Due to the increase in the requirements for the quality of gasolines and diesel fuels at the beginning of the 1990s, series GP catalysts were developed [1] and have been successfully used in oil refineries (OR) in Russia and CIS countries in hydrotreating of both straight-run diesel cuts [2] and vacuum gasoil in the sections of 100 G-43-107 complexes [3, 4].In the middle of that period, the requirements for the content of not only sulfur (maximum of 500 ppm) but also aromatic hydrocarbons (maximum of 5 and 20 vol. %) were stiffened. To satisfy these requirements, VAMIK-KATALIZ together with SORBENT Co. developed GP-497S catalyst based on a support obtained by fast thermal decomposition of gibbsite. The strength of the catalyst is greater than 20 N/mm.One-stage technology for hydrotreating of straight-run diesel cuts mixed with secondary distillates in the industrial L-24-5 unit at Ufa OR Co. was created in 1996 using this catalyst [4]. GP-497S catalyst was loaded in reactor R-2, the second in the process, and GP-497G was contained in the first reactor R-1, which had previously run for three years with mixed feedstock and had been regenerated once. In summer, a mixture of the straight-run diesel cut with catalytic cracking gasoils are refined in the unit, and winter diesel fuel is refined in winter (from December to February). The data on the work of GP-497S catalyst for more than eight years are reported in Table 1. During this time, the catalyst, regenerated three times, stably ensured obtaining winter diesel fuel with a sulfur content of less than 300 ppm in the winter and environmentally clean diesel fuel with a sulfur content of less than 350 ppm and polyaromatic hydrocarbons of less than 11 vol. % according to TU 38.401.58-296-2001 or with a sulfur content of 0.1-0.12 wt. % as needed in the summer.The degree of removal of aromatic hydrocarbons as a function of the feedstock composition was 25-40%. After eight years of use in refining mixed straight-run diesel cut and catalytic gas oil, diesel fuel with a sulfur content of less than 350 ppm was obtained.With stiffening of the standards for the sulfur content of gasolines (10-50 ppm) and benzene (under 1%) after 2005, refineries will be required to use new catalysts and technologies [5]. Two versions of the solution of the problem are possible:0009-3092/04/4004-0358