Abstract: This invention relates to a method of producing benzene carboxylic acids from an aromatic material, especially coal, by the oxidation of the aromatic material in an aqueous alkaline mixture containing an aliphatic organic acid promoter agent with a source of gaseous oxygen. Use of the aliphatic organic acid promoter agent results in a surprising and unexpected increase in the benzene carboxylic acid yield which is higher than that obtained without the promoter agent.A finely divided coal, potassium carbonate, water, and aliphatic carboxylic acid promoter agent are charged to a feed tank (10) where they are mixed with an agitator (14). A slurry pump (18) pumps the mixture through a preheater (20) to an autoclave (30). Air is continuously fed to the autoclave (30) by a gas compressor (34). The coal slurry is oxidized in the autoclave (30) while being agitated by a mixer (36). Gaseous products, and in particular carbon dioxide, is continuously removed from the autoclave (30) through a vent conduit (42).

Abstract: This invention relates to a method of producing an aqueous solution which comprises soluble benzene carboxylic acid salts which is substantially free of soluble humic acid salts. A first aqueous solution (22) which comprises soluble humic acid salts and soluble benzene carboxylic acid salts is reacted with carbon dioxide (32) and an inorganic chemical (34) selected from the group consisting of magnesium bicarbonate, magnesium carbonate, a double salt of magnesium carbonate, and mixtures thereof in a mixing zone (30) under conditions operable for converting the soluble humic acid salts to precipitated magnesium humic acid salts while maintaining the soluble benzene carboxylic acid salts in solution.