Neutral deinking with a deinking composition comprising a lipase and a fatty acid ester
AssigneeNovozymes North America, Inc.
InventorsNeal Franks, Kelly W. Page
Life of this patent
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Abstract
The present invention relates to methods for deinking wastepaper by pulping wastepaper at a pH between 4 and 8.5 in the presence of deinking agents comprising a lipase and a fatty acid ester and removing the thereby dislodged ink particles.
Claims27
A method for deinking wastepaper comprising the steps of
- i) pulping the wastepaper at a pH between 4 and 8.5 in the presence of deinking agent comprising a lipase and a fatty acid ester;
- and
- ii) removing the thereby dislodged ink particles.
A method according to any of the preceding claims, wherein the wastepaper comprises old newspapers (ONP).
A method according to any of the preceding claims, wherein the pulping with the deinking agent is carried out at a pH between 4.5 and 8.5.
A method according to any of the preceding claims, wherein the pulping with the deinking agent is carried out at a temperature from 25 to 75° C.
A method according to any of the preceding claims, wherein the fatty acid ester is a methyl ester, an ethyl ester, a n-propyl ester, an isopropyl ester, a n-butyl ester, an isobutyl ester, a sec-butyl ester, a tert-butyl ester, a monoglyceride, a diglyceride or a triglyceride of a C6-C22 fatty acid, the C6-C22 fatty acid being optionally substituted with one or more hydroxy, ethoxy, n-propoxy and/or isopropoxy groups.
A method according to any of the preceding claims, wherein the pulping step is carried out in the presence of a starch degrading enzyme.
A method according to any of the preceding claims, wherein the pulping step is carried out in the presence of a cellulase.
A method according to any of the preceding claims, wherein the lipase is added in an amount corresponding to 0.001 - 0.15% by weight of the dry pulp.
A method according to any of the preceding claims, wherein the fatty acid ester is added in an amount corresponding to 0.025 - 1% by weight of the dry pulp.
Dependencies are inferred from the claim text.