Pre-hydrotreatment method of reforming feedstocks

Abstract

The invention provides a pre-hydrotreatment method of reforming feedstocks. The pre-hydrotreatment process undergoes in the conditions that: the reaction inlet is at a temperature of 200-320DEG C, the operation pressure is over 2.4MPa, the volume space velocity of fresh raw oil is 4-12h<-1>, and the volume ratio of hydrogen to oil is 50-300; the hydrotreatment catalyst employed takes silicon-containing alumina as the carrier, cobalt and molybdenum as the active constituents, boron and alkali metal and / or alkaline earth metal as the auxiliary agents, and the precursor of the silicon-containing alumina carrier is amorphous silica-alumina containing pseudo-boehmite, which is obtained by preparation of an amorphous silica-alumina slurry and a pseudo-boehmite slurry first, followed by mixing and ageing of the two slurries, and the post-treatments of filtering, washing and drying. The method of the invention can be used to treat catalytic reforming feedstocks of high sulfur and nitrogen content as well as high olefin content in a low pressure condition, and can provide qualified feedstocks with sulfur and nitrogen content both less than 0.5 microgram / gram for catalytic reforming units.

Description

technical field [0001] The invention relates to a reforming raw material prehydrotreating method, which is especially suitable for the hydrotreating of the feed of a catalytic reforming unit. Background technique [0002] Catalytic reforming process is one of the important processes in oil refining and petrochemical industry. 6 ~C 11 The naphtha distillate is used as the raw material, and the reformed oil rich in aromatics is produced through hydrogen-catalyzed reaction, and hydrogen is produced as a by-product. The catalytic reforming process usually uses double (multi) noble metal catalysts such as platinum-rhenium and platinum-iridium. In order to prevent catalyst poisoning, the sulfur and nitrogen content in the feed are required to be less than 0.5 μg / g. Therefore, the raw material needs to be pre-hydrotreated before entering the reforming unit to remove impurities in the raw oil that are harmful to the catalytic reforming catalyst, including sulfur, nitrogen, olefins...

AI Technical Summary

Problems solved by technology

[0005] CN1267187C discloses a silica-alumina containing pseudo-boehmite structure, the carrier silica content is high, and the silicon-containing compound solution is directly or co-currently introduced into the pseudo-boehmite slurry, the purpose It is to increase the content of four-coordinated aluminum to increase the acid strength and acid amount of alumina. The prepared silicon-containing alumina has high cracking activity. However, the higher cracking activity is used as a hydrogenation catalyst carrier, which reduces the liquid yield.

However, the composite oxide prepared by this method has a large number of micropores, which is not suitable for use as a carrier for hydrotreating catalysts for low- and medium-distillate oils.

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