Method for recovering free starch in papermaking white water

A technology of papermaking white water and anionic starch, applied in the field of pulp and papermaking, can solve the problems of wastewater biological treatment, increase of microbial growth, deposition of starch stickies, etc., to reduce starch consumption, improve recycling rate, and reduce COD concentration Effect

Active Publication Date: 2020-09-22
RISINGSTAR BIOTECH GUANGZHOU
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] However, there are some deficiencies in the above-mentioned technologies: in order to prevent the shortening of the starch chain, it is necessary to fully and effectively control the microorganisms and prevent them from secreting amylase. These methods need to add a large amount of Bactericides will affect the subsequent biological treatment of wastewater
In addition, because the starch in papermaking white water mainly comes from surface sizing, its starch molecular weight is low, it is uncharged, and it is difficult to retain it in the paper, resulting in a large amount of starch remaining in the pulping and papermaking system. These starches not only serve as Microbial nutrients will increase microbial growth, and starch accumulation will eventually cause "starch sticky" deposition problems, resulting in paper defects and end breaks, affecting operational efficiency
[0008] So far, there is no real effective solution to the recycling of starch dissolved in papermaking white water

Method used

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  • Method for recovering free starch in papermaking white water
  • Method for recovering free starch in papermaking white water
  • Method for recovering free starch in papermaking white water

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0236] Example 1 The influence of the structure of the hydrophobic group in the starch binder on the reaction between the binder and starch

[0237] This example tested the reaction of starch binders of different structures with native starch (only cured and unmodified).

[0238] Experimental steps: (1) Take a sample of corn starch and prepare a 7% "standard starch solution"; (2) Take an appropriate amount of standard starch solution and dilute with deionized water to a starch concentration of 1600 mg / L; (3) Take the prepared concentration of starch Put 500mL of the solution in a beaker, and put it in a constant temperature water bath set at 45℃; (4) According to the concentration of the prepared starch complexing agent, add 3-30mg / L starch complexing agent to make the starch : The weight ratio of complexing agent is 50:1, and then react for 30 minutes to obtain modified starch solution; (5) Take a sample and centrifuge (4000x g) for 5 minutes, take the supernatant to test the star...

Embodiment 2

[0246] Example 2 Effect of reaction time on starch binding reaction

[0247] In this example, the effect of the reaction time between the starch binding agent and the starch on the modified starch was investigated.

[0248] Experimental steps: (1) Take a sample of corn starch and prepare a 7% "standard starch solution"; (2) Dilute an appropriate amount of standard starch solution with deionized water to a starch concentration of 1800 mg / L (or other required concentration); (3) ) Take 500mL of starch solution or OCC white water of the prepared concentration, place it in a beaker, and put it in a constant temperature water bath at 45℃, and equilibrate to the specified temperature; (4) Add 30mg / L starch binder as required, and after the reaction reaches 10 At 30, 60 and 120 minutes, samples were centrifuged (4000x g) for 5 minutes, and the supernatant was taken to test the starch content and COD concentration.

[0249] In this example, a variety of anionic starch complexing agents were...

Embodiment 3

[0250] Example 3 The influence of reaction temperature on starch binding reaction and the adsorption effect of modified starch

[0251] This example investigated the effect of reaction temperature on the reaction of starch binder and starch and the properties of modified starch (reaction product)

[0252] Experimental steps: (1) Take a sample of corn starch to prepare a 7% "standard starch solution"; (2) Take an appropriate amount of standard starch solution and dilute with deionized water to a starch concentration of 600 mg / L; (3) Take a starch solution of the prepared concentration 500mL, put it in a beaker, and put it in a constant temperature water bath with the required test temperature in advance, and equilibrate to the specified temperature; (4) Add 30mg / L anionic starch complexing agent A6 as required for the test, and react for 60 minutes. Obtain the modified starch solution; (5) take a sample and centrifuge (4000x g) for 5 minutes, take the supernatant to test the starch ...

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Abstract

The invention relates to a method for recovering free starch in papermaking white water. The method comprises the following steps: (a) reacting an anionic starch complexing agent with the free starchin the papermaking white water to modify the free starch; wherein the chemical structure of the anionic starch complexing agent is composed of i) one or more hydrophobic groups, at least one of whichis capable of reacting with starch to generate an inclusion complex, and ii) one or more hydrophilic groups, at least one of which is an anionic hydrophilic group; wherein the hydrophobic group and the hydrophilic group are respectively positioned at two ends of the same molecular structure and are connected through chemical bonds to form an asymmetric and polar structure. The method can effectively reduce the content of free starch in papermaking white water, thereby reducing the COD discharge amount of papermaking wastewater.

Description

Technical field [0001] The invention relates to the technical field of pulping and papermaking, in particular to a method for recovering free starch in papermaking white water. Background technique [0002] The entire production process of the pulp and paper industry, from material preparation to paper forming, chemical recycling, paper processing, etc., requires a large amount of water for conveying, washing, dispersing materials, and cooling equipment. Although there are also recycling, treatment, and reuse in the production process, a large amount of waste water is still discharged into the water body, causing serious pollution of the water environment. In the world, wastewater from the paper industry is an important source of pollution. For example, Japan and the United States respectively list paper industry wastewater as one of the six major public hazards and one of the five major public hazards. [0003] At present, the discharge of wastewater and COD in my country's paper...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D21C11/00
CPCD21C11/0007
Inventor 王祥槐张福山李志军胡维维刘波
Owner RISINGSTAR BIOTECH GUANGZHOU
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