Method for preparing naphthalene series additive from low-acidity process waste water

Abstract

The invention provides a method for preparing a naphthalene series additive from low-acidity process waste water. The method comprises the following steps of: firstly, carrying out a sulfonation reaction on naphthalene or naphthalene series derivatives at the temperature of 80-200DEG C in the presence of a sulfonating agent; secondly, after the sulfonation reaction is ended, adding the low-acidity process waste water and carrying out a hydrolysis reaction at the temperature of 100-130DEG C under the condition that the total acidity of a reaction system is controlled to be 20-30 percent; and thirdly, after the hydrolysis is ended, adding formaldehyde, raising the temperature and controlling the temperature to be 100-150DEG C for a condensation reaction, adding the low-acidity process wastewater in the condensation process and adjusting the acidity of a material system to be 10-30 percent; and after the condensation is ended, adding an alkali liquor and adjusting the pH value to be 5-9to obtain the naphthalene series additive. According to the method disclosed by the invention, dye and process waste water in the preparation process of a dye intermediate can be recycled; the subsequent treatment cost can be reduced; the consumption of the sulfonating agent in the preparation process of the naphthalene series additive can be reduced; the production cost is reduced; meanwhile, the addition amount of fresh water in the condensation reaction of the naphthalene series additive is reduced, so that water resources are saved; and better economic benefit and social benefit are obtained.

Description

(1) Technical field [0001] The invention relates to a method for recycling low-acidity process wastewater, in particular to a method for preparing naphthalene-based additives from low-acidity process wastewater. (2) Background technology [0002] In chemical production, especially in the production of dyes and their intermediates, a large amount of acid-containing process wastewater is often produced. At present, most manufacturers adopt first treatment before discharge, such as chemical oxidation method, coagulation precipitation method, adsorption method reported in the literature. method, electrochemical method, biochemical method, etc. to discharge after treatment. The above-mentioned methods not only have high treatment costs, but also do not utilize the active ingredients in the process wastewater, resulting in waste; in addition, there are also literatures on the recycling of the process wastewater. It is reported, but only limited to the recycling washing of the same...

AI Technical Summary

Problems solved by technology

[0002] In chemical production, especially in the production of dyes and their intermediates, a large amount of acid-containing process wastewater is often produced. At present, most manufacturers adopt first treatment before discharge, such as chemical oxidation method, coagulation precipitation method, adsorption method reported in the literature. method, electrochemical method, biochemical method, etc. to discharge after treatment. The above-mentioned methods not only have high treatment costs, but also do not utilize the active ingredients in the process wastewater, resulting in waste; in addition, there are also literatures on the recycling of the process wastewater. However, it is only limited to the reuse and washing of the same type of products, and there is no report on the synthesis of auxiliary agents for this process wastewater

Images