METHOD AND INSTALLATION FOR REGENERATION OF WASTE SULFURIC ACID FROM NITRATION PROCESSES Russian patent published in 2014 - IPC C01B17/94 C07C201/16 

FIELD: chemistry.

SUBSTANCE: invention relates to field of chemistry. Waste, preliminarily heated acid from processes of obtaining dinitrotoluol or trinitrotoluol is supplied via inlet 1 into first stripper K1 with jointly operating evaporator V1 for preliminary concentration of sulfuric acid. Concentrated sulfuric acid, obtained in the bottom part of column K1 is supplied into upper part of second stripper K2. Obtained vapour phase is condensed with formation of acid-water-nitroorganic condensate. Purified sulfuric acid is formed in the bottom part V2 of column K2. To supply initial flows into K1 column pipelines 1, 7 are used. To transport, distribute and discharge vapour and liquid phases pipelines 2, 5, 8, 10, 21, and obtained as intermediate and final products, and discharged gases pipelines 4, 12, 13, 17, 18, 21 are used. Highly concentrated sulfuric acid obtained in regeneration is supplied via inlets 3, 3a, connected with, at least, one evaporator V3, into first stripper K1.

EFFECT: invention makes it possible to reduce exploitation costs, energy consumption and emissions.

18 cl, 2 dwg