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 accounts for 2wt%-10wt% by element, the modifier B accounts for 3wt%-15wt% by oxide, and a group VIII metal sulfide accounts for 2wt%-10wt%; and the infrared acid amount at a temperature of 250-450DEG C is 0.18-0.55mmol / g. The preparation method comprises the following steps: (1) adding an aluminum source and a precipitant into a precursor aqueous solution containing a modifier A in parallel, carrying out precipitation reaction, carrying out hydrothermal treatment, and then performing filtering and drying to obtain modified pseudo-boehmite; (2) uniformly mixing the modified pseudo-boehmite with a peptizing agent and an extrusion aid, carrying out extrusion molding, and performing drying and roasting to obtain an alumina carrier; and (3) loading a VIII group metal onto the alumina carrier, and carrying out vulcanization treatment to obtain the modified alumina carrier. The modified alumina carrier has the characteristics of appropriate medium-strength acid amount, high B acid content, low L acid content, large pore size, centralized pore size and pore distribution and the like, and is suitable for the hydrogenation reaction process of aviation kerosene, diesel oil and coker naphtha.

Description

technical field [0001] The invention relates to the technical field of hydrogenation of oil products, 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 compound that is easy to deposit carbon is 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 surface utilization of the catalyst, resulting in Catalyst carbon deposit deactivation. The deactivation rate of the diesel hydrodesulfurization catalyst is related to the deactivation of the catalyst's carbon deposition, and the carbon deposition reaction is closely related to the medium-strong acid strength of the catalyst. At the same time, the interaction between Lewis acid and basic nitrogen compounds is the main char formation pathway, and the Lewis a...

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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