A revival method of spent FCC catalysts with controlled leaching, metal passivation and active component compensation

Abstract

The invention discloses a method for revitalizing spent FCC catalysts through controlled leaching, metal nickel passivation and active component compensation reaction, and relates to the technical field of solid waste reuse. Specific resurrection method: It uses controlled impurity removal agent to control leaching, impurity removal and pore expansion, which can effectively prevent the dissolution of aluminum oxide in the process of removing heavy metals; use boric acid as a passivator for nickel to make the remaining nickel catalytic Active inertization, at the same time, the passivator can further inert the deposited new metal nickel in the process of petroleum cracking, and then compensate for the loss of rare earth lanthanum oxide in the process of impurity removal, so as to realize the efficient revival of spent FCC catalysts and the micro-reaction of revived catalysts The activity increased by 8.68% compared with the fresh catalyst. The light oil yield of the revived catalyst was close to that of the fresh catalyst. Therefore, the technology of the present invention has a significant catalyst revival effect, and at the same time does not produce secondary pollution to the environment, and is cleaner and easier to implement.

Description

technical field [0001] The invention designs a boric acid controlled leaching method, metal nickel passivation and effective component compensation reaction waste FCC waste catalyst revival method, and belongs to the technical field of solid waste treatment and comprehensive utilization. Background technique [0002] The FCC catalyst is obtained by beating alumina sol, pseudoboehmite, silica sol and adhesive with acid, spray drying, ion exchange, and loaded with rare earth RE 2 o 3 Ions, roasted to prepare petroleum cracking catalysts. FCC catalyst has become one of the most widely used catalysts in the petroleum industry due to its good selectivity, high activity, stability, excellent heat resistance, and good suppression, dehydrogenation, desulfurization, and carbon deposition prevention effects. However, when the FCC catalyst is used for a period of time, due to the pollution of heavy metals (nickel, alum, and iron), carbon deposition, particle size refinement, sinterin...

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Problems solved by technology

However, due to the complex process, harsh reaction conditions, environmental pollution, and high one-time speculation, this technology has not been applied.

Domestic Zheng Lianyi et al. used oxidation-acid leaching-washing-drying-activation to obtain the FCC revived catalyst, and the micropores of the catalyst obtained after treatment were restored, but the removal rate of heavy metal nickel and alum was low, and a part of the aluminum was dissolved into the strong acid solution, resulting in Catalyst Acid Reduction

Li Chunyi et al. used inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, and perchloric acid to conduct demetallization and revival research on spent FCC catalysts. The results showed that the effect of inorganic acids on nickel removal was very poor, resulting in poor activity of the revived catalyst.

The applicant adopted the method of using mixed acid controlled leaching to remove nickel and iron, retaining the acidic component of the catalyst, aluminum oxide, and reactivating the catalyst with rare earth metals. The results showed that the removal rate of Ni reached 45%, but the reaction Both alumina and rare earth lanthanum oxide are lost during the process, and the removal of nickel is not complete, resulting in a shorter service life of the revived catalyst despite an increase in activity

The domestic patent "A Method for Reviving FCC Waste Catalyst" application number (Patent No.: 200810014209.8) discloses a method for reviving spent FCC catalysts, which uses the synergistic effect of inorganic acids and organic acids to unblock the blocked catalyst micropores , the skeleton of the catalyst has been reconstructed, but the effect of leaching heavy metal nickel with hydrochloric acid is only about 30%. inactivation faster

The application number of the domestic patent "Roasting and Silicon Tetrachloride Mixed Reaction Catalytic Cracking Spent Catalyst Resurrection Method" (Patent No.: 201510178636.X) discloses the use of gas-phase silicon tetrachloride and waste FCC catalyst for gas-solid phase reaction to revive the spent catalyst. The method utilizes the decomposition of silicon tetrachloride at a certain temperature to generate chlorine gas to form nickel chloride and wash it with water to remove nickel. The effect of removing nickel is poor, and silicon tetrachloride has a toxic gas with suffocating and irritating odor, and the production environment is harsh.

[0005] Most of the above existing waste FCC catalyst revival methods use hydrochloric acid, sulfuric acid or sulfidation or chlorination to remove heavy metal nickel. Not only the removal efficiency is low, but the process is complicated. The catalyst skeleton collapsed, and a large amount of waste acid was produced at the same time, causing secondary pollution to the environment

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