The influence of the diesel fuel hydrotreating temperature on the regularities of silicon sorption on grains of a NiMo/Al2O3 guard bed catalyst with a diameter of 2.5 mm was studied. The tests were carried out on a laboratory stand with a reactor in which the catalyst layer was divided (sectioned) into five parts along the height by metal perforated partitions that are permeable to the feedstock. This made it possible to obtain silicon concentration profiles along the height of the catalyst layer. Decamethylcyclopentasiloxane was used as silicon compound in the diesel fraction, the content of which was 200 ppm. Three series of experiments were conducted for 200 h at temperatures of 315, 340, and 365°C. The feedstock was straight-run diesel fraction containing decamethylcyclopentasiloxane additive as an additional source of silicon. It has been established that with an increase in the process temperature, the ability of the catalyst to absorb silicon increases.
Golubev et al. (Mon,) studied this question.