Fully automated determination of TAN/TBN in industrial samples according to ASTM standards D664 and D2896


As manifested by the numerous standard procedures used all over the world, the determination of the total acid number (TAN) and total base number (TBN) of petroleum products is crucial for quality control in the oil industry. These parameters provide invaluable information regarding petroleum degradation (oil aging) as well as the corrosion enhancement properties and alkaline buffer capacity of the material. The standards ASTM D664 and ASTM D2896 describe two simple methods for the determination of TAN and TBN based on potentiometric titration of the acidic and basic constituents, respectively. Despite being relatively simple, these procedures, if carried out manually, are time-consuming and labor-intensive. Further drawbacks are the handling of toxic solvent mixtures and the tedious cleaning of oil-smeared beakers and electrodes. The 864 Robotic Balance Sample Processor allows the circumvention of these drawbacks. The fully automated and computer-controlled TAN/TBN determinations include weighing, solvent addition, waiting times for complete dissolution and optimized electrode conditioning procedures between samples, as well as convenient collection of all data in a sophisticated database. Results are available within minutes and even very low TAN/TBN values can be determined with reproducibilities better than 2%.