Verfahren zur Reinigung von Vorrichtungen fuer die Herstellung von Maleinsaeureanhydrid

• Main Authors: L. RUSSELL JOSEPH, B. FEDER,JACK
• Format: Patent
• Language: German
• Published: 24.10.1968
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; THEIR RELEVANT APPARATUS; TRANSPORTING

A process for removing a solid deposit of crude maleic acid and tars, formed during the production of maleic anhydride by the partial catalytic oxidation of benzene, from apparatus in which the deposit has formed comprises contacting the deposit with at least sufficient molten maleic anhydride to dissolve the deposit and draining off the resulting solution. The removal of the deposit may be carried out simultaneously with the flow of the hot gaseous reaction mixture through the apparatus or may be carried out on apparatus which has been removed from service. The gaseous mixture resulting from the catalytic oxidation may be partially condensed to give liquid maleic anhydride and slow formation of the solid deposit, the uncondensed vapours being passed to a water scrubber where any maleic anhydride present is hydrolysed to maleic acid which is subsequently dehydrated to maleic anhydride. Examples are given. Specification 853,849 is referred to.