Hydrofining catalyst

Abstract

The invention relates to a hydrofining catalyst which is obtained by adding a carrier into a dipping liquid for aging and drying after dipping, and then activating. The catalyst, containing the carrier, molybdenum and cobalt, is characterized by containing molybdenum oxide 5-25%, cobalt oxide 1-6%, tungstic oxide 0-15%, nickel oxide 0-4%, and alkali metal oxides 0-4.5%, by the catalyst weight of 100%. Besides, the catalyst pore volume is 0.30-0.85ml / g, and the specific surface area is 110-380 m <2> / g. Compound solvent in the catalyst preparation contains ammonia water and polyamine complexingagent at the same time. The catalyst of the invention while undergoing hydrodesulfurization, saturates monoolefine to the maximum through hydrogenation, to be able to meet the requirements of an oil product with changeable sulfur and diene contents and high air speed running. Catalyst has good hydrogenation activity, high selectivity, long running time and superior anti coking performance.

Description

technical field [0001] The invention relates to a hydrorefining catalyst, which is suitable for hydrorefining of middle and low distillate oil. Background technique [0002] At present, there are many reports on hydrotreating catalysts whose active components are Ni-Mo, Co-Mo, Ni-W, Co-W, Co-Mo-Ni, W-Mo-Ni and their preparation methods. In the process of preparing catalysts containing cobalt and molybdenum by impregnation, the main problem is that the active components Co and Mo are difficult to dissolve, especially the simultaneous dissolution of two active components in one solvent. However, the step-by-step impregnation method to prepare the catalyst will increase the cost of catalyst preparation. The catalyst is prepared by a one-step impregnation method. The problem in the prior art is that it is necessary to add an organic acid / base to promote the dissolution of the active component. Controlling, it is easy to produce overheating phenomenon, and it will release a lar...

AI Technical Summary

Problems solved by technology

In the process of preparing catalysts containing cobalt and molybdenum by impregnation, the main problem is that the active components Co and Mo are difficult to dissolve, especially when dissolving two active components in one solvent at the same time.

However, the step-by-step impregnation method to prepare the catalyst will cause an increase in the cost of catalyst preparation.

The catalyst is prepared by a one-step impregnation method. The problem in the prior art is that it is necessary to add an organic acid / base to promote the dissolution of the active component. Controlling, prone to overheating phenomenon, and a large amount of gas will be released, and the loss of catalyst is also large

[0012] (1) The dispersion of the active metal components on the catalyst is not good, and there are too strong active centers, resulting in a high loss rate in the hydrogenation of aromatics, especially the hydrogenation of benzene;

[0013] (2) There are a certain number of B acid sites on the catalyst, and there are more strong L acid sites in the L acid, which makes the catalyst easy to coke at high temperature, increases the pressure drop of the bed, affects the circulation of hydrogen, and makes it difficult to operate the hydrogen compressor. Hydrogenation products are unqualified and forced to stop for regeneration

[0015] (4) In order to improve catalyst activity, one way is to increase the content of active components, but increasing the content of active components will bring about the problem of poor dispersion

In order to solve this problem, multi-step impregnation can be used in the catalyst preparation process, that is, one step of impregnation followed by drying, roasting and then the next step of impregnation, which makes the preparation process complicated and energy waste is serious, resulting in higher catalyst production costs.

[0016] Although there are reports of one-step impregnation by adding organic acids or complexing agents such as ammonia and ethylenediamine when preparing the impregnation solution, adding a large amount of macromolecular organic acids and bases will increase the difficulty of the subsequent roasting process, and ammonia is highly volatile , its addition will bring more troubles to the preparation process of the impregnation solution, and it is not obvious to improve the dispersion of the active components

Images