Investigation of the hydroisomerization of diesel fractions with different concentration of nitrogen-containing compounds on bifunctional catalysts based on ZSM-23 and non-noble metals

Bifunctional catalysts based on NiMo(W) sulfides and a ZSM-23-Al2O3 composite support have been synthesized. Their properties were studied in the transformations of diesel fractions with different nitrogen content (< 1, 10 and 20 ppm). It was demonstrated that the synthesized catalysts could be used to obtain hydrogenizates with the limiting filterability temperature  –38 °C, which comply with the requirements of GOST R 55475-2013 to the content of gasoline fraction and aromatic compounds, and the derived cetane number. Properties of the developed catalysts based on NiMo and NiW sulfides and characteristics of the corresponding hydrogenizates were compared with each other. In addition, properties of the developed samples were compared with the properties of a foreign commercial platinum catalyst for isodeparaffinization. The synthesized catalysts were found to be less selective than the reference sample, but more stable to N-containing compounds in the feedstock.