Total Nitrogen
Total Nitrogen (TN) stands for the sum parameter of all organic and inorganic nitrogen compounds. Trace levels (0.02 – 10.000 mg/kg or ppm by weight) of Total Nitrogen are measured with an elemental combustion analyzer according to Chemiluminescence detection technique. These measurements are mainly carried out in:
• Oil & Gas industry (Refineries): Total Nitrogen in fuels (NO2) pollutes the environment, it’s corrosive to steel and poisons catalysts. Nitrogen compounds are more thermally stable compared to sulfur compounds and are often concentrated in heavier petroleum fractions and residues. Examples of Organic Nitrogen compounds that contribute to the Total Nitrogen number in petroleum products are Pyridines, Quinolines and Carbazoles. Hydrotreating of petroleum fractions is an established technique to remove nitrogen compounds.
• Fats and oils processing plants: The amount of Total Nitrogen is related to the quality of the intermediate or final products in the food industry. Fats and Oils are also used to produce Biodiesel, therefore the Total Nitrogen number needs to be below the maximum allowable amount for fuels.
• Plastic Manufacturing Facilities: Nitrogen containing additives present in a polyolefin sample are measured to monitor physical properties and quality control of polymers in general.
International methods to measure the amount of Total Nitrogen at trace level: ASTM D4629, ASTM D5762, ASTM D6069, ASTM D7184, SHT 0657.