Diesel hydro-refining catalyst and preparation method thereof

Abstract

The invention relates to a diesel hydro-refining catalyst and a preparation method thereof. The catalyst is composed of an active component nickel-molybdenum metal oxide, a composite dispersion medium silicon dioxide and aluminum trioxide, and an organic salt mixture. The method is a deposition sedimentation method. According to the method, metal salts of nickel, molybdenum, silicon and aluminum are added into water according to a certain ratio, and a homogenous transparent SiO2-gamma-Al2O3 gel is formed through a sol-gel process; with the decomposition of urea, the pH value increases; a reaction of Ni and Mo is carried out under an alkaline condition, such that an Ni-Mo composition is produced and is deposited on the surface of SiO2-gamma-Al2O3; and steps such as filtering, drying, roasting are carried out, such that the bulk catalyst with relatively high dispersion activity is obtained. The catalyst has the advantages of high active component content, uniform active component dispersion, large specific surface area, and high catalytic activity. The catalyst can be used for producing clean diesel with ultralow sulfur content.

Description

technical field [0001] The invention relates to a diesel hydrotreating catalyst and a preparation method thereof, belonging to the technical field of fine chemicals, in particular to a catalyst used for removing sulfur, nitrogen and aromatic compounds in inferior diesel oil and a preparation method thereof. Background technique [0002] Sulfur in diesel fuel generates sulfur oxides during high-temperature combustion, which not only corrodes mechanical parts such as automobile engines, but also is a major automobile exhaust pollutant, which is extremely harmful to the environment and human health. [0003] At present, most of the catalysts used for diesel desulfurization are supported catalysts, and the active components are one or more of NI-W-MO-CO, with aluminum oxide as the carrier, and the loading of active components is relatively low. The best unsupported catalysts recognized in the world are Nebula-1 and Nebula-20 jointly developed by Albemarle, ExxonMobil and NipponKe...

AI Technical Summary

Problems solved by technology

[0005] Zhou Yasong et al. used titanium dioxide as the carrier of Co-Mo catalyst, at a reaction temperature of 360 ° C, a hydrogen partial pressure of 4 MPa, and a volumetric space velocity of 2 h -1 1. Under the condition that the volume ratio of hydrogen to oil is 600:1, the desulfurization rate of catalytic cracking diesel with a sulfur content of 1500 ppm is 88.7%. The desulfurization rate of this catalyst is low, and it is difficult to produce ultra-low sulfur diesel with a sulfur content of less than 50 ppm.

[0006] The industrial application results of the FH-40C diesel oil deep desulfurization catalyst developed by Fushun Petrochemical Research Institute using W-Mo-Ni-Co multi-metal composite active component catalysts show that the sulfur content of 23800ppm in catalytic cracked diesel and coked diesel is high Sulfur mixed feed oil, at a reaction temperature of 350-360°C, a hydrogen partial pressure of 6.5MPa, and a volumetric space velocity of 1.7h -1 1. Under the condition that the volume ratio of hydrogen to oil is 500:1, the sulfur content of the finished diesel is less than 300ppm. When this catalyst is used to produce ultra-low sulfur diesel with a sulfur content of less than 50ppm, the hydrogen partial pressure required is too high, which will cause equipment Increased costs

[0007] Due to the limitation of the specific surface area and pore volume of the carrier, the effective active metal loading in the supported catalyst has reached the limit, making it difficult to greatly improve the catalyst activity. For example, increasing the reaction temperature and pressure can also increase the hydrodesulfurization rate, but As the temperature increases, the side reactions will increase, the life of the catalyst will also be shortened, and the product quality will be reduced, and the pressure will be increased, which will inevitably increase equipment investment and operating costs.