein the organic peroxyacid is fed in an amount sufficient to delignify the unbleached pulp and produce a delignified sulphite paper pulp.
A process for improving the selectivity of the delignification of a chemical paper pulp, obtained by a cooking process employing solvents, by means of an organic peroxyacid, comprising the step of treating an unbleached pulp originating from a cooking operation with an aqueous solution of the organic peroxyacid containing at least 10% by weight of peroxyacid in the presence of a stabiliser for the peroxyacid, said stabiliser comprising at least one compound selected from the group consisting of phosphonic acids and their salts, wherein the organic peroxyacid is fed in an amount sufficient to deliqnify the unbleached pulp and produce a delignified chemical pulp.
Dependencies are inferred from the claim text.