阅读说明：本技术 一种pvdc树脂衍生微孔碳材料在吸附分离二甲苯异构体上的应用 (Application of PVDC resin derived microporous carbon material in adsorption separation of xylene isomers ) 是由 鲍宗必 任其龙 陈富强 张治国 杨启炜 杨亦文 于 2019-09-12 设计创作，主要内容包括：本发明公开了一种PVDC树脂衍生微孔碳材料在吸附分离二甲苯异构体上的应用；所述二甲苯异构体选自乙苯、对二甲苯、间二甲苯和邻二甲苯中的至少两种；所述PVDC树脂衍生微孔碳材料以PVDC树脂材料为原料,在惰性气体氛围中,以1-10℃/min的升温速率上升至500-1200℃进行高温活化,得到PVDC树脂衍生微孔碳材料。本发明提供的PVDC树脂衍生微孔碳材料的稳定性好、孔隙结构发达、比表面积大,应用在吸附分离二甲苯异构体上的吸附容量高、吸附分离选择性高。(The invention discloses an application of a PVDC resin derived microporous carbon material in adsorption separation of xylene isomers; the xylene isomers are selected from at least two of ethylbenzene, para-xylene, meta-xylene, and ortho-xylene; the PVDC resin derived microporous carbon material takes a PVDC resin material as a raw material, and is activated at a high temperature of 500-1200 ℃ at a heating rate of 1-10 ℃/min in an inert gas atmosphere to obtain the PVDC resin derived microporous carbon material. The PVDC resin derived microporous carbon material provided by the invention has the advantages of good stability, developed pore structure, large specific surface area, high adsorption capacity and high adsorption separation selectivity when being applied to the adsorption separation of xylene isomers.)

1. An application of PVDC resin derived microporous carbon material in adsorption separation of xylene isomers.

2. Use of a PVDC resin-derived microporous carbon material according to claim 1 for adsorptive separation of xylene isomers, wherein the xylene isomers are selected from at least two of ethylbenzene, para-xylene, meta-xylene and ortho-xylene.

3. The use of a PVDC resin-derived microporous carbon material for adsorptive separation of xylene isomers according to claim 1 or 2, wherein the preparation method of the PVDC resin-derived microporous carbon material is: taking a PVDC resin material as a raw material, and raising the temperature to 500-1200 ℃ at the heating rate of 1-10 ℃/min in an inert gas atmosphere for high-temperature activation to obtain the PVDC resin derived microporous carbon material.

4. The use of a PVDC resin-derived microporous carbon material for adsorptive separation of xylene isomers according to claim 1 or 2, wherein the specific surface area of the PVDC resin-derived microporous carbon material is 1000-2000 m²A pore diameter of 0.5-2.0nm, a microporosity of 100%.

5. The use of a PVDC resin-derived microporous carbon material for adsorptive separation of xylene isomers according to claim 1 or 2, wherein the preparation method of the PVDC resin-derived microporous carbon material is: PVDC resin material is used as raw material, the temperature is raised to 500 ℃ at the heating rate of 1 ℃/min in the inert gas atmosphere, and then the temperature is raised to 600-700 ℃ at the heating rate of 5 ℃/min for high-temperature activation, thus obtaining 1300 m-1300 m with the specific surface area of 1000-²And a PVDC resin-derived microporous carbon material having a microporosity of 100% and a pore diameter of 0.5 to 0.8 nm.

6. The use of the PVDC resin-derived microporous carbon material in adsorption separation of xylene isomers according to claim 1 or 2, wherein when the PVDC resin-derived microporous carbon material is used as an adsorbent to perform adsorption separation of xylene isomers, the temperature of the adsorption separation is 15-300 ℃, and the total pressure of the mixed gas is 100-1000 kPa.

7. The use of a PVDC resin-derived microporous carbon material for adsorptive separation of xylene isomers according to claim 6, wherein the PVDC resin-derived microporous carbon material is spherical, columnar, particulate or membrane-shaped.

Technical Field

The invention belongs to the technical field of adsorption separation materials, and particularly relates to an application of a PVDC resin derived microporous carbon material in adsorption separation of xylene isomers.

Background

Xylene isomers include four isomers of o-xylene (OX), m-xylene (MX), p-xylene (PX) and Ethylbenzene (EB), which are important raw materials for producing bulk chemicals such as terephthalic acid (used for synthesizing polyester), phthalic anhydride (used for synthesizing plasticizer), styrene (used for synthesizing resin and rubber), and mainly come from petroleum processing processes such as toluene disproportionation, catalytic reforming, gasoline cracking, light hydrocarbon aromatization, and the like. However, the toluene industry requires the separation of mixed xylene isomers to obtain a single isomer component. Because the isomers have similar structures and similar boiling points, especially the boiling points of m/p-xylene are only 0.75 ℃ different, the extraction and rectification technology is difficult to realize high-efficiency separation and purification. Therefore, there is a need to develop efficient separation and enrichment technology to meet the huge market demand of the toluene industry.

The technologies for industrially separating xylene isomers mainly include crystallization, simulated moving bed, membrane separation, adsorption separation, and the like. Crystallization processes mainly utilize the significant difference in solubility of different mixture components in cold and hot conditions for crystallization separation. The united states patent (US 5448005) proposes a crystallization process consisting of pre-cooling, crystallization, centrifugal separation and product washing 4 parts, in order to increase the PX recovery rate of the whole process, a recovery section can be correspondingly added to recrystallize PX in the crystallization mother liquor for recovery, the number of crystallization stages of the recovery section can adopt multiple stages or single stage according to the actual situation and the PX recovery rate required, and the crystallization temperature of the crystallizer of each recovery section is sequentially reduced. The process can obtain higher PX yield, but has the disadvantages of complex operation and high operation and equipment investment cost. The simulated moving bed technology is the most widely applied technology for separating dimethyl isomers in industry at present. U.S. UOP corporation designed Par using simulated moving bed technology as early as 1969The ex process (chem. eng.prog., 1970, 66: 70-75.) is used for the separation of meta-xylene from para-xylene. However, the simulated moving bed technology has the following disadvantages, which limit its development: 1) the chromatographic stationary phase with the best separation performance is Ba²⁺The exchanged Y-type zeolite molecular sieve has smaller adsorption capacity and separation selectivity to xylene; 2) the process flow is complex, up to 24 chromatographic columns with almost completely consistent filling properties are connected in series and switched according to a certain period, the requirements on the particle size and the filling uniformity of a chromatographic packing are very strict, otherwise, the separation process is easy to destabilize; 3) the introduction of a third component as the eluent (e.g., p-diethylbenzene) is required to regenerate the saturated adsorption column, adding to the subsequent separation procedure of the eluent and the desired product. The membrane separation technology mainly utilizes the difference of diffusion coefficients of different components passing through a membrane to realize the separation of mixed components. The literature reports a single b-axis oriented high-performance ZSM-5 molecular sieve membrane (Science, 2003, 300 (5618): 456-^-7mol/(m²s.Pa). Although membrane separation has the advantages of low energy consumption, high efficiency, simple process and the like, the membrane is complex to manufacture, high in cost and difficult to realize the balance of high flux and high selectivity, and the industrial application of the membrane is restricted.

The gas phase pressure swing adsorption has the advantages of flexible operation, short flow, less equipment investment, low operation energy consumption and the like, is considered to be the separation technology with the most industrial application prospect in the future, and has attracted attention in recent years. Pressure swing adsorption is centered on the performance of the adsorbent. The global PX max producer BP company invented a process for pressure swing adsorption separation of PX and EB from mixed xylenes (US6600083B 2). The method comprises the steps of taking an MFI type non-acidic mesoporous molecular sieve as an adsorbent, enabling a mixed xylene raw material to directly pass through a fixed bed at the temperature of about 200 ℃ and at the bar of 3-20 bar, enabling the adsorbent to preferentially adsorb PX and EB in the material, reducing partial pressure for desorption after adsorption saturation to obtain PX-rich and EB-rich material flow, enabling the MX/OX-rich material flow to enter an isomerization reactor for conversion among isomers, and enabling adsorption and desorption processes to be rapidly carried out in a cycle within a few minutes. CN 109529764A discloses a method for preparing a shape-selective adsorbent by taking a ten-membered ring molecular sieve matched with p-xylene in shape and size as an active component through special shape-selective modification treatment of metal oxides, shape-selective modification treatment of non-metal oxides and shape-selective modification treatment of deposited carbon, wherein the adsorbent has high adsorption capacity and adsorption rate on p-xylene, and can be separated to obtain high-purity p-xylene. However, in the preparation process, shape-selective modification treatment is complex and operation is difficult.

Microporous carbon materials have been extensively studied for their good stability, developed pore structure, and large specific surface area. However, in the general preparation process of the carbon material, an organic pore regulating agent needs to be added for activating and pore forming treatment, the obtained carbon material has a wide pore size, which is not beneficial to improving the selectivity of adsorption separation, and the addition of the pore regulating agent causes environmental pollution. At present, no report is seen on the direct pyrolysis treatment of raw materials to obtain microporous carbon materials for xylene isomer separation.

Disclosure of Invention

The invention aims to provide an application of a PVDC resin derived microporous carbon material in adsorption separation of xylene isomers.

The invention provides the following technical scheme:

an application of PVDC resin derived microporous carbon material in adsorption separation of xylene isomers.

The xylene isomers are selected from at least two of ethylbenzene, para-xylene, meta-xylene, and ortho-xylene.

The preparation method of the PVDC resin derived microporous carbon material comprises the following steps: taking a PVDC resin material as a raw material, and raising the temperature to 500-1200 ℃ at the heating rate of 1-10 ℃/min in an inert gas atmosphere for high-temperature activation to obtain the PVDC resin derived microporous carbon material. The PVDC resin derived microporous carbon material prepared by the method has stable structural performance and regular particle shape when used as an adsorbent, and has higher selectivity and adsorption capacity for adsorbing and separating xylene isomers.

The specific surface area of the PVDC resin derived microporous carbon material is 1000-2000 m²A pore diameter of 0.5-2.0nm, a microporosity of 100%.

Preferably, the preparation method of the PVDC resin-derived microporous carbon material comprises the following steps: PVDC resin material is used as raw material, the temperature is raised to 500 ℃ at the heating rate of 1 ℃/min in the inert gas atmosphere, and then the temperature is raised to 600-700 ℃ at the heating rate of 5 ℃/min for high-temperature activation, thus obtaining 1300 m-1300 m with the specific surface area of 1000-²And a PVDC resin-derived microporous carbon material having a microporosity of 100% and a pore diameter of 0.5 to 0.8 nm.

More preferably, the PVDC resin material is used as a raw material, the temperature is raised to 500 ℃ at the heating rate of 1 ℃/min in an inert gas atmosphere, and then the temperature is raised to 700 ℃ at the heating rate of 5 ℃/min for high-temperature activation, so that the specific surface area is 1230m²And a PVDC resin-derived microporous carbon material having a microporosity of 100% and a pore diameter of 0.5 to 0.8 nm.

When the PVDC resin derived microporous carbon material is used as an adsorbent to carry out adsorption separation on xylene isomers, the temperature of the adsorption separation is 15-300 ℃, and the total pressure of mixed gas is 100-1000 kPa.

The PVDC resin derived microporous carbon material is spherical, columnar, granular or membrane-shaped.

The PVDC resin derived microporous carbon product provided by the invention has the characteristics of narrow and uniform pore size distribution, large specific surface area and high adsorption capacity; the specific surface area reaches 1100-2000 m²The microporosity is 100 percent, the adsorption strength of the four xylene isomers EB (ethylbenzene), PX (paraxylene), MX (metaxylene) and OX (orthoxylene) is different, and the product can be used for pressure swing adsorption of the xylene isomers.

Compared with the prior art, the invention has the following advantages:

the PVDC resin used for preparing the PVDC resin-derived microporous carbon material is a common bulk chemical and has stable property. The preparation method of the PVDC resin derived microporous carbon material is simple, does not need to add a chemical pore-forming agent, and has no pollution to the environment and low preparation cost. The PVDC resin derived microporous carbon material has stable structure and performance, and the adsorption performance still keeps the original effect after repeated adsorption-regeneration. The performance in the adsorption separation of xylene isomers is far superior to that of most solid adsorbents.

Drawings

Fig. 1 is a graph of a breakthrough test of a xylene isomer mixed gas in example 2.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the detailed description and specific examples, while indicating the scope of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.