Device and method for recovering sulfuric acid from waste sulfuric acid generated in process of producing perylene series pigment

Abstract

The invention relates to a device and method for recovering sulfuric acid in waste sulfuric acid generated in the process of producing a perylene-3,4,9,10-tetracarboxylic dianhydride pigment, mainly solving the problem that the waste sulfuric acid generated when perylene series pigments are produced can not be recovered. The device comprises a concentrating pan, a fractionating tower, a dilute sulfuric acid preheater, a concentrated sulfuric acid cooler, a concentrated sulfuric acid buffer tank, a concentrated sulfuric acid head tank, a waste sulfuric acid head tank, a medicament head tank and the like. The method is characterized in that concentrated sulfuric acid in the concentrated sulfuric acid buffer tank is circularly preheated in the concentrated sulfuric acid head tank, the preheater, the fractionating tower, the concentrating pan and the concentrated sulfuric acid cooler; the sulfuric acid enters the fractionating tower after being evaporated, and the waste sulfuric acid in the concentrating pan is sent to the waste sulfuric acid head tank and then enters the preheater; the waste sulfuric acid enters the fractionating tower; the waste sulfuric acid enters the concentrating pan after being concentrated, and a medicament is added to the concentrating pan; and the hot sulfuric acid enters the cooler after being cooled and then enters the concentrated sulfuric acid buffer tank, and part of the sulfuric acid is sent to the head tanks and part of the sulfuric acid is sent to a product storage tank by a pump. The device and the method have the advantage that the sulfuric acid in the waste sulfuric acid can be effectively recovered.

Description

Technical field: [0001] The invention relates to a device for recovering sulfuric acid in waste sulfuric acid produced in the production of 3,4,9,10-perylenetetracarboxylic dianhydride pigments and a recovery method thereof. Background technique: [0002] The content of sulfuric acid in the waste sulfuric acid produced during the production of 3,4,9,10-perylenetetracarboxylic dianhydride pigment is about 90~95%, fluctuating from time to time, and the color is dark red with granular precipitation at the bottom. Contains about 1% organic matter, fluctuating. Organic matter is: perylene tetracarboxylic acid diimide, perylene tetracarboxylic acid dianhydride, 1,8 naphthalimide, perylene tetracarboxylic acid diimide incomplete hydrolyzate and other impurities. This type of organic matter has a complex and stable structure, a large molecular weight, a high melting point, and is difficult to separate and decompose. Even if it reacts with an oxidant in high-temperature concentrated...

AI Technical Summary

Problems solved by technology

This type of organic matter has a complex and stable structure, a large molecular weight, a high melting point, and is difficult to separate and decompose. Even if it reacts with an oxidant in high-temperature concentrated sulfuric acid, it will take a certain amount of time to decompose.

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