METHOD (VERSIONS) AND SYSTEMS FOR PRODUCING ISOPHTHALIC ACID AND TEREPHTHALIC ACID Russian patent published in 2013 - IPC C07C51/265 C07C63/24 C07C63/26 C07C15/08 C07C15/73 C08G63/183 

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of converting a raw material stream containing at least one C8 aromatic compound, ortho-xylene, meta-xylene, para-xylene and ethylbenzene, into at least one product stream containing isophthalic acid and terephthalic acid (IPA/TA), which comprises the following steps: a) removing ethylbenzene from said raw material stream to form a raw material stream poor in ethylbenzene; b) removing ortho-xylene from said ethylbenzene-poor raw material stream to form a raw material stream poor in ortho-xylene, containing meta-xylene and para-xylene; c) oxidising said ortho-xylene-poor raw material stream to form a product stream containing IPA/TA in ratio of 0.5% to 99.5% IPA and 0.5% to 99.5% TA; d) drying said product stream in a drier to remove residual solvent and water; e) removing the substantially purified IPA/TA product stream; f) dissolving said product stream; and g) separating said IPA and said TA from said dissolved product stream.

EFFECT: method enables to obtain optimum amounts of IPA and TA from a raw material stream containing at least one C8 aromatic compound, in order to optimise output of IPA and TA.

7 cl, 4 dwg