Coker gasoline hydrorefining process

Abstract

The invention discloses a coker gasoline hydrorefining process. According to the process, a fixed bed reactor is adopted and is filled with hydrogen desulfurization and denitrification catalyst; the catalyst comprises a carrier and an active ingredient; the carrier is SAPO-5 doped with heteroatom Co<2+> in a synthetic framework structure; the active ingredient is a mixture of dimolybdenum nitride MO2N, tungsten nitride, molybdenum carbide and tungsten carbide WC; the reaction conditions of the fixed bed reactor comprise the reaction temperature of 240-350 DEG C, the hydrogen partial pressure of 2-3.5MPa, the hydrogen to oil volume ratio of 450-700 and the volume space velocity of 1-2h<-1>. According to the process, the total sulfur content of coker gasoline is controlled to be lower than 5ppm, and the service life of the catalyst is prolonged to be 8a or longer.

Description

technical field [0001] The invention relates to a coking gasoline hydrodesulfurization refining process, in particular to a coking gasoline hydrorefining process using a specific catalyst. Background technique [0002] Coker naphtha, also known as coker naphtha, is a fraction with an initial boiling point to 180 (205°C) produced in a delayed coking process. Coker gasoline has high sulfur content and high olefin content, low motor octane number (about 60), and poor stability (bromine value 40-60gBr / 100g). The stabilized coker gasoline can only be used as a semi-finished product. Hydrorefining removes nitrogen-containing, sulfur-containing compounds and diolefins before it can be used as a gasoline blending component for vehicles or as a petrochemical raw material (light oil) to produce ethylene, as a raw material for ammonia synthesis or as a raw material for catalytic reforming . [0003] The sulfur content of coker gasoline is generally 0.6%-1.0%, that is, 6,000 to 10,000...

AI Technical Summary

Problems solved by technology

[0004] In the existing desulfurization process, hydrofining has been widely used due to its mature environment-friendly technology. However, the sulfur content of the raw materials targeted by the existing hydrogenation process is mostly at the level of several hundred ppm, and for as high as 6000ppm-10,000 The sulfur content in ppm, the catalyst used in the existing hydrorefining process is difficult to adapt to such a high sulfur content, generally there will be two problems: first, the activity of the catalyst decreases rapidly, and the device is under the condition of processing other raw materials The service life of the catalyst can reach 6a (6 years) or even longer, but after dealing with coked gasoline, the service life of the catalyst is only 1-2a

[0005] After analysis, it is found that when the catalyst used in the existing hydrofinishing is used for the hydrofinishing of coked gasoline, the loss of the metal components of the catalyst is relatively large, indicating that the active components on the catalyst are reduced, and the pore volume is much smaller, resulting in the reaction between the reactant and the catalyst. The contact area of ​​the catalyst decreases, which is directly reflected in the decrease of the catalyst activity

At the same time, when producing ethylene feedstock, reformate feedstock, and synthetic ammonia feedstock, coking gasoline requires high operating severity and high hydrogenation depth, which leads to aggravated carbon deposition in the catalyst bed and a rapid increase in pressure drop