Oil refining alkaline residue wet oxidation catalyst and preparation method thereof

Abstract

The invention discloses an oil refining alkaline residue wet oxidation catalyst and a preparation method thereof, and relates to the field of catalysts. The preparation method of the catalyst comprises the following steps: dissolving activated carbon in a solution to form a mixed solution, stirring and reacting in an oxygen atmosphere of 0.5-5MPa and at the temperature of 200-260 DEG C, filtering and drying to obtain the catalyst, and degrading organic matters and sulfur-containing compounds in the oil refining alkaline residues into CO2, H2O and SO4 < 2-> under high-temperature and high-pressure conditions in a wet oxidation reaction process by the catalyst, therefore, the effect of reducing the COD of the wastewater is achieved. The modified activated carbon is used as the oil refining alkaline residue wet oxidation catalyst, the problem of active component dissolution does not exist, the active center of the catalyst is a functional group generated through oxidation and is not prone to inactivation, the catalyst can be produced through a simple process, and yield expansion and application are facilitated.

Description

Technical Field

[0001] The invention relates to the field of catalysts, and in particular to an oil refining alkali residue wet oxidation catalyst and a preparation method thereof. Background Art

[0002] The waste alkali liquid produced after washing catalytic cracking gasoline, liquid hydrocarbons in gas separation units, etc. with alkali liquid is collectively called alkali slag. It contains components such as floating oil, sulfides, phenols, etc., with a complex composition and a COD as high as hundreds of thousands. It is one of the most difficult waste liquids to treat in the refining and chemical industry.

[0003] At present, the main treatment process for oil refining alkali residue is wet oxidation (WAO), which oxidizes the sulfide in the alkali residue to sulfate and degrades the organic matter into carbon dioxide and water under high temperature and medium-high pressure conditions. However, this treatment process requires high temperature and pressure, resulting in high energy consumption and high processing costs. In order to reduce energy consumption and treatment costs, catalytic wet oxidation, which introduces catalysts into the traditional wet oxidation system, has attracted more and more attention. It can reduce the temperature and pressure required for treatment and improve reaction efficiency.

[0004] The current wet oxidation catalyst is mainly a metal catalyst, which has a complex preparation process and requires multiple steps such as impregnation and calcination. It is mainly a precious metal catalyst such as platinum, palladium, rhodium, iridium, and ruthenium. Because precious metal catalysts have superior performance, high catalytic activity, and strong acid and alkali resistance, but their application is very limited due to their high price. Non-precious metal catalyst technology is still immature, and there is often a problem of easy loss of active metals, resulting in poisoning and inactivation, which needs further research and improvement. Summary of the invention

[0005] The invention provides a refinery alkali residue wet oxidation catalyst and a preparation method thereof. Modified activated carbon is used as the refinery alkali residue wet oxidation catalyst, there is no problem of active component dissolution, the catalyst is not easy to deactivate, and the refinery alkali residue wet oxidation catalytic efficiency is high.

[0006] In order to solve the above technical problems, one of the purposes of the present invention is to provide a method for preparing a refinery alkali residue wet oxidation catalyst, comprising the following steps:

[0007] S1, dissolving activated carbon in a solution to form a mixed solution;

[0008] S2. After the mixed solution is stirred for reaction in an oxygen atmosphere of 0.5MPa-5MPa and a temperature of 200°C-260°C, the activated carbon is filtered out and the filter residue is dried to obtain a catalyst.

[0009] As a preferred solution, in S1, the solution is water or a strong alkaline solution with a mass fraction of 0.01wt%-1wt%.

[0010] As a preferred embodiment, the strong base is NaOH or KOH.

[0011] As a preferred embodiment, in S1, 30 mL to 60 mL of the solution is added for every 1 g of the activated carbon.

[0012] As a preferred embodiment, in S1, the activated carbon is at least one of coal-based activated carbon, coconut shell activated carbon, and fruit shell activated carbon.

[0013] As a preferred embodiment, in S2, the stirring reaction time is 1 h-8 h.

[0014] As a preferred embodiment, in S2, the filter residue is dried by natural drying, oven drying, vacuum drying or freeze drying.

[0015] As a preferred embodiment, in S2, the drying temperature is below 250°C.

[0016] In order to solve the above technical problems, the second object of the present invention is to provide a method for preparing a refinery alkali residue wet oxidation catalyst to obtain a refinery alkali residue wet oxidation catalyst.

[0017] In order to solve the above technical problems, the third purpose of the present invention provides a method for treating oil refining alkali slag, using an oil refining alkali slag wet oxidation catalyst, comprising the following steps: placing the oil refining alkali slag wet oxidation catalyst and the oil refining alkali slag in a high-pressure reactor, and reacting for more than 1 hour in an oxygen environment at a temperature of 180°C-240°C and a pressure of 1MPa-4MPa.

[0018] As a preferred solution, the COD of the oil refining alkali residue is below 10000 mg / L, and 0.2 g to 1 g of the oil refining alkali residue wet oxidation catalyst is added to every 100 mL of the oil refining alkali residue.

[0019] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0020] 1. The present application uses modified activated carbon as a wet oxidation catalyst for oil refining alkali slag, and does not use metal as an active component. The modified activated carbon is a non-supported catalyst, and there is no problem of active component dissolution. The active center of the catalyst is a functional group generated by oxidation. The conditions of the wet oxidation reaction process of oil refining alkali slag are similar to those of activated carbon modification, so the functional groups of the catalyst will not be destroyed, making the catalyst less likely to deactivate.

[0021] 2. During the wet oxidation reaction, the catalyst of this application degrades organic matter and sulfur-containing compounds in the oil refining alkali residue into CO under high temperature and high pressure conditions. 2 , H 2 O and SO 4 2-, thereby achieving the effect of reducing the COD of wastewater, and the catalyst can be produced through a simple process, which is conducive to expanding production and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 : It is a statistical chart of COD within 4 hours of the reaction of oil refining alkali residue in Example 2 of the present invention and Comparative Examples 2 and 4 (Note: Catalyst 2-Example 2; Coconut shell activated carbon-Comparative Example 2; Blank-Comparative Example 4). DETAILED DESCRIPTION

[0023] The following will be combined with the accompanying drawings of the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Preparation Example 1

[0025] A refinery alkali residue wet oxidation catalyst comprises the following preparation steps:

[0026] S1. Weigh 4 g of coal-based activated carbon and dissolve it in 150 ml of water to form a mixed solution;

[0027] S2. Stir the mixed solution in an oxygen atmosphere of 0.5 MPa at 260° C. for 2 hours, filter out the activated carbon, and dry the filter residue naturally for 24 hours to obtain a catalyst.

[0028] Preparation Example 2

[0029] A refinery alkali residue wet oxidation catalyst comprises the following preparation steps:

[0030] S1. Weigh 4 g of coconut shell activated carbon and dissolve it in 150 ml of 0.01% NaOH solution to form a mixed solution;

[0031] S2. Stir the mixed solution in an oxygen atmosphere of 0.5 MPa and 200° C. for 4 hours, filter out the activated carbon, and dry the filter residue in an air atmosphere of 100° C. for 16 hours to obtain a catalyst.

[0032] Preparation Example 3

[0033] A refinery alkali residue wet oxidation catalyst comprises the following preparation steps:

[0034] S1. Weigh 4 g of coconut shell activated carbon and dissolve it in 150 ml of 0.01% NaOH solution to form a mixed solution;

[0035] S2. Stir the mixed solution in an oxygen atmosphere of 5 MPa and 200° C. for 4 hours, filter out the activated carbon, and dry the filter residue in an air atmosphere of 100° C. for 16 hours to obtain a catalyst.

[0036] Preparation Example 4

[0037] A refinery alkali residue wet oxidation catalyst comprises the following preparation steps:

[0038] S1. Weigh 4 g of fruit shell activated carbon and dissolve it in 150 ml of 0.1% NaOH solution to form a mixed solution;

[0039] S2. The mixed solution was stirred in an oxygen atmosphere of 0.5 MPa and 240° C. for 8 hours, and then the activated carbon was filtered out. The filter residue was dried in an air atmosphere at 120° C. for 8 hours to obtain a catalyst.

[0040] Preparation Example 5

[0041] A refinery alkali residue wet oxidation catalyst comprises the following preparation steps:

[0042] S1. Weigh 4 g of coal-based activated carbon and dissolve it in 150 ml of 0.5% NaOH solution to form a mixed solution;

[0043] S2. Stir the mixed solution in an oxygen atmosphere of 0.5 MPa at 260° C. for 2 hours, filter out the activated carbon, and dry the filter residue naturally for 24 hours to obtain a catalyst.

[0044] Preparation Example 6

[0045] A refinery alkali residue wet oxidation catalyst comprises the following preparation steps:

[0046] S1. Weigh 4 g of coal-based activated carbon and dissolve it in 150 ml of 1% NaOH solution to form a mixed solution;

[0047] S2. Stir the mixed solution in an oxygen atmosphere of 0.5 MPa at 260° C. for 2 hours, filter out the activated carbon, and dry the filter residue naturally for 24 hours to obtain a catalyst.

[0048] Comparative Preparation Example 1

[0049] A refinery alkali residue wet oxidation catalyst comprises the following preparation steps:

[0050] S1. Weigh 4 g of coal-based activated carbon and dissolve it in 150 ml of water to form a mixed solution;

[0051] S2. Stir the mixed solution in an oxygen atmosphere of 0.02 MPa at 180° C. for 2 hours, filter out the activated carbon, and dry the filter residue naturally for 24 hours to obtain a catalyst.

[0052] Embodiment 1

[0053] A method for treating oil refining alkali residue comprises the following steps:

[0054] 0.5 g of the catalyst prepared in Example 1 and 150 mL of diluted oil refining alkali slag (COD after dilution was 7500 mg / L) were placed in a high pressure reactor and reacted for 2 hours under an oxygen environment at a high temperature of 200°C and a high pressure of 4 MPa to degrade the organic matter and sulfur-containing compounds in the oil refining alkali slag into CO 2 , H 2 O and SO 4 2- , thereby achieving the effect of reducing the COD of the wastewater, the COD (chemical oxygen demand) of the alkali residue after the reaction was tested, and the results are shown in Table 1 below.

[0055] Embodiment 2

[0056] A method for treating oil refining alkali residue comprises the following steps:

[0057] 0.5 g of the catalyst prepared in Preparation Example 2 and 150 mL of diluted oil refining alkali slag (COD after dilution was 7500 mg / L) were placed in a high pressure reactor and reacted for 2 hours under an oxygen environment at a high temperature of 200°C and a high pressure of 4 MPa to degrade the organic matter and sulfur-containing compounds in the oil refining alkali slag into CO 2 , H 2 O and SO 4 2- , thereby achieving the effect of reducing the COD of the wastewater, the COD of the alkali residue after the reaction was tested, and the results are shown in Table 1 and Figure 1 shown.

[0058] Embodiment 3

[0059] A method for treating oil refining alkali residue comprises the following steps:

[0060] 0.5 g of the catalyst of Preparation Example 3 and 150 mL of diluted oil refining alkali slag (COD after dilution is 7500 mg / L) were placed in a high-pressure reactor and reacted for 2 hours under an oxygen environment, a high temperature of 200°C and a high pressure of 4 MPa to degrade the organic matter and sulfur-containing compounds in the oil refining alkali slag into CO 2 , H 2 O and SO 4 2- , thereby achieving the effect of reducing the COD of the wastewater, the COD of the alkali residue after the reaction was tested, and the results are shown in Table 1 below.

[0061] Embodiment 4

[0062] A method for treating oil refining alkali residue comprises the following steps:

[0063] 0.5 g of the catalyst of Preparation Example 4 and 150 mL of diluted oil refining alkali slag (COD after dilution was 7500 mg / L) were placed in a high-pressure reactor and reacted for 2 hours under an oxygen environment, a high temperature of 200°C and a high pressure of 4 MPa to degrade the organic matter and sulfur-containing compounds in the oil refining alkali slag into CO 2 , H 2 O and SO 4 2- , thereby achieving the effect of reducing the COD of the wastewater, the COD of the alkali residue after the reaction was tested, and the results are shown in Table 1 below.

[0064] Embodiment 5

[0065] A method for treating oil refining alkali residue comprises the following steps:

[0066] 0.5 g of the catalyst of Preparation Example 5 and 150 mL of diluted oil refining alkali slag (COD after dilution was 7500 mg / L) were placed in a high-pressure reactor and reacted for 2 hours under an oxygen environment, a high temperature of 200°C, and a high pressure of 4 MPa to degrade the organic matter and sulfur-containing compounds in the oil refining alkali slag into CO 2 , H 2 O and SO 4 2- , thereby achieving the effect of reducing the COD of the wastewater, the COD of the alkali residue after the reaction was tested, and the results are shown in Table 1 below.

[0067] Embodiment 6

[0068] A method for treating oil refining alkali residue comprises the following steps:

[0069] 0.5 g of the catalyst prepared in Preparation Example 6 and 150 mL of diluted oil refining alkali slag (COD after dilution was 7500 mg / L) were placed in a high pressure reactor and reacted for 2 hours under an oxygen environment at a high temperature of 200°C and a high pressure of 4 MPa to degrade the organic matter and sulfur-containing compounds in the oil refining alkali slag into CO 2 , H 2 O and SO 4 2- , thereby achieving the effect of reducing the COD of the wastewater, the COD of the alkali residue after the reaction was tested, and the results are shown in Table 1 below.

[0070] Comparative Example 1

[0071] A method for treating oil refining alkali residue comprises the following steps:

[0072] 0.5 g of coal-based activated carbon and 150 mL of diluted oil refining alkali slag (COD after dilution is 7500 mg / L) were placed in a high-pressure reactor and reacted for 2 hours under an oxygen environment, a high temperature of 200 ° C, and a high pressure of 4 MPa to degrade the organic matter and sulfur-containing compounds in the oil refining alkali slag into CO 2 , H 2 O and SO 4 2- , thereby achieving the effect of reducing the COD of the wastewater, the COD of the alkali residue after the reaction was tested, and the results are shown in Table 1 below.

[0073] Comparative Example 2

[0074] A method for treating oil refining alkali residue comprises the following steps:

[0075] 0.5 g coconut shell activated carbon and 150 mL diluted oil refining alkali residue (COD after dilution is 7500 mg / L) were placed in a high pressure reactor and reacted for 2 hours under the conditions of oxygen environment, high temperature of 200 ° C and high pressure of 4 MPa to degrade the organic matter and sulfur-containing compounds in the oil refining alkali residue into CO 2 , H 2 O and SO 4 2- , thereby achieving the effect of reducing the COD of the wastewater, the COD of the alkali residue after the reaction was tested, and the results are shown in Table 1 and Figure 1 shown.

[0076] Comparative Example 3

[0077] A method for treating oil refining alkali residue comprises the following steps:

[0078] 0.5g of fruit shell activated carbon and 150mL of diluted oil refining alkali residue (COD after dilution is 7500mg / L) were placed in a high-pressure reactor and reacted for 2 hours under the conditions of oxygen environment, high temperature of 200℃ and high pressure of 4MPa to degrade the organic matter and sulfur-containing compounds in the oil refining alkali residue into CO 2 , H 2 O and SO 4 2- , thereby achieving the effect of reducing the COD of the wastewater, the COD of the alkali residue after the reaction was tested, and the results are shown in Table 1 below.

[0079] Comparative Example 4

[0080] A method for treating oil refining alkali residue comprises the following steps:

[0081] 150 mL of diluted oil refining alkali residue (COD after dilution is 7500 mg / L) was placed in a high-pressure reactor and reacted for 2 hours under the conditions of oxygen environment, high temperature of 200°C and high pressure of 4 MPa to degrade the organic matter and sulfur-containing compounds in the oil refining alkali residue into CO 2 , H 2 O and SO 4 2- , thereby achieving the effect of reducing the COD of the wastewater, the COD of the alkali residue after the reaction was tested, and the results are shown in Table 1 and Figure 1 shown.

[0082] Comparative Example 5

[0083] A method for treating oil refining alkali residue comprises the following steps:

[0084] 0.5 g of the catalyst of Comparative Preparation Example 1 and 150 mL of diluted oil refining alkali slag (COD after dilution is 7500 mg / L) were placed in a high-pressure reactor and reacted for 2 hours under an oxygen environment, a high temperature of 200°C, and a high pressure of 4 MPa to degrade the organic matter and sulfur-containing compounds in the oil refining alkali slag into CO 2 , H 2 O and SO 4 2- , thereby achieving the effect of reducing the COD of the wastewater, the COD of the alkali residue after the reaction was tested, and the results are shown in Table 1 below.

[0085] Table 1 - COD results of alkali residue after reaction in the examples and comparative examples of the present application

[0086]

[0087]

[0088] Combining the comparison of the alkali residue COD results after the wet oxidation reaction of Examples 1, 5-6 in Table 1, it can be seen that the catalyst of Example 1 is modified by using an aqueous solution under specific temperature and pressure conditions during the preparation process, and the catalysts of Examples 4-5 are treated with a strong alkaline solution during the preparation process. In the hydrothermal process, sodium ions will play a catalytic role, promote the formation of oxygen-containing functional groups, and improve the activity of the catalyst.

[0089] By comparing the COD results of alkali residue after wet oxidation reaction of Example 1 and Comparative Examples 1 and 5 in Table 1, it can be seen that compared with Example 1, the catalyst of Comparative Example 5 has extremely poor modification effect of coal-based activated carbon due to the low temperature and pressure of its modification process, and its catalytic efficiency is basically equivalent to that of the unmodified coal-based activated carbon in Comparative Example 1; in addition, if the temperature and pressure of the catalyst modification are too high, the coal-based activated carbon will be oxidized, destroyed and crushed, and the crushed activated carbon particles cannot be recovered, which is not suitable as a heterogeneous catalyst.

[0090] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a refinery alkali residue wet oxidation catalyst, characterized in that: The following steps are involved: S1, dissolving activated carbon in a solution to form a mixed solution; S2. After the mixed solution is stirred for reaction in an oxygen atmosphere of 0.5MPa-5MPa and a temperature of 200°C-260°C, the activated carbon is filtered out and the filter residue is dried to obtain a catalyst.

2. The method for preparing a refinery alkali residue wet oxidation catalyst according to claim 1, characterized in that: In S1, the solution is water or a strong alkaline solution with a mass fraction of 0.01wt%-1wt%.

3. The method for preparing a refinery alkali residue wet oxidation catalyst according to claim 1, characterized in that: In S1, 30 mL to 60 mL of the solution is added for every 1 g of the activated carbon.

4. The method for preparing a refinery alkali residue wet oxidation catalyst according to claim 1, characterized in that: In S1, the activated carbon is at least one of coal-based activated carbon, coconut shell activated carbon, and fruit shell activated carbon.

5. The method for preparing a refinery alkali residue wet oxidation catalyst according to claim 1, characterized in that: In S2, the stirring reaction time is 1 h-8 h.

6. The method for preparing a refinery alkali residue wet oxidation catalyst according to claim 1, characterized in that: In S2, the filter residue is dried by natural drying, oven drying, vacuum drying or freeze drying.

7. The method for preparing a refinery alkali residue wet oxidation catalyst according to claim 1, characterized in that: In S2, the drying temperature is below 250°C.

8. An oil refining alkali residue wet oxidation catalyst prepared by the method for preparing an oil refining alkali residue wet oxidation catalyst as claimed in any one of claims 1 to 7.

9. A method for treating oil refining alkali residue, characterized in that: The method of using the oil refining alkali residue wet oxidation catalyst as described in claim 8 comprises the following steps: placing the oil refining alkali residue wet oxidation catalyst and the oil refining alkali residue in a high-pressure reactor, and reacting for more than 1 hour in an oxygen environment at a temperature of 180°C-240°C and a pressure of 1MPa-4MPa.

10. The method for treating oil refining alkali residue according to claim 9, characterized in that: The COD of the oil refining alkali residue is below 10000 mg / L, and 0.2 g to 1 g of the oil refining alkali residue wet oxidation catalyst is added to every 100 mL of the oil refining alkali residue.

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