Patent ID: 6398917
Filing Date: 2002-06-04
Classification: B01D,C07C,Y10S

Abstract:
An apparatus for the purification of N,Nâ€²-diphenyl-p-phenylenediamine (DPPD), which comprises:an extraction unit, said extraction unit comprising a liquid-permeable container in which DPPD is extracted from crude DPPD placed therein and a downstream adsorption layer comprising an adsorbent, a solvent evaporator downstream of the adsorption layer in the extraction unit, a filter unit downstream of the solvent evaporator, a lock in a line connecting the solvent evaporator to the filter unit, a filtrate line from the filter unit, in which there is a pump leading to the solvent evaporator, a condenser downstream of the solvent evaporator for recovering and condensing the gas phase from the solvent evaporator, and a solvent line for returning the condensed gas phase from the condenser to the extraction unit upstream of the liquid-permeable container.