The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 10, 1995
Filed:
Sep. 09, 1994
Shigeki Shimokawa, Yokkaichi, JP;
Yoshitsugu Minamikawa, Yokkaichi, JP;
Seishi Murakami, Yokkaichi, JP;
Abstract
Proposed is an improvement in a method for the preparation of an enriched and purified aqueous hydrogen peroxide solution from a crude aqueous hydrogen peroxide solution comprising the steps of evaporating the crude aqueous hydrogen peroxide solution in an evaporator into vapor with accompanying liquid in the form of a mist, separating the vapor from the mist of liquid in a gas-liquid separator and subjecting the vapor to fractionating distillation in a fractionating distillation column in order to greatly upgrade the product solution relative to the impurity content. The improvement is achieved by subjecting the crude aqueous hydrogen peroxide solution, prior to introduction into the evaporator, to a contacting treatment with a porous synthetic adsorbent resin to remove organic impurities from the crude aqueous hydrogen peroxide solution to such an extent that the crude aqueous hydrogen peroxide solution after the contacting treatment contains organic impurities in an amount not exceeding 50 ppm by weight calculated as organic carbon. Although the mechanism is not well understood, the preliminary removal of organic impurities from the crude aqueous hydrogen peroxide solution has an effect of greatly increasing the efficiency of gas-liquid separation of the vapor accompanied by a mist of liquid in the gas-liquid separator to decrease the amount of contaminant impurities introduced into the distillation column as carried by the mist.