Preparation method of hydrodesulfurization catalyst

Abstract

The invention discloses a preparation method of a hydrodesulfurization catalyst. The preparation method of the hydrodesulfurization catalyst is as follows: using a coprecipitation method for preparation of a W, Ni, Al and Mg composite oxide precursor, introducing high molecular polyethylene glycol in the precipitation process, forming, washing, drying and roasting to obtain a catalyst intermediate, using a specific Co and Mo-containing impregnation liquid for impregnation, drying and roasting to obtain the hydrodesulfurization catalyst. The prepared catalyst is smaller in particle and larger in surface area, and enables an active metal to form a hybrid active center with excellently-matched hydrogenation performance and hydrogenolysis performance in the premise of uniform dispersion of the active metal, so that the hydrogenation and hydrogenolysis desulfurization effects of the catalyst active component can be better cooperatively played, ultra-deep desulfurization can be achieved, meanwhile no excess hydrogen consumption is produced, and the processing cost is reduced.

Description

technical field [0001] The invention relates to a method for preparing a hydrodesulfurization catalyst, in particular to a method for preparing a diesel ultra-deep hydrodesulfurization catalyst. Background technique [0002] The trend of high-sulfur crude oil caused by heavy and inferior crude oil is further expanding. According to reports, currently the world's low-sulfur crude oil accounts for only 17wt%, and high-sulfur crude oil with sulfur content > 2wt% is as high as 58wt%. [0003] The SOx, NOx, CH and soot emitted during the combustion process of sulfur, nitrogen and aromatics in diesel can lead to the formation of acid rain, photochemical smog, carcinogens, etc., causing serious pollution to the environment and serious harm to the health of residents. Based on this, governments of various countries are paying more and more attention to air cleanliness, and have stricter requirements on vehicle diesel specifications. In the future, clean diesel specifications are...

AI Technical Summary

Problems solved by technology

Although high-metal W-Mo-Ni hydrogenation catalysts have good hydrogenation performance and can achieve the purpose of ultra-deep desulfurization, in the process of diesel hydrodesulfurization, highly reactive sulfides and unsubstituted bis Part of the benzothiophene sulfides will also be desulfurized through the hydrogenation route, which consumes too much hydrogen and increases the processing cost. At the same time, the excessively high total metal amount also increases the investment cost of the catalyst.

[0011] Most of the currently disclosed bulk catalysts do not impose any restrictions on the size of the particles during the co-precipitation process at the beginning of the formation of the active phase. If large crystal particles are formed at this step, it will be difficult to make them in subsequent steps. The final catalyst has a high specific surface area. Even if the metal is evenly distributed, some metals wrapped in large particles will not be able to fully play their role and become ineffective components, reducing the utilization rate of the metal.

[0012] CN101089132A discloses a hydrodesulfurization catalyst of four active metal components of W-Mo-Ni-Co, although a specific ratio of W-Mo-Ni-Co-P active components is used to make the Co-Mo type The hydrolysis desulfurization performance and the good hydrodesulfurization performance of the W-Ni type have been comprehensively utilized, but the loading of its active components is achieved by saturated co-impregnation technology, and the loading amount of active metals is limited, so it is impossible to provide more The total amount of active metals is more; at the same time, the active component W-Mo-Ni-Co-P cannot control the conditions for the formation of the hydrogenation active phase and the hydrogenolysis active phase precursor during a dry roasting process, so that the catalyst's hydrogenation and Hydrolysis desulfurization activity does not work well together

Adding phosphorus to the impregnation solution can adjust the surface properties of the carrier and improve the interaction between the carrier and the active metal, but during the impregnation process, the interaction between phosphorus and the surface groups of the carrier will weaken the adsorption of active components on the carrier. , so that the active components are prone to agglomeration, reducing the dispersion of the active components in the catalyst, thereby reducing the catalyst activity