Acid Isomers Of The System Of Oxidation Of Bituminous Coal And Product Coal Terephthalic Acid

This investigation is about the influence of fatty acid used as the promoter on the product of bituminous coal oxidation by oxygen and alkaline solution acting in an autoclave. It' s proved that the yield of coal acids (CA) can be improved by adding acetic acid or propanoic acid . The activities of the two kinds of promoter are about the same, but the influences on different kinds of coal are different. For meager coal oxidation in K2C03 medium with 15% acetic acid as promoter, the yield of CA increases from 27.0% (daf) to 35.3% (daf). For gas coal oxidation under same conditions, the yield of CA increases from 21. 3% (daf) to 23. 3% (daf). Similar results were obtained when promoter was added into KOH medium. The more helpful effect of promoter is that it can improve the content of BPCA in CA sharply. With or without the promoter, the changes in the yields of CA with the reaction ratio of alkali to coal, temperature, reaction time is similar.The isomerization of the ensemble kali salt of CA , with CdCO3 as catalyst and in C02 in a mini reactor (25ml) , has been investigated. The main factors investigated are the content of catalyst, initial pressure of C02, reaction temperature and reaction time. It is found that the BPCA in CA can be converted into TPA and the crude TPA (pureness>90%) could be obtained after separating isomerazated product. The better conditions of kali salt of CA isomerazating are: reaction temperature, 430-450; initial pressure of C02, 4. OMpa; content of catalyst, 4%; reaction time, 2h. The optimum conditions of isomerizating by kali salt of CA and kali salt of benzene carboxylic acid are similar to that of kali salt of CA isomerazation only. The yield of crude TPA to CA is about 34% in the case of CA isomerizating. It equals to 75% of the theoretical yield to BPCA. The yield of crude TPA reaches up to 68% when kali salt of CA and salt of benzene carboxylic acid isomerizating under the best conditions. The yield of TPA to CA is up to 70% after deducting the theoretical yield of BA disproportionation, which is two times of CA isomerization only. The TPA purity can be further improved by refining crude TPA, reaching 99%.