To provide a method for recovering a tar acid from aromatic compounds in a good efficiency by decomposing phenolates extracted from an aromatic oil with an aqueous alkali solution, with a gas containing carbon dioxide in the presence of a specific liquid hydrocarbon in a specific ratio.
This method for recovering a tar acid is constituted by extracting an aromatic oil consisting of 150-250°C fraction obtained by distilling a coal tar with an aqueous 10% sodium hydroxide solution to obtain an aqueous solution of phenolates, charging the solution into the inside of a first decomposition column 4 through a line 1, at the same time supplying a gas containing carbon dioxide into the inside of the first decomposition column 4 through a line 2, maintaining the temperature in the first decomposition column at 600°C and holding for approximately 1hr, then continuously discharging a reaction mixture through a line 5 and transferring it to a mixing vessel 7, charging the mixture to a second decomposition column 9 through a line 8 after mixing with xylene supplied from a line 6, supplying the gas containing carbon dioxide through the line 2 and contacting with the reaction mixture, then transferring into a separating vessel 11 through a line 10 for separating an oil from water, transferring the oil layer to a water washing tower 15 through a line 13 and recovering a tar acid from a line 16.
FURUMOTO MASASHI
NAGAI MUNEHITO
SUGATA MASAYASU
