Stamicarbon B.v.

Jan Elmendorp

Abraham H De Rooij

Willem J Wassen

Crude benzaldehyde, and especially benzaldehyde prepared by the oxidation of toluene with a gas containing molecular oxygen, will contain certain impurities which will cause unwarranted discoloration and olfactory problems. These impurities can be effectively removed by treating the benzaldehyde with an oxidizing agent and then distillation.

Process for the purification of benzaldehyde

In commercial processes for producing epsilon-caprolactam, the caprolactam product is in admixture with sulfuric acid. An improved process for removing sulfuric acid from the caprolactam results from treating the admixture with ammonia at superatmospheric pressure.

Process for the recovery of .epsilon.-caprolactam from reaction mixture

Organic sulfoxides such as dimethylsulfoxide are used in the transformation of alicyclic ketoximes into the corresponding lactams according to the Beckmann rearrangement in the presence of a strong acid cation exchange resin as disclosed. Thus cyclohexanone is dissolved in DMSO and contacted with a sulfonated copolymer of styrene and divinyl benzene to produce caprolactam in a continuous process.

Growing community of inventors

Brunssum, Netherlands

Jan Elmendorp