Process for the purification of caprolactam from a solution of crude caprolactam without organic solvent extraction

A facility for purification of caprolactam comprising:

• a first reactor made of stainless steel and equipped with an agitator and outer jacket to treat a solution of crude caprolactam by direct contact with one or more alkaline compounds of polyvalent metals, at a temperature between approximately 50° C. and approximately 110° C., for a duration from approximately 1 hour to approximately 5 hours, under stirring, so as to thus obtain a suspension, wherein said one or more alkaline compounds of polyvalent metals, the polyvalent metals are selected from a group formed of bivalent alkaline earth metal hydroxides, bivalent alkaline earth metal oxides, amphoteric polyvalent metal hydroxides having alkaline behavior when placed in contact with acids, amphoteric polyvalent metal oxides having alkaline behavior when placed in contact with acids, and mixtures thereof;
• a second reactor made of stainless steel and equipped with an agitator and outer jacket to cool the suspension from the first reactor and hold it at a temperature between approximately 20° C. and approximately 35° C., for a duration between approximately 1 hour and approximately 6 hours, under stirring;
• a separation station, comprising a centrifuge and one or more pressurized filters equipped with filter cloths, to separate solids from a suspension from the second reactor to obtain an aqueous solution of crude caprolactam;
• a column to dehydrate filtered caprolactam solution obtained from the separation station, to remove water therefrom;
• an evaporation station to remove salts of the one or more alkaline compounds by evaporating the caprolactam;
• and
• a distillation station, comprising a plurality of columns for vacuum fractional distillation, equipped with structured packages to separate the caprolactam from light byproducts and to separate the caprolactam from heavy byproducts.