Class / Patent application number | Description | Number of patent applications / Date published |
540540000 | Purification or recovery | 6 |
20090312542 | SYSTEM AND METHOD FOR RECOVERING CAPROLACTAM FROM REARRANGEMENT MIXTURES - A system and a method for recovering caprolactam from a rearrangement mixture are provided. The system includes a neutralization unit; a buffering unit for receiving a crude lactam solution containing impurities content below a standard value and being fed from the neutralization unit; a temporary storage unit for receiving a crude lactam solution containing impurities above the standard value and being fed from the neutralization unit; a temporary extraction unit for performing batch extraction to separate out a first lactam solution; an extraction unit for performing continuous extraction to separate out a second lactam solution; and a recovery unit for allowing caprolactam to be recovered. In the present system and method, the crude lactam solution is selectively fed into the extraction unit for continuous extraction or to the temporary extraction unit for batch extraction, thereby maintaining continuity of operation, enhancing separation efficiency, and reducing both material consumption and purification loadings. | 12-17-2009 |
20110224428 | WASHING OF AN ORGANIC PHASE COMPRISING CAPROLACTAM - The invention relates to a process for extracting an impurity from an organic phase comprising caprolactam, comprising extracting the impurity by washing said organic phase as a discontinuous phase with an aqueous phase as a continuous phase, the ratio of the flow of the aqueous phase in m | 09-15-2011 |
20120330006 | METHOD OF MANUFACTURING EPSILON-CAPROLACTAM - An epsilon-caprolactam manufacturing method capable of manufacturing in good yield, high-quality epsilon-caprolactam containing less impurity has an epsilon-caprolactam purification step A of obtaining purified epsilon-caprolactam from raw epsilon-caprolactam by applying a drop crystallization method, a first-stage epsilon-caprolactam recovery step B of obtaining first recovered epsilon-caprolactam and a first recovered mother liquor by applying an evaporative crystallization method to a crystallization mother liquor obtained in the epsilon-caprolactam purification step A, and a second-stage epsilon-caprolactam recovery step C of obtaining second recovered purified epsilon-caprolactam by applying a melt crystallization method to the first recovered mother liquor, first recovered epsilon-caprolactam being recovered as a raw material for the epsilon-caprolactam purification step A and second recovered purified epsilon-caprolactam being recovered as a raw material for the epsilon-caprolactam purification step A and/or the first-stage epsilon-caprolactam recovery step B. | 12-27-2012 |
20130211072 | CAPROLACTAM RECOVERY WITH MEMBRANE TREATMENT - The invention relates to a process for treating an aqueous solution containing ε-caprolactam, ammonium sulphate and one or more other impurities, comprising one or more organic impurities from a caprolactam production process and optionally other salts than ammonium sulphate, by means of a membrane process, thereby obtaining a retentate and a permeate, in which process the membrane used is selected from the group of polyether sulphone membranes, sulphonated polyether sulphone membranes, polyester membranes, polysulphone membranes, aromatic polyamide membranes, polyvinyl alcohol membranes, polypiperazine membranes, cellulose acetate membranes, titanium oxide membranes, zirconium oxide membranes and aluminium oxide membranes, having a molecular weight cut off in the range of 100-1000 g/mol; and wherein more than 60 wt. % of the caprolactam in the aqueous solution is passed through a membrane to the permeate side, to obtain a purified caprolactam containing permeate stream, and wherein at least 50 wt. % of the organic impurities are retained in the retentate solution. | 08-15-2013 |
20140135491 | EXTRACTION REACTOR AND ALSO METHOD FOR EXTRACTION FROM GRANULAR MATERIAL - The present disclosure relates to an extraction reactor with which granular material, in particular granular polyamide, can undergo extraction, soluble components being dissolved out of the granular material with an extraction liquid during the extraction. In the case of polyamide materials, these are for example oligomeric or monomeric components which have remained in the granular material during the polycondensation reaction for the production of the polyamide materials. | 05-15-2014 |
20140171638 | PROCESS FOR PREPARING PURIFIED CAPROLACTAM FROM THE BECKMANN REARRANGEMENT OF CYCLOHEXANE OXIME - A process is described for preparing purified caprolactam, comprising the steps
| 06-19-2014 |