Process for the delignifcation and bleaching of a lignocellulose material
AssigneeElf Aquitaine Production
InventorsJean-Fran.cedilla.ois Boe, Jean-Jacques Girerd, Claude Guignard, Jean-Louis Seris, Jean-Baptiste Verlhac
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Abstract
A method is provided for delignifying and bleaching a lignocellulose material, wherein an aqueous solution of a redox catalyst and an oxidant is reacted with the material. The catalyst comprises an organometallic cation of the general formula [(1)Mno.sub.2 Mn(L)].sup.n+, wherein Mn is manganese (III) or (IV) oxide, the two Mn's of this cation may form a pair in a III-III, III-IV or IV-IV oxidative state, n is 2, 3 or 4, O is oxygen, and L is a ligand comprising 4 nitrogen atoms co-ordinating the manganese.
Claims13
Process for the delignification and bleaching of a lignocellulose material in which an aqueous solution of a redox catalyst and of an oxidizing agent is reacted with the said material, wherein the said catalyst contains an organometallic cation of general formula (VII) ##STR11## in which:
- Mn represents manganese in a III or IV oxidation state, it being possible for the two Mn atoms of this cation to form the pair in the III-III or III-IV or IV-IV oxidation state,
- n has the value 2, 3 or 4,
- O representing oxygen,
- L represents a ligand of general formula (VIII):
- ##STR12## in which either R.sub.1 represents the radical:
- ##STR13## R.sub.2 then representing the radical:
- ##STR14## R.sub.3, R'.sub.3 and R".sub.3 each representing, independently of one another, a group chosen from hydrogen, C.sub.1 to C.sub.4 lower alkyl, C.sub.1 to C.sub.4 lower alkoxy or halogen,
- or R.sub.1 represents the radical:
- ##STR15## R.sub.2 and R'.sub.2 then being identical and representing a group chosen from hydrogen or C.sub.1 to C.sub.4 lower alkyl,
- R.sub.3 representing a group chosen from hydrogen, C.sub.1 to C.sub.4 lower alkyl, C.sub.1 to C.sub.4 lower alkoxy or halogen.
Dependencies are inferred from the claim text.