A method for producing activated carbon fiber, activated carbon fiber, and adsorption method

Abstract

The present application relates to a kind of preparation method of activated carbon fiber, activated carbon fiber, adsorption method, the preparation method includes: the material containing polycyclic aromatic hydrocarbon and extraction oil are mixed, obtain initial material;The obtained initial material is carried out thermal polycondensation, obtain spinning pitch;The obtained spinning pitch is ground and then melt spinning is carried out, obtain pitch fiber;The obtained pitch fiber is sequentially not fused and carbonized activation, obtain pitch-based activated carbon fiber.The preparation method provided by the present application, by the design of raw material used for the preparation of activated carbon fiber and the combination of preparation process, the preparation of high-performance activated carbon fiber can be realized, the specific surface area of the obtained activated carbon fiber can reach 1000m 2 / g or more, and the yield can reach 50% or more.

Description

Technical Field

[0001] This invention relates to the field of activated carbon fiber technology, specifically to a method for preparing activated carbon fiber, activated carbon fiber, and an adsorption method. Background Technology

[0002] Currently, activated carbon fiber is a novel and highly efficient adsorption material with characteristics such as large specific surface area, abundant micropores, narrow pore size distribution, large adsorption capacity, fast adsorption-desorption rate, easy recycling, high temperature resistance, corrosion resistance, conductivity, biocompatibility, and good processing performance. It is expected to become an upgraded replacement for powdered and granular activated carbon. The advantages of activated carbon fiber are mainly reflected in the following aspects:

[0003] (1) It has a large adsorption capacity, and its specific surface area can generally reach 1000-1500 m². 2 / g, even as high as 2000m 2 / g or more;

[0004] (2) The adsorption and desorption speed is fast. Most of the effective adsorption pores are micropores, and there are few or no macropores. They are radially open and directly contact the adsorbate. The adsorption and desorption path is short, which makes the adsorption and desorption speed 10-100 times that of activated carbon.

[0005] (3) It has high adsorption efficiency and can adsorb low concentrations of harmful gases and trace amounts of precious metal ions.

[0006] (4) High purity, few impurities, and will not contaminate the adsorbate;

[0007] (5) High operating temperature: Due to the high carbon content of 85-95%, it can be used normally at temperatures below 400℃;

[0008] (6) It is easy to regenerate and can be reused hundreds or thousands of times, resulting in good economic benefits;

[0009] (7) It has good post-processing performance and can be processed into various customized products such as yarn, cloth, paper, felt, honeycomb structure, and corrugated board as needed. It has strong adaptability and facilitates continuous and automated production.

[0010] Activated carbon fiber has been widely used in solvent recovery, drinking water purification, indoor air purification, flue gas desulfurization, catalyst carriers, gas masks, hemostatic bandages and dressings, etc., involving industries such as petroleum, chemical, environmental protection, energy, military, medicine, food and protection. In the future, it will also have broad application prospects in carbon dioxide capture, natural gas storage, supercapacitor electrode materials, blood filtration, artificial organs and adsorption refrigeration.

[0011] Depending on the raw materials, activated carbon fibers are mainly classified into four types: viscose-based, polyacrylonitrile-based, pitch-based, and phenolic-based.

[0012] Viscose-based activated carbon fiber is made from regenerated cellulose fiber. It has a large specific surface area and good adsorption performance, but it has problems such as low yield, low strength, and easy pulverization, which can cause secondary pollution.

[0013] Phenolic activated carbon fiber is made from phenolic resin, which has advantages such as large specific surface area and high strength. However, phenolic fiber is currently mainly imported, and its price is relatively high.

[0014] Polyacrylonitrile-based activated carbon fiber is made from polyacrylonitrile-based fibers. It has a low degree of pulverization and high strength, but a small specific surface area and a high cost.

[0015] The raw materials for pitch-based activated carbon fiber are derived from coal tar or heavy petroleum oil. Its outstanding features are abundant raw material resources, low cost, high carbon content, high yield, and large specific surface area, making it suitable for industrial production.

[0016] For example, CN107447298A discloses a method for preparing pitch-based activated carbon fibers using mesophase pitch as raw material, which includes the following steps: mesophase pitch is melt-spun into pitch fibers, the pitch fibers are subjected to non-melting treatment to produce non-melting pitch fibers, the non-melting pitch fibers are subjected to carbonization and graphitization treatment to produce high-performance pitch-based carbon fibers, and finally the pitch-based carbon fibers are activated to produce high-performance pitch-based activated carbon fibers.

[0017] However, the pitch-based activated carbon fibers currently used still suffer from problems such as small specific surface area and low yield. Summary of the Invention

[0018] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for preparing activated carbon fiber, activated carbon fiber, and adsorption method, so as to solve the problems of small specific surface area and low yield in the preparation of pitch-based activated carbon fiber in the prior art.

[0019] To achieve this objective, the present invention adopts the following technical solution:

[0020] In a first aspect, the present invention provides a method for preparing activated carbon fibers, the method comprising:

[0021] The material containing polycyclic aromatic hydrocarbons is mixed with the extracted oil to obtain the initial feedstock;

[0022] The obtained raw material is subjected to thermal polycondensation to obtain spinning pitch;

[0023] The obtained spinning pitch was ground and then melt-spun to obtain pitch fibers;

[0024] The obtained pitch fibers were sequentially subjected to infusible and carbonization activation to obtain pitch-based activated carbon fibers.

[0025] The preparation method provided by this invention, by combining the design of the raw materials used in the preparation of activated carbon fibers with the preparation process, can achieve the preparation of high-performance activated carbon fibers with a specific surface area >1000 m². 2 / g, yield can reach over 50%.

[0026] As a preferred embodiment of the present invention, the polycyclic aromatic hydrocarbon is a polycyclic aromatic hydrocarbon containing 3-5 benzene rings.

[0027] Preferably, the polycyclic aromatic hydrocarbon (PAH) containing 3-5 benzene rings in the material contains ≥60% by mass.

[0028] Preferably, the ash content in the polycyclic aromatic hydrocarbon-containing material is ≤0.01wt%.

[0029] Preferably, the material containing polycyclic aromatic hydrocarbons is obtained by sequential solid-liquid separation, deasphalting and distillation of catalytic slurry oil and / or ethylene tar.

[0030] As a preferred technical solution of the present invention, the mass ratio of the material containing polycyclic aromatic hydrocarbons in the mixture to the extracted oil is (2-5):(1-3).

[0031] As a preferred technical solution of the present invention, the thermal polycondensation is carried out under stirring at a stirring speed of 100-400 r / min.

[0032] As a preferred technical solution of the present invention, the thermal polycondensation includes sequentially performing a first heating, a second heating, heat preservation, pressure relief purging, and cooling purging.

[0033] Preferably, the heating rate of the first heating is 5-10℃ / min.

[0034] Preferably, the endpoint temperature of the first heating is 348-350°C.

[0035] Preferably, the heating rate of the second heating is 0.5-1℃ / min.

[0036] Preferably, the endpoint temperature of the second heating is 380-430°C.

[0037] Preferably, the temperature of the heat preservation is the final temperature of the second heating.

[0038] Preferably, the heat preservation time is 5-6 hours.

[0039] Preferably, the pressure during the insulation is 1-4 MPa.

[0040] Preferably, the pressure relief during the purging process ends at a pressure of 0.1-0.15 MPa.

[0041] Preferably, the flow rate of the purging gas in the pressure relief purging is 5-30 L / (min·kg).

[0042] Preferably, the pressure relief purging time is 15-30 minutes.

[0043] Preferably, the endpoint temperature of the cooling purging cooling is 280-350℃.

[0044] Preferably, the flow rate of the purging gas in the cooling purging process is 0.5-3 L / (min·kg).

[0045] Preferably, the cooling and purging time is 5-6 hours.

[0046] As a preferred embodiment of the present invention, the operating temperature in the melt spinning process is 250-310℃.

[0047] Preferably, the winding speed in the melt spinning process is 200-500 m / min.

[0048] As a preferred embodiment of the present invention, the non-melting process is carried out in an atmospheric environment with a gas flow rate of 1-3 L / (min·kg).

[0049] Preferably, the non-melting process includes a first heating, a second heating, and a non-melting heat preservation process performed sequentially.

[0050] Preferably, the heating rate for a single heating cycle is 3-5°C / min.

[0051] Preferably, the final temperature of the first heating is 140-150℃.

[0052] Preferably, the heating rate of the secondary heating is 0.5-1℃ / min.

[0053] Preferably, the final temperature of the secondary heating is 200-300℃.

[0054] Preferably, the temperature of the non-melting heat preservation is the final temperature of the secondary heating.

[0055] Preferably, the non-melting heat preservation time is 0.5-2.5h.

[0056] As a preferred technical solution of the present invention, the carbonization activation includes a first heat preservation, a second heat preservation, and a cooling process performed sequentially.

[0057] Preferably, the temperature of the first insulation is 650-700℃, and the heating rate is 10-20℃ / min.

[0058] Preferably, the heat preservation time of the first heat preservation is 20-30 minutes.

[0059] Preferably, the temperature of the second heat preservation is 750-850℃, and the heating rate is 5-10℃ / min.

[0060] Preferably, water vapor is circulated in the second insulation layer, and the flow rate of the water vapor is 300-1000 L / (min·kg).

[0061] Preferably, the heat preservation time for the second heat preservation is 1-2 hours.

[0062] Preferably, both the first and second insulation processes are supplied with protective gas, and the flow rate of the protective gas is 1-3 L / (min·kg).

[0063] Preferably, the cooling is performed under a protective atmosphere to 10-40°C, and the flow rate of the gas in the protective atmosphere is 1-3 L / (min·kg).

[0064] In a second aspect, the present invention provides an activated carbon fiber, which is prepared by the method described in the first aspect.

[0065] Thirdly, the present invention provides an adsorption method comprising using activated carbon fibers as described in the second aspect to adsorb volatile organic compounds.

[0066] Compared with existing technical solutions, the present invention has the following beneficial effects:

[0067] (1) The raw material blending process used in this invention can effectively prevent mononuclear polycyclic aromatic hydrocarbon molecules in a single raw material from forming a large planar optical anisotropic structure due to excessive condensation, and can also prevent polynuclear polycyclic aromatic hydrocarbon molecules from undergoing excessively rapid pyrolysis reactions, resulting in a high-viscosity system that reduces the spinnability of the spinning pitch. After raw material blending, aromatic hydrocarbon molecules can form a certain three-dimensional structure through cross-linking reactions, which is beneficial for pore formation in the later activation process, thereby obtaining activated carbon fibers with a large specific surface area. The specific surface area of ​​the obtained activated carbon fibers is ≥1074.5 m². 2 / g, pore volume ≥0.589cm³ 3 / g.

[0068] (2) The present invention uses a one-step carbonization and activation method to prepare pitch-based activated carbon fibers, that is, carbonization and activation are carried out simultaneously under certain temperature and atmosphere conditions, which shortens the process, reduces energy consumption, and improves product yield. Attached Figure Description

[0069] Figure 1 This is a pore size distribution diagram of the activated carbon fiber obtained in Example 1 of the present invention;

[0070] Figure 2 This is the nitrogen adsorption-desorption curve of the activated carbon fiber obtained in Example 1 of the present invention;

[0071] Figure 3 This is a pore size distribution diagram of the activated carbon fiber obtained in Example 2 of the present invention;

[0072] Figure 4 This is the nitrogen adsorption-desorption curve of the activated carbon fiber obtained in Example 2 of the present invention;

[0073] Figure 5 This is a pore size distribution diagram of the activated carbon fiber obtained in Example 3 of the present invention;

[0074] Figure 6 This is the nitrogen adsorption-desorption curve of the activated carbon fiber obtained in Example 3 of the present invention.

[0075] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims. Detailed Implementation

[0076] To better illustrate the present invention and facilitate understanding of its technical solutions, typical but non-limiting embodiments of the present invention are as follows:

[0077] This embodiment provides a method for preparing activated carbon fibers, the method comprising:

[0078] The material containing polycyclic aromatic hydrocarbons is mixed with the extracted oil to obtain the initial feedstock;

[0079] The obtained raw material is subjected to thermal polycondensation to obtain spinning pitch;

[0080] The obtained spinning pitch was ground and then melt-spun to obtain pitch fibers;

[0081] The obtained pitch fibers were sequentially subjected to infusible and carbonization activation to obtain pitch-based activated carbon fibers.

[0082] Specifically, the polycyclic aromatic hydrocarbon is a polycyclic aromatic hydrocarbon containing 3-5 benzene rings;

[0083] In this invention, the polycyclic aromatic hydrocarbon containing 3-5 benzene rings can be selected from phenanthrene, cycloalkenylphenanthrene, pyrene, chrysoprase, perylene, dibenzanthracene, etc. Short side chains, such as methyl, ethyl, vinyl, or other shorter carbon chains, may also be attached to the benzene rings.

[0084] In this invention, the extracted oil includes reduced-three extracted oil and / or reduced-four extracted oil.

[0085] The extracted oil from the reduced-pressure crude oil can be selected from the reduced-pressure crude oil fraction obtained by vacuum distillation of paraffinic crude oil, intermediate-base crude oil or naphthenic crude oil, and then extracted by solvent extraction.

[0086] The extracted oil from the reduced-pressure crude oil can be selected from the reduced-pressure crude oil fraction obtained by vacuum distillation of paraffinic crude oil, intermediate-base crude oil or naphthenic crude oil, and then extracted by solvent extraction.

[0087] In this invention, the softening point of the obtained spinning pitch is 200-260℃.

[0088] Specifically, the polycyclic aromatic hydrocarbon (PAH) containing 3-5 benzene rings in the material contains ≥60% by mass, for example, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, or 70%, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0089] Specifically, the ash content in the polycyclic aromatic hydrocarbon-containing material is ≤0.01wt%, for example, it can be 0.01wt%, 0.008wt%, 0.006wt%, 0.004wt%, 0.002wt%, or 0.001wt%, etc., but is not limited to the listed values. Other unlisted values ​​within this range also apply.

[0090] In this invention, wt% refers to the percentage content by mass.

[0091] Specifically, the material containing polycyclic aromatic hydrocarbons is obtained by sequential solid-liquid separation, deasphalting, and distillation of catalytic slurry oil and / or ethylene tar.

[0092] Among them, solid-liquid separation methods can include ceramic membrane filtration, etc.

[0093] The deasphalting method can be solvent deasphalting, and the solvent used can be propane, butane or pentane.

[0094] The distillation process is carried out using vacuum distillation, with the temperature controlled at 160-270℃ and the pressure at 0.6-1mbar.

[0095] Specifically, the mass ratio of the material containing polycyclic aromatic hydrocarbons to the extracted oil in the mixture is (2-5):(1-3), for example, it can be 2:1, 1:1, 2:3, 2:1, 3:1, 3:2, 4:1, 4:3, 5:1, 5:2 or 5:3, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0096] Specifically, the thermal polycondensation is carried out under stirring at a speed of 100-400 r / min, such as 100 r / min, 150 r / min, 200 r / min, 250 r / min, 300 r / min, 350 r / min or 400 r / min, but not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0097] Specifically, the thermal polycondensation includes a first heating, a second heating, heat preservation, pressure relief purging, and cooling purging performed sequentially.

[0098] Specifically, the heating rate of the first heating is 5-10℃ / min, for example, it can be 5℃ / min, 6℃ / min, 7℃ / min, 8℃ / min, 9℃ / min or 10℃ / min, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0099] Specifically, the endpoint temperature of the first heating is 348-350℃, for example, it can be 348℃, 349℃ or 350℃, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0100] Specifically, the heating rate of the second heating is 0.5-1℃ / min, for example, it can be 0.5℃ / min, 0.6℃ / min, 0.7℃ / min, 0.8℃ / min, 0.9℃ / min or 1℃ / min, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0101] Specifically, the endpoint temperature of the second heating is 380-430℃, for example, it can be 380℃, 385℃, 400℃, 405℃, 410℃, 415℃, 420℃, 425℃ or 430℃, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0102] Specifically, the temperature at which the heat is maintained is the final temperature of the second heating process.

[0103] Specifically, the heat preservation time is 5-6 hours, for example, it can be 5 hours, 5.2 hours, 5.4 hours, 5.6 hours, 5.8 hours or 6 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0104] Specifically, the pressure during the insulation is 1-4 MPa, for example, it can be 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa or 4 MPa, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0105] Specifically, the endpoint of the pressure relief purging is a pressure of 0.1-0.15 MPa; atmospheric pressure is sufficient.

[0106] Specifically, the flow rate of the purging gas in the pressure relief purging is 5-30 L / (min·kg), for example, it can be 6 L / (min·kg), 8 L / (min·kg), 10 L / (min·kg), 12 L / (min·kg), 14 L / (min·kg), 16 L / (min·kg), 18 L / (min·kg), 20 L / (min·kg), 22 L / (min·kg), 24 L / (min·kg), 26 L / (min·kg), 28 L / (min·kg) or 30 L / (min·kg), but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0107] In this invention, the purging gas used in the pressure relief purging can be an inert gas, which is a gas that does not affect the performance of the activated carbon fiber of this invention, such as nitrogen, helium, neon, argon, etc.

[0108] Specifically, the pressure relief and purging time is 15-30 minutes, for example, it can be 15 minutes, 20 minutes, 25 minutes or 30 minutes, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0109] Specifically, the endpoint temperature of the cooling purge is 280-350℃, for example, it can be 280℃, 285℃, 290℃, 295℃, 300℃, 305℃, 310℃, 315℃, 320℃, 325℃, 330℃, 335℃, 340℃, 345℃ or 350℃, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0110] Specifically, the flow rate of the purging gas in the cooling purging process is 0.5-3 L / (min·kg), for example, it can be 0.5 L / (min·kg), 1.5 L / (min·kg), 2 L / (min·kg), 2.5 L / (min·kg) or 3 L / (min·kg), but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0111] In this invention, the purging gas used in the cooling purging process can be selected as air, oxygen, or ozone, or other oxidizing gases that do not affect the performance of the activated carbon fiber of this invention.

[0112] Specifically, the cooling and purging time is 5-6 hours, for example, it can be 5 hours, 5.2 hours, 5.4 hours, 5.6 hours, 5.8 hours or 6 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0113] Specifically, the operating temperature in the melt spinning process is 250-310℃, for example, it can be 250℃, 260℃, 270℃, 280℃, 290℃, 300℃ or 310℃, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0114] Specifically, the winding speed in the melt spinning process is 200-500 m / min, for example, it can be 200 r / min, 250 r / min, 300 r / min, 350 r / min, 400 r / min, 450 r / min or 500 r / min, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0115] In this invention, the melt spinning can be carried out under a protective atmosphere, such as a gas that does not affect the properties of the activated carbon fiber of this invention, such as nitrogen, helium, neon, argon, etc.

[0116] Specifically, the non-melting is carried out in an atmospheric environment with a gas flow rate of 1-3 L / (min·kg), such as 1 L / (min·kg), 1.5 L / (min·kg), 2 L / (min·kg), 2.5 L / (min·kg) or 3 L / (min·kg), but not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0117] In this invention, the non-melting atmosphere can be selected as an air environment, or as an oxidizing gas such as oxygen or ozone that does not affect the performance of the activated carbon fiber of this invention.

[0118] Specifically, the non-melting process includes a first heating, a second heating, and a non-melting heat preservation process performed sequentially.

[0119] Specifically, the heating rate for a single heating step is 3-5℃ / min, for example, it can be 3℃ / min, 3.2℃ / min, 3.4℃ / min, 3.6℃ / min, 3.8℃ / min, 4℃ / min, 4.2℃ / min, 4.4℃ / min, 4.6℃ / min, 4.8℃ / min or 5℃ / min, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0120] Specifically, the final temperature of the first heating is 140-150℃, for example, it can be 140℃, 142℃, 144℃, 146℃, 148℃ or 150℃, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0121] Specifically, the heating rate of the secondary heating is 0.5-1℃ / min, for example, it can be 0.5℃ / min, 0.6℃ / min, 0.7℃ / min, 0.8℃ / min, 0.9℃ / min or 1℃ / min, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0122] Specifically, the endpoint temperature of the secondary heating is 200-300℃, for example, it can be 200℃, 220℃, 240℃, 260℃, 280℃ or 300℃, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0123] Specifically, the temperature at which the non-melting heat is maintained is the final temperature of the second heating.

[0124] Specifically, the non-melting heat preservation time is 0.5-2.5h, for example, it can be 0.5h, 1h, 1.5h, 2h or 2.5h, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0125] Specifically, the carbonization activation includes a first heat preservation, a second heat preservation, and a cooling process performed sequentially.

[0126] Specifically, the temperature of the first heat preservation is 650-700℃, for example, it can be 650℃, 660℃, 670℃, 680℃, 690℃ or 700℃, etc., and the heating rate is 10-20℃ / min, for example, it can be 10℃ / min, 12℃ / min, 14℃ / min, 16℃ / min, 18℃ / min or 20℃ / min, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0127] Specifically, the heat preservation time of the first heat preservation is 20-30 minutes, such as 20 minutes, 22 minutes, 24 minutes, 26 minutes, 28 minutes or 30 minutes, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0128] Specifically, the second insulation temperature is 750-850℃, for example, it can be 750℃, 760℃, 780℃, 800℃, 820℃, 840℃ or 850℃, etc., and the heating rate is 5-10℃ / min, for example, it can be 5℃ / min, 6℃ / min, 7℃ / min, 8℃ / min, 9℃ / min or 10℃ / min, etc., but is not limited to the listed values, and other unlisted values ​​within this range are also applicable.

[0129] Specifically, water vapor is circulated in the second insulation layer, and the flow rate of the water vapor is 300-1000 L / (min·kg), for example, it can be 300 L / (min·kg), 400 L / (min·kg), 500 L / (min·kg), 600 L / (min·kg), 700 L / (min·kg), 800 L / (min·kg), 900 L / (min·kg) or 1000 L / (min·kg), but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0130] Specifically, the second heat preservation time is 1-2 hours, for example, it can be 1 hour, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours or 2 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0131] Specifically, both the first and second insulations are supplied with protective gas, and the flow rate of the protective gas is 1-3 L / (min·kg), such as 1 L / (min·kg), 1.5 L / (min·kg), 2 L / (min·kg), 2.5 L / (min·kg) or 3 L / (min·kg), but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0132] In this invention, the protective gas in the first and second insulation processes is a gas that does not affect the performance of the activated carbon fiber of this invention, such as nitrogen, helium, neon, argon, etc.

[0133] Specifically, the cooling is performed under a protective atmosphere to 10-40°C, for example, 10°C, 20°C, 30°C, or 40°C, etc. The flow rate of the gas in the protective atmosphere is 1-3L / (min·kg), for example, 1L / (min·kg), 1.5L / (min·kg), 2L / (min·kg), 2.5L / (min·kg), or 3L / (min·kg), etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0134] In this invention, the protective atmosphere during cooling is a gas that does not affect the performance of the activated carbon fiber of this invention, such as nitrogen, helium, neon, argon, etc.

[0135] Furthermore, the present invention provides an activated carbon fiber, which is obtained by the preparation method described above.

[0136] Furthermore, this invention provides an adsorption method, which includes using activated carbon fibers as described above to adsorb volatile organic compounds. Simultaneously, the activated carbon fibers prepared by this invention can also be used to adsorb other small-molecule liquid or gas molecules, such as solvents in chemical plants (e.g., benzene, carbon tetrachloride, ethanol, chloroform, propionaldehyde), or to adsorb metal elements (e.g., heavy metals), or various harmful gases (e.g., ammonia, hydrogen sulfide, carbon monoxide).

[0137] To further illustrate the superior properties of the activated carbon fibers obtained in this invention, the following specific examples are provided:

[0138] In the following embodiments, the reduced-pressure 3 extract oil used is the extracted oil obtained by solvent extraction from the reduced-pressure 3 fraction of naphthenic crude oil obtained by vacuum distillation; the reduced-pressure 4 extract oil is the extracted oil obtained by solvent extraction from the reduced-pressure 4 fraction of naphthenic crude oil obtained by vacuum distillation.

[0139] Example 1

[0140] This embodiment provides a method for preparing carbon fiber, as detailed below:

[0141] (1) The catalytic oil slurry and ethylene tar are mixed evenly at a mass ratio of 1:1, and then refined by ceramic membrane filtration, solvent deasphalting and vacuum distillation to obtain refined raw material. The ash content of the refined raw material is 0.01%, and the mass percentage of polycyclic aromatic hydrocarbons containing 3-5 benzene rings is 60%.

[0142] (2) Mix the refined raw materials and the reduced-thickness extracted oil at a mass ratio of 2:1 to obtain the blended raw materials, i.e. the initial materials.

[0143] (3) Place the initial material in the reactor, start heating and stirring, stirring speed 300 r / min, first heat up to 350℃ at a rate of 10℃ / min, then heat up to 420℃ at a rate of 1℃ / min, keep at the temperature for 5h, keep the pressure at 2MPa, then depressurize to atmospheric pressure and purge with nitrogen for 20min, nitrogen flow rate is 10L / (min·kg); cool down to 330℃, purge with air for 5h, air flow rate is 1L / (min·kg), the softening point of the resulting spinning pitch is 243℃.

[0144] (4) The spinning pitch is crushed and ground, placed in a melt spinning machine, heated to 293°C in a nitrogen atmosphere, and melt-spun at a winding speed of 300 m / min to obtain pitch fiber.

[0145] (5) Place the asphalt fiber in a non-melting furnace, introduce air at a flow rate of 1.5 L / (min·kg), first heat it to 150℃ at a rate of 5℃ / min, then heat it to 280℃ at a rate of 1℃ / min, and keep it at that temperature for 2 hours to obtain non-melting fiber.

[0146] (6) Place the infusible fiber in a carbonization activation furnace, first heat it to 650°C at a rate of 15°C / min, hold it for 20 min, then heat it to 800°C at a rate of 10°C / min, introduce steam at a flow rate of 800 L / (min·kg), and hold it for 1.5 h, while maintaining a nitrogen flow rate of 1 L / (min·kg) during the process; after the reaction is completed, stop the steam supply, introduce nitrogen to cool it to room temperature of 30°C, and maintain a nitrogen flow rate of 1.5 L / (min·kg).

[0147] The performance parameters of the obtained activated carbon fibers are detailed in Table 1. Among them, Figure 1 The pore size distribution diagram of the obtained activated carbon fibers shows that most of the pore sizes are below 2 nm, which conforms to the IUPAC definition of micropores. The abundant distribution of micropores helps activated carbon fibers to adsorb small molecule gases and liquids. Figure 2 The figure shows the nitrogen adsorption-desorption curve of the obtained activated carbon fiber. As can be seen from the figure, the curve belongs to the type I adsorption curve defined by IUPAC, which is a typical microporous adsorption curve.

[0148] Example 2

[0149] This embodiment provides a method for preparing carbon fiber, as detailed below:

[0150] (1) The catalytic oil slurry and ethylene tar are mixed evenly at a mass ratio of 1:1, and then refined by ceramic membrane filtration, solvent deasphalting and vacuum distillation to obtain refined raw material. The ash content of the refined raw material is 0.001%, and the mass percentage of polycyclic aromatic hydrocarbons containing 3-5 benzene rings is 70%.

[0151] (2) Mix the refined raw materials and reduced-4 extract oil at a mass ratio of 1:1 to obtain the blended raw materials, i.e. the initial materials.

[0152] (3) Place the initial material in the reactor, start heating and stirring at a stirring speed of 100 r / min. First, raise the temperature to 348℃ at a rate of 5℃ / min, then raise it to 380℃ at a rate of 0.5℃ / min. Hold the temperature for 6 hours and maintain the pressure at 1 MPa. Then, release the pressure to atmospheric pressure and purge with nitrogen for 30 minutes at a nitrogen flow rate of 5 L / (min·kg). Cool down to 350℃ and purge with air for 6 hours at an air flow rate of 0.5 L / (min·kg). The softening point of the resulting spinning pitch is 200℃.

[0153] (4) The spinning pitch is crushed and ground, placed in a melt spinning machine, heated to 250°C in a nitrogen atmosphere, and melt-spun at a winding speed of 200 m / min to obtain pitch fiber.

[0154] (5) Place the asphalt fiber in a non-melting furnace, introduce air at a flow rate of 1L / (min·kg), first heat it to 140℃ at a rate of 3℃ / min, then heat it to 270℃ at a rate of 0.5℃ / min, and keep it at that temperature for 2.5h to obtain non-melting fiber.

[0155] (6) Place the infusible fiber in a carbonization activation furnace, first heat it to 700°C at a rate of 10°C / min, hold it at that temperature for 30 min, then heat it to 750°C at a rate of 5°C / min, introduce steam at a flow rate of 300 L / (min·kg), and hold it at that temperature for 2 h, while maintaining a nitrogen flow rate of 3 L / (min·kg) during the process; after the reaction is completed, stop the steam supply, introduce nitrogen to cool it to room temperature of 25°C, and maintain a nitrogen flow rate of 1 L / (min·kg).

[0156] The performance parameters of the obtained activated carbon fibers are detailed in Table 1. Among them, Figure 3 The pore size distribution diagram of the obtained activated carbon fibers shows that most of the pore sizes are below 2 nm, which conforms to the IUPAC definition of micropores. The abundant distribution of micropores helps activated carbon fibers to adsorb small molecule gases and liquids. Figure 4 The figure shows the nitrogen adsorption-desorption curve of the obtained activated carbon fiber. As can be seen from the figure, the curve belongs to the type I adsorption curve defined by IUPAC, which is a typical microporous adsorption curve.

[0157] Example 3

[0158] This embodiment provides a method for preparing carbon fiber, as detailed below:

[0159] (1) The catalytic oil slurry and ethylene tar are mixed evenly at a mass ratio of 1:1, and then refined by ceramic membrane filtration, solvent deasphalting and vacuum distillation to obtain refined raw material. The ash content of the refined raw material is 0.05%, and the mass percentage of polycyclic aromatic hydrocarbons containing 3-5 benzene rings is 65%.

[0160] (2) The refined raw materials, reduced-3 extraction oil and reduced-4 extraction oil are mixed in a mass ratio of 4:1:2 to obtain the blended raw materials, i.e. the initial materials.

[0161] (3) Place the initial material in the reactor, start heating and stirring, stirring speed 400 r / min, first heat up to 349℃ at a rate of 7℃ / min, then heat up to 430℃ at a rate of 0.7℃ / min, keep at the temperature for 5h, keep the pressure at 4MPa, then depressurize to atmospheric pressure and purge with nitrogen for 15min, nitrogen flow rate is 30L / (min·kg); cool down to 280℃, purge with air for 5h, air flow rate is 3L / (min·kg), the softening point of the resulting spinning pitch is 260℃.

[0162] (4) The spinning pitch is crushed and ground, placed in a melt spinning machine, heated to 310°C in a nitrogen atmosphere, and melt-spun at a winding speed of 500 m / min to obtain pitch fiber.

[0163] (5) Place the asphalt fiber in a non-melting furnace, introduce air at a flow rate of 3L / (min·kg), first heat it to 145℃ at a rate of 4℃ / min, then heat it to 300℃ at a rate of 0.8℃ / min, and keep it at that temperature for 0.5h to obtain non-melting fiber.

[0164] (6) Place the infusible fiber in a carbonization activation furnace, first heat it to 670°C at a rate of 20°C / min, hold it at that temperature for 25 min, then heat it to 850°C at a rate of 7°C / min, introduce steam at a flow rate of 1000 L / (min·kg), and hold it at that temperature for 1 h, while maintaining a nitrogen flow rate of 2 L / (min·kg) during the process; after the reaction is completed, stop the steam supply, introduce nitrogen to cool it to room temperature of 20°C, and maintain a nitrogen flow rate of 2 L / (min·kg).

[0165] The performance parameters of the obtained activated carbon fibers are detailed in Table 1. Among them, Figure 5 The pore size distribution diagram of the obtained activated carbon fibers shows that most of the pore sizes are below 2 nm, which conforms to the IUPAC definition of micropores. The abundant distribution of micropores helps activated carbon fibers to adsorb small molecule gases and liquids. Figure 6 The figure shows the nitrogen adsorption-desorption curve of the obtained activated carbon fiber. As can be seen from the figure, the curve belongs to the type I adsorption curve defined by IUPAC, which is a typical microporous adsorption curve.

[0166] Comparative Example 1

[0167] The only difference from Example 1 is that no reduced-extracting oil is added to the initial material, that is, the activated carbon fiber is prepared directly from the refined raw materials.

[0168] The performance parameters of the obtained activated carbon fibers are detailed in Table 1.

[0169] Comparative Example 2

[0170] The only difference from Example 1 is that the mass ratio of refined raw materials to reduced-thickness extracted oil is 1:4.

[0171] The performance parameters of the obtained activated carbon fibers are detailed in Table 1.

[0172] Comparative Example 3

[0173] The only difference from Example 1 is that the reduced-3 extract oil is replaced with an equal amount of ethylene tar.

[0174] The performance parameters of the obtained activated carbon fibers are detailed in Table 1.

[0175] Comparative Example 4

[0176] The only difference from Example 1 is that the temperature is increased to 700°C at a rate of 10°C / min, water vapor is introduced at a flow rate of 800L / (min·kg), and the temperature is maintained for 1.5h.

[0177] The performance parameters of the obtained activated carbon fibers are detailed in Table 1.

[0178] Comparative Example 5

[0179] The only difference from Example 1 is that the temperature is increased to 800°C at a rate of 10°C / min, water vapor is introduced at a flow rate of 200L / (min·kg), and the temperature is maintained for 1.5h.

[0180] The performance parameters of the obtained activated carbon fibers are detailed in Table 1.

[0181] Comparative Example 6

[0182] The only difference from Example 1 is that the temperature is increased to 800°C at a rate of 10°C / min, water vapor is introduced at a flow rate of 800L / (min·kg), and the temperature is maintained for 0.5h.

[0183] The performance parameters of the obtained activated carbon fibers are detailed in Table 1.

[0184] The yield of activated carbon fiber obtained in the above embodiments was calculated as (mass of activated carbon fiber obtained / mass of pitch fiber) × 100%. The specific surface area and pore volume were determined according to GB / T 19587-2017 Gas Adsorption BET Method for Determining Specific Surface Area of ​​Solid Matter and HG / T 3922-2006 Activated Carbon Fiber Felt.

[0185] Table 1

[0186]

[0187]

[0188] The results from the above embodiments demonstrate that the preparation method provided by the present invention, through the combination of the design and preparation process of the raw materials used in the preparation of activated carbon fibers, can achieve the preparation of high-performance activated carbon fibers, with the specific surface area of ​​the obtained activated carbon fibers reaching 1000 m². 2 / g or more.

[0189] The present invention is described in detail through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the components used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0190] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0191] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0192] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for producing activated carbon fiber, characterized by, The preparation method comprises: mixing a polycyclic aromatic hydrocarbon-containing material and extract oil to obtain a primary material; performing thermal polycondensation on the obtained primary material to obtain spinning pitch; grinding the obtained spinning pitch and then performing melt spinning to obtain pitch fiber; performing infusibilization and carbonization activation on the obtained pitch fiber in sequence to obtain pitch-based activated carbon fiber; the polycyclic aromatic hydrocarbon-containing material is obtained by mixing catalytic slurry and ethylene tar at a mass ratio of 1:1 and then performing solid-liquid separation, de-pitching and distillation in sequence; the extract oil comprises reduced three extract oil and / or reduced four extract oil; the mass ratio of the polycyclic aromatic hydrocarbon-containing material to the extract oil in the mixing is (2-5):(1-3); the thermal polycondensation comprises first temperature rising, second temperature rising, temperature holding, pressure relief purging and temperature lowering purging in sequence; the carbonization activation comprises first temperature holding, second temperature holding and cooling in sequence; water vapor is supplied in the second temperature holding, and the flow rate of the water vapor is 300-1000 L / (min·kg); the temperature of the second temperature holding is 750-850 ℃, and the temperature rising speed is 5-10 ℃ / min; the temperature holding time of the second temperature holding is 1-2 h; protective gas is supplied in the first temperature holding and the second temperature holding, and the flow rate of the protective gas is 1-3 L / (min·kg).

2. The preparation method according to claim 1, characterized in that, the polycyclic aromatic hydrocarbon is a polycyclic aromatic hydrocarbon containing 3-5 benzene rings.

3. The preparation method according to claim 2, characterized in that, the mass percentage of the polycyclic aromatic hydrocarbon containing 3-5 benzene rings in the polycyclic aromatic hydrocarbon-containing material is ≥60%.

4. The preparation method according to claim 1, characterized in that, the ash content in the polycyclic aromatic hydrocarbon-containing material is ≤0.01 wt%.

5. The method of claim 1, wherein the step of forming the first and second layers is performed by a method selected from the group consisting of: sputtering, evaporation, and chemical vapor deposition. the thermal polycondensation is performed under stirring, and the stirring speed is 100-400 r / min.

6. The preparation method according to claim 1, characterized in that, the temperature rising speed of the first temperature rising is 5-10 ℃ / min.

7. The preparation method according to claim 1, characterized in that, the terminal temperature of the first temperature rising is 348-350 ℃.

8. The method of claim 1, wherein the step of forming the first and second layers is performed by a method selected from the group consisting of: sputtering, evaporation, and chemical vapor deposition. the temperature rising speed of the second temperature rising is 0.5-1 ℃ / min.

9. The method of claim 1, wherein the step of forming the first and second layers is performed by a method selected from the group consisting of: sputtering, evaporation, and chemical vapor deposition. the terminal temperature of the second temperature rising is 380-430 ℃.

10. The method of claim 1, wherein the step of forming the first and second layers is performed by a method selected from the group consisting of: sputtering, evaporation, and chemical vapor deposition. the temperature of the temperature holding is the terminal temperature of the second temperature rising.

11. The method of claim 1, wherein the step of forming the first and second layers is performed by a method selected from the group consisting of: sputtering, evaporation, and chemical vapor deposition. the temperature holding time is 5-6 h.

12. The method of claim 1, wherein the step of forming the first and second layers is performed by a method selected from the group consisting of: sputtering, evaporation, and chemical vapor deposition. the pressure in the temperature holding is 1-4 MPa.

13. The method of claim 1, wherein the step of forming the first and second layers is performed by a method selected from the group consisting of: sputtering, evaporation, and chemical vapor deposition. the terminal pressure of the pressure relief in the pressure relief purging is 0.1-0.15 MPa.

14. The method of claim 1, wherein the step of forming the first and second layers is performed by a method selected from the group consisting of: sputtering, evaporation, and chemical vapor deposition. the flow rate of the purging gas in the pressure relief purging is 5-30 L / (min·kg).

15. The method of claim 1, wherein the step of forming the first and second layers is performed by a method selected from the group consisting of: sputtering, evaporation, and chemical vapor deposition. the time of the pressure relief purging is 15-30 min.

16. The method of claim 1, wherein the step of forming the first and second layers is performed by a method selected from the group consisting of: sputtering, evaporation, and chemical vapor deposition. the terminal temperature of the temperature lowering in the temperature lowering purging is 280-350 ℃.

17. The method of claim 1, wherein the step of forming the first and second layers is performed by a method selected from the group consisting of: sputtering, evaporation, and chemical vapor deposition. the flow rate of the purging gas in the temperature lowering purging is 0.5-3 L / (min·kg).

18. The preparation method according to claim 1, characterized in that, the time of the temperature lowering purging is 5-6 h.

19. The preparation method according to claim 1, characterized in that, the operation temperature in the melt spinning is 250-310 ℃.

20. The method of claim 1, wherein the step of forming the first and second layers is performed by a method selected from the group consisting of: sputtering, evaporation, and chemical vapor deposition. the winding speed in the melt spinning is 200-500 m / min.

21. The method of claim 1, wherein the step of forming the first and second layers is performed by a method selected from the group consisting of: sputtering, evaporation, and chemical vapor deposition. the infusibilization is performed in an atmosphere, and the flow rate of the gas in the atmosphere is 1-3 L / (min·kg).

22. The preparation method according to claim 1, characterized in that, the infusibilization comprises first temperature rising, second temperature rising and infusibilization temperature holding in sequence.

23. The method of claim 22, wherein the step of preparing is characterized by, the temperature rising speed of the first temperature rising is 3-5 ℃ / min.

24. The method of claim 22, wherein the step of preparing is characterized by, the terminal temperature of the first temperature rising is 140-150 ℃.

25. The preparation method according to claim 22, characterized in that, the temperature rising speed of the second temperature rising is 0.5-1 ℃ / min.

26. The preparation method according to claim 22, characterized in that, the terminal temperature of the second temperature rising is 200-300 ℃.

27. The preparation method according to claim 22, characterized in that, The temperature of the non-melting holding is the terminal temperature of the secondary heating.

28. The method of claim 22, wherein the step of preparing is characterized by, The time of the non-melting holding is 0.5-2.5h.

29. The preparation method according to claim 1, characterized in that, The temperature of the first holding is 650-700℃, and the heating rate is 10-20℃ / min.

30. The preparation method according to claim 1, characterized in that, The holding time of the first holding is 20-30min.

31. The method of claim 1, wherein the step of forming the first and second layers is performed by a method selected from the group consisting of: sputtering, evaporation, and chemical vapor deposition. The cooling is under a protective atmosphere, and the flow rate of the gas in the protective atmosphere is 1-3L / (min·kg).

32. An activated carbon fiber, characterized by, The active carbon fiber is prepared by the method of any one of claims 1-31.

33. An adsorption process characterized by, The adsorption method comprises using the active carbon fiber of claim 32 to adsorb volatile organic compounds.

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