Hledat publikace

A high sulfur and nitrogen content in a feedstock for hydrocracking unit negatively affect further processing on products. Based on the sulfur and nitrogen contents, the conditions of the hydrocracking unit are adjusted for its high performance. The elementary analysis determines the total content of sulfur and nitrogen, nevertheless, it is time and cost consuming method (hours, reaction gas, filling CuO). A rapid and inexpensive method was optimized and developed for the determination of total sulfur and nitrogen content in the feedstock using near-infrared spectroscopy (NIRS). The calibration NIRS models were verified by chemometric diagnostics and external validation. The NIRS model of sulfur predicted values in the range of 1.700 – 2.190 % and nitrogen model in the range of 753 – 1348 ppm. The maximum absolute difference between a reference and NIRS value of validation samples was determined of 0.084 % for sulfur and 94 ppm for nitrogen. Furthermore, the influence of sample temperature (70 °C, 80 °C, 90 °C and 100 °C) was tested on the NIRS determination. One sample was analyzed 60 s without the need of other reagents. NIRS is a rapid and cost-effective method to determine the sulfur and nitrogen content in the feedstock for the hydrocracking unit.