Thermal treatment of precursor material of catalytically active material, for partial gas-phase oxidation of acrolein to acrylic acid, involves circulating gas stream flowing through rotary tube furnace

摘要

Thermal treatment of the precursor material of a catalytically active material in a rotary tube furnace involves circulating at least a portion of a gas stream flowing through the rotary tube furnace. Independent claims are also included for: (1) A rotary tube furnace apparatus comprising recycle gas compressor(s); exit gas compressor(s); pressure reducer(s); fresh gas feed(s); heatable rotary tube(s); and recycle gas pipe(s); and (2) A tube-bundle reactor comprising 5000-40000 catalyst tubes filled with a load whose catalysts contain a multi-element oxide material as active material. The load of the catalyst tube for a partial oxidation of acrolein to acrylic acid is such that when a random sample of 12 catalyst tubes is taken, the difference between the arithmetic mean activity and the highest or lowest activity is not >8[deg]C.