Claims
- 1. A process for producing a papermaking pulp from starch-containing printed paper, comprising:
a) disintegrating the paper to produce a pulp, b) treating with a starch-degrading enzyme and a pectate lyase during or after step a), and c) separating ink particles from the pulp after steps a) and b).
- 2. The process according to claim 1 wherein the starch-degrading enzyme is an alkaline stable enzyme.
- 3. The process according to claim 1 wherein the starch-degrading enzyme is an Δ-amylase.
- 4. The process according to claim 1 wherein the starch-degrading enzyme is derived from a strain of Bacillus.
- 5. The process according to claim 4 wherein the starch-degrading enzyme is derived from B. amyloliquefaciens, B. licheniformis or B. stearothermophilus.
- 6. The process according to any of claims 1 to 4 wherein the enzymatic treatment is performed with an amount of starch-degrading enzyme in the range 0.01-10 KNU/g of dry matter.
- 7. The process according to claim 1 wherein the pectate lyase is derived from or produced by a strain of Bacillus.
- 8. The process according to claim 7 wherein the pectate lyase is derived from or produced by B. licheniformis.
- 9. The process according to any of claims 1, 6 and 7 wherein the enzymatic treatment is performed with an amount of pectate lyase in the range 0.01-10 APSU/g of dry matter.
- 10. The process according to claim 1 wherein the enzymatic treatment is performed at a pH in the range 6-10.
- 11. The process according to claim 10 wherein the enzymatic treatment is performed at a pH in the range 8-10.
- 12. The process according to claim 1 wherein the starch-containing paper is mixed office waste.
- 13. The process of claim 1 wherein the enzyme treatment is performed simultaneously with the disintegration.
- 14. The process according to claim 13 wherein the enzyme treatment and disintegration are performed in the presence of a surfactant.
- 15. The process according to claim 13-14 wherein the enzyme treatment is continued after the disintegration.
- 16. The process according to any of claims 1 and 13-15 wherein said c) comprises the following sequential steps after the disintegration and the enzyme treatment:
separation of ink particles, bleaching, and separation of ink particles.
- 17. The process according to claim 1 wherein the enzyme treatment is performed after the disintegration.
- 18. The process of any of the preceding claims wherein the enzyme treatment is performed simultaneously with bleaching.
- 19. The process according to claim 18 wherein the enzyme treatment and bleaching are performed in the presence of hydrogen peroxide and a surfactant.
- 20. A process for making new paper or tissue from starch-containing printed paper, comprising producing papermaking pulp by the process of any preceding claim, and making new paper or tissue from the pulp.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 09/826,691, filed on Apr. 5, 2001, the contents of which are fully incorporated herein by reference.
Continuations (1)
|
Number |
Date |
Country |
Parent |
09826691 |
Apr 2001 |
US |
Child |
10413335 |
Apr 2003 |
US |