Refineries use a multitude of different processes, such as distillation, hydrotreating or catalytic reforming to convert crude oil into useful products. The search for improved catalysts is an important and worthwhile task to further increase the process efficiency and therefore lower the production costs. For example, the most important part of determining the efficiency of hydrogenation is to measure accurate hydrogen concentrations. On the other hand, expensive, high-performance catalysts degrade fast in the presence of sulfur and nitrogen. Together with regulatory reasons for environmental protection, refineries are interested in keeping the sulfur concentration as low as possible. As a result, processes such as hydrotreating are common to desulfurize intermediates during the process chain.

One System for Multiple Tasks

The vario EL cube is fully compliant with ASTM D5291 (“Standard Test Methods for Instrumental Determination of Carbon, Hydrogen, and Nitrogen in Petroleum Products and Lubricant”), the most important standard for elemental analysis of fuels. For the determination of very low S concentrations down to 2 ppm, the vario EL cube can be equipped with an optional IR detector. Even optional conversion kits for O or Cl can be added at any time for special applications.

Maximize catalyst efficiency through high precision hydrogen measurements

Monitoring hydrogen concentration puts you in total control of the efficiency of the hydrogenation process. Elementar offers industry-leading solutions for this specialized analytical need. The vario EL cube is optimized for highly precise hydrogen concentration measurements. Through detection with a reliable thermal conductivity detector, possible interferences and imprecisions of H2O measurements encountered with infrared detection are avoided. Furthermore, all tubing in contact with water is actively heated to avoid condensation of trace water inside the system, which would affect the data quality. These benefits give you the advantage in a competitive market.

Sulfur and Nitrogen Determination down to trace-level

For refineries 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 refinery intermediates and final products in conformity to these international standards.

Direct high-precision oxygen measurement

Direct oxygen concentration analysis is gaining importance. 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.

Unique low-level, matrix independent nitrogen measurement

Determination of low nitrogen concentrations in difficult samples, such as refinery intermediates, additives or lubricants, can be challenging with typical nitrogen analyzers using chemiluminescence detection (CLD) to measure nitrogen as NO. This approach often shows a matrix dependency which requires extensive calibration for every sample type. The rapid MICRO N cube uses a new approach. With the latest advancements in thermal conductivity detection (TCD) technology, it is possible to determine nitrogen as N2 gas, eliminating all matrix effects. This allows a matrix independent nitrogen determination down to 10 ppm without the need for sample-specific calibration.