Process for preparing caprolactam by Beckmann rearrangement
AssigneeDsm IP Assets B.V.
InventorsPetrus Jozef Hubertus Thomissen, Joannes Albertus Wilhelmus Lemmens, Theodorus Maria Smeets
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Abstract
The invention relates to a process for preparing caprolactam by Beckmann rearrangement of cyclohexanone oxime by feeding cyclohexanone oxime to a reaction mixture comprising (i) sulfuric acid (ii) SO3 and (iii) caprolactam , wherein the SO3 content of the reaction mixture is between 9 and 20 wt. % and the molar ratio M of the reaction mixture defined as (nso3+nH2SO4)/ncap is between 1 and 1.4, wherein nso3=quantity of SO3 in reaction mixture, in mol nso3=quantity of H2SO4 in reaction mixture, in mol ncap=quantity of caprolactam in reaction mixture, in mol.
Claims7
Process for preparing caprolactam in a multi-stage Beckmann rearrangement of cyclohexanone oxime by feeding cyclohexanone oxime to a reaction mixture comprising (i) sulfuric acid (ii) SO3 and (iii) caprolactam, wherein in at least a last stage of the rearrangement (1) the SO3 content of the reaction mixture is between 9 and 20 wt. % and (2) the molar ratio M of the reaction mixture defined as (nSO3+nH2SO4)/ncap is between 1 and 1.4, wherein
- nSO3=quantity of SO3 in reaction mixture, in mol
- nH2SO4=quantity of H2SO4 in reaction mixture, in mol
- ncap=quantity of caprolactam in reaction mixture, in mol.
Dependencies are inferred from the claim text.