公开(公告)号：DE4209633A1

公开(公告)日：1993-09-30

申请号：DE4209633

申请日：1992-03-25

Applicant: BASF AG

Inventor： HEDTMANN-REIN CAROLA DR ,  HUEBINGER WOLFGANG DR ,  THEIS RAPHAEL ,  FISCHER HERMANN DR ,  SCHWOEBEL GERD ,  SEITZ FRIEDRICH DR ,  ZEHNER PETER DR

IPC: B01J10/00 ,  C08G65/44

Abstract: A process is claimed for producing polyphenylene ethers (I) by continuous 2-stage catalytic reaction of oxygen with aromatic mono-hydroxy cpd(s). (II). Stage (1) is carried out in a reactor with largely complete back-mixing, and stage (2) in a reactor with partial back-mixing. Also claimed in an appts. for the process, with 2 reactor (systems) as above. Pref. stage 1 is carried out in a ga/liq. reactor (jet reactor) with a jacket tube which is blanked off at the top and in which one or more downwardly directed liq. jets are mounted at the highest point and fed from a liq. pump circuit, so that a gas phase is entrained with and then completely dispersed in the liq.; before starting the liq. circulation, the static reactor is filled with only enough liq. to leave a gas space at the top of the reactor corresp. to the subsequent hold-up under operating conditions, this gas space is filled with inert gas at pressure pl, and the gaseous reactants are only introduced into the reactor when the action of the liq. jets has produced a dispersion of inert gas such that a coherent gas phase no longer exists. The reactor system in stage 1 consists of a jet reactor, a circulating pump and a heat exchanger. Stage 2 is carried out in a continuous flow-tube reactor. USE/ADVANTAGE - The process enables the prodn. of (I) with higher space-time yields (w.r.t. prior-art processes for PPE with comparable mol. wt.), shorter residence times, smaller amts. of off-gas and reduced by-prod. formation

公开(公告)号：DE4328059A1

公开(公告)日：1994-03-03

申请号：DE4328059

申请日：1993-08-20

Applicant: BASF AG

Inventor： HEDTMANN-REIN CAROLA DR ,  THEIS RAPHAEL ,  SCHWOEBEL GERD ,  THELEN HANS-GUENTER DR ,  HUEBINGER WOLFGANG DR

IPC: B01J10/00 ,  C08G65/44 ,  F28D13/00

Abstract: A reaction system for prodn. of polyphenylene-ethers comprising a propulsive jet reactor, a heat exchanger and a circulation pump, characterised in that instead of a conventional cooled tube heat exchanger, a heat exchanger with circulating eddy layer is used. ADVANTAGE - The use of a heat exchanger with circulating eddy layer reduces the progressive increases in pressure loss over the heat exchanger which occurs with conventional cooled tube heat exchangers due to deposition of high mol. wt. PPE fractions on the tube walls, and thus allows the system to be operated for extended periods without maintenance.