Method for comprehensively recovering waste hydrogenation catalyst with low energy consumption

Abstract

The invention relates to the technical field of recovery processes of waste oil refining catalysts, in particular to a low-energy-consumption method for comprehensively recovering a waste hydrogenation catalyst. The method comprises the following steps: firstly, carrying out vacuum pyrolysis on the waste hydrogenation catalyst to obtain heavy oil and a deoiled waste catalyst; then the deoiled waste catalyst is smashed and then subjected to oxidizing roasting to remove sulfur and carbon in the waste catalyst, and roasted clinker is obtained; carrying out acid leaching and solid-liquid separation on the roasted clinker to obtain a leaching solution and leaching residues; wherein valuable metal ions in the leachate are respectively recovered by using a solvent extraction method; and after leaching residues are subjected to secondary leaching through sodium hydroxide, aluminum in the leaching residues is recycled, and a sodium metaaluminate solution is obtained. According to the technical scheme, selective recovery of molybdenum, vanadium, nickel and aluminum in the waste hydrogenation catalyst can be achieved, the recovery rate is high, energy consumption is low, pollution of the waste hydrogenation catalyst to the environment can be relieved, and sustainable utilization of non-ferrous metal resources can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of waste oil refining catalyst recovery process, and in particular to a method for comprehensive recovery of waste hydrogenation catalyst with low energy consumption. Background Art

[0002] As the quality of crude oil continues to decline, the use of hydrogenation catalysts has increased significantly. At present, the total amount of hydrogenation catalysts used worldwide exceeds 270,000 tons per year, and it is growing at a rate of 2.5-4%. After a certain period of use, the hydrogenation catalyst will gradually lose its activity due to carbon deposition, metal deposition and other reasons. The service life of a general petroleum hydrogenation catalyst is about 1-3 years, while the service life of a catalyst for processing high-sulfur heavy oil is only 0.5-1 year. As a result, a large amount of waste hydrogenation catalysts is produced every year in the oil refining industry. Usually, waste hydrogenation catalysts contain metal elements such as molybdenum (3-12wt%), vanadium (1-15wt%), nickel (0-7wt%), aluminum (15-30wt%) and a large amount of oil (>20wt%), so they are listed as hazardous wastes by countries around the world. However, the valuable metals such as aluminum, molybdenum, vanadium, and nickel in waste hydrogenation catalysts are all important strategic resources, so it is imperative to recycle them as secondary resources.

[0003] Most of the waste hydrogenation catalyst recovery processes use an oxidative pre-roasting process to remove carbon deposits and oil on the surface of the waste catalyst, and convert the metal sulfide into an oxide for subsequent treatment. For example, CN114231733A discloses a metal recovery process based on a hydrogenation catalyst, which roasts the waste hydrogenation catalyst in air at 450-500°C for 2h to facilitate subsequent alkaline leaching. Although oxidative roasting has a high oil removal rate and obvious desulfurization and decarbonization effects, during the roasting process, the deflagration of the oil will cause the local temperature to run away and generate insoluble spinel complexes, thereby reducing the recovery rate of valuable metals. In addition, the direct combustion of oil will not only produce a large amount of gaseous pollutants (such as SOx, NOx, etc.), but also cause a waste of oil resources.

[0004] At present, the alkali roasting process is mostly used in industry to further process the oxidation pre-roasting product. For example, CN116397100A discloses a method for efficiently recovering molybdic acid and ammonium metavanadate from waste catalysts for oil hydrogenation. In this method, the waste material after thermal desorption and deoiling is mixed with an alkali material and roasted. After water leaching, calcium oxide is used to precipitate calcium molybdate and calcium vanadate. The precipitate is then leached with an ammonium solution and crystallized to obtain ammonium metavanadate and molybdic acid, respectively. The recovery rate and purity of the molybdenum and vanadium products obtained by this method are both low. CN112646977A discloses a method for recovering vanadium, molybdenum, nickel, and aluminum from waste catalysts for petroleum refining. The deoiled waste catalyst is roasted with soda ash at 600-800°C for 2-3h, and then leached with water to obtain vanadium-molybdenum leaching solution and aluminum-nickel slag; the molybdenum-vanadium leaching solution is used to obtain ammonium metavanadate and molybdenum acid solids respectively by precipitation; the leached slag is pressurized with alkali at 0.5-2MPa to recover nickel and aluminum, respectively. This method successfully recovered vanadium, molybdenum, aluminum and nickel respectively, but the process conditions were harsh, the recovery process was complicated and the product purity was low.

[0005] In summary, in the existing methods for recovering valuable metals from spent hydrogenation catalysts, since the valuable metals are separated and recovered by precipitation method, the purity of the product is low. At the same time, the recovery of spent hydrogenation catalysts mostly focuses on molybdenum and vanadium, and the comprehensive utilization rate is not high. Summary of the invention

[0006] The purpose of the present invention is to provide a method for comprehensive recovery of spent hydrogenation catalysts with low energy consumption, so as to solve the problem that in the existing method for recovering valuable metals from spent hydrogenation catalysts, the purity of the product is low because the valuable metals are separated and recovered by precipitation method, and at the same time, the recovery of spent hydrogenation catalysts is mostly based on molybdenum and vanadium as the main targets, and the comprehensive utilization rate is not high.

[0007] To achieve the above object, the present invention provides a method for comprehensive recovery of spent hydrogenation catalyst with low energy consumption, the method comprising the following steps:

[0008] S1: vacuum pyrolysis of the spent hydrogenation catalyst to obtain deoiled spent catalyst and heavy oil;

[0009] S2: crushing the de-oiled waste catalyst by a ball mill or a crusher, and then oxidizing and roasting the de-oiled waste catalyst to remove sulfur and carbon therein to obtain roasted clinker;

[0010] S3: leaching the roasted clinker with acid in a reaction kettle to obtain a leaching solution and leaching residue;

[0011] S4: adjusting the pH value of the leachate to 0-1.5 with aqueous ammonia, and using the first extraction organic phase for single-stage or multi-stage countercurrent extraction, and obtaining a raffinate 1 and a molybdenum-loaded organic phase after phase separation;

[0012] S5: The molybdenum-loaded organic phase is stripped with an alkaline solution to obtain a stripping solution 1, the stripping solution 1 is adjusted to a pH value of 1 to 2 using concentrated sulfuric acid, allowed to stand for precipitation, filtered, and sintered at 500° C. to obtain molybdenum oxide, the raffinate 1 is adjusted to a pH value of 1.8 to 2.5 using aqueous ammonia, and an oxidant is added for oxidation treatment, and then a single-stage or multi-stage countercurrent extraction is performed using the first extraction organic phase, and after phase separation, a raffinate 2 and a vanadium-loaded organic phase are obtained;

[0013] S6: stripping the vanadium-containing organic phase with an alkaline solution to obtain a stripping solution 2, adding a precipitant to the stripping solution 2 for precipitation, and sintering at 550° C. to obtain vanadium pentoxide;

[0014] S7: subjecting the raffinate 2 to single-stage or multi-stage countercurrent extraction using a second extraction organic phase, and obtaining a raffinate 3 and an aluminum-containing organic phase after phase separation. The aluminum-containing organic phase is stripped with an acidic solution to obtain an aluminum salt solution. A precipitant is added to the raffinate 3 for precipitation and sintering to obtain nickel oxide.

[0015] S8: Leaching the leached residue with sodium hydroxide to obtain a sodium aluminate solution.

[0016] Wherein, in step S1, the temperature of the vacuum pyrolysis is 250 to 550°C, the time of the vacuum pyrolysis is 1 to 4 hours, and the pressure of the vacuum pyrolysis is -2 to -0.5 MPa.

[0017] Wherein, in step S2, the particle size of the crushed de-oiled waste catalyst is 0.1-0.075 μm, the temperature of the oxidative roasting is 300-600° C., and the time of the oxidative roasting is 1-4 hours.

[0018] Wherein, in step S3, the acid in the acid leaching is selected from at least one of sulfuric acid, hydrochloric acid and nitric acid, the concentration of the acid is 0.5-2 mol / L, the temperature of the acid leaching is 20-100°C, the liquid-to-solid ratio of the acid leaching is 5-15:1, and the time of the acid leaching is 0.5-2h.

[0019] Wherein, in step S4 and step S5, the first extraction organic phase includes a first extractant and a first diluent, the first extractant is at least one of trioctyldecyl tertiary amine, trioctylamine, and trioctylmethylammonium chloride, the first diluent is at least one of sulfonated kerosene, No. 260 solvent oil, and toluene, and the concentration of the first extractant in the first extraction organic phase is 5 to 40 vol.%, and the concentration of the first diluent is 60 to 95 vol.%.

[0020] Wherein, in step S4 and step S5, the extraction conditions of the first extraction organic phase are: the ratio of organic phase to aqueous phase is 1:0.5-4, the extraction temperature is 20-35°C, and the extraction time is 5-30 min.

[0021] Wherein, in step S5, the oxidant used for oxidation treatment of the raffinate 1 is at least one of sodium hypochlorite, hypochlorous acid and hydrogen peroxide.

[0022] Wherein, in step S5 and step S6, the alkaline solution used for stripping is at least one of ammonia water, sodium hydroxide, sodium carbonate or ammonium carbonate solution, and the stripping conditions are: the concentration of the alkaline solution is 0.5-2 mol / L, the ratio of the organic phase to the aqueous phase is 1-5:1, the stripping temperature is 25-40°C, and the stripping time is 5-30 min.

[0023] Wherein, in step S7, the second extraction organic phase includes a second extraction agent and a second diluent, the second extraction agent is di(2-ethylhexyl) phosphate, the second diluent is at least one of sulfonated kerosene, No. 260 solvent oil, and toluene, and the extraction conditions of the second extraction organic phase are: the extraction agent concentration is 20-50 vol.%, the ratio of the organic phase to the aqueous phase is 1-5:1, the extraction temperature is 20-35°C, and the extraction time is 5-30 min.

[0024] Among them, in step S7, the acidic solution used for stripping is at least one of sulfuric acid, hydrochloric acid or nitric acid, and the stripping conditions are: the concentration of the stripping acidic solution is 4-6 mol / L, the ratio of the organic phase to the aqueous phase is 5-0.5:1, the stripping temperature is 20-60°C, and the stripping time is 5-30 min.

[0025] The present invention discloses a method for comprehensive recovery of waste hydrogenation catalysts with low energy consumption, firstly, the waste hydrogenation catalysts are subjected to vacuum pyrolysis to obtain heavy oil and deoiled waste catalysts; then, the deoiled waste catalysts are crushed and oxidatively roasted to remove sulfur and carbon in the waste catalysts to obtain roasted clinker; the roasted clinker is subjected to acid leaching and solid-liquid separation to obtain leachate and leach residue; wherein the leachate is used to respectively recover the valuable metal ions therein by solvent extraction; the leach residue is subjected to secondary leaching with sodium hydroxide to recover the aluminum therein to obtain a sodium aluminate solution. The technical scheme can realize the selective recovery of molybdenum, vanadium, nickel and aluminum in waste hydrogenation catalysts, with high recovery rate and low energy consumption, which can not only reduce the pollution of waste hydrogenation catalysts to the environment, but also realize the sustainable utilization of non-ferrous metal resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1It is a flow chart of the steps of the method for comprehensive recovery of waste hydrogenation catalyst with low energy consumption provided by the present invention. DETAILED DESCRIPTION

[0028] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0029] See also Figure 1 The present invention provides a method for comprehensively recovering waste hydrogenation catalysts with low energy consumption, and the method for comprehensively recovering waste hydrogenation catalysts with low energy consumption comprises the following steps:

[0030] S1: vacuum pyrolysis of the spent hydrogenation catalyst to obtain deoiled spent catalyst and heavy oil;

[0031] According to this specific embodiment, the temperature of the vacuum pyrolysis is 250 to 550°C, the time of the vacuum pyrolysis is 1 to 4 hours, and the pressure of the vacuum pyrolysis is -2 to -0.5 MPa;

[0032] S2: crushing the de-oiled waste catalyst by a ball mill or a crusher, and then oxidizing and roasting the de-oiled waste catalyst to remove sulfur and carbon therein to obtain roasted clinker;

[0033] According to this specific embodiment, the particle size of the de-oiled waste catalyst after crushing is 0.1-0.075 μm, the temperature of the oxidative roasting is 300-600° C., and the time of the oxidative roasting is 1-4 hours;

[0034] S3: leaching the roasted clinker with acid in a reaction kettle to obtain a leaching solution and leaching residue;

[0035] According to this specific embodiment, the acid in the acid leaching is selected from at least one of sulfuric acid, hydrochloric acid and nitric acid, the concentration of the acid is 0.5 to 2 mol / L, the temperature of the acid leaching is 20 to 100° C., the liquid-to-solid ratio of the acid leaching is 5 to 15:1, and the time of the acid leaching is 0.5 to 2 h;

[0036] S4: adjusting the pH value of the leachate to 0-1.5 with ammonia water, and using the first extraction organic phase for single-stage or multi-stage countercurrent extraction, after phase separation, obtaining a raffinate 1 and a molybdenum-loaded organic phase, the molybdenum-loaded organic phase is stripped with an alkaline solution to obtain a stripping solution 1, the stripping solution 1 is adjusted to a pH value of 1-2 with concentrated sulfuric acid, allowed to stand for precipitation, filtered and sintered at 500° C. to obtain molybdenum oxide, the raffinate 1 is adjusted to a pH value of 1.8-2.5 with ammonia water, and an oxidant is added for oxidation treatment, and then the first extraction organic phase is used for single-stage or multi-stage countercurrent extraction, after phase separation, obtaining a raffinate 2 and a vanadium-loaded organic phase, the vanadium-containing organic phase is stripped with an alkaline solution to obtain a stripping solution 2, a precipitant is added to the stripping solution 2 for precipitation, and sintered at 550° C. to obtain vanadium pentoxide;

[0037] According to this specific embodiment, the first extraction organic phase includes a first extraction agent and a first diluent, the first extraction agent is at least one of trioctyldecane tertiary amine, trioctylamine, and trioctylmethylammonium chloride, the first diluent is at least one of sulfonated kerosene, No. 260 solvent oil, and toluene, the concentration of the first extraction agent in the first extraction organic phase is 5-40 vol.%, the concentration of the first diluent is 60-95 vol.%, the extraction conditions of the first extraction organic phase are: the ratio of the organic phase to the aqueous phase is 1:0.5-4, the extraction temperature is 20-35°C, and the extraction time is 5-30 min. The oxidant used for oxidation treatment of the raffinate 1 is at least one of sodium hypochlorite, hypochlorous acid, and hydrogen peroxide, the alkaline solution used for stripping is at least one of ammonia water, sodium hydroxide, sodium carbonate, or ammonium carbonate solution, and the stripping conditions are: the concentration of the alkaline solution is 0.5-2 mol / L, the ratio of the organic phase to the aqueous phase is 1-5:1, the stripping temperature is 25-40°C, and the stripping time is 5-30 min;

[0038] S5: subjecting the raffinate 2 to single-stage or multi-stage countercurrent extraction using a second extraction organic phase, and obtaining a raffinate 3 and an aluminum-containing organic phase after phase separation. The aluminum-containing organic phase is stripped with an acidic solution to obtain an aluminum salt solution. A precipitant is added to the raffinate 3 for precipitation and sintering to obtain nickel oxide.

[0039] According to this specific embodiment, the second extraction organic phase includes a second extractant and a second diluent, the second extractant is di(2-ethylhexyl) phosphate, the second diluent is at least one of sulfonated kerosene, No. 260 solvent oil, and toluene, and the extraction conditions of the second extraction organic phase are: the concentration of the extractant is 20-50 vol.%, the ratio of the organic phase to the aqueous phase is 1-5:1, the extraction temperature is 20-35°C, and the extraction time is 5-30 min. The acidic solution used for stripping is at least one of sulfuric acid, hydrochloric acid or nitric acid, and the stripping conditions are: the concentration of the stripping acidic solution is 4-6 mol / L, the ratio of the organic phase to the aqueous phase is 5-0.5:1, the stripping temperature is 20-60°C, and the stripping time is 5-30 min.

[0040] S6: Leaching the leached residue with sodium hydroxide to obtain a sodium aluminate solution.

[0041] When using the low-energy comprehensive recovery method of waste hydrogenation catalyst of the present invention, the waste hydrogenation catalyst in the technical scheme does not adopt direct oxidation roasting, but first undergoes vacuum low-temperature pyrolysis to deoil, and the recovered oil is reused as a product. The deoiled raw material is roasted by rotary kiln equipment for further decarbonization and desulfurization, and the tail gas is discharged after dust removal and desulfurization, which can greatly reduce the emission of gas pollutants. Compared with direct oxidation roasting, the technical scheme has the advantages of energy saving and environmental protection, high comprehensive utilization rate, and no difficult to dissolve spinel phase formation. In addition, the technical scheme only uses dilute acid solution leaching to convert molybdenum, vanadium, nickel and a small part of aluminum into metal ions and enter the solution, avoiding high-temperature roasting to convert the carrier γ-Al2O3 into α-Al2O3, reducing the difficulty of alkali leaching to separate aluminum and nickel. At the same time, the technical scheme has a strong processing capacity for waste catalysts and can simultaneously recover a variety of valuable metals in waste hydrogenation catalysts, among which the comprehensive recovery rates of molybdenum, vanadium and nickel are all ≥95%, and the comprehensive recovery rate of aluminum is ≥90%, which effectively improves the economic effect of waste hydrogenation catalyst recovery.

[0042] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A method for comprehensive recovery of spent hydrogenation catalyst with low energy consumption, characterized in that: The steps include: S1: vacuum pyrolysis of the spent hydrogenation catalyst to obtain deoiled spent catalyst and heavy oil; S2: crushing the de-oiled waste catalyst by a ball mill or a crusher, and then oxidizing and roasting the de-oiled waste catalyst to remove sulfur and carbon therein to obtain roasted clinker; S3: leaching the roasted clinker with acid in a reaction kettle to obtain a leaching solution and leaching residue; S4: adjusting the pH value of the leachate to 0-1.5 with aqueous ammonia, and using the first extraction organic phase for single-stage or multi-stage countercurrent extraction, and obtaining a raffinate 1 and a molybdenum-loaded organic phase after phase separation; S5: The molybdenum-loaded organic phase is stripped with an alkaline solution to obtain a stripping solution 1, the stripping solution 1 is adjusted to a pH value of 1 to 2 using concentrated sulfuric acid, allowed to stand for precipitation, filtered, and sintered at 500° C. to obtain molybdenum oxide, the raffinate 1 is adjusted to a pH value of 1.8 to 2.5 using aqueous ammonia, and an oxidant is added for oxidation treatment, and then a single-stage or multi-stage countercurrent extraction is performed using the first extraction organic phase, and after phase separation, a raffinate 2 and a vanadium-loaded organic phase are obtained; S6: stripping the vanadium-containing organic phase with an alkaline solution to obtain a stripping solution 2, adding a precipitant to the stripping solution 2 for precipitation, and sintering at 550° C. to obtain vanadium pentoxide; S7: subjecting the raffinate 2 to single-stage or multi-stage countercurrent extraction using a second extraction organic phase, and obtaining a raffinate 3 and an aluminum-containing organic phase after phase separation. The aluminum-containing organic phase is stripped with an acidic solution to obtain an aluminum salt solution. A precipitant is added to the raffinate 3 for precipitation and sintering to obtain nickel oxide. S8: Leaching the leached residue with sodium hydroxide to obtain a sodium aluminate solution.

2. The method for comprehensive recovery of spent hydrogenation catalyst with low energy consumption as claimed in claim 1, characterized in that: In step S1, the temperature of the vacuum pyrolysis is 250 to 550°C, the time of the vacuum pyrolysis is 1 to 4 hours, and the pressure of the vacuum pyrolysis is -2 to -0.5 MPa.

3. The method for comprehensive recovery of spent hydrogenation catalyst with low energy consumption as claimed in claim 2, characterized in that: In step S2, the particle size of the crushed de-oiled waste catalyst is 0.1-0.075 μm, the temperature of the oxidative roasting is 300-600° C., and the time of the oxidative roasting is 1-4 hours.

4. The method for comprehensive recovery of spent hydrogenation catalyst with low energy consumption as claimed in claim 3, characterized in that: In step S3, the acid in the acid leaching is selected from at least one of sulfuric acid, hydrochloric acid and nitric acid, the concentration of the acid is 0.5-2 mol / L, the temperature of the acid leaching is 20-100°C, the liquid-to-solid ratio of the acid leaching is 5-15:1, and the time of the acid leaching is 0.5-2h.

5. The method for comprehensive recovery of spent hydrogenation catalyst with low energy consumption as claimed in claim 4, characterized in that: In step S4 and step S5, the first extraction organic phase includes a first extractant and a first diluent, the first extractant is at least one of trioctyldecyl tertiary amine, trioctylamine, and trioctylmethylammonium chloride, the first diluent is at least one of sulfonated kerosene, No. 260 solvent oil, and toluene, and the concentration of the first extractant in the first extraction organic phase is 5 to 40 vol.%, and the concentration of the first diluent is 60 to 95 vol.%.

6. The method for comprehensive recovery of spent hydrogenation catalyst with low energy consumption as claimed in claim 5, characterized in that: In step S4 and step S5, the extraction conditions of the first extraction organic phase are: the ratio of organic phase to aqueous phase is 1:0.5-4, the extraction temperature is 20-35°C, and the extraction time is 5-30 min.

7. The method for comprehensive recovery of spent hydrogenation catalyst with low energy consumption as claimed in claim 6, characterized in that: In step S5, the oxidant used for oxidation treatment of the raffinate 1 is at least one of sodium hypochlorite, hypochlorous acid, and hydrogen peroxide.

8. The method for comprehensive recovery of spent hydrogenation catalyst with low energy consumption as claimed in claim 7, characterized in that: In step S5 and step S6, the alkaline solution used for stripping is at least one of aqueous ammonia, sodium hydroxide, sodium carbonate or ammonium carbonate solution, and the stripping conditions are: the concentration of the alkaline solution is 0.5-2 mol / L, the ratio of the organic phase to the aqueous phase is 1-5:1, the stripping temperature is 25-40°C, and the stripping time is 5-30 min.

9. The method for comprehensive recovery of spent hydrogenation catalyst with low energy consumption as claimed in claim 8, characterized in that: In step S7, the second extraction organic phase includes a second extractant and a second diluent, the second extractant is di(2-ethylhexyl) phosphate, the second diluent is at least one of sulfonated kerosene, No. 260 solvent oil, and toluene, and the extraction conditions of the second extraction organic phase are: the extraction agent concentration is 20-50 vol.%, the ratio of the organic phase to the aqueous phase is 1-5:1, the extraction temperature is 20-35°C, and the extraction time is 5-30 min.

10. The method for comprehensive recovery of spent hydrogenation catalyst with low energy consumption as claimed in claim 9, characterized in that: In step S7, the acidic solution used for stripping is at least one of sulfuric acid, hydrochloric acid or nitric acid, and the stripping conditions are: the concentration of the stripping acidic solution is 4-6 mol / L, the ratio of the organic phase to the aqueous phase is 5-0.5:1, the stripping temperature is 20-60°C, and the stripping time is 5-30 min.

Images