Preparation Of Adsorbent In Denitrogenation Of Diesel Oil

Hydrodesulfurization(HDS) is a common method of removing the sulfur species in diesel. Researches have showed that the nitrogen compounds in diesel could inhibit the depth of HDS. According to the preliminary findings of current researches abroad, if the nitrogen compounds in diesel were removed by more than 90%, the effects of HDS would be greatly improved under the conventional hydrogenation condition, and sulfur content in diesel could be lowered to less than 30μg/g, even to 15μg/g.This paper was conducted to prepare a selective adsorbent for removing the nitrogen compounds in the diesel. The common methods for preparation includes: prepare a new Mesoporous zeolite MCM-41 with different Si/Al ratio; Load the metal components which have complex adsorption to nitrogen on the NaY zeolite; Load the metal components which have selective adsorption to nitrogen on the silica gel and Alumina; Modify and Optimize activated carbon with different materials.The selectivity of this adsorbent was studied by the adsorptive experiment with model nitrogen compound such as quinoline, indole, carbazole. The results showed that silica gel and modified activated carbon had better adsorptive effects for the basic nitrogen compound such as quinoline and non-basic nitrogen compound such as indole, carbozole in the model diesel.Select the adsorbent which have better adsorptive capability by the adsorptive experiments with the coked diesel from Tianjin Dagang refinery, then optimized the conditions of the reaction. The results showed that the msoporous zeolite MCM-41 whose Si/Al ratio is 20 and 60 have better adsorptive capability for removing the nitrogen compounds in the diesel, which was processed by successive fixed bed at the temperature of 120℃, its equilibrium adsorption was 3.09g and 3.21g, respectively; The modified silicon gel loading with Ni also had good adsorptive capability for nitrogen compounds, and its equilibrium adsorption was 2.33g.The regeneration capacity was examined by regeneration experiments with the alcohols and ketones as regenerant. The results showed that using acetone and propanol as regenerants had better effect. That could meet the demands of this project, and offered powerful gist for the industrial application in the future.