General Electric Company

Sabic Innovative Plastics IP B.v.

Versum Materials Us, LLC

Guohua Xiu

Tong Sun

Peng Zhang

Gurram Kishan

Sunil Ashtekar

Jingwu Yang

Pushpa Narayanan

Mahesh Malusare

Jan Plen Lens

Zhongqi Xu

This invention is aimed at recovering and purifying nitrous oxide from the gas stream containing NO to produce different grade of nitrous oxide by combination of unit operation including, but not limited to, wet scrubbing, adsorption, liquefaction, flash distillation or continuous distillation with reflux.

Process for recovery and purification of nitrous oxide

A method for decoloring 2-phenyl-3,3-bis(4-hydroxyphenyl)phthalimidine ('p,p-PPPBP') is disclosed. The method comprises contacting a liquid solution containing p,p-PPPBP and the common impurities o,p-PPPBP and aminophenone with activated carbon fibers. The activated carbon fibers adsorb the impurities, resulting in a purified solution of p,p-PPPBP. The activated carbon fibers can then be regenerated, such as with a methanol solution having a highly basic pH.

Process for purifying PPPBP

A process comprising the steps of dissolving a dihydric phenol in a solvent to form a solution A; contacting the solution A with a zeolite; filtering the zeolite to form a solution B; adding an anti-solvent to the solution B to form a solution C; and distilling the solution C; wherein the dihydric phenol is represented by Formula (I): wherein R is a hydrogen atom or an aliphatic functionality having 1 to 6 carbon atoms and n is an integer having a value 1 to 4.

Method of purification of dihydric phenols

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Shanghai, China

Guohua Xiu