Delignification of wood pulp by vanadium-substituted polyoxometalates
AssigneeThe United States of America as represented by the Secretary of Agriculture
InventorsIra A. Weinstock, Craig L. Hill
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Abstract
A method for delignifying wood pulp is disclosed. The method comprises the steps of obtaining a wood pulp and exposing the wood pulp to a polyoxometalate of the formula [V.sub.n Mo.sub.m W.sub.l Nb.sub.o Ta.sub.p (TM).sub.q (MG).sub.r O.sub.s ].sup.x- where n is 1-18, m is 0-40, l is 0-40, o is 0-10, p is 0-10, q.ltoreq.6, r.ltoreq.6, TM is a d-electron-containing transition metal ion, and MG is a main group ion, provided that n+m+o+l+p.gtoreq.4 and s is sufficiently large that x>o. The exposure is under conditions wherein the polyoxometalate is reduced. In a preferable form of the invention, the method additionally comprises the step of reoxidizing the polyoxometalate.
Claims13
A method for delignifying wood pulp comprising the steps of:
- obtaining a wood pulp;
- and
- exposing the wood pulp to a solution of a polyoxometalate of the formula [V.sub.n Mo.sub.m W.sub.l Nb.sub.o Ta.sub.p (TM).sub.q (MG).sub.r O.sub.s ].sup.x- wherein n is 1-18, m is 0-40, l is 0-40, o is 0-10, p is 0-10, q.ltoreq.6, r.ltoreq.6, TM is a d-electron-containing transition metal ion, and MG is a main group ion, n+m+o+l+p.gtoreq.4, and s is sufficiently large that x>o, under conditions of temperature, time, consistency, pH and reactor design wherein the polyoxometalate is reduced and enhanced delignification occurs.
A method for delignifying wood comprising the steps of
- obtaining a sample of wood fibers;
- and
- exposing the wood fibers to a solution of polyoxometalate of the formula [V.sub.n Mo.sub.m W.sub.l Nb.sub.o Ta.sub.p (TM).sub.q (MG).sub.r O.sub.s ].sup.x- where n is 1-18, m is 0-40, l is 0-40, o is 0-10, p is 0-10, q.ltoreq.6, r.ltoreq.6, TM is a d-electron-containing transition metal ion, and MG is a main group ion, n+m+o+l+p.gtoreq.4 and s is sufficiently large that x>o, under conditions of temperature, time, consistency, pH and reactor design wherein the polyoxometalate is reduced and enhanced delignification occurs.
Dependencies are inferred from the claim text.