| 摘要 |
A method for purifying crude naphthalene dicarboxylic acid(cNDA) is provided to mass-produce highly pure 2,6-naphthalene dicarboxylic acid crystals by purifying and crystallizing the cNDA through a continuous purification process using a microorganism fixated on celite and capable of converting 2-formyl-6-naphthoic acid(FNA) into 2,6-naphthalene dicarboxylic acid(NDA). A method for purifying cNDA comprises the steps of: (a) washing the cNDA with water at a temperature of 150-300 deg.C to remove impurities therefrom; (b) after mixing the washed cNDA with a buffer solution, adding an alkaline solution thereto to prepare a purification reaction solution; (c) reacting a Pseudomonas sp. or a Bacillus sp. microorganism fixated on celite and converting FNA into NDA such as Bacillus sp. F-1(deposition no. KCTC-10342BP), Bacillus sp. F-3(KCTC-10335BP) and Pseudomonas sp. HN-72(KCTC-10819BP) with the purification reaction solution at a temperature of 25-50 deg.C for 10-60 minutes to remove FNA from the cNDA; (d) after putting an acidic solution in a reaction solution obtained from the step(c) to adjust a pH into 1 to 4, allowing it to react with agitation with a speed of 0-1,000 rpm at a temperature of 4-80 deg.C for 1 minute to 10 hours to crystallize the cNDA; (e) washing the crystallized cNDA with water at a temperature of 30-100 deg.C to remove salts therefrom; and (f) washing a washed material obtained from the step(e) to obtain a pure crystalline form of NDA. Further, the alkaline solution of the step(b) is KOH or NaOH. |
