A kind of modified alumina carrier and preparation method thereof

Abstract

The invention discloses a modified alumina carrier and a preparation method thereof. Based on the weight of the modified alumina carrier, the modifier A is 2wt%-10wt% in terms of elements, the modifier B is 3wt%-15wt% in terms of oxides, and the Group VIII metal sulfide is 2wt%-10wt% %; The amount of infrared acid at 250-450℃ is 0.18-0.55mmol / g. The preparation method is as follows: (1) adding an aluminum source and a precipitant into an aqueous solution containing a precursor of modifier A, performing a precipitation reaction, then hydrothermally treating, then filtering and drying to obtain a modified pseudoboehmite; (2) ) Mixing the modified pseudo-boehmite with peptizer and extrusion aid and extruding uniformly, and drying and calcining to obtain an alumina carrier; (3) Loading the metal containing Group VIII onto the alumina carrier and carrying out vulcanization treatment , to obtain a modified alumina carrier. The modified alumina carrier of the invention has the characteristics of suitable medium-strength acid content, high B acid content, low L acid content, large pore size and concentrated pore size distribution, and is suitable for the hydrogenation reaction of jet fuel, diesel oil and coker naphtha. process.

Description

technical field [0001] The invention relates to the technical field of oil hydrogenation, in particular to a modified alumina carrier and a preparation method thereof. Background technique [0002] Due to the existence of the acid center of the hydrogenation catalyst, the compounds that are prone to carbon deposition are strongly adsorbed on the acid center of the catalyst, covering the active center and gradually blocking the pores, so that the reactants cannot approach the active center, which greatly reduces the catalyst surface utilization rate. Catalyst coke deactivation. The deactivation rate of diesel hydrodesulfurization catalyst is related to the deactivation of catalyst coke deposition, and the coke deposition reaction is closely related to the medium-strong acid strength of the catalyst. At the same time, the interaction of Lewis acid and basic nitrogen compounds is the main way of carbon generation, and the Lewis acid center is the starting point for the formati...

AI Technical Summary

Problems solved by technology

However, when increasing the amount of carrier B acid, the total acid amount of the carrier is too large, or the ratio of the amount of B acid is increased but the amount of B acid is not significantly improved. In addition, while increasing the pore size of the carrier, the carrier Excessive loss of specific surface area

Excessive amount of carrier acid will easily lead to carbon deposition, poisoning and deactivation of the catalyst, which will reduce the stability of the catalyst. If the specific surface area of ​​the carrier is too small, the active number of catalysts will be reduced, and the reactivity of the catalyst will be reduced.

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