A petroleum-based / biomass-based activated carbon adsorbent, a preparation method thereof, and use thereof

Abstract

The application provides a petroleum-based / biomass-based activated carbon adsorbent, a preparation method and application thereof. The activated carbon adsorbent takes residual oil and biomass with high carbon content as raw materials, realizes self-assembly of biomass macromolecules and inorganic nanoparticle polyacid at the same time, realizes regulation of the surface polarity and pore structure of the activated carbon, improves the adsorption capacity and desorption efficiency, and makes the specific surface area of the activated carbon adsorbent reach 800-2000 m 2 / g, has high adsorption capacity for C1-C6 hydrocarbons, and the desorption rate can reach more than 95% at normal temperature.

Description

Technical Field

[0001] This invention relates to the field of light hydrocarbon adsorption and recovery technology, and more specifically to a petroleum-based / biomass-based activated carbon adsorbent, its preparation method, and its applications. Background Technology

[0002] In recent years, with increasingly stringent environmental protection requirements, oil and gas losses during extraction, transportation, and processing have received growing attention. Oil products contain various hydrocarbons, among which lighter hydrocarbon components can escape into the atmosphere through liquefaction. According to incomplete statistics, my country's oil loss rate is as high as 1.5% to 3%, with an annual loss of nearly ten million tons of crude oil, representing a serious waste of resources. Furthermore, these lost oil and gas products cause air pollution and may pose a potential fire risk. Oil and gas recovery is currently one of the important methods for reusing escaped oil and gas.

[0003] Adsorption is a crucial method for reusing escaped oil and gas due to its advantages such as low cost, simple operation, high safety, and small footprint. Among various adsorption materials, activated carbon, a porous carbonaceous material, possesses advantages such as tunable polarity, well-developed pore structure, good chemical stability and acid / alkali resistance, certain mechanical strength, low production cost, and easy regeneration, making it one of the most widely used adsorbents. For example, the specific surface area of ​​activated carbon can reach 1000–3000 m². 2 / g, with a surface mainly consisting of non-polar structures, making it highly suitable for the adsorption of non-polar hydrocarbon components. The adsorption capacity of activated carbon for C2 is approximately 0.01 g / g, for C3 approximately 0.08 g / g, for C4 approximately 0.3 g / g, for C5 approximately 0.45 g / g, and for C6 to C7 it is even higher. Compared with other adsorbents such as molecular sieves, porous resins, and MOFs, it shows significant advantages.

[0004] Patent CN110723736 discloses a biomass porous activated carbon material and its preparation method. The biomass activated carbon material is prepared from sunflower seed shells through washing, drying, carbonization, pulverization, activation, and then washing and drying again. This biomass porous activated carbon material has a large specific surface area and adjustable pore size, meeting the needs of supercapacitors and lead-carbon batteries. As a negative electrode additive for lead-carbon batteries, it can significantly improve negative electrode sulfation and extend battery cycle life. The preparation method uses readily available and abundant raw materials, is low-cost, and simple, facilitating industrial production. However, this patent is mainly used in the field of capacitors and electrode materials, focusing more on the electrical properties of the material. Therefore, different application fields require different structures and compositions of the adsorbent material, making it unsuitable for the adsorption of non-polar hydrocarbon components.

[0005] Patent CN106582529 discloses the application of biomass-residue oil co-coking activated carbon in crude oil adsorption desulfurization. The biomass-residue oil co-coking activated carbon is prepared by a method including the following steps: under inert gas protection, biomass and residue oil are co-coked to obtain co-coke; the co-coke is subjected to hydrophilic pretreatment and ash removal pretreatment sequentially to obtain pretreated co-coke; under inert gas protection, the pretreated co-coke is calcined to obtain bio-based carbon material; under inert gas protection, the bio-based carbon material is activated with an activator to obtain biomass-residue oil co-coking activated carbon. However, this activated carbon is mainly used in the field of adsorption desulfurization, targeting sulfur-containing compounds with a certain degree of polarity, and is not suitable for the adsorption of non-polar hydrocarbons. Furthermore, the preparation process involves a relatively long timeframe, requiring hydrophilic treatment and post-treatment after activated carbon impregnation to achieve additive loading.

[0006] Current activated carbon still faces challenges in adsorption and desorption of nonpolar light hydrocarbons, including insufficient adsorption capacity and low desorption rates. Furthermore, waste products from petroleum processing, such as residual oil, possess high carbon content, similar composition to oil and gas, and readily form graphitized structures and composite materials, making them ideal raw materials for activated carbon preparation. However, preparation methods and control techniques are limited. Moreover, current activated carbon preparation processes often involve single-function carbon sources, polarity control components, and activators, necessitating the introduction of various additives.

[0007] Therefore, it is an urgent problem to develop an activated carbon adsorbent that exhibits controllable polarity and pore structure, high adsorption capacity for light hydrocarbons, high desorption efficiency, and green raw materials. Summary of the Invention

[0008] To address the problems of existing technologies, this invention provides a petroleum-based / biomass-based activated carbon adsorbent. The activated carbon adsorbent uses high-carbon residue oil and biomass as raw materials, and is formed through the self-assembly of biomass polymers and inorganic nanoparticles with polyacids. This process simultaneously regulates the surface polarity and pore structure of the activated carbon, improving both adsorption capacity and desorption efficiency, resulting in a specific surface area of ​​800–2000 m². 2 / g, it has a high adsorption capacity for C1 to C6 hydrocarbons, and the desorption rate can reach more than 95% at room temperature.

[0009] The technical solution of the present invention is as follows:

[0010] A petroleum-based / biomass-based activated carbon adsorbent is disclosed. The adsorbent uses petroleum-based and biomass polymers as raw materials and polyacids as activators. It is obtained by blending, carbonizing, and activating a complex formed by the self-assembly of the polyacids and biomass polymers with the petroleum-based materials. The biomass polymers contain at least one of N, O, and S elements, and the polyacids contain at least one of non-metallic and transition metal elements. The activated carbon adsorbent has a specific surface area of ​​800–2000 m². 2 / g.

[0011] Furthermore, the petroleum-based component is residual oil. The petroleum-based component originates from the aromatic-rich components obtained by centrifugal distillation of residual oil, preferably a mixture of large molecular weight hydrocarbons with C12 or higher, exhibiting a high degree of molecular aromatization. During carbonization and activation, the residual oil promotes regular molecular arrangement, achieving controllable preparation of the pore structure, and possesses suitable adsorption channels for molecules of different sizes from C1 to C6 light hydrocarbons.

[0012] Furthermore, the aromatic components obtained by centrifugal distillation of the residue oil are bicyclic and polycyclic aromatic compounds;

[0013] Furthermore, the biomass polymer includes one or more of the following: sodium lignin sulfonate containing S and O; cellulose and starch containing O; gelatin and chitosan containing O and N; and heparin containing S, O, and N.

[0014] Furthermore, the polyacid contains at least one of nonmetallic elements such as O, P, Si, and B, and at least one of transition metal elements such as Mo and W.

[0015] Further, the polyacid includes at least one of Lindqvist-type isopolyacids, Keggin-type, or Dawson-type heteropolyacids. The Lindqvist-type is a molybdenum-containing polyacid; the Keggin-type polyacid includes tungstic acid or molybdic acid containing P, Si, or B heteroatoms, preferably H3PMo. 12 O 40 H3PW 12 O 40 H3SiMo 12 O 40 H3SiW 12 O 40 H5BMo 12 O 40 H5BW 12 O 40 At least one of the following; the Dawson-type polyacid includes a classic Dawson structure with a P heteroatom or a corner-deficient Dawson structure, preferably H6P2W. 18 O 62 H6P2Mo18 O 62 H 10 P2W 17 O 61 H 10 P2Mo 17 O 61 At least one of them.

[0016] Furthermore, the doping amount of the biomass polymer is 5wt% to 30wt%, and the doping amount of the polyacid is 0.2wt% to 5wt%, based on the mass of the activated carbon adsorbent.

[0017] Furthermore, the complex formed by the self-assembly of the polyacid and the biomass polymer is a composite solution formed by the biomass polymer and the polyacid in an acidic aqueous solution.

[0018] This invention uses polyacids as activators, which have acidic and oxidizing properties and are bifunctional catalysts used to control the decomposition (pore-forming) rate of raw materials during carbonization and activation. At the same time, the heteroatoms contained in the polyacids can adjust the polarity of the adsorbent, thereby affecting the ease of adsorption and desorption processes.

[0019] In the adsorption process of porous materials, on the one hand, the adsorbent needs abundant pores and a large specific surface area; on the other hand, there needs to be a certain interaction between the adsorbate and the adsorbent. Stronger interactions are beneficial to the adsorption process; however, excessively strong interactions can lead to desorption difficulties and poor adsorption selectivity. Furthermore, strong interactions often require the adsorbent to have a certain degree of polarity, but excessive polarity is not conducive to the adsorption of non-polar substances. Therefore, the regulation of the pore structure and surface polarity of activated carbon is crucial. The carbon source of activated carbon mainly comes from petroleum-based and biomass sources. On the one hand, these materials have a high carbon content; on the other hand, these raw materials themselves contain elements such as S, N, and O, which have a certain degree of polarity. In addition, the pore structure and surface polarity of activated carbon can be regulated by changing the reaction conditions during the activation and carbonization stages, thereby expanding the adsorption capacity and optimizing the desorption efficiency. In terms of polarity regulation, this invention mainly achieves control by adjusting the content of components containing N, O, and S or by doping with metal elements. In terms of pore structure regulation, it mainly controls the rate of organic matter decomposition by changing additives and regulating reaction conditions, thus controlling the pore structure.

[0020] The present invention also provides a method for preparing the aforementioned activated carbon adsorbent, the method comprising the following steps:

[0021] Step 1: Centrifugal distillation of the residue oil yields aromatic components;

[0022] Step 2: Combine biomass polymers and polyacids in an acidic aqueous solution to form a composite solution, and then obtain the biomass complex by centrifugation and drying of the composite solution.

[0023] Step 3: After blending the aromatic component and the biomass composite, the mixture is transferred to a tube furnace and subjected to a carbonization-activation reaction through three gradient heating processes under the purging of multiple inert gases. Then, it is cooled to room temperature and extruded into strips to obtain the activated carbon adsorbent.

[0024] Further, in step 1, the residue oil is mixed with toluene, and after repeated shaking and stirring, it is centrifuged at 5000-8000 rpm for 10-30 min, and centrifuged multiple times until the supernatant is colorless. The organic solvent is collected, and the mixture is distilled under reduced pressure to obtain the petroleum-based raw material.

[0025] Furthermore, in step 1, the mass ratio of the residual oil to the toluene is 1 / 2.

[0026] Furthermore, in step 2, the biomass polymer and polyacid are combined in an acidic aqueous solution to form a composite solution, wherein the pH value of the acidic aqueous solution is 3 to 5.

[0027] Furthermore, in step 2, the acidic aqueous solution is a hydrochloric acid solution.

[0028] Further, in step 2, the composite solution is centrifuged and vacuum dried to obtain a biomass composite. The centrifugation speed is 5000-8000 rpm, the centrifugation time is 10-30 min, the vacuum drying temperature is 30-80℃, and the vacuum drying time is 12 h.

[0029] Furthermore, in step 3, the carbonization-activation reaction is carried out under Ar purging and is divided into three stages: the first stage temperature is 340℃~380℃, and the temperature is held for 2~4h; the second stage temperature is 420℃~480℃, and the temperature is held for 2~4h; the third stage temperature is 550-650℃, and the temperature is held for 1~2h, after which the temperature is lowered to room temperature; the heating rate of each stage is 3-10℃ / min, and the Ar flow rate is 100ml / min.

[0030] The present invention also provides a use of the aforementioned activated carbon adsorbent for adsorbing or desorbing nonpolar light hydrocarbons.

[0031] Furthermore, the adsorption is carried out in an environment with a temperature of 25°C and a pressure of atmospheric pressure.

[0032] Furthermore, the desorption is carried out at a temperature of 25°C and a vacuum of 0.1 atm to 0.3 atm.

[0033] The beneficial effects of this invention are as follows:

[0034] This invention provides a novel method for preparing petroleum-based / biomass activated carbon adsorbents. By using residue oil to produce aromatic components as raw materials and employing a staged carbonization-activation process, an ordered pore structure is constructed. One or more elements such as O, N, S, B, P, Si, and metals are introduced through co-carbonization to regulate the surface polarity of the adsorbent. Uniform elemental distribution in the adsorbent is achieved through the self-assembly of biomass polymers and inorganic components.

[0035] The raw materials selected in this invention are inexpensive industrial wastes such as molecular or residual oil with mature process routes. This is an important manifestation of waste resource utilization and green chemistry. The activated carbon obtained by the preparation method has flexible and adjustable pore structure and surface polarity, is simple to operate, and has an adsorption saturation capacity for light hydrocarbons that is higher than the average level of similar adsorbents. It has application prospects in the fields of oil and gas recovery. Detailed Implementation

[0036] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the described examples are only some embodiments of the invention, and not all embodiments.

[0037] The present invention does not impose any special restrictions on the source and purity of the non-gaseous raw materials, which can be commercially available. The organic solvents and polyacids are preferably of analytical grade. There are no special restrictions on the source and purity of argon, which can be commercially available, and the purity is preferably 99.999%.

[0038] The reaction vessel for the staged carbonization-activation phase is a tubular furnace.

[0039] The adsorption-desorption device is a two-stage type, with an adsorption column size of [missing information]. It is equipped with an air compressor, a gas flow meter and a circulating condenser. The online detection instrument is a gas chromatograph, Agilent (7890A-5975C), and the chromatographic column is PONA (50m x 0.2mm x 0.5μm).

[0040] The present invention does not impose any particular limitations on the method for centrifugation enrichment of aromatic components in residual oil, which is a method known to those skilled in the art.

[0041] Example

[0042] Example 1

[0043] A petroleum-based / biomass-based activated carbon adsorbent, using residual oil and chitosan as raw materials, and H3PMo 12 O 40 As an activator, the specific surface area of ​​the activated carbon adsorbent reaches 839.2 m². 2 / g.

[0044] The preparation method is as follows:

[0045] Enrichment of aromatic components in residual oil: Mix 20g of residual oil with 50ml of toluene, repeatedly shake and stir, centrifuge at 5000 rpm for 15min, centrifuge multiple times until the supernatant is colorless, collect the organic solvent, and distill under reduced pressure to obtain petroleum-based feedstock; enrich multiple times to obtain sufficient petroleum-based feedstock.

[0046] Preparation of composite activated carbon adsorbent: 5g chitosan, 0.5g H3PMo 12 O 40 Dissolved in 20 ml of acidic aqueous solution (pH approximately 4.5), stirred vigorously for 2 h, centrifuged at 8000 rpm for 30 min, and vacuum dried at 60 °C for 12 h to obtain a biomass composite. This composite was then blended with 100 g of petroleum-based feedstock and transferred to a tube furnace. Under Ar purging at 100 ml / min, the temperature was raised to 360 °C and held for 4 h. The temperature was then further raised to 460 °C and held for 2 h, followed by a further increase to 600 °C and held for 1 h. The mixture was then slowly cooled to room temperature and extruded to obtain the desired product. Columnar activated carbon Ch5 / PMo0.5-360(4)-460(2)-600(1).

[0047] In Example 1 and below, the two letters before " / " represent the abbreviation for biomass polymer, and the number represents the mass of the biomass polymer; PMo after " / " is H3PMo. 12 O 40 The abbreviations are as follows: 0.5 represents the mass of PMo; 360, 460, and 600 represent the temperature, and the numbers in parentheses represent the time spent at that temperature.

[0048] Example 2

[0049] A petroleum-based / biomass-based activated carbon adsorbent, using residual oil and chitosan as raw materials, and H3PMo 12 O 40 As an activator, the specific surface area of ​​the activated carbon adsorbent reaches 1684.6 m². 2 / g.

[0050] The preparation method is as follows:

[0051] Enrichment of aromatic components in residual oil: Mix 20g of residual oil with 50ml of toluene, repeatedly shake and stir, centrifuge at 5000 rpm for 15min, centrifuge multiple times until the supernatant is colorless, collect the organic solvent, and distill under reduced pressure to obtain petroleum-based feedstock; enrich multiple times to obtain sufficient petroleum-based feedstock.

[0052] Preparation of composite activated carbon adsorbent: 20g chitosan, 2g H3PMo 12 O 40Dissolved in 100 ml of acidic aqueous solution (pH approximately 4.5), stirred vigorously for 2 h, centrifuged at 8000 rpm for 30 min, and vacuum dried at 60 °C for 12 h to obtain a biomass composite. This composite was then blended with 100 g of petroleum-based feedstock and transferred to a tube furnace. Under Ar purging at 100 ml / min, the temperature was raised to 360 °C and held for 4 h. The temperature was then further raised to 460 °C and held for 2 h, followed by a further increase to 600 °C and held for 1 h. The mixture was then slowly cooled to room temperature and extruded to obtain... Columnar activated carbon Ch20 / PMo2-360(4)-460(2)-600(1).

[0053] Example 3

[0054] A petroleum-based / biomass-based activated carbon adsorbent, using residual oil and chitosan as raw materials, and H3PMo 12 O 40 As an activator, the specific surface area of ​​the activated carbon adsorbent reaches 1852.8 m². 2 / g.

[0055] The preparation method is as follows:

[0056] Enrichment of aromatic components in residual oil: Mix 20g of residual oil with 50ml of toluene, repeatedly shake and stir, centrifuge at 5000 rpm for 15min, centrifuge multiple times until the supernatant is colorless, collect the organic solvent, and distill under reduced pressure to obtain petroleum-based feedstock; enrich multiple times to obtain sufficient petroleum-based feedstock.

[0057] Preparation of composite activated carbon adsorbent: 20g chitosan, 5g H3PMo 12 O 40 Dissolved in 100 ml of acidic aqueous solution (pH approximately 4.5), stirred vigorously for 2 h, centrifuged at 8000 rpm for 30 min, and vacuum dried at 60 °C for 12 h to obtain a biomass composite. This composite was then blended with 100 g of petroleum-based feedstock and transferred to a tube furnace. Under Ar purging at 100 ml / min, the temperature was raised to 360 °C and held for 4 h. The temperature was then further raised to 460 °C and held for 2 h, followed by a further increase to 600 °C and held for 1 h. The mixture was then slowly cooled to room temperature and extruded to obtain... Columnar activated carbon Ch20 / PMo5-360(4)-460(2)-600(1).

[0058] Example 4

[0059] A petroleum-based / biomass-based activated carbon adsorbent, using residual oil and chitosan as raw materials, and H3PMo 12 O 40 As an activator, the specific surface area of ​​activated carbon adsorbent reaches 1463.5 m². 2 / g.

[0060] The preparation method is as follows:

[0061] Enrichment of aromatic components in residual oil: Mix 20g of residual oil with 50ml of toluene, repeatedly shake and stir, centrifuge at 5000 rpm for 15min, centrifuge multiple times until the supernatant is colorless, collect the organic solvent, and distill under reduced pressure to obtain petroleum-based feedstock; enrich multiple times to obtain sufficient petroleum-based feedstock.

[0062] Preparation of composite activated carbon adsorbent: 20g chitosan, 2g H3PMo 12 O 40 Dissolved in 100 ml of acidic aqueous solution (pH approximately 4.5), stirred vigorously for 2 h, centrifuged at 8000 rpm for 30 min, and vacuum dried at 60 °C for 12 h to obtain a biomass composite. This composite was then blended with 100 g of petroleum-based feedstock and transferred to a tube furnace. Under Ar purging at 100 ml / min, the temperature was raised to 320 °C and held for 4 h. The temperature was then further raised to 480 °C and held for 2 h, followed by a further increase to 600 °C and held for 1 h. The mixture was then slowly cooled to room temperature and extruded to obtain... Columnar activated carbon Ch20 / PMo2-320(4)-480(2)-600(1).

[0063] Example 5

[0064] A petroleum-based / biomass-based activated carbon adsorbent, using residual oil and sodium lignosulfonate as raw materials, and H3PMo 12 O 40 As an activator, the specific surface area of ​​the activated carbon adsorbent reaches 1756.2 m². 2 / g.

[0065] The preparation method is as follows:

[0066] Enrichment of aromatic components in residual oil: Mix 20g of residual oil with 50ml of toluene, repeatedly shake and stir, centrifuge at 5000 rpm for 15min, centrifuge multiple times until the supernatant is colorless, collect the organic solvent, and distill under reduced pressure to obtain petroleum-based feedstock; enrich multiple times to obtain sufficient petroleum-based feedstock.

[0067] Preparation of composite activated carbon adsorbent: 20g sodium lignosulfonate, 2g H3PMo 12 O 40 Dissolved in 50 ml of aqueous solution, stirred vigorously for 2 h, centrifuged at 8000 rpm for 30 min, and vacuum dried at 60 °C for 12 h to obtain a biomass composite. This composite was then blended with 100 g of petroleum-based feedstock and transferred to a tube furnace. Under Ar purging at 100 ml / min, the temperature was raised to 360 °C and held for 4 h. The temperature was then further raised to 460 °C and held for 2 h, followed by a further increase to 600 °C and held for 1 h. The mixture was then slowly cooled to room temperature and extruded to obtain... Columnar activated carbon LS20 / PMo2-360(4)-460(2)-600(1).

[0068] Example 6

[0069] A petroleum-based / biomass-based activated carbon adsorbent, using residual oil and heparin as raw materials, and H3PMo 12 O 40 As an activator, the specific surface area of ​​the activated carbon adsorbent reaches 1659.3 m². 2 / g.

[0070] The preparation method is as follows:

[0071] Enrichment of aromatic components in residual oil: Mix 20g of residual oil with 50ml of toluene, repeatedly shake and stir, centrifuge at 5000 rpm for 15min, centrifuge multiple times until the supernatant is colorless, collect the organic solvent, and distill under reduced pressure to obtain petroleum-based feedstock; enrich multiple times to obtain sufficient petroleum-based feedstock.

[0072] Preparation of composite activated carbon adsorbent: 20g heparin, 2g H3PMo 12 O 40 Dissolved in 100 ml of aqueous solution, stirred vigorously for 2 h, centrifuged at 6000 rpm for 30 min, and vacuum dried at 60 °C for 12 h to obtain a biomass composite. This composite was then blended with 100 g of petroleum-based feedstock and transferred to a tube furnace. Under Ar purging at 100 ml / min, the temperature was raised to 360 °C and held for 4 h. The temperature was then further raised to 460 °C and held for 2 h, followed by a further increase to 600 °C and held for 1 h. The mixture was then slowly cooled to room temperature and extruded to obtain... Columnar activated carbon He20 / PMo2-360(4)-460(2)-600(1).

[0073] Example 7

[0074] A petroleum-based / biomass-based activated carbon adsorbent, using residual oil and chitosan as raw materials, with H7P2W 17 O 61 As an activator, the specific surface area of ​​the activated carbon adsorbent reaches 1282.4 m². 2 / g.

[0075] The preparation method is as follows:

[0076] Enrichment of aromatic components in residual oil: Mix 20g of residual oil with 50ml of toluene, repeatedly shake and stir, centrifuge at 5000 rpm for 15min, centrifuge multiple times until the supernatant is colorless, collect the organic solvent, and distill under reduced pressure to obtain petroleum-based feedstock; enrich multiple times to obtain sufficient petroleum-based feedstock.

[0077] Preparation of composite activated carbon adsorbent: 20g chitosan, 2g H7P2W 17 O 61 Dissolved in 100 ml of acidic aqueous solution (pH approximately 4.5), stirred vigorously for 2 h, centrifuged at 8000 rpm for 30 min, and vacuum dried at 60 °C for 12 h to obtain a biomass composite. This composite was then blended with 100 g of petroleum-based feedstock and transferred to a tube furnace. Under Ar purging at 100 ml / min, the temperature was raised to 360 °C and held for 4 h. The temperature was then further raised to 460 °C and held for 2 h, followed by a further increase to 600 °C and held for 1 h. The mixture was then slowly cooled to room temperature and extruded to obtain... Columnar activated carbon Ch20 / P2W172-360(4)-460(2)-600(1).

[0078] Comparative Example 1

[0079] A petroleum-based / biomass-based activated carbon adsorbent, using residual oil and chitosan as raw materials, and H3PMo 12 O 40 Using a two-stage carbonization-activation process as the activator, the specific surface area of ​​the activated carbon adsorbent reaches 1735.2 m². 2 / g.

[0080] The preparation method is as follows:

[0081] Enrichment of aromatic components in residual oil: Mix 20g of residual oil with 50ml of toluene, repeatedly shake and stir, centrifuge at 5000 rpm for 15min, centrifuge multiple times until the supernatant is colorless, collect the organic solvent, and distill under reduced pressure to obtain petroleum-based feedstock; enrich multiple times to obtain sufficient petroleum-based feedstock.

[0082] Preparation of composite activated carbon adsorbent: 20g chitosan, 5g H3PMo 12 O 40 Dissolved in 100 ml of acidic aqueous solution (pH approximately 4.5), stirred vigorously for 2 h, centrifuged at 8000 rpm for 30 min, and vacuum dried at 60 °C for 12 h to obtain a biomass composite. This composite was then blended with 100 g of petroleum-based feedstock and transferred to a tube furnace. Under Ar purging at 100 ml / min, the temperature was raised to 460 °C and held for 6 h. The temperature was then further raised to 600 °C and held for 1 h, followed by slow cooling to room temperature. The resulting product was then extruded into strips. Columnar activated carbon Ch20 / PMo5-460(6)-600(1).

[0083] Comparative Example 2

[0084] A petroleum-based / biomass-based activated carbon adsorbent, using residual oil and chitosan as raw materials and KOH as an activating agent, achieves a specific surface area of ​​1228.6 m². 2 / g.

[0085] The preparation method is as follows:

[0086] Enrichment of aromatic components in residual oil: Mix 20g of residual oil with 50ml of toluene, repeatedly shake and stir, centrifuge at 5000 rpm for 15min, centrifuge multiple times until the supernatant is colorless, collect the organic solvent, and distill under reduced pressure to obtain petroleum-based feedstock; enrich multiple times to obtain sufficient petroleum-based feedstock.

[0087] Preparation of composite activated carbon adsorbent: 20g chitosan, 5g KOH, and 100g petroleum-based raw materials were blended and transferred to a tube furnace. Under Ar purging at 100ml / min, the temperature was raised to 360℃ and held for 4 hours. The temperature was then raised to 460℃ and held for 2 hours. Finally, the temperature was raised to 600℃ and held for 1 hour. The mixture was then slowly cooled to room temperature and extruded into strips to obtain the desired product. Columnar activated carbon Ch20 / KOH5-360(4)-460(2)-600(1).

[0088] Comparative Example 3

[0089] A petroleum-based / biomass-based activated carbon adsorbent, using residual oil and chitosan as raw materials, and H3PMo 12 O 40 As an activator, the raw materials and activator are blended together, resulting in an activated carbon adsorbent with a specific surface area of ​​1154.7 m². 2 / g.

[0090] The preparation method is as follows:

[0091] Enrichment of aromatic components in residual oil: Mix 20g of residual oil with 50ml of toluene, repeatedly shake and stir, centrifuge at 5000 rpm for 15min, centrifuge multiple times until the supernatant is colorless, collect the organic solvent, and distill under reduced pressure to obtain petroleum-based feedstock; enrich multiple times to obtain sufficient petroleum-based feedstock.

[0092] Preparation of composite activated carbon adsorbent: 20g chitosan, 5g H3PMo 12 O 40 After blending 100g of petroleum-based raw materials, the mixture was transferred to a tube furnace and heated to 360℃ under Ar purging at 100ml / min. The temperature was held for 4 hours, then increased to 460℃ and held for 2 hours. The temperature was then further increased to 600℃ and held for 1 hour. The mixture was then slowly cooled to room temperature and extruded to obtain the desired product. Columnar activated carbon gh-Ch20 / PMo5-360(4)-460(2)-600(1).

[0093] In Comparative Example 3, "gh" represents "blending".

[0094] Test case

[0095] The activated carbon adsorbents obtained in Examples 1-7 and Comparative Examples 1-3 were packed into adsorption columns and adsorbed C1, C2, C3, C4, C5, and C6 saturated hydrocarbons at 25°C, respectively, where C4 was n-butane, C5 was n-pentane / isopentane (v / v = 1 / 1), and C6 was n-hexane / 2,3-dimethylbutane (v / v = 1 / 1). After reaching saturation adsorption capacity, desorption was carried out at room temperature for 4 hours at 0.3 atm. The specific surface area of ​​the adsorbent, the saturation adsorption capacity for light hydrocarbons, and the desorption rate are statistically shown in Table 1.

[0096] Table 1. Statistical table of specific surface area and adsorption / desorption efficiency of activated carbon adsorbent.

[0097]

[0098] Of all the above embodiments, Example 3 has the largest specific surface area and the highest adsorption capacity and better desorption efficiency for C1-C6.

[0099] Examples 1-3 illustrate the effects of activator H3PW. 12 O 40 Increasing the dosage helps to increase the specific surface area of ​​the adsorbent and the amount of light hydrocarbons it can adsorb.

[0100] Comparing Examples 2 and 4, the specific surface area and adsorption effect of the adsorbent in Example 2 are better than those in Example 4. This may be because, compared to adsorbent 4, the first stage of the preparation process of adsorbent 2 has a higher temperature, which is conducive to the rapid formation of the pore structure. The relatively lower temperature in the second stage can avoid the appearance of too many large pores and better achieve orderly control of the pore structure.

[0101] The comparison of Examples 2, 5, and 6 illustrates that different biomass polymers can affect the specific surface area and adsorption performance of the adsorbent. This may be because different biomass polymers have different compositions and structures, different self-assembly capabilities of heteropoly acids, and different decomposition rates under the same conditions, resulting in different pore structures and surface polarities of the adsorbent, which ultimately affect the adsorption performance.

[0102] Compared to Example 2, Example 7 has a lower specific surface area, possibly due to H7P2W 17 O 61 This is caused by low activation performance.

[0103] Comparing Example 3 with Comparative Example 1, it is shown that three-stage heating is more conducive to obtaining high specific surface area pores and better adsorption performance than two-stage heating. Comparing Example 3 with Comparative Example 2, it is shown that heteropolyacids have excellent activation effects as activators in this system. Comparing Example 3 with Comparative Example 3, it is shown that the self-assembly process is necessary.

[0104] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any modifications or equivalent changes made based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

Claims

1. A petroleum-based / biomass-based activated carbon adsorbent, characterized in that, The activated carbon adsorbent uses petroleum-based and biomass polymers as raw materials and polyacids as activators. It is obtained by blending, carbonizing, and activating a complex formed by the self-assembly of the polyacids and biomass polymers with the petroleum-based materials. The biomass polymers contain at least one of N, O, and S elements, and the polyacids contain at least one of non-metallic and transition metal elements. The specific surface area of ​​the activated carbon adsorbent reaches 800-2000 m². 2 / g; The biomass polymers include one or more of the following: sodium lignin sulfonate containing S and O, cellulose containing O, starch, gelatin containing O and N, chitosan, and heparin containing S, O, and N. The polyacid contains at least one of the nonmetallic elements O, P, Si, and B, and at least one of the transition metal elements Mo and W.

2. The activated carbon adsorbent according to claim 1, characterized in that, The petroleum-based material is residual oil.

3. The activated carbon adsorbent according to claim 2, characterized in that, The polyacids include at least one of Lindqvist-type isopolyacids, Keggin-type or Dawson-type heteropolyacids.

4. The activated carbon adsorbent according to claim 3, characterized in that, The doping amount of the biomass polymer is 5 wt% to 30 wt%, and the doping amount of the polyacid is 0.2 wt% to 5 wt%, based on the mass of the activated carbon adsorbent.

5. A method for preparing the activated carbon adsorbent according to any one of claims 1 to 4, characterized in that, The method includes the following steps: Step 1: Centrifugal distillation of the residue oil yields aromatic components; Step 2: Combine biomass polymers with polyacids in an acidic aqueous solution to form a composite solution, and then obtain the biomass complex by centrifugation and drying of the composite solution; Step 3: After blending the aromatic component and the biomass composite, the mixture is transferred to a tube furnace and carbonized-activated under three gradient heating processes under inert gas purging. Then, it is cooled to room temperature and extruded to obtain the activated carbon adsorbent.

6. The method for preparing activated carbon adsorbent according to claim 5, characterized in that, In step 1, the residue oil is mixed with toluene, and after repeated shaking and stirring, it is centrifuged at 5000~8000 rpm for 10~30 min, and centrifuged multiple times until the supernatant is colorless. The organic solvent is collected, and the mixture is distilled under reduced pressure to obtain the petroleum-based raw material. The mass ratio of the residue oil to the toluene is 1 / 2.

7. The method for preparing activated carbon adsorbent according to claim 6, characterized in that, In step 3, the carbonization-activation reaction is carried out under Ar purging and is divided into three stages: the first stage temperature is 340 °C~380 °C, and the temperature is held for 2~4 h; the second stage temperature is 420 °C~480 °C, and the temperature is held for 2~4 h; the third stage temperature is 550-650 °C, and the temperature is held for 1~2 h, after which the temperature is lowered to room temperature; the heating rate in each stage is 3-10 °C / min, and the Ar flow rate is 100 ml / min.

8. The use of the activated carbon adsorbent according to any one of claims 1 to 4 for adsorbing or desorbing nonpolar light hydrocarbons.

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