Global Patent Index - EP 1061173 A1

EP 1061173 A1 2000-12-20 - Oxygen delignification of lignocellulosic material

Title (en)

Oxygen delignification of lignocellulosic material

Title (de)

Delignifizierung von lignocellulosischem Material mittels Sauerstoff

Title (fr)

Délignification de matériaux lignocellulosiques avec de l'oxygène

Publication

EP 1061173 A1 (EN)

Application

EP 00111891 A

Priority

US 33098399 A

Abstract (en)

The invention configures a process for delignifying pulp wherein one stage of a two stage oxygen delignification plant is obviated. In particular, a pulp soak stage enables a pulp stream to be mixed with an alkali feed and held in residence for a sufficient period of time to allow an alkali hydrolysis leaching of colored materials from the pulp and a swelling of the pulp fibers. Next, the pulp stream is combined with an oxygen feed and is processed through a mixer. The output of the mixer is fed to a pressurized reactor where oxygen reacts with lignin of the pulp fibers. The swelled pulp fibers facilitate the oxygen reaction with lignin and removal of additional colored materials. <IMAGE>

IPC 1-7 (main, further and additional classification)

D21C 9/10; D21C 9/147

IPC 8 full level (invention and additional information)

D21C 9/10 (2006.01); D21C 9/147 (2006.01)

CPC (invention and additional information)

D21C 9/1005 (2013.01); D21C 9/147 (2013.01)

Citation (search report)

  • [X] US 4806203 A 19890221 - ELTON EDWARD F [US]
  • [X] US 5085734 A 19920204 - GRIGGS BRUCE F [US]
  • [A] WO 9727358 A2 19970731 - BELOIT TECHNOLOGIES INC [US]
  • [X] VILPPONEN A ET AL: "DELIGNIFICATION BY HOT ALKALI EXTRACTION", TAPPI JOURNAL,US,TECHNICAL ASSOCIATION OF THE PULP & PAPER INDUSTRY. ATLANTA, vol. 76, no. 2, 1 February 1993 (1993-02-01), pages 134 - 138, XP000345097, ISSN: 0734-1415

Designated contracting state (EPC)

AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

EPO simple patent family

EP 1061173 A1 20001220; BR 0002634 A 20010102; CA 2311718 A1 20001214; CN 1277283 A 20001220; JP 2001003287 A 20010109; KR 100538083 B1 20051222; KR 20010049536 A 20010615; NO 20003014 A 20001215; NO 20003014 D0 20000613

INPADOC legal status


2004-06-16 [18D] DEEMED TO BE WITHDRAWN

- Ref Legal Event Code: 18D

- Effective date: 20031216

2002-09-18 [17Q] FIRST EXAMINATION REPORT

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- Effective date: 20020805

2001-09-05 [AKX] PAYMENT OF DESIGNATION FEES

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- Free Format Text: AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

2001-03-07 [17P] REQUEST FOR EXAMINATION FILED

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- Effective date: 20010105

2000-12-20 [AK] DESIGNATED CONTRACTING STATES:

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- Designated State(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

2000-12-20 [AX] REQUEST FOR EXTENSION OF THE EUROPEAN PATENT TO

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- Free Format Text: AL;LT;LV;MK;RO;SI