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.

Abstract: The invention relates to a process for purifying caprolactam, said process comprising (a) subjecting the caprolactam to a hydrogenation by treating the caprolactam with hydrogen in the presence of a heterogeneous nickel containing hydrogenation catalyst, (b) distilling at least a portion of the hydrogenated caprolactam in a distillation column containing nickel in an amount sufficiently low such that ?PANNi?3, wherein ?PANNi=?PAN=?PANNi=0, ?PAN=increase of the PAN number of caprolactam during distilling, ?PANNi=0 increase of the PAN number of caprolactam during distilling under the same conditions in a distillation column free of nickel. Nickel is removed from the caprolactam solution prior to the distillation step.

Abstract: The invention relates to a process for preparing caprolactam by admixture of cyclohexanone oxime to a reaction mixture comprising caprolactam and sulfuric acid using a mixing device, said mixing device comprising (i) a tube through which the reaction mixture can flow, and (ii) channels disposed around the tube, said channels opening into the tube, said process comprising: passing the reaction mixture through the tube, and feeding the cyclohexanone oxime into the reaction mixture through one or more of said channels, wherein Re>5000, Re being the Reynolds number as defined by ?·V·D/?, wherein ?=density (in kg/m3) of the reaction mixture that is fed to the tube V=velocity of the reaction mixture, V being defined as W/A, wherein W is the flow rate (in m3/s) of the reaction mixture that is fed into the tube and A is the cross section area of the tube (in m2) at the level where said channels open into the tube D=diameter of the tube at the level where said channels open into the tube (in m) ?=viscosity of the

Abstract: The invention relates to a continuous process for preparing caprolactam by Beckmann rearrangement of cyclohexanone oxime, said process comprising a) feeding (i) oleum and (ii) cyclohexanone oxime into a first reaction mixture comprising caprolactam, sulfuric acid and SO3, b) feeding (iii) a portion of the first reaction mixture and (iv) cyclohexanone oxime into a second reaction mixture comprising caprolactam, sulfuric acid and SO3, c) withdrawing a portion of the second reaction mixture, wherein the process further comprises obtaining the cyclohexanone oxime that is fed to the reaction mixtures by: 1) preparing an organic medium comprising cyclohexanone oxime dissolved in an organic solvent 2) separating, by distillation, cyclohexanone oxime from said organic medium.

Abstract: Process for recovering caprolactam from a solution comprising caprolactam dissolved in an organic solvent, said process comprising: a) washing the solution with water or an aqueous alkaline solution, resulting in a washed solution comprising caprolactam and organic solvent and in a washing residue, b) evaporating organic solvent from the washed solution, resulting in caprolactam product, c) optionally, hydrogenating the caprolactam product, d) optionally, evaporating water from the caprolactam product, e) distilling the caprolactam product to recover caprolactam and a distillation residue, f) extracting the distillation residue with an organic solvent in the presence of water to obtain (i) an extract comprising caprolactam dissolved in organic solvent and (ii) an aqueous effluent, and g) recycling the extract to step a) or b).

Abstract: Process for recovering caprolactam from a solution comprising caprolactam dissolved in an organic solvent, said process comprising: