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Preparation of High‐Purity 2,6‐Naphthalenedicarboxylic Acid from Coal Tar Distillate
Author(s) -
Ban Heng,
Cheng Youwei,
Wang Lijun,
Li Xi,
Zhou Xiaoye,
Zhang Xinjian
Publication year - 2019
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.201800129
Subject(s) - distillation , chemistry , raw material , tar (computing) , coal tar , crystallization , fraction (chemistry) , acetic acid , solvent , organic chemistry , coal , catalysis , vacuum distillation , chromatography , waste management , chemical engineering , computer science , engineering , programming language
Using coal tar distillate as the starting material, a novel high‐purity 2,6‐naphthalenedicarboxylic acid (2,6‐NDA) preparation method was developed. Firstly, the 2,6‐dimethylnaphthalene (2,6‐DMN) precursor was separated by successive vacuum distillation, melt crystallization, and solvent crystallization from the 250–270 °C fraction of the coal tar distillate. Then, over Co‐Mn‐Br as catalysts, oxidation of 2,6‐DMN was carried out in acetic acid to produce crude 2,6‐NDA with molecular oxygen. By high‐temperature hydrogenation, the crude 2,6‐NDA was further purified to obtain high‐purity 2,6‐NDA. From the coal tar distillate to pure 2,6‐NDA, the operation parameters and reaction conditions of each process were optimized and evaluated, indicating that the proposed 2,6‐NDA synthesis method has great potential for industrial application to create cheap feedstock in viable yields.