Carbon-based composite material based on resource utilization of oil-based rock cuttings, synthesis method thereof, and application thereof in purifying wastewater

Abstract

The present invention relates to a carbon-based composite material based on resource utilization of oil-based rock cuttings, a synthesis method thereof, and an application thereof for purifying wastewater. A chelating agent and a dissolving agent are prepared using cheap, readily available, safe, and green raw materials to achieve the capture of heavy metal ions in oil-based rock cuttings. Organic matter and metal elements in the oil-based rock cuttings are carbonized and converted into a porous carbon-based composite material through freeze drying and carbonization reaction. The prepared porous carbon-based composite material is rich in active components required by catalysts such as nitrogen, carbon, manganese, cobalt, and iron, and has a rich pore structure and a large specific surface area. It can be used as a type of economical, efficient, and highly applicable catalyst, and can efficiently catalyze and activate potassium permonosulfate to purify organic wastewater, and has a high economic value. The present invention simultaneously solves the environmental pollution risks of organic matter and metal elements in oil-based rock cuttings, and achieves resource recovery and utilization of all components of oil-based rock cuttings.

Description

Technical Field

[0001] The present invention relates to the technical field of resource utilization of oil-based rock cuttings, and in particular to a carbon-based composite material based on resource utilization of oil-based rock cuttings, a synthesis method thereof, and an application of the carbon-based composite material in purifying wastewater. Background Technology

[0002] During the exploration and exploitation of shale gas, drilling fluid needs to be injected to lubricate and cool the drill bit, build walls and prevent leaks, and carry rock fragments back to the ground. Oil-based drilling fluid can reduce the shedding of rock fragments and produce less drill cuttings. Therefore, the vast majority of shale gas wells in China currently use oil-based drilling fluid. This has generated a large amount of solid waste, namely oil-based drill cuttings. Oil-based drill cuttings are mainly composed of base oil, rock fragments and drilling additives. They contain a large amount of diesel, heavy metals and high-molecular organic pollutants. They have the dual attributes of waste and resources. Generally, they have a high oil content and have been included in the "National List of Hazardous Wastes" (waste category is HW08). During their generation, stacking, transportation and treatment, they may pose a serious threat to the local ecological environment. The country attaches great importance to the treatment and disposal of oil-based cuttings and has successively formulated relevant laws, regulations and standards. Proper safe treatment and disposal of oil-based cuttings and reducing environmental risks have become important issues that need to be urgently addressed to achieve sustainable and green development of shale gas.

[0003] Under the background of my country's high-quality development and dual carbon goals, the resource utilization of oil-based cuttings has become an inevitable path in the field of oil-based cuttings processing. At present, thermal analysis technology is to put oil-based cuttings into a heating furnace and distill mineral oil at high temperature under anaerobic conditions. The recovered mineral oil can be used to prepare oil-based drilling fluid or as fuel oil to realize the resource utilization of oil in oil-based cuttings. However, this technology still has shortcomings such as high operating cost, low oil recovery rate, and secondary pollutants. At the same time, this technology will produce a large amount of pyrolysis residues, containing a large amount of heavy metal pollutants, and there are problems such as the risk of secondary pollution and difficulty in resource utilization. Therefore, the development of efficient and environmentally friendly oil-based cuttings resource utilization technology, while realizing efficient recovery of waste oil and resource utilization of residues, is one of the key issues that need to be urgently solved in the field of oil-based cuttings processing.

[0004] To this end, the present invention provides a carbon-based composite material based on the resource utilization of oil-based rock cuttings, a synthesis method thereof, and an application thereof in purifying wastewater. SUMMARY OF THE INVENTION

[0005] Based on this, it is necessary to provide a carbon-based composite material based on the resource utilization of oil-based rock cuttings, its synthesis method and its application in purifying wastewater in response to the above technical problems. This method uses chelating agents and solvent promoters to dissolve and capture metal elements in oil-based rock cuttings. After freeze-drying and carbonization treatment, high-quality oil products are obtained, and the carbonization of organic matter and metal elements in oil-based rock cuttings is converted into high-performance porous carbon-based composite materials. At the same time, the environmental pollution risks of organic matter and metal elements in oil-based rock cuttings are solved, and the resource recovery and utilization of all components of oil-based rock cuttings are realized. This material can be used to activate persulfate to degrade organic pollutants in sewage, thereby increasing the economic value of the product and reducing the cost of oil-based rock cuttings treatment and disposal.

[0006] In order to achieve the above purpose, the technical solution of the present invention is as follows:

[0007] The synthesis method of carbon-based composite materials based on the resource utilization of oil-based rock cuttings includes:

[0008] Step S1, preparing a chelating agent, adding potassium carbonate, polybasic organic acid sodium salt and ethanol to water in sequence, adjusting the pH value of the solution with hydrochloric acid or potassium hydroxide, and magnetically stirring for 2 hours to obtain a chelating agent;

[0009] Step S2, preparing a solubilizing agent, adding hexadecyl ammonium bromide and Tween 80 to water in sequence, and stirring magnetically for 12 hours to obtain a solubilizing agent;

[0010] Step S3, crushing the oil-based rock cuttings to be treated by a crusher, and then passing through a vibrating screen to form a uniform sample, and then adding the chelating agent obtained in step S1, and adding a dissolving agent, and magnetically stirring for 24 hours to obtain a uniformly dispersed mixture;

[0011] Step S4, placing the mixture obtained in step S3 in a freeze dryer, setting the freezing time, performing freeze drying, removing moisture, and obtaining a loose block solid;

[0012] Step S5, placing the block solid obtained in step S4 in a quartz tube of a tube furnace, setting a branch pipe below the gas outlet end of the quartz tube, placing quartz tube plugs at both ends, connecting the two ends of the quartz tube through flanges, and then passing inert gas into the quartz tube to exclude air;

[0013] Step S6, after setting the gas velocity, heating rate, target temperature and retention time of the tube furnace, start the carbonization reaction, cool down to room temperature after the reaction, collect the oil product at the quartz tube branch and the solid phase product inside the quartz tube, wherein the solid phase product is the porous carbon-based composite material based on the resource utilization of oil-based rock cuttings.

[0014] Preferably, the chelating agent comprises an aqueous solution of potassium carbonate, polybasic sodium organic salt and ethanol, wherein the concentration of potassium carbonate is 1-2 mol / L, the concentration of polybasic sodium organic salt is 0.001-0.01 mol / L, the dosage of ethanol is 1-5% (v:v), and the pH of the solution is 4-6.

[0015] Preferably, the polybasic sodium organic salt is at least one of sodium citrate, halogenated succinic acid sodium salt and mellitic acid tetrasodium salt.

[0016] Preferably, the volume ratio of the oil-based cuttings to the chelating agent is 1:(1-5).

[0017] Preferably, the solubilizer is a mixture of cetyltrimethylammonium bromide and Tween 80, and the mass ratio is 1:(1-20), and the volume ratio of the oil-based cuttings to the solubilizer is 1:(0.001-0.05).

[0018] Preferably, the freezing time is 24-48 h.

[0019] Preferably, the inert gas is at least one of nitrogen and argon, the gas velocity is 10-200 ml / min, the heating rate of the tubular furnace is 1-10 °C / min, the target temperature is 500-900 °C, and the residence time is 1-3 h.

[0020] As a general technical concept, the present invention also provides a carbon-based composite material prepared by the above synthesis method.

[0021] Meanwhile, as a general technical concept, the present invention also provides an application of the above carbon-based composite material in the field of wastewater purification. Among them, the dosage of the carbon composite material is 0.1-2 g / L, the concentration of potassium monopersulfate is 0.1-1 g / L, the concentration of organic pollutants is 5-50 mg / L, the reaction time is 5-120 min, and the removal efficiency of organic pollutants reaches more than 85%. Therefore, the material can be used to catalytically activate potassium monopersulfate to degrade organic pollutants in organic wastewater, improve the economic value of the product, and reduce the treatment and disposal cost of oil-based cuttings.

[0022] The advantages and beneficial effects of the present invention are as follows:

[0023] (1) The present invention uses cheap, readily available, safe and green raw materials to prepare a chelating agent and a solubilizer. With their assistance, heavy metal ions are captured and evenly dispersed, and then dried by freeze-drying to form a variety of pore structures, ensuring the stability of its structure. Finally, through a carbonization reaction, not only high-quality oil products are obtained, but also organic matter and metal elements are carbonized and transformed into a porous carbon-based composite material, while solving the environmental pollution risks of organic matter and metal elements in oil-based cuttings, and realizing the resource recovery and utilization of all components of oil-based cuttings.

[0024] (2) The present invention makes full use of the heavy metal components in oil-based cuttings to form a functional material, which plays a catalytic role, promotes the cracking of heavy oil in oil-based cuttings, improves the recovery rate of waste oil, and reduces the oil content of the residue.

[0025] (3) The present invention carbonizes and transforms the organic matter and metal elements in oil-based cuttings into high-performance functional materials, which are rich in active components required for catalysts such as nitrogen, carbon, manganese, cobalt, and iron, and have a rich pore structure and a large specific surface area. They can be used as a kind of economic, efficient and highly applicable catalyst, which can efficiently catalyze and activate potassium monopersulfate to purify organic wastewater, and has high economic value.

[0026] (4) The present invention has the advantages of strong practicability, simple process, convenient operation, good general applicability, etc. It also realizes the efficient recovery of waste oil from oil-based cuttings and the high-value utilization of residues, improves the economic value of products, reduces the environmental risks of oil-based cuttings, and has good environmental and economic benefits. Description of the Drawings

[0027] Figure 1 It is a flow chart of the synthesis method of the carbon-based composite material based on the resource utilization of oil-based cuttings in the embodiment of the present invention;

[0028] Figure 2 It is a photo of the oil-based cuttings raw material used in Example 1 of the present invention;

[0029] Figure 3 It is a scanning electron microscope photo of the oil-based cuttings raw material used in Example 1 of the present invention;

[0030] Figure 4 It is a comparison photo of the carbon-based composite materials prepared by using Examples 1-5 and Comparative Example 1 in the embodiment of the present invention;

[0031] Figure 5 It is an XRD pattern of the carbon-based composite materials prepared by using Examples 1-5 in the embodiment of the present invention;

[0032] Figure 6 It is the N of Examples 1-5 and Comparative Example 1 in the embodiment of the present invention 2Adsorption / desorption isotherms and pore size distribution diagrams;

[0033] Figure 7 This is a scanning electron microscope photo of the carbon-based composite material prepared in Example 5 of the present invention. Specific implementation method

[0034] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below through specific implementation methods combined with the accompanying drawings. It should be understood that the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0035] The synthesis method of carbon-based composite materials based on the resource utilization of oil-based rock cuttings includes:

[0036] Step S101, prepare a chelating agent, add potassium carbonate, polybasic organic acid sodium salt and ethanol to water in sequence, adjust the pH value of the solution with hydrochloric acid or potassium hydroxide, and stir magnetically for 2 hours to obtain a chelating agent.

[0037] Step S102, preparing a solubilizing agent, adding hexadecyl ammonium bromide and Tween 80 to water in sequence, and stirring magnetically for 12 hours to obtain a solubilizing agent.

[0038] Step S103, the oil-based rock cuttings to be processed are crushed by a crusher, and then passed through a vibrating screen to form a uniform sample, and then added to the chelating agent obtained in step S1, and a dissolving agent is added, and magnetic stirring is performed for 24 hours to obtain a uniformly dispersed mixture.

[0039] Step S104, placing the mixture obtained in step S3 in a freeze dryer, setting the freezing time, freeze drying, removing moisture, and obtaining a loose block solid.

[0040] Step S105, placing the block solid obtained in step S4 in a quartz tube of a tube furnace, setting a branch pipe below the gas outlet end of the quartz tube, placing quartz tube plugs at both ends, connecting the two ends of the quartz tube through flanges, and then passing inert gas into the quartz tube to exclude air.

[0041] Step S106, after setting the gas velocity, heating rate, target temperature and retention time of the tube furnace, start the carbonization reaction, cool down to room temperature after the reaction, collect the oil product at the quartz tube branch and the solid phase product inside the quartz tube, wherein the solid phase product is the porous carbon-based composite material based on the resource utilization of oil-based rock cuttings.

[0042] In this embodiment, the chelating agent includes an aqueous solution of potassium carbonate, polybasic organic acid sodium salt and ethanol, wherein the concentration of the potassium carbonate is 1-2 mol / L, the concentration of the polybasic organic acid sodium salt is 0.001-0.01 mol / L, the amount of the ethanol is 1-5% (v:v), and the solution pH is 4-6.​

[0043] In this embodiment, the polyvalent organic sodium salt is at least one of sodium citrate, sodium halide succinate, and sodium pyromellitate.

[0044] In this embodiment, the volume ratio of the oil-based cuttings to the chelating agent is 1:(1-5).

[0045] In this embodiment, the co-solvent is a mixture of cetyltrimethylammonium bromide and Tween 80, and the mass ratio is 1:(1-20). The volume ratio of the oil-based cuttings to the co-solvent is 1:(0.001-0.05).

[0046] In this embodiment, the freezing time is 24-48 h.

[0047] In this embodiment, the inert gas is at least one of nitrogen and argon. The gas velocity is 10-200 ml / min. The heating rate of the tubular furnace is 1-10 °C / min. The target temperature is 500-900 °C. The residence time is 1-3 h.

[0048] As a general technical concept, the present invention also provides a carbon-based composite material prepared by the above synthesis method. At the same time, as a general technical concept, the present invention also provides an application of the above carbon-based composite material in the field of wastewater purification. Among them, the dosage of the carbon composite material is 0.1-2 g / L, the concentration of potassium monopersulfate is 0.1-1 g / L, the concentration of organic pollutants is 5-50 mg / L, the reaction time is 5-120 min, and the removal efficiency of organic pollutants reaches more than 85%. Therefore, this material can be used to catalytically activate potassium monopersulfate to degrade organic pollutants in organic wastewater, improve the economic value of the product, and reduce the treatment and disposal cost of oil-based cuttings.

[0049] Example 1

[0050] The oil-based cuttings used in Example 1 are from a shale gas development platform. The appearance and scanning electron microscope photos of the oil-based cuttings raw materials are as Figure 2 and Figure 3 shown, and their components are shown in Table 1 and Table 2.

[0051] The specific method is as follows:

[0052] Step S1, add 1 mol of potassium carbonate, 0.005 mol of sodium citrate, and 20 ml of ethanol to 1 L of water in sequence. Adjust the pH of the solution to 4 with hydrochloric acid or potassium hydroxide. After magnetic stirring for 2 h, the obtained solution is the chelating agent.

[0053] Step S2: Configure the solubilizer. Add 1.5 g of cetyltrimethylammonium bromide and 1.5 g of Tween 80 to 100 ml of water, and stir magnetically for 12 h to obtain the solubilizer.

[0054] Step S3: Crush the oil-based cuttings to be treated with a crusher for 20 min, then screen them through a 100-mesh vibrating screen. Add 100 g of the screened oil-based cuttings to 100 ml of chelating agent, and add 1 ml of solubilizer. Stir magnetically for 24 h to allow them to react fully to obtain a uniformly dispersed mixture.

[0055] Step S4: Place the mixture obtained in Step S3 in a freeze dryer, set the freezing time to 24 h, perform freeze drying to remove moisture, and obtain a porous block solid.

[0056] Step S5: Place the block solid obtained in Step S4 in the quartz tube of a tubular furnace. A branch pipe is configured below the gas outlet end of the quartz tube to receive the oil product. Place quartz tube plugs at both ends and connect the two ends of the quartz tube with a flange. Then, introduce nitrogen into the quartz tube at a gas velocity of 200 ml / min to remove air.

[0057] Step S6: Set the gas velocity to 50 ml / min, the heating rate to 5 °C / min, the target temperature to 500 °C, and the reaction time to 2 h. Start the carbonization reaction. After the reaction ends, cool it down to room temperature, collect the oil-phase product at the branch pipe of the quartz tube, and the obtained solid-phase product is the porous carbon-based composite material for resource utilization of oil-based cuttings. Its appearance is shown in Figure 4 The phase structure and pore size distribution curve are shown in Figure 5 and Figure 6 The specific surface area and pore structure parameters are shown in Table 3.

[0058] Evaluation of the performance of treating organic wastewater:

[0059] Weigh 10 mg of the cuttings residue, ultrasonically disperse it in 100 mL of bisphenol A solution with a concentration of 10 mg / L, add a certain amount of potassium persulfate, and then place it in the dark in a constant temperature oscillator. Set the oscillation speed to 150 r·min-1 and the temperature to 25 °C. After reacting for 30 min, take 2 mL of the liquid sample with a syringe, immediately add 1 mL of methanol, and then filter it through a 0.22-μm polytetrafluoroethylene filter membrane to obtain a clear solution. Immediately test its concentration with high-performance liquid chromatography. After calculation, the removal rate of bisphenol A reaches 85.1%.

[0060] Table 1 Main inorganic components in oil-based cuttings (%)

[0061]

[0062]

[0063] Table 2 Composition of main organic pollutants in oil-based cuttings (mg / kg)

[0064] Serial number Test name Content 1 Ethylbenzene 0.0436 2 o-Xylene 0.074 3 Terephthalic acid 0.156 4 Styrene 0.0849 5 Toluene 0.0911 6 m,p-Xylene 0.118 7 Petroleum hydrocarbon 123515

[0065] Example 2

[0066] Step S1, sequentially adding 1 mol potassium carbonate, 0.010 mol sodium citrate and 20 ml ethanol to 1 L water, adjusting the solution pH to 6, stirring magnetically for 2 h, and then preparing a chelating agent;

[0067] Step S2, preparing a chaotropic agent, adding 2g of hexadecyl ammonium bromide and 2g of Tween 80 to 100ml of water, and stirring with a magnetic force for 12h to obtain a chaotropic agent;

[0068] Step S3, adding 100 g of the sieved oil-based cuttings to 100 ml of a chelating agent, and adding 1 ml of a dissolving agent, and magnetically stirring for 24 hours to allow the mixture to react fully to obtain a uniformly dispersed mixture;

[0069] Step S4, placing the mixture obtained in step S3 in a freeze dryer, setting the freezing time to 24 hours, freeze drying, removing moisture, and obtaining a loose block solid;

[0070] Step S4, freeze-drying the mixture obtained in step S3 for 24 hours to obtain a loose block solid;

[0071] Step S5, placing the block solid in a tube furnace, connecting the two ends of a quartz tube with flanges, and then introducing nitrogen into the quartz tube at a gas speed of 200 ml / min to exclude air;

[0072] Step S6, set the gas speed to 100ml / min, the heating rate to 10℃ / min, the target temperature to 600℃, the reaction time to 2h, start the carbonization reaction, cool down to room temperature after the reaction, collect the oil phase product at the quartz tube branch, and the obtained solid phase product is the porous carbon-based composite material based on the resource utilization of oil-based rock cuttings, and its appearance is shown in Figure 4 , phase structure and pore size distribution curve see Figure 5 and Figure 6 , specific surface area and pore structure parameters are shown in Table 3.

[0073] Evaluation of organic wastewater treatment performance: According to the method in Example 1, the removal rate of bisphenol A was calculated to be 92.1%.

[0074] Example 3

[0075] Step S1, sequentially adding 2 mol potassium carbonate, 0.005 mol sodium bromosuccinate and 20 ml ethanol to 1 L water, adjusting the solution pH to 6, stirring magnetically for 2 h, and then preparing a chelating agent;​

[0076] Step S2: Configure the solubilizer. Add 0.5 g of cetyltrimethylammonium bromide and 2 g of Tween 80 to 100 ml of water, and stir magnetically for 12 h to obtain the solubilizer.

[0077] Step S3: Add 100 g of the screened oil-based cuttings to 200 ml of the chelating agent, and add 10 ml of the solubilizer. Stir magnetically for 24 h to allow full reaction, obtaining a uniformly dispersed mixture.

[0078] Step S4: Lyophilize the mixture obtained in Step S3 for 36 h to obtain a porous block solid.

[0079] Step S5: Place the block solid obtained in Step S4 into the quartz tube of the tube furnace, connect both ends of the quartz tube with a flange. Then, introduce nitrogen into the quartz tube at a gas velocity of 100 ml / min to remove air.

[0080] Step S6: Set the gas velocity to 50 ml / min, the heating rate to 3 °C / min, the target temperature to 700 °C, and the reaction time to 2 h. Initiate the carbonization reaction. After the reaction ends, collect the oil-phase product at the branch of the quartz tube. The obtained solid-phase product is the porous carbon-based composite material for resource utilization of oil-based cuttings, and its appearance is shown in Figure 4 The phase structure and pore size distribution curve are shown in Figure 5 and Figure 6 The specific surface area and pore structure parameters are shown in Table 3.

[0081] Evaluation of the performance of treating organic wastewater: Operate according to the method in Example 1. After calculation, the removal rate of bisphenol A reaches 93.1%.

[0082] Example 4

[0083] Step S1: Add 2 mol of potassium carbonate, 0.005 mol of sodium terephthalate, and 50 ml of ethanol to 1 L of water in sequence, adjust the pH of the solution to 6, and stir magnetically for 2 h to configure the chelating agent.

[0084] Step S2: Configure the solubilizer. Add 0.5 g of cetyltrimethylammonium bromide and 2 g of Tween 80 to 100 ml of water, and stir magnetically for 12 h to obtain the solubilizer.

[0085] Step S3: Add 100 g of the screened oil-based cuttings to 200 ml of the chelating agent, and add 10 ml of the solubilizer. Stir magnetically for 24 h to allow full reaction, obtaining a uniformly dispersed mixture.

[0086] Step S4: Lyophilize the mixture obtained in Step S3 for 36 h to obtain a porous block solid.

[0087] Step S5: Place the blocky solid obtained in step S4 into the quartz tube of the tube furnace, connect both ends of the quartz tube with a flange. Then, introduce nitrogen into the quartz tube at a gas velocity of 100 ml / min to remove air.

[0088] Step S6: Set the gas velocity to 50 ml / min, the heating rate to 3 °C / min, the target temperature to 800 °C, and the reaction time to 2 h. Initiate the carbonization reaction. After the reaction ends, collect the oil-phase product at the branch of the quartz tube. The obtained solid-phase product, i.e., the porous carbon-based composite material, is shown in Figure 4 , and the phase structure and pore size distribution curve are shown in Figure 5 and Figure 6 , and the specific surface area and pore structure parameters are shown in Table 3.

[0089] Evaluation of the performance of treating organic wastewater: Operate according to the method in Example 1. After calculation, the removal rate of bisphenol A reaches 98.3%.

[0090] Example 5

[0091] Step S1: Add 2 mol of potassium carbonate, 0.005 mol of sodium terephthalate, and 50 ml of ethanol to 1 L of water in sequence. Adjust the pH of the solution to 5. After magnetic stirring for 2 h, prepare the chelating agent.

[0092] Step S2: Prepare the co-solvent. Add 1 g of cetyltrimethylammonium bromide and 1 g of Tween 80 to 100 ml of water. After magnetic stirring for 12 h, the co-solvent is obtained.

[0093] Step S3: Add 100 g of the screened oil-based cuttings to 200 ml of the chelating agent, and add 10 ml of the co-solvent. Magnetic stir for 24 h to make them react fully to obtain a uniformly dispersed mixture.

[0094] Step S4: Freeze-dry the mixture obtained in step S3 for 24 h to obtain a loose blocky solid.

[0095] Step S5: Place the blocky solid obtained in step S4 into the quartz tube of the tube furnace, connect both ends of the quartz tube with a flange. Then, introduce nitrogen into the quartz tube at a gas velocity of 100 ml / min to remove air.

[0096] Step S6: Set the gas velocity to 50 ml / min, the heating rate to 3 °C / min, the target temperature to 900 °C, and the reaction time to 2 h. Initiate the carbonization reaction. After the reaction ends, the obtained porous carbon-based composite material and oil-phase product are shown in Figure 4 , and the phase structure and pore size distribution curve are shown in Figure 5 and Figure 6 , and the specific surface area and pore structure parameters are shown in Table 3, and the microscopic morphology is shown in Figure 7 .

[0097] Performance evaluation of organic wastewater treatment: Operate according to the method in Example 1. After calculation, the removal rate of bisphenol A reaches 90.4%.

[0098] Comparative Example 1

[0099] In the preparation process of this Comparative Example 1, referring to Example 1, the difference is that no chelating agent and solubilizer are added. The appearance of the obtained ash residue is shown in Figure 4 , and the pore size distribution curve, specific surface area and pore structure parameters are shown in Figure 6 and Table 3.

[0100] Performance evaluation of organic wastewater treatment: Operate according to the method in Example 1. After calculation, the removal rate of bisphenol A only reaches 35.1%.

[0101] Table 3 Specific surface area and pore structure parameters of Examples 1 - 5 and Comparative Example 1

[0102] Sample name BET Surface Area Pore volume (cm3 / g) Pore size (cm2 / g) Example 1 11.3002 0.046769 17.1489 Example 2 10.9167 0.046095 17.43274 Example 3 10.957 0.053736 20.2316 Example 4 9.718 0.034739 14.74735 Example 5 9.7719 0.041348 17.37813 Comparative example 1 0.6939 0.0033 23.84179

[0103] In summary, the present invention discloses a carbon - based composite material based on the resource utilization of oil - based cuttings, its synthesis method and its application in purifying wastewater. This method uses a chelating agent and a solubilizer to dissolve and capture metal elements in oil - based cuttings, enabling them to come into full contact. Then, it is dried by freeze - drying, which ensures the stability of its structure and forms various pore structures. Finally, through a carbonization reaction, a porous carbon - based composite material is obtained. It not only obtains high - quality oil products but also realizes the carbonization conversion of organic matter and metal elements in oil - based cuttings into high - performance functional materials. At the same time, it solves the environmental pollution risks of organic matter and metal elements in oil - based cuttings, realizes the resource recovery and utilization of all components of oil - based cuttings. This material can be used to activate persulfate to degrade organic pollutants in sewage, enhancing the economic value of the product and reducing the treatment and disposal cost of oil - based cuttings.

[0104] In addition, the porous carbon - based composite material based on the resource utilization of oil - based cuttings can be used to catalytically activate potassium monopersulfate to degrade organic pollutants in organic wastewater, improving the economic value of the product and reducing the treatment and disposal cost of oil - based cuttings.

[0105] Finally, it should be noted that the above content is a further detailed description of the present invention in combination with specific implementation manners. It cannot be determined that the specific implementation of the present invention is only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, which should all be regarded as belonging to the protection scope of the present invention.

Claims

1. A method for synthesizing a carbon-based composite material based on resource utilization of oil-based rock cuttings, characterized in that: include: Step S1, preparing a chelating agent, adding potassium carbonate, polybasic organic acid sodium salt and ethanol to water in sequence, adjusting the pH value of the solution with hydrochloric acid or potassium hydroxide, and magnetically stirring for 2 hours to obtain a chelating agent; Step S2, preparing a solubilizing agent, adding hexadecyl ammonium bromide and Tween 80 to water in sequence, and stirring magnetically for 12 hours to obtain a solubilizing agent; Step S3, crushing the oil-based rock cuttings to be processed by a crusher, and then passing through a vibrating screen to form a uniform sample, and then adding the chelating agent obtained in step S1, and adding a dissolving agent, and magnetically stirring for 24 hours to obtain a uniformly dispersed mixture; Step S4, placing the mixture obtained in step S3 in a freeze dryer, setting the freezing time, and freeze drying to remove moisture to obtain a loose block solid; Step S5, placing the block solid obtained in step S4 in a quartz tube of a tube furnace, setting a branch pipe below the gas outlet end of the quartz tube, placing quartz tube plugs at both ends, connecting the two ends of the quartz tube through flanges, and then passing inert gas into the quartz tube to exclude air; Step S6, after setting the gas velocity, heating rate, target temperature and retention time of the tube furnace, start the carbonization reaction, cool down to room temperature after the reaction, collect the oil products at the quartz tube branch and the solid phase products inside the quartz tube, wherein the solid phase products are porous carbon-based composite materials based on the resource utilization of oil-based rock cuttings.

2. The method for synthesizing a carbon-based composite material based on resource utilization of oil-based rock cuttings according to claim 1, characterized in that: The chelating agent includes an aqueous solution of potassium carbonate, polybasic organic acid sodium salt and ethanol, wherein the concentration of the potassium carbonate is 1-2 mol / L, the concentration of the polybasic organic acid sodium salt is 0.001-0.01 mol / L, the amount of the ethanol is 1-5% (v:v), and the solution pH is 4-6.

3. The method for synthesizing a carbon-based composite material based on resource utilization of oil-based rock cuttings according to claim 2, characterized in that: The polybasic organic acid sodium salt is at least one of sodium citrate, sodium halogenated succinate and sodium pyromellitic acid.

4. The method for synthesizing a carbon-based composite material based on resource utilization of oil-based rock cuttings according to claim 1, characterized in that: The volume ratio of the oil-based rock cuttings to the chelating agent is 1:(1-5).

5. The method for synthesizing a carbon-based composite material based on resource utilization of oil-based rock cuttings according to claim 1, characterized in that: The dissolving agent is a mixture of hexadecyl ammonium bromide and Tween 80, and the mass ratio is 1: (1-20), and the volume ratio of the oil-based rock cuttings to the dissolving agent is 1: (0.001-0.05).

6. The method for synthesizing a carbon-based composite material based on resource utilization of oil-based rock cuttings according to claim 1, characterized in that: The freezing time is 24 to 48 hours.

7. The method for synthesizing a carbon-based composite material based on resource utilization of oil-based rock cuttings according to claim 1, characterized in that: The inert gas is at least one of nitrogen and argon, the gas velocity is 10 to 200 ml / min, the heating rate of the tubular furnace is 1 to 10° C. / min, the target temperature is 500 to 900° C., and the retention time is 1 to 3 hours.

8. A carbon-based composite material obtained by the synthesis method of a carbon-based composite material based on resource utilization of oil-based rock cuttings according to any one of claims 1 to 7.

9. The use of the carbon-based composite material according to claim 8 in the field of wastewater purification, characterized in that: The dosage of the carbon composite material is 0.1-2 g / L, the concentration of potassium persulfate is 0.1-1 g / L, the concentration of organic pollutants is 5-50 mg / L, the reaction time is 5-120 min, and the removal efficiency of organic pollutants reaches more than 85%.

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