A method for activating mixed mud-based carbon

Abstract

The application discloses a mixed mud-based carbon compound activation method, which comprises the following steps: placing oil-containing sludge and biochemical sludge generated by a refining enterprise in a tubular furnace in an inert atmosphere for pre-carbonization treatment to obtain mixed mud-based carbon; placing the mixed mud-based carbon in a quartz boat; impregnating the mixed mud-based carbon with a compound activator prepared by mixing a potassium dihydrogen phosphate solution and a phosphoric acid solution; sequentially performing low-temperature activation treatment and high-temperature activation treatment on the mixed mud-based carbon sample impregnated with the compound activator; and drying the sample after high-temperature activation treatment after constant-temperature water bath washing, thereby obtaining mixed mud-based activated carbon activated by the compound. The application optimizes a typical hazardous / solid waste synergic carbon resourceization treatment process of a petrochemical enterprise, realizes synergic resourceization recycling of the three kinds of sludge of the petrochemical enterprise through the compound activation mode, improves the adsorption performance of the original technology, is simple in operation, and is suitable for batch treatment of the three kinds of sludge of the petrochemical enterprise.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of resource type porous carbon-based material preparation, and belongs to the process of resource treatment and disposal of three muds in the petroleum and chemical industry, in particular to a compounding and activating method of mixed mud-based carbon. BACKGROUND

[0002] Crude oil produces refining three muds in the whole process from production development, transportation and storage, refining and processing to wastewater treatment. The production of refining three muds is large and has high risk. However, due to the existence of a large proportion of recyclable oil and heavy component organic matter in the refining three muds, the refining three muds have good resource recycling potential.

[0003] Pyrolysis is one of the main ways to realize the reduction and resource recycling of hazardous / solid waste such as refining three muds. At present, the research on resource utilization of refining three muds mainly focuses on obtaining gas, liquid and solid three-phase components through direct or indirect pyrolysis and recycling. Among them, the gas phase recovery objects after pyrolysis of refining three muds are mostly light hydrocarbons, CO, CH4, H2, etc., the pyrolysis temperature is high, and the energy consumption is large; the liquid phase recovery after pyrolysis of refining three muds is mainly refined regenerated oil, and the oil purity requirement increases the complexity of the process; the solid phase recovery after pyrolysis of refining three muds is concentrated on regenerated carbon-based products. Compared with gas phase recovery, the solid phase recovery after pyrolysis of refining three muds has lower pyrolysis temperature and lower process complexity. At the same time, compared with gas phase recovery and liquid phase recovery, the obtained pyrolysis carbon can fix part of the heavy metals, and the fixed part of the heavy metals can play a special functional role in the subsequent carbon product utilization process. In general, through pyrolysis carbonization, the yield of refining three muds can be greatly reduced, and the pore size structure of carbon-based products can be selectively controlled to meet the functional requirements in multiple scenarios (such as catalytic pyrolysis, adsorption separation, electrode materials, land conditioning, etc.).

[0004] Based on the research conclusion at present, the main ways to obtain porous carbon-based products from hazardous / solid waste are direct carbonization (self-template, external template and co-pyrolysis) and activator activation (physical, chemical and physical-chemical combined activation). The preparation conditions and process greatly determine the pore size structure and functional performance of carbon-based products. Selecting appropriate preparation conditions and process can promote the shortening of pyrolysis time, the reduction of carbonization temperature, the increase of activated carbon yield, the optimization of pore size distribution and the directional obtaining of functional carbon products. As one of the main ways to obtain high specific surface area carbon-based products, chemical activation method has simple equipment, low pyrolysis temperature and strong operability (various activators are easy to develop targeted pore size and functional regulation), and has been widely used in the preparation process of carbon-based products.

[0005] However, due to the problem of residual agent under insufficient pyrolysis of the activator in chemical activation, it is often necessary to remove the excess agent by washing, increasing the workload and wastewater discharge. Therefore, in view of the above problems, the present patent proposes a mixed mud-based carbon compounding activation method, which not only solves the above problems, but also improves the adsorption performance of the product obtained by the conversion of the three muds in the refining process, providing a good collaborative resource utilization way for solving the problem of the three muds in the refining process. SUMMARY

[0006] The present application proposes a mixed mud-based carbon compounding activation method for the typical hazardous / solid waste collaborative value-added resource utilization process in petrochemical enterprises. The mixed mud-based carbon is prepared by pre-carbonization treatment of oil-containing sludge and biochemical sludge generated in petrochemical enterprises as carbonization raw materials. Phosphoric acid and potassium dihydrogen phosphate are used as compounding activators. After impregnation, low-temperature activation treatment, high-temperature activation treatment, and constant-temperature water bath washing of the mixed mud-based carbon, the compounding activated mixed mud-based activated carbon is obtained by drying, realizing the collaborative resource utilization of the three muds in the refining process, which is simple to operate and suitable for batch processing of the three muds in petrochemical enterprises.

[0007] The present application specifically adopts the following technical solutions:

[0008] A mixed mud-based carbon compounding activation method, specifically comprising the following steps:

[0009] Step 1, pre-carbonization of mixed sludge;

[0010] Oil-containing sludge and biochemical sludge generated in petrochemical enterprises are used as carbonization raw materials. The oil-containing sludge and biochemical sludge are uniformly mixed and then placed in a tube furnace in an inert atmosphere for pre-carbonization treatment to obtain mixed mud-based carbon;

[0011] Step 2, impregnation of compounding activator;

[0012] The mixed mud-based carbon is placed in a quartz boat, and a compounding activator composed of a potassium dihydrogen phosphate solution and a phosphoric acid solution is added. After thorough stirring and mixing to obtain a homogeneous phase, the mixture is impregnated and then dried in an oven;

[0013] Step 3, low-temperature activation treatment of mixed mud-based carbon sample compounding activation;

[0014] The mixed mud-based carbon sample impregnated with the compounding activator is placed in a tube furnace in a nitrogen atmosphere, and the tube furnace is used for low-temperature activation treatment of the mixed mud-based carbon sample. The temperature of the tube furnace is increased according to the preset temperature program. When the temperature of the tube furnace reaches the preset middle temperature, the temperature of the tube furnace is kept constant for 1 hour, and then the low-temperature activation treatment of the mixed mud-based carbon sample compounding activation is completed;

[0015] Step 4, high-temperature activation treatment of mixed mud-based carbon sample compounding activation;

[0016] After the low-temperature activation treatment of the mixed mud-based carbon sample is completed, the tubular furnace automatically enters the next temperature rising stage, and when the temperature in the tubular furnace rises to the preset terminal temperature, the temperature in the tubular furnace is kept constant for 1.5 h, and then the high-temperature activation treatment of the mixed mud-based carbon sample is completed.

[0017] Step 5: After the mixed mud-based carbon sample after the high-temperature activation treatment is washed in a constant-temperature water bath and dried, a mixed mud-based activated carbon after the mixed activation is prepared.

[0018] Preferably, in the step 1, the pre-carbonization treatment temperature of the carbonized raw material is set to 600℃, and the pre-carbonization treatment time is set to 2h.

[0019] Preferably, in the step 2, the volume of the mixed mud-based carbon added with the mixed activation agent is 1-3 mL / g.

[0020] Preferably, in the mixed activation agent, the concentration of the potassium dihydrogen phosphate solution is set to 12wt%, and the concentration of the phosphoric acid solution is set to 20wt%.

[0021] Preferably, the immersion time of the mixed mud-based carbon is set to 22h.

[0022] Preferably, in the step 3, the nitrogen flow rate in the tubular furnace is set to 50 mL / min, and the temperature rising rate of the tubular furnace is set to 10℃ / min.

[0023] Preferably, in the step 3, the middle-stage temperature is set to 500℃-600℃.

[0024] Preferably, in the step 4, the nitrogen flow rate in the tubular furnace is set to 50 mL / min, and the temperature rising rate of the tubular furnace is set to 10℃ / min.

[0025] Preferably, in the step 4, the terminal temperature is set to 750℃-850℃.

[0026] Preferably, the step 6 is further included, which evaluates the adsorption performance of the mixed mud-based activated carbon after the mixed activation.

[0027] After the mixed mud-based activated carbon after the mixed activation prepared in the step 5 is ground and sieved, a mixed mud-based activated carbon particle after the mixed activation is obtained, and the mixed mud-based activated carbon particle after the mixed activation is subjected to a characteristic adsorption evaluation, a mesopore adsorption performance of the mud-based activated carbon is evaluated based on methylene blue adsorption, and a micropore adsorption performance of the mud-based activated carbon is evaluated based on iodine adsorption.

[0028] Preferably, the iodine adsorption performance of the compound activated mixed mud-based carbon particles is evaluated according to the test method for wood-based activated carbon in GB / T 12496.8-2015-determination of iodine adsorption value, and the methylene blue adsorption performance of the compound activated mixed mud-based carbon particles is evaluated according to the test method for coal-based activated carbon in GB / T 7702.6-2008-determination of methylene blue adsorption value.

[0029] Preferably, the particle size of the compound activated mixed mud-based activated carbon particles is 200 mesh.

[0030] The present application has the beneficial effects of:

[0031] The mixed mud-based carbon compound activation method provided by the present application optimizes the treatment process of typical hazardous / solid waste in petrochemical enterprises, uses potassium dihydrogen phosphate with good environmental properties as the main activator, and uses a small amount of phosphoric acid as the compound activator, and through continuous low-temperature activation treatment and high-temperature activation treatment of the mixed mud-based carbon obtained by simple co-pyrolysis of oil-containing sludge and sewage sludge, mud-based activated carbon with certain pore size characteristics is obtained, realizing the collaborative resource recycling of three types of sludge, effectively improving the adsorption performance of the mud-based activated carbon after compound activation, reducing the washing frequency, and reducing the environmental impact of residual reagents. Simple operation, suitable for but not limited to batch treatment of three types of sludge in petrochemical enterprises. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The flowchart of the compound activation method of the mixed mud-based carbon of the present application.

[0033] Figure 2 The temperature rising program diagram of the tubular furnace in the compound activation process of the present application. DETAILED DESCRIPTION

[0034] The present application will be further described in detail below in combination with the drawings and specific embodiments:

[0035] A compound activation method of mixed mud-based carbon, as shown in Figure 1 specifically comprising the following steps:

[0036] Step 1, pre-carbonization of mixed sludge;

[0037] The oil-containing sludge and biochemical sludge generated by the petrochemical enterprise are used as carbonization raw materials, and the mass ratio of the oil-containing sludge and the biochemical sludge is set to 6:4. The oil-containing sludge and the biochemical sludge are uniformly mixed and then placed in a tubular furnace with an inert atmosphere for pre-carbonization treatment. The temperature of the tubular furnace in the pre-carbonization treatment is set to 600℃, and the pre-carbonization treatment time is set to 2h. The mixed mud-based carbon is obtained through the pre-carbonization process.

[0038] Step 2, impregnation of compound activator;

[0039] The mixed mud-based carbon is placed in a quartz boat, a compounded activator is prepared by mixing a 12wt% potassium dihydrogen phosphate solution and a 20wt% phosphoric acid solution, the compounded activator is added to the mixed mud-based carbon at a ratio of 1-3mL / g, and after stirring and mixing uniformly, the mixed mud-based carbon is immersed for 22h, and then is placed in an oven for drying.

[0040] Step 3, low-temperature activation treatment of the mixed mud-based carbon sample compounded with the activator;

[0041] After the mixed mud-based carbon sample compounded with the activator is sufficiently immersed and dried, the sample is placed in a tube furnace in which a nitrogen atmosphere has been formed, the nitrogen flow rate of the tube furnace is set to 50mL / min, a temperature rising program is set, in which the temperature rising rate is set to 10℃ / min, the temperature rising program of the tube furnace is started to slowly raise the temperature in the furnace, when the temperature in the tube furnace rises to a preset middle-stage temperature of 500-600℃, the temperature is kept constant for 1h, and then the low-temperature activation treatment of the mixed mud-based carbon sample compounded with the activator is ended.

[0042] Step 4, high-temperature activation treatment of the mixed mud-based carbon sample compounded with the activator;

[0043] After the low-temperature activation treatment of the mixed mud-based carbon sample compounded with the activator is ended, the tube furnace automatically enters the next temperature rising stage, the nitrogen flow rate of the tube furnace is set to 50mL / min, the temperature rising rate of the tube furnace is set to 10℃ / min, and the temperature in the tube furnace is raised. When the temperature in the tube furnace rises to a preset final-stage temperature of 750-850℃, the temperature is kept constant for 1.5h, and then the high-temperature activation treatment of the mixed mud-based carbon sample compounded with the activator is ended.

[0044] Step 5, after the high-temperature activation treatment, the mixed mud-based activated carbon sample is washed in a constant-temperature water bath and dried to obtain a compounded activation mixed mud-based activated carbon, and the specific operation process is as follows:

[0045] When the pyrolysis program of the tube furnace is ended, the tube furnace is closed, but the nitrogen atmosphere in the tube furnace is maintained, the input of nitrogen into the tube furnace is stopped after the temperature in the tube furnace is naturally cooled to room temperature, and after the activated sample is cooled to room temperature, the sample is taken out from the tube furnace and washed in a constant-temperature water bath to remove the excess reagent residues and residual ash in the mixed mud-based activated carbon, and the washing is continued until the pH of the upper clear liquid is close to neutral, and then the mixed mud-based activated carbon is dried to obtain a new compounded activation mixed mud-based activated carbon.

[0046] Step 6, evaluation of the adsorption performance of the compounded activation mixed mud-based activated carbon;

[0047] The mixed activated sludge-based activated carbon prepared in step 5 is ground and sieved through a 200-mesh screen to obtain mixed activated sludge-based activated carbon particles. The pore adsorption performance of the mixed activated sludge-based activated carbon particles is evaluated by using the methylene blue adsorption value. The evaluation process refers to GB / T 7702.6-2008 “Test method for coal-based granular activated carbon: determination of methylene blue adsorption value”, GB / T 12496.10-1999 “Test method for wood-based activated carbon: determination of methylene blue adsorption value”. The micropore adsorption performance of the mixed activated sludge-based activated carbon particles is evaluated by using the iodine adsorption value. The evaluation process refers to GB / T 12496.8-2015 “Test method for wood-based activated carbon: determination of iodine adsorption value”.

[0048] Example 1

[0049] The present embodiment proposes a mixed sludge-based activated carbon compounding activation method, which specifically includes the following steps:

[0050] Step 1, pre-carbonization of mixed sludge;

[0051] The oil-containing sludge and biochemical sludge generated by a refining enterprise are used as carbonization raw materials. The mass ratio of the oil-containing sludge to the biochemical sludge is set to 6:4. The oil-containing sludge and the biochemical sludge are uniformly mixed and then placed in a tube furnace in an inert atmosphere for pre-carbonization treatment. The temperature of the tube furnace is set to 600°C during the pre-carbonization treatment. The pre-carbonization treatment time is set to 2h. The mixed sludge-based activated carbon is obtained through the pre-carbonization process.

[0052] Step 2, impregnation of the compounding activator;

[0053] 2.0g of the mixed sludge-based activated carbon is placed in a quartz boat. A compounding activator is prepared by mixing 2.5mL of a 12wt% potassium dihydrogen phosphate solution and 0.5mL of a 20wt% phosphoric acid solution. 3mL of the compounding activator is added to the mixed sludge-based activated carbon. After stirring and mixing until the phases are uniform, the mixed sludge-based activated carbon is impregnated for 22h and then dried in an oven.

[0054] Step 3, low-temperature activation treatment of the compounding activation of the mixed sludge-based activated carbon sample;

[0055] The mixed sludge-based activated carbon sample that has been fully impregnated with the compounding activator and dried is placed in a tube furnace in a nitrogen atmosphere. The nitrogen flow rate in the tube furnace is set to 50mL / min. The temperature rising program is set, with a temperature rising rate of 10°C / min. The tube furnace is started to slowly raise the temperature in the furnace. When the temperature in the furnace rises to the preset middle temperature of 500°C, the temperature is kept constant for 1h. The low-temperature activation process of the compounding activation of the mixed sludge-based activated carbon sample is completed. The temperature rising process is shown in the first half of Figure 2 .

[0056] Step 4, high-temperature activation treatment of the compounding activation of the mixed sludge-based activated carbon sample;

[0057] After the low-temperature activation treatment of the mixed sludge-based carbon sample is completed, the tubular furnace automatically enters the next temperature rising stage, the nitrogen flow in the tubular furnace is set to 50 mL / min, and the temperature rising rate of the tubular furnace is set to 10 ℃ / min. When the temperature in the tubular furnace rises to the preset final temperature of 800 ℃, the temperature is kept constant for 1.5 h, and the high-temperature activation treatment of the mixed sludge-based carbon sample is completed. The temperature rising process is as shown in the latter half of the following table. Figure 2

[0058] Step 5, when the pyrolysis program of the tubular furnace is completed, the tubular furnace is turned off, but the nitrogen atmosphere in the tubular furnace is maintained. After the temperature in the tubular furnace naturally cools to room temperature, the input of nitrogen into the tubular furnace is stopped. After the activated sample cools to room temperature, it is taken out of the tubular furnace and washed in a constant-temperature water bath to remove excess reagent residues and residual ash in the mixed sludge-based activated carbon. The pH of the supernatant is close to neutral after washing. After drying, the mixed sludge-based activated carbon activated by compounding is obtained.

[0059] Step 6, evaluate the adsorption performance of the mixed sludge-based carbon activated by compounding.

[0060] The mixed sludge-based activated carbon activated by compounding prepared in step 5 is ground and sieved through a 200-mesh sieve for characteristic adsorption evaluation. The methylene blue adsorption evaluation is used to evaluate the mesopore adsorption performance, and the evaluation process refers to GB / T 7702.6-2008 “Coal Particle Activated Carbon Test Method for Determination of Methylene Blue Adsorption Value”, GB / T 12496.10-1999 “Wood Activated Carbon Test Method for Determination of Methylene Blue Adsorption Value”. The iodine adsorption is used to evaluate the micropore adsorption performance, and the evaluation process refers to GB / T 12496.8-2015 “Wood Activated Carbon Test Method for Determination of Iodine Adsorption Value”. The iodine adsorption value of the mixed sludge-based activated carbon activated by compounding is calculated to be 246.32 mg / g, and the methylene blue adsorption value is 117.65 mg / g.

[0061] Example 2

[0062] The present embodiment proposes a compounding activation method for mixed sludge-based carbon, which specifically includes the following steps:

[0063] Step 1, pre-carbonization of mixed sludge

[0064] The oil-containing sludge and biochemical sludge generated by a refining enterprise are used as carbonization raw materials, and the mass ratio of the oil-containing sludge and the biochemical sludge is set to 6:4. The oil-containing sludge and the biochemical sludge are uniformly mixed and then placed in a tubular furnace in an inert atmosphere for pre-carbonization treatment. The temperature of the tubular furnace is set to 600 ℃ during the pre-carbonization treatment, and the pre-carbonization treatment time is set to 2 h. The mixed sludge-based carbon is obtained through the pre-carbonization process.

[0065] Step 2, impregnation of compounding activator

[0066] ​2.0 g of mixed mud-based carbon was placed in a quartz boat, a mixed activator was prepared by mixing 2.0 mL of a 12 wt% potassium dihydrogen phosphate solution and 1.0 mL of a 20 wt% phosphoric acid solution, 3 mL of the mixed activator was added to the mixed mud-based carbon, and after stirring and mixing until uniform and fully impregnated for 22 h, it was placed in an oven for drying.

[0067] Step 3, low-temperature activation treatment of the mixed mud-based carbon sample after mixed activation;

[0068] After the mixed mud-based carbon sample was fully impregnated with the mixed activator and dried, it was placed in a tube furnace with a nitrogen atmosphere, the nitrogen flow rate of the tube furnace was set to 50 mL / min, and the temperature program was set with a heating rate of 10°C / min. The tube furnace was started to slowly heat the furnace, and when the temperature in the furnace rose to the preset middle temperature of 500°C, it was kept constant for 1 h to complete the low-temperature activation treatment of the mixed mud-based carbon sample after mixed activation.

[0069] Step 4, high-temperature activation treatment of the mixed mud-based carbon sample after mixed activation;

[0070] After the low-temperature activation treatment of the mixed mud-based carbon sample after mixed activation was completed, the tube furnace automatically entered the next temperature stage, the nitrogen flow rate of the tube furnace was set to 50 mL / min, and the heating rate of the tube furnace was set to 10°C / min. When the temperature in the tube furnace rose to the preset final temperature of 800°C, it was kept constant for 1.5 h, and the high-temperature activation treatment of the mixed mud-based carbon sample after mixed activation was completed.

[0071] Step 5, when the pyrolysis program of the tube furnace was completed, the tube furnace was turned off, but the nitrogen atmosphere in the tube furnace was maintained. After the temperature in the tube furnace naturally cooled to room temperature, the nitrogen input to the tube furnace was stopped. After the activated sample cooled to room temperature, it was removed from the tube furnace and washed in a constant temperature water bath to remove excess reagent residues and residual ash in the mixed mud-based activated carbon. The pH of the supernatant was close to neutral after washing, and the mixed mud-based activated carbon after mixed activation was obtained after drying.

[0072] Step 6, evaluation of the adsorption performance of the mixed mud-based carbon after mixed activation;

[0073] The mixed mud-based activated carbon prepared in step 5 is ground and sieved through a 200-mesh screen, and then subjected to characteristic adsorption evaluation. The methylene blue adsorption evaluation is used to evaluate the pore adsorption performance, and the evaluation process refers to GB / T 7702.6-2008 “Coal Particle Activated Carbon Test Method for Determination of Methylene Blue Adsorption Value”, GB / T 12496.10-1999 “Wood Activated Carbon Test Method for Determination of Methylene Blue Adsorption Value”. The iodine adsorption is used to evaluate the micropore adsorption performance, and the evaluation process refers to GB / T 12496.8-2015 “Wood Activated Carbon Test Method for Determination of Iodine Adsorption Value”. The iodine adsorption value of the mixed mud-based activated carbon prepared by compounding and activation is calculated to be 253.06 mg / g, and the methylene blue adsorption value is 139.78 mg / g.

[0074] Example 3

[0075] The present embodiment proposes a compounding and activation method for mixed mud-based carbon, which specifically includes the following steps:

[0076] Step 1, pre-carbonization of mixed sludge;

[0077] The oil-containing sludge and biochemical sludge generated by a refining enterprise are used as carbonization raw materials, and the mass ratio of the oil-containing sludge to the biochemical sludge is set to 6:4. The oil-containing sludge and the biochemical sludge are uniformly mixed and then placed in a tube furnace in an inert atmosphere for pre-carbonization treatment. The temperature of the tube furnace is set to 600°C during the pre-carbonization treatment, and the pre-carbonization treatment time is set to 2h. The mixed mud-based carbon is obtained through the pre-carbonization process.

[0078] Step 2, impregnation of compounding activator;

[0079] 2.0g of mixed mud-based carbon is placed in a quartz boat, and a compounding activator is prepared by mixing 1.5mL of 12wt% potassium dihydrogen phosphate solution and 1.5mL of 20wt% phosphoric acid solution. 3mL of the compounding activator is added to the mixed mud-based carbon, and after stirring and mixing to form a homogeneous phase, the mixture is impregnated for 22h and then dried in an oven.

[0080] Step 3, low-temperature activation treatment of the mixed mud-based carbon sample after compounding and activation;

[0081] The mixed mud-based carbon sample after compounding and activation is placed in a tube furnace with a nitrogen atmosphere, and the nitrogen flow rate of the tube furnace is set to 50mL / min. The temperature rising program is set, and the temperature rising rate is set to 10°C / min. The tube furnace is started to slowly raise the temperature in the furnace. When the temperature in the furnace rises to the preset middle temperature of 500°C, it is kept constant for 1h. The low-temperature activation treatment process of the mixed mud-based carbon sample after compounding and activation is completed.

[0082] Step 4, high-temperature activation treatment of the mixed mud-based carbon sample after compounding and activation;

[0083] After the low-temperature activation treatment of the mixed mud-based carbon sample is completed, the tube furnace automatically enters the next temperature rising stage, the nitrogen flow in the tube furnace is set to 50 mL / min, and the temperature rising rate of the tube furnace is set to 10 ℃ / min. When the temperature in the tube furnace rises to the preset final temperature of 800 ℃, the high-temperature activation treatment of the mixed mud-based carbon sample is completed after constant temperature stays for 1.5 h.

[0084] Step 5, when the pyrolysis program of the tube furnace is completed, the tube furnace is closed, but the nitrogen atmosphere in the tube furnace is maintained. After the temperature in the tube furnace naturally cools to room temperature, the input of nitrogen into the tube furnace is stopped. After the activated sample cools to room temperature, it is taken out of the tube furnace and washed in a constant temperature water bath to remove excess reagent residues and residual ash in the mixed mud-based activated carbon. The pH of the supernatant is close to neutral after washing. After drying, the mixed mud-based activated carbon activated by compounding is obtained.

[0085] Step 6, evaluate the adsorption performance of the mixed mud-based carbon activated by compounding;

[0086] The mixed mud-based activated carbon activated by compounding prepared in step 5 is ground and sieved through a 200-mesh sieve for characteristic adsorption evaluation. The methylene blue adsorption evaluation is used to evaluate the mesopore adsorption performance, and the evaluation process refers to GB / T 7702.6-2008 “Coal Particle Activated Carbon Test Method for Determination of Methylene Blue Adsorption Value”, GB / T 12496.10-1999 “Wood Activated Carbon Test Method for Determination of Methylene Blue Adsorption Value”. The iodine adsorption is used to evaluate the micropore adsorption performance, and the evaluation process refers to GB / T 12496.8-2015 “Wood Activated Carbon Test Method for Determination of Iodine Adsorption Value”. The iodine adsorption value of the mixed mud-based activated carbon activated by compounding is calculated to be 238.59 mg / g, and the methylene blue adsorption value is 125.77 mg / g.

[0087] Example 4

[0088] The present embodiment proposes a compounding activation method for mixed mud-based carbon, which specifically includes the following steps:

[0089] Step 1, pre-carbonization of mixed sludge;

[0090] The oil-containing sludge and biochemical sludge generated by a refining enterprise are used as carbonization raw materials, and the mass ratio of the oil-containing sludge and the biochemical sludge is set to 6:4. The oil-containing sludge and the biochemical sludge are uniformly mixed and then placed in an inert atmosphere tube furnace for pre-carbonization treatment. The temperature of the tube furnace in the pre-carbonization treatment is set to 600 ℃, and the pre-carbonization treatment time is set to 2 h. The mixed mud-based carbon is obtained through the pre-carbonization process.

[0091] Step 2, impregnation of compounding activator;

[0092] 2.0 g of mixed mud-based carbon was placed in a quartz boat, a mixed activator was prepared by mixing 1.0 mL of a 12 wt% potassium dihydrogen phosphate solution and 2.0 mL of a 20 wt% phosphoric acid solution, 3 mL of the mixed activator was added to the mixed mud-based carbon, and after stirring and mixing until uniform and fully impregnated for 22 h, it was placed in an oven for drying.

[0093] Step 3, low-temperature activation treatment of the mixed mud-based carbon sample after mixed activation;

[0094] The mixed mud-based carbon sample after fully impregnated with the mixed activator and dried was placed in a tube furnace with a nitrogen atmosphere, the nitrogen flow rate of the tube furnace was set to 50 mL / min, and the temperature rising program was set, with a temperature rising rate of 10 ℃ / min, the tube furnace temperature rising program was started to slowly raise the temperature in the furnace, when the temperature in the furnace rose to the preset middle temperature of 500 ℃, it was kept constant for 1 h, and the low-temperature activation treatment of the mixed mud-based carbon sample after mixed activation was completed.

[0095] Step 4, high-temperature activation treatment of the mixed mud-based carbon sample after mixed activation;

[0096] After the low-temperature activation treatment of the mixed mud-based carbon sample after mixed activation was completed, the tube furnace automatically entered the next temperature rising stage, the nitrogen flow rate of the tube furnace was set to 50 mL / min, and the temperature rising rate of the tube furnace was set to 10 ℃ / min, when the temperature in the tube furnace rose to the preset final temperature of 800 ℃, it was kept constant for 1.5 h, and the high-temperature activation treatment of the mixed mud-based carbon sample after mixed activation was completed.

[0097] Step 5, when the pyrolysis program of the tube furnace was completed, the tube furnace was closed, but the nitrogen atmosphere in the tube furnace was maintained, after the temperature in the tube furnace naturally cooled to room temperature, the nitrogen input to the tube furnace was stopped, after the activated sample cooled to room temperature, it was taken out of the tube furnace and washed in a constant temperature water bath to remove excess reagent residues and residual ash in the mixed mud-based activated carbon, the washing was continued until the pH of the supernatant was close to neutral, and after drying, the mixed mud-based activated carbon after mixed activation was obtained.

[0098] Step 6, evaluation of the adsorption performance of the mixed mud-based carbon after mixed activation;

[0099] The mixed mud-based activated carbon activated by the compound activator prepared in step 5 is ground, sieved through a 200-mesh sieve, and then subjected to characteristic adsorption evaluation, methylene blue adsorption evaluation of pore adsorption performance, and iodine adsorption evaluation of micropore adsorption performance. The evaluation process refers to GB / T 7702.6-2008 “Coal Particle Activated Carbon Test Method for Determination of Methylene Blue Adsorption Value”, GB / T 12496.10-1999 “Wood Activated Carbon Test Method for Determination of Methylene Blue Adsorption Value”, and GB / T 12496.8-2015 “Wood Activated Carbon Test Method for Determination of Iodine Adsorption Value”. The iodine adsorption value of the mixed mud-based activated carbon activated by the compound is calculated to be 221.39 mg / g, and the methylene blue adsorption value is 109.50 mg / g.

[0100] Example 5

[0101] The iodine adsorption values and methylene blue adsorption values of the mixed mud-based activated carbon activated by the compound prepared in Comparative Examples 1-4 are shown in Table 1.

[0102] Table 1 Iodine adsorption values and methylene blue adsorption values of the mixed mud-based activated carbon activated by the compound prepared in Comparative Examples 1-4

[0103]

[0104] By comparing the iodine adsorption values and methylene blue adsorption values of the mixed mud-based activated carbon activated by the compound prepared in Comparative Examples 1-4, it is found that the mesopore and micropore adsorption effects of the mixed mud-based activated carbon activated by the compound prepared in the present application are better than those of the mixed mud-based activated carbon activated by a single activator. At the same time, by comparing the compound activation effects of the compound activators prepared by mixing potassium dihydrogen phosphate and phosphoric acid in different proportions in Comparative Examples 1-4, it is easy to obtain that when the volume ratio of the 12wt% potassium dihydrogen phosphate solution and the 20wt% phosphoric acid solution in the compound activator is 4:2, the iodine adsorption value and the methylene blue adsorption value of the mixed mud-based activated carbon activated by the compound are relatively high, that is, the mixed mud-based activated carbon prepared under this condition exhibits good micropore and mesopore adsorption activity.

[0105] It can be seen that the mixed mud-based carbon compound activation method based on oil-containing sludge and sewage sludge co-pyrolysis has simple operation process and can obtain certain technical effect. The activation mode of using potassium dihydrogen phosphate as the main activator and a small amount of phosphoric acid as the auxiliary activator is more environmentally friendly than the traditional acid (sulfuric acid), alkali (potassium hydroxide) and salt (zinc chloride) activation, and the multi-activator compound activation is better than the single activator activation. At the same time, according to the activation characteristics of potassium dihydrogen phosphate and phosphoric acid, low-temperature and high-temperature continuous activation is designed, which is beneficial to develop the best activation performance of each activator compound process. Overall, the technical scheme improves the micropore and mesopore adsorption performance of the product obtained by the conversion of oil-containing sludge and biochemical sludge. The technical scheme is suitable for but not limited to the treatment and disposal of refinery three mud, and has good guiding significance for the comprehensive utilization and value-added of typical petrochemical enterprise hazardous / solid waste.

[0106] Of course, the above description is not a limitation of the present application, and the present application is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present application should also be within the scope of the present application.

Claims

1. A method of reactivation of mixed mud-based carbon, characterized in that, Specifically comprising the following steps: Step 1, pre-carbonization of mixed sludge; The oil-containing sludge and the biochemical sludge generated by the refining enterprise are used as carbonization raw materials. After the oil-containing sludge and the biochemical sludge are uniformly mixed, the mixed sludge is placed in a tube furnace in an inert atmosphere for pre-carbonization treatment to obtain mixed sludge-based carbon; Step 2, impregnation of the compounded activator; The mixed sludge-based carbon is placed in a quartz boat, a compounded activator prepared by mixing a potassium dihydrogen phosphate solution and a phosphoric acid solution is added, and the mixed sludge-based carbon is fully stirred and impregnated until it is uniformly mixed and then is placed in an oven for drying; Step 3, low-temperature activation treatment of the mixed sludge-based carbon sample after compounded activation; The mixed sludge-based carbon sample after the impregnation treatment of the compounded activator is placed in a tube furnace in a nitrogen atmosphere, and the tube furnace is used to perform low-temperature activation treatment on the mixed sludge-based carbon sample. When the temperature in the tube furnace reaches a preset middle temperature, the temperature in the tube furnace is kept constant for 1 hour, and then the low-temperature activation treatment of the mixed sludge-based carbon sample after compounded activation is ended. Step 4, high-temperature activation treatment of the mixed sludge-based carbon sample after compounded activation; After the low-temperature activation treatment of the mixed sludge-based carbon sample after compounded activation is completed, the tube furnace automatically enters the next temperature rising stage. When the temperature in the tube furnace reaches a preset final temperature, the temperature in the tube furnace is kept constant for 1.5 hours, and then the high-temperature activation treatment of the mixed sludge-based carbon sample after compounded activation is ended. Step 5, the mixed sludge-based carbon sample after high-temperature activation treatment is washed in a constant-temperature water bath and then is dried to obtain compounded activated mixed sludge-based activated carbon.

2. A method of combined activation of mixed clay-based carbon according to claim 1, characterized in that, In step 1, the pre-carbonization treatment temperature of the carbonization raw material is set to 600°C, and the pre-carbonization treatment time is set to 2 hours.

3. A method of combined activation of mixed clay-based carbon according to claim 1, characterized in that, In step 2, the volume of the compounded activator added to the mixed sludge-based carbon is 1-3 mL / g.

4. A method of combined mud-based carbon activation according to claim 3, characterized in that, In the compounded activator, the concentration of the potassium dihydrogen phosphate solution is set to 12 wt%, and the concentration of the phosphoric acid solution is set to 20 wt%.

5. A method of combined mud-based carbon activation according to claim 3, characterized in that, The impregnation time of the mixed sludge-based carbon is set to 22 hours.

6. The method of claim 1, wherein the mixture of the clay and the carbon is activated by a combination of the following: In step 3, the nitrogen flow rate in the tube furnace is set to 50 mL / min, and the temperature rising rate of the tube furnace is set to 10°C / min. ​ 7. The method of claim 1, wherein the mixture of the clay and the carbon is activated by a combination of the following: In step 3, the middle temperature is set to 500-600°C. ​ 8. The method of claim 1, wherein the mixture of the clay and the carbon is activated by a combination of the following: In step 4, the nitrogen flow rate in the tube furnace is set to 50 mL / min, and the temperature rising rate of the tube furnace is set to 10°C / min. ​ 9. The method of claim 1, wherein the mixture of the clay and the carbon is activated by a combination of the following: In step 4, the final temperature is set to 750-850°C. ​ 10. The method of claim 1, wherein the mixture of the clay and the carbon is activated by a combination of the following: Step 6, evaluation of the adsorption performance of the compounded activated mixed sludge-based activated carbon; ​ The compounded activated mixed sludge-based activated carbon prepared in step 5 is ground and sieved to obtain compounded activated mixed sludge-based carbon particles. The compounded activated mixed sludge-based carbon particles are subjected to characteristic adsorption evaluation. The mesopore adsorption performance of the sludge-based activated carbon is evaluated based on the methylene blue adsorption value, and the micropore adsorption performance of the sludge-based activated carbon is evaluated based on the iodine adsorption value.

11. The method of claim 10, wherein the mixture of the clay and the carbon is activated by a combination of the following: The iodine adsorption performance of the compound activated mixed mud-based activated carbon particles is evaluated according to the wood activated carbon test method in GB / T 12496.8-2015 - determination of iodine adsorption value, and the methylene blue adsorption performance of the compound activated mixed mud-based activated carbon particles is evaluated according to the coal quality activated carbon test method in GB / T 7702.6-2008 - determination of methylene blue adsorption value. ​ 12. The method of claim 10, wherein the mixture of the clay and the carbon is activated by a combination of the following: The particle size of the compound activated mixed mud-based activated carbon particles is 200 meshes. ​

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