Method for recovering free starch in papermaking white water

A papermaking white water and anionic starch technology, applied in the field of pulp and papermaking, can solve the problems of wastewater biological treatment, starch sticky matter deposition, increased microbial growth, etc., to achieve the goal of reducing starch consumption, reducing COD concentration, and improving recycling rate Effect

Active Publication Date: 2022-06-21
RISINGSTAR BIOTECH GUANGZHOU
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  • 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] The structure of hydrophobic group in embodiment 1 starch binding agent is to the influence of binding agent and starch reaction

[0237] In this example, the reaction of starch binders with different structures and native starch (only cured, not modified) was tested.

[0238] Experimental steps: (1) take a cornstarch sample and prepare 7% "standard starch solution"; (2) take an appropriate amount of standard starch solution and dilute it with deionized water until the starch concentration is 1600mg / L; (3) take the prepared starch concentration Put 500mL of the solution in a beaker and put it into a preset constant temperature water bath at 45°C; (4) According to the concentration of the prepared starch complexing agent, add 3-30mg / L starch complexing agent to make the starch : Complexing agent weight ratio is 50: 1, reacts 30 minutes then, obtains modified starch solution; (5) sampling is centrifuged (4000x g) 5 minutes, gets supernatant liquid test starch content and ...

Embodiment 2

[0246] The impact of embodiment 2 reaction time on starch binding reaction

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

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

[0249] This embodiment tests multiple anionic starch complexing agents, and their r...

Embodiment 3

[0250] Embodiment 3 Reaction temperature is to the influence of starch binding reaction and the adsorption effect of modified starch

[0251] This embodiment examines the influence of reaction temperature on the reaction between starch binder and starch and the performance of modified starch (reaction product)

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

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Abstract

The invention relates to a method for recovering free starch in papermaking white water, comprising step (a): reacting an anionic starch complexing agent with free starch in papermaking white water to modify the free starch; The chemical structure of the mixture consists of the following parts: i) one or more hydrophobic groups, wherein at least one hydrophobic group can react with starch to form an inclusion complex, and ii) one or more hydrophilic groups, wherein At least one hydrophilic group is an anionic hydrophilic group; the hydrophobic group and the hydrophilic group are located at both ends of the same molecular structure and connected by chemical bonds to form an asymmetric, polar structure. The method can effectively reduce the content of free starch in papermaking white water, thereby reducing the COD discharge 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, including from material preparation to paper making, chemical recycling, and paper processing, requires a large amount of water for conveying, washing, dispersing materials, and cooling equipment. Although there are recycling, treatment, and reuse in the production process, a large amount of waste water is still discharged into the water body, causing serious pollution to the water environment. Worldwide, paper industry wastewater is an important source of pollution. For example, Japan and the United States list paper industry wastewater as one of the six major public hazards and one of the five major public hazards. [0003] At present, my country's paper industry wastewater discharge and COD discharge rank f...

Claims

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Application Information

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Patent Type & Authority Patents(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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