Basf Aktiengesellschaft

Hubert Suter

Hartwig Fuchs

Friedrich Wirth

Reinhard Billet

Hans Von Ammon

Erich Renauer

Karl Von Erden

Curt Schneider

Horst Goelz

Maleic anhydride is recovered by evaporating the effluent from the production of phthalic anhydride at from 40.degree. to 150.degree.C and from 50 to 760 mm to a water content of less than 10% by weight, heating the concentrate in a thin-film or falling-film evaporator at from 100 to 600 mm at from 120.degree. to 180.degree.C and distilling it in a column. The pure maleic anhydride is withdrawn laterally and the aqueous condensate is recycled to the offgas scrubber.

Recovering maleic anhydride from the effluent from the production of

A process for the production of cyanuric acid in which urea and an inert solvent are passed into a reaction zone in which pyrolysis of the urea with the formation of cyanuric acid takes place at 200.degree. to 300.degree.C, from 50 to 760 mm and a space-time yield of from 0.1 to 2 kg of cyanuric acid per liter of reaction volume per hour, and the cyanuric acid is separated in a crystal separation zone and freed from solvent in a falling film evaporator.

Continuous production of cyanuric acid

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Ludwigshafen, Germany

Hubert Suter