The effect of the nature of nitrogen-containing compounds introduced into a model cracking feedstock (n-hexadecane) on the composition of flue gases formed during catalyst regeneration has been studied. It has been found that the content of CO and NOx in the flue gases grows with an increase in the basicity and molecular weight of nitrogen compounds in the following order: pyridine < n-butylamine < pyrrole < quinoline < indole. The effect of a Pt-based CO afterburning promoter on the regeneration gas composition has been studied. The introduction of this additive provides a decrease in the CO concentration in the regeneration gases by 99.4%; however, it leads to an increase in the NOx concentration by 72.1%. Additives for decreasing the nitrogen oxide content in cracking catalyst regeneration gases have been synthesized and studied. These additives are represented by МеОх (Me = Cu, Fe, Ce, Co, Mn, La) oxide systems supported on γ-alumina. The introduction of the studied additives into the catalyst system at the regeneration stage provides a decrease in the content of nitrogen oxides formed during regeneration. For the additive based on copper oxide, the efficiency in decreasing the nitrogen oxide content in regeneration gases is up to 12.2%.
Kobzar’ et al. (Mon,) studied this question.