Liquid Fuels

Understanding the concentrations of sulfur and nitrogen in liquid fuels is of critical importance in refining operations for two main reasons: regulatory purposes and process optimization. In most markets world-wide regulatory agencies, such as the Environmental Protection Agency (EPA), limit the total amount of sulfur and nitrogen in fuel and refined products. This is because fuels containing high levels of sulfur release sulfur dioxide gas when burned, causing a range of health issues as well as environmental issues such as acid rain. As regulations push for cleaner fuels, greater pressure will be placed on manufacturers to better monitor pollutants such as SO2 and NOx. Moreover, expensive catalysts utilized in refining processes degrade much faster in the presence of high sulfur and nitrogen concentrations.

Sulfur and Nitrogen Determination down to trace-level

For the manufacturer to know the final concentrations, it is imperative that analytical technology is capable of detecting low levels. According to international standards, e.g. ASTM D4629 or ASTM D5453, the content of sulfur and nitrogen in fuels or light hydrocarbons has to be determined via high temperature combustion of the sample. The determination of the formed NO is performed with a chemiluminescence detector and of SO2 with a UV-fluorescence detector. The trace SN cube is especially developed for high-sensitivity sulfur and nitrogen determination in diesel, gasoline, and related samples in conformity to these international standards.

Direct high-precision oxygen measurement

Direct oxygen concentration analysis is gaining importance in the fuel industry. In the past, oxygen concentrations were often determined indirectly, by subtracting from 100 the sum of C, H, N, and S concentrations (cf., ASTM D3176). However, the accuracy of indirect oxygen determination via calculation suffers from the cumulative errors inherent in the analytical methods used for each of the other elements. In addition, it is dependent on the ash content which is obtained, thus introducing another source of error into the indirect oxygen determination. Accurate, unbiased determination of oxygen concentration is therefore only possible through direct measurement. In the fuel industry, as well as in other markets, regulations (cf., ASTM D5622) require precise direct determination of oxygen concentrations. The rapid OXY cube® with its patented backflush technology perfectly fits to these analytical demands with its unrivaled precision.