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Volker Franz

Martin Hirsch

Rolf Geissen

Rolg Geissen

Phthalic acid anhydride is recovered from a gas stream containing phthalic acid anhydride vapors by passing the gas stream upwardly through a vertical tube so that the gases expand at the orifice at the upper end of the tube and mix with granules entrained above the tube by fluidizing gas of a fluidized bed of phthalic acid anhydride granules around the tube. The tube, kept free from phthalic acid anhydride granules and the fluidized bed, is indirectly cooled.

Method for separating vaporous phthalic acid anhydride from a gas stream

A multitube reactor for exothermic or endothermic reactions carried out in a multiplicity of tubes, which are surrounded by a liquid, at least part of which is circulated by a circulating pump, which is disposed outside the reactor structure, to flow through heating and cooling means and is the recycled to the reactor structure. The tubes and the surrounding liquid are disposed between a cylindrical inner wall and an outer wall which surrounds and is coaxial to the inner wall. The circulating pump is disposed in the liquid-free space that is surrounded by the inner wall.

Multi-tube reactor

In a method of periodically heating a product separator of a plant for producing anhydride or maleic anhydride, a PA or MA product is deposited on cooling surfaces of the product separator. To melt the product, the cooling surfaces are indirectly heated by means of a heated liquid, which is circulated through the product separator. The liquid heat transfer medium is indirectly heated with steam in a heater for the heat transfer medium. At least during the time of the largest steam demand, most of that steam is taken from a steam accumulator, which is charged with steam supplied from the plant for producing PA or MA. The charging of the steam accumulator is effected to at least a substantial degree during the time in which the heater for the heat transfer medium is out of operation or is operated under a low load.

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Frankfurt am Main, Germany

Volker Franz