HYDROGEN PEROXIDE PURIFICATION METHOD Russian patent published in 2003 - IPC

FIELD: chemical engineering. SUBSTANCE: method, suitable for chemical, textile, and paper-and-pulp industry, can be used in production of bleaching agents and deodorants and when treating industrial and domestic sewages and gas emissions. Method consists in four-step rectification of hydrogen peroxide prepared via oxidation of secondary alcohols. Phlegm containing phosphoric acid and ammonium nitrate is fed into the top sections of rectification columns. Into the top section of the first column is also fed acetic acid-containing 30-40% aqueous hydrogen peroxide solution preheated to 58-72 C. From bottom of the first column, live steam is passed in countercurrent direction. In this column, fraction 70-95 C containing 35-55 wt % H₂O₂ and 0.04-0.08 wt % AcOH is obtained. This fraction is diluted with water to 30-35% H₂O₂ and evaporated. Vapor phase obtained at 60-70 C is introduced into the second column. In the 2nd, 3rd, and 4th columns, high-boiling fractions are obtained containing hydrogen peroxide and acetic acid, wt %, respectively: 60-70 and 0.01-0.02; 70-80 and 0.002-0.005; and 75-85 and 0.001- 0.002. 2nd, 3rd, and 4th-column fractions are diluted with water to 35-50, 50-55, and 30-35% H₂O₂, respectively. Diluted 2nd- and 3rd-column fractions are evaporated and vapor phases obtained at 60-70 C are transferred into next columns. acetic acid level in thus obtained hydrogen peroxide solutions do not exceed 0.002 wt %. EFFECT: improved product purity. 3 cl, 2 dwg, 1 tbl