ACIDIC HYDROXYL-GROUPS DETERMINATION IN COAL DERIVED LIQUIDS BY THERMOMETRIC TITRATION

Usefulness of the method of thermometric titration for acidic hydroxyl groups determination in coal derived liquids coming from pyrolysis, extraction and hydrogenation processes as well as in group components of these materials (oils, asphaltenes, preasphaltenes) was investigated. Titrations were performed in pyridine-acetone solution using 0,7 mol.l-1 potassium hydroxide in isopropanol as titrant. The effect of titrant concentration, presence of water or other solvents in the acetone on the titration curve were studied in series of benzoic acid titrations. Accuracy and precision of the method was evaluated with several model components, low temperature coal tars and group components separated from coal tars. In conclusion, the method can be used to determine the acidic hydroxyl groups in coal derived liquids with satisfactory results.