Method for producing pulp fibres for saccharification, and aqueous solution of pulp fibres for saccharification

Patent metadata

Field	Value
Publication number	US-2020141055-A1
Application number	US-201816624957-A
Country	US
Kind code	A1
Filing date	May 10, 2018
Priority date	Jun 28, 2017
Publication date	May 7, 2020
Grant date	—

Abstract

The purpose of the present disclosure is to provide a method for producing pulp fibres for saccharification from the pulp fibres of used sanitary items, said pulp fibres for saccharification having low lignin contents distributed within a narrow range, and enabling the production of pulp fibres for saccharification having superior saccharification properties. The production method according to the present disclosure is characterised by comprising the following: a step for supplying a mixed solution ( 51 ) containing pulp fibres and highly-absorbent polymers sourced from used sanitary items to a treatment tank ( 31 ) via a mixed-solution supply port ( 32 ); a step for supplying an ozone-containing gas ( 53 ) to a treatment solution ( 52 ) within the treatment tank ( 31 ) via an ozone-containing-gas supply port ( 43 ); a step for lifting the ozone-containing gas ( 53 ) whilst lowering the pulp fibres and highly-absorbent polymers within the treatment tank ( 31 ), thereby bringing the ozone-containing gas ( 53 ) into contact with the pulp fibres and highly-absorbent polymers, and forming pulp fibres for saccharification from the pulp fibres; and a step for discharging the treatment solution ( 52 ) via a treatment-solution discharge port ( 33 ). The method is further characterised in that the pulp fibres for saccharification have lignin contents of 0.1% or less.

First claim

1 . A method of manufacturing pulp fibers for saccharification from pulp fibers of used hygiene products, comprising steps of:
a preparation step of preparing a treatment tank which includes a liquid mixture supply port, and a treatment liquid discharge port and an ozone containing gas supply port that are arranged below the liquid mixture supply port, a liquid mixture supply step of supplying a liquid mixture which includes super absorbent polymers and the pulp fibers that derive from the used hygiene products and water, from the liquid mixture supply port to the treatment tank, an ozone containing gas supply step of supplying ozone containing gas from the ozone containing gas supply port to a treatment liquid in the treatment tank, a pulp fibers for saccharification formation step of forming the pulp fibers for saccharification from the pulp fibers while dissolving at least a portion of the super absorbent polymers in the treatment liquid, by, in the treatment tank, raising the ozone containing gas while lowering the super absorbent polymers and the pulp fibers so as to make the ozone containing gas come into contact with the super absorbent polymers and the pulp fibers, and a treatment liquid discharge step of discharging the treatment liquid which includes the pulp fibers for saccharification from the treatment liquid discharge port, wherein the pulp fibers for saccharification have a lignin content ratio of 0.1 mass % or less.

2 . The method according to claim 1 , wherein the pulp fibers for saccharification have a water contact angle of 20° or less.

3 . The method according to claim 1 , wherein the pulp fibers for saccharification have a beating degree reduction speed of 300 mL/h or more.

4 . The method according to claim 1 wherein in the pulp fibers for saccharification formation step, the ozone containing gas is supplied from the ozone containing gas supply port as microbubbles or nanobubbles.

5 . The method according to claim 1 , wherein the treatment liquid is acidic.

6 . The method according to claim 1 , further comprising an inactivation step of inactivating the super absorbent polymers by an acid, before the liquid mixture supply step.

7 . The method according to claim 6 , wherein the acid is an acid which can form a complex with metal ions included in an excrement.

8 . The method according to claim 1 , wherein the pulp fibers for saccharification have an ash content ratio of 0.65 mass % or less.

9 . The method according to claim 1 , wherein in the liquid mixture supply step, the liquid mixture is supplied continuously from the liquid mixture supply port to the treatment tank in a first flow rate, and in the treatment liquid discharge step, the treatment liquid is discharged continuously from the treatment liquid discharge port in a second flow rate.

10 . The method according to claim 1 , further comprising a saccharification step of saccharifying the pulp fibers for saccharification, after the treatment liquid discharge step.

11 . An aqueous solution of pulp fibers for saccharification which derives from used hygiene products that include pulp fibers and super absorbent polymers, wherein the pulp fibers for saccharification have a lignin content ratio of 0.1 mass % or less.

12 . The aqueous solution of pulp fibers for saccharification according to claim 11 , wherein the pulp fibers for saccharification have a beating degree reduction speed of 300 mL/h or more.

13 . The aqueous solution of pulp fibers for saccharification according to claim 11 , wherein the aqueous solution of pulp fibers for saccharification is acidic.

14 . The aqueous solution of pulp fibers for saccharification according to claim 13 , wherein the aqueous solution of pulp fibers for saccharification includes an acid which can form a complex with metal ions included in an excrement.

15 . The aqueous solution of pulp fibers for saccharification according to claim 1 , wherein the pulp fibers for saccharification have an ash content ratio of 0.65 mass % or less.

Assignees

• Unicharm Corp

Inventors

• Yamaki Kouichi
• Konishi Takayoshi
• Ohashi Naoto
• Hiraoka Toshio
• Kurita Noritomo

Classifications

• C08J11/10

  by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation (depolymerisation to the original monomer C07) · CPC title

• D21C9/153 Primary

  with ozone · CPC title

• A61F2013/530116

  with recycled material, e.g. paper · CPC title

• A61L2/18

  Liquid substances · CPC title

• D21C5/022 Primary

  Chemicals therefor · CPC title