Method for preparing lignin-based dispersing agent by purifying pulping black liquor through capacitive deionization method

Abstract

The invention discloses a method for preparing a lignin-based dispersing agent by purifying pulping black liquor through a capacitive deionization method. The preparation method comprises the following steps of (1), adding the pulping black liquor into a reactor, removing a charged impurity in the pulping black liquor with a direct-current voltage of 1.0V to 3.0V by using an electrode, making the pulping black liquor flow through the electrode at a flow speed of 0.1m / min to 0.5m / min, interrupting a power supply once per 5min to 30min to clean the electrode, then recycling the electrode again, and treating a raw material of the pulping black liquor; (2), adding the pulping black liquor from which the charged impurity is removed into another reactor, raising temperature to 60 to 80 DEG C, adding an oxidant into the another reactor, making an obtained first mixture react for 0.5h to 2.0h, afterwards, adding an aldehyde type compound into the another reactor, making an obtained second mixture react for 0.5h to 3.0h at 60 to 100 DEG C, then adding a sulfonating agent into the another reactor, making an obtained third mixture react for 2.0h to 5.0h at 90 to 130 DEG C, then regulating the PH (Potential of Hydrogen) of a reaction system to be 11 to 13, adding sodium hypophosphite into the another reactor, making an obtained fourth mixture react for 1.0h to 4.0h at 80 to 120 DEG C, then adding a quaternizing agent into the another reactor, making an obtained fifth mixture react for 1.0h to 4.0h, then carrying out cooling and discharging to obtain a black-brown liquid product, and drying the black-brown liquid product, so that powder of the lignin-based dispersing agent is obtained.

Description

technical field [0001] The invention belongs to the fields of fine chemicals, environment-friendly materials and surfactants, and in particular relates to a method for purifying pulping black liquor by capacitive deionization and preparing a lignin-based dispersant. Background technique [0002] Lignin, a natural resource that exists in abundance for sustainable use, is the only non-fossil resource that can provide renewable aryl compounds in nature. At present, the pulping and papermaking industry in my country is dominated by alkaline and sulfite pulping waste liquor. Some large pulping and papermaking enterprises use alkali recovery technology to burn pulping black liquor and recover alkali liquor to eliminate pulping black liquor. pollution, but this method will cause a huge waste of lignin resources, so lignin has not been well utilized, and only 6% of lignin in my country has been utilized [1] Most of them are abandoned in nature as waste, which not only wastes resourc...

AI Technical Summary

Problems solved by technology

Lignin itself lacks strong hydrophilic functional groups and insufficient highly active reaction sites, so its water solubility and chemical reactivity are poor, which limits its application range and value

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