Production of high-purity hydrogen peroxide solution for use in electronics industry

摘要

Process for producing a high-purity aqueous hydrogen peroxide (H2O2) solution comprises passing a distilled and purified aqueous H2O2 solution through an ion-exchange column packed with cation and anion exchangers at a liquid hourly space velocity (LHSV) of 15-60 and a temperature of -5 to 15 deg C. The cation exchanger is a strongly acidic cation-exchange resin with a degree of crosslinking of at least 10%. The anion exchanger is a strongly basic anion-exchange resin in carbonate or bicarbonate form. The column has internal walls and fractionation elements made of a fluorinated resin. Preferably the solution is contacted with the cation exchanger before the anion exchanger or before and after the anion exchanger. The starting solution is produced by distilling a crude H2O2 solution, containing organic and inorganic impurities, in a bottom-fed distillation column whose internal walls and fractionation elements are made of a fluorinated resin, in which the overhead stream (OHS) is withdrawn without reflux and replaced by ultrapure water (UPW) in a UPW/(OHS-UPW) ratio of 0.1-20 and the purified H2O2 solution is withdrawn from the middle of the column. The crude solution contains 20-60% H2O2, 10-300 ppm total organic carbon and 5-500 ppm inorganic impurities. The distillation column is equipped with a downflow reboiler. The cation exchanger is a macroporous resin, preferably a divinylbenzene-crosslinked polystyrene resin with sulphonic acid groups. The anion exchanger is a macroporous resin, preferably a polystyrene resin with quaternary ammonium groups.