Basf Aktiengesellschaft

Dieter Karau

Klaus Barthold

Friedrich Wirth

Franz-Dieter Martischius

Joachim Wagner

Paul Hornberger

Wolfgang Kube

Otto Leman

Werner Arnold

The invention relates to a process for optimizing the properties of aqueous polymer solutions used for polymer flooding which comprises treating the polymer solutions under turbulent flow conditions in dynamic fluid dispersing or pumping equipment such that the residence time of the polymer solution in this equipment is less than approximately 20 seconds and the pump energy used is from about 1 to about 15 watts/liter of solution processed. This process permits the optimization of flow properties important in polymer flooding which results in the improved efficiency of the polymer flooding process.

Process for optimizing the properties of aqueous polymer solutions used

Process for the recovery of phthalic anhydride in which gases as obtained in the catalytic atmospheric oxidation of o-xylene or naphthalene are treated with a hydrocarbon containing C.sub.26.sub.- paraffins, cooling, if necessary, the hydrocarbon laden with phthalic anhydride, separating the solid phthalic anhydride followed by melting and distillation thereof.

Recovery of phthalic anhydride

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Oftersheim, Germany

Dieter Karau