A process for integrated high temperature filtration of pyrolysis gas from a porous carbon precursor low temperature carbonization

Abstract

The application discloses a kind of porous carbon precursor low-temperature carbonization pyrolysis gas integration high-temperature filtration process, comprising: preheating high-temperature filter to 850 DEG C;Pyrolysis gas is passed in;Gas-solid separation is realized by high-temperature filter core;Regenerate filter core using nitrogen pulse jet;Dust is recycled to discharge cover;Cyclic operation.Device includes parallel high-temperature filter, electric heat tracing system, nitrogen jet unit and integrated discharge cover top mounting structure.The application prevents tar coking by maintaining 850 DEG C operating temperature, realizes more than 99.5% filtration efficiency using special modified high-temperature filter core, and double filter alternately running ensures continuous production, dust closed-loop recovery improves yield by 8~12%;Compared with traditional process, it solves the problems of low filtration efficiency, serious blockage, wastewater discharge and other industry problems, equipment area is reduced by 40%, annual operating time reaches more than 8000 hours, and is suitable for resin-based porous carbon precursor production process pyrolysis gas purification treatment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas filtration, in particular to a porous carbon precursor low-temperature carbonization pyrolysis gas integrated high-temperature filtration process. BACKGROUND

[0002] At present, the main filtering means of low-temperature carbonization pyrolysis gas includes scrubbing tower, condensing filter, cyclone dust collector and other treatment means. The above treatment means are all from the treatment process of conventional flue gas in other traditional industries such as electric power and chemical industry, but there are great differences from the pyrolysis gas of negative carbonization industry. The main problems existing in the prior art are: the existing low-temperature carbonization pyrolysis gas does not have a high-temperature filtering device, which causes the following problems: the material is entrained by the atmosphere in the kiln and runs out, reducing the yield of the material; the tar and dust content in the exhaust pipe is too high, causing serious blockage; the device of the later stage incineration system is prone to blockage, and the general end process is a fan plus an incinerator, and too much dust will easily block the equipment. The coarse filtering device provided on the discharge cover of the existing low-temperature carbonization rotary kiln is generally a cyclone dust collector, which has low filtering efficiency and low dust removal efficiency. The coarse filtering device provided on the discharge cover of the existing low-temperature carbonization rotary kiln, such as the cyclone dust collector, has no backwashing function and is prone to blockage. The discharge cover of the existing low-temperature carbonization rotary kiln is provided with a condensing cooling plus wire mesh filtering device, which not only has low filtering efficiency, but also is prone to blockage in the pipeline and equipment due to the characteristics of the pyrolysis gas after cooling. The discharge cover of the existing low-temperature carbonization rotary kiln is provided with a spray scrubbing tower for cooling and dust removal, which not only has low filtering efficiency, but also causes high dust in the scrubbing tower, resulting in waste of material, and the need for external discharge of waste water and frequent replacement of slurry.

[0003] The filtering precision is poor, and the filtering efficiency of the adopted scrubbing tower, condensing filter and cyclone is only about 50%; the material loss is serious, and the dust that cannot be filtered will enter the later stage incineration system with the pyrolysis gas, resulting in reduced production capacity; the blockage is serious, and whether it is a scrubbing tower, a condensing filter or a cyclone dust collector, the equipment is prone to blockage and the pyrolysis gas in the pipeline is prone to coking; there are other external pollutants, the scrubbing tower needs to discharge waste water and waste residue, the condensing filter needs to discharge waste residue and waste oil, and the cyclone needs to discharge collected material dust; it cannot run stably for a long time, because the above treatment processes are prone to blockage, the system is often shut down for maintenance, which affects the continuous production of the low-temperature carbonization rotary kiln; it occupies a large space, and the above treatment processes need a separate space to place the treatment equipment, so more space is needed.

[0004] The above problems cannot be solved, which will directly lead to the fact that the low-temperature carbonization rotary kiln cannot run stably for a long time, and the production capacity is low and the economic effect is poor. At present, the resin low-temperature carbonization rotary kiln on the market cannot run stably for a long time, and can only run for a few days before being shut down for maintenance and cleaning, which has a very negative impact on the operation cost, equipment maintenance and other aspects.

[0005] Therefore, aiming at the above problems, the application provides a kind of porous carbon precursor low-temperature carbonization pyrolysis gas integrated high-temperature filtering process, the porous carbon precursor carbonization technology is a relatively novel technology at present, indirect rotary kiln is used to carry out anaerobic pyrolysis on the porous carbon precursor, the porous carbon precursor is resin-based carbon source material, anaerobic pyrolysis can remove the moisture and volatile matter of the carbon source material, to ensure that the material after calcination can meet the process requirements of the next negative electrode material. SUMMARY

[0006] The purpose of the application is to provide a kind of porous carbon precursor low-temperature carbonization pyrolysis gas integrated high-temperature filtering process, to realize efficient dust removal of pyrolysis gas under high-temperature conditions above 400 DEG C, tar gas penetration, dust closed-loop recovery and long-term stable operation of the system, solve the problems of running, blocking and secondary pollution in the prior art.

[0007] The purpose of the application is achieved by the following technical solutions:

[0008] A kind of porous carbon precursor low-temperature carbonization pyrolysis gas integrated high-temperature filtering process, comprising the following steps:

[0009] S1, system starting stage: first, start the electric heat tracing system (3), preheat the high-temperature filter to the working temperature of 850 DEG C, the volume expansion of the high-temperature filter shell (12) in this process is absorbed by the high-temperature metal expansion joint (13);

[0010] S2, pyrolysis gas input stage: pyrolysis gas enters the inside of the high-temperature filter shell (12) from the discharge cover of the low-temperature carbonization rotary kiln through the pyrolysis gas inlet pipeline (1) and the inlet pneumatic valve (2);

[0011] S3, filtering and separating stage: when pyrolysis gas passes through the high-temperature filter element (4), gaseous tar penetrates the high-temperature filter element and enters the rear-end incineration system through the outlet pneumatic valve (7) and the pyrolysis gas outlet pipeline (8), and dust is intercepted by the filter element and adheres to the surface of the filter element;

[0012] S4, filter element regeneration stage: when the filter element differential pressure reaches the set value, start the nitrogen heater (9) to heat nitrogen to 300~400 DEG C, high-temperature nitrogen enters the nitrogen blowing system (5) through the gas pocket (6) and the pneumatic high-temperature ball valve (11), and pulse blowing is carried out on the high-temperature filter element;

[0013] S5, dust recovery stage: the dust blown off falls to the bottom of the high-temperature filter shell (12), returns to the discharge cover through the discharge airlock valve (10), and enters the product system;

[0014] S6, circulating operation stage: repeat steps S2~S5 to realize continuous and stable operation of the system.

[0015] Preferably, in step S1, the high-temperature filter is preheated to an operating temperature of 850°C.

[0016] Preferably, in step S1, the high-temperature filter housing (12) is cylindrical in shape and made of 310S stainless steel, which expands uniformly when heated, has low thermal stress, and excellent anti-creep performance.

[0017] Preferably, in step S3, the pyrolysis gas is filtered through the high-temperature filter element (4) at a filtering air speed of 0.8-0.85 m / min.

[0018] Preferably, in step S3, the high-temperature filter element (4) is made of alkali earth silicate glass fiber that can withstand a temperature of 850°C and has a filtering accuracy of ≤5 um; the specific material of the high-temperature filter element is alkali earth silicate glass fiber composed of CaO+MgO+SiO2, and a special modified organic+inorganic composite binder is used to improve the strength and toughness of the filter element.

[0019] Preferably, the special modified organic+inorganic composite binder is a composite binder composed of organic silicone resin+silica sol+alumina sol.

[0020] The preparation method of the high-temperature filter element includes the following steps:

[0021] The alkali earth silicate glass fiber, organic polyester or polypropylene fiber, composite binder, coupling agent (aminosilane), and dispersant are put into a pulp pool, and mechanical stirring is performed to thoroughly disperse the fibers in water to form a uniform slurry; the slurry is introduced into an inclined net former, and a wet mat blank is taken up and vacuum dried; the wet mat is sent to a drying oven, and the physically combined free water is slowly removed at 100-150°C; low-temperature curing is performed at 200-300°C to cause crosslinking and curing of the organic silicone resin, form a strong and flexible bond at the fiber intersection points, and the coupling agent plays a bridging role to establish a firm molecular bridge between the organic-inorganic phases; the temperature is increased to 400-600°C, and held for 1-2 hours to decompose the organic fibers, dispersants, and other organic matters, leaving additional pores; high-temperature heat treatment is performed at 900-950°C to completely decompose and burn off the organic groups in the organic silicone resin, convert the main chain Si-O-Si structure into amorphous silicon dioxide, and integrate it with the inorganic sol network; the inorganic phase is further dehydrated and condensed to form a strong ceramic bonding phase with nano-pores; the sintered mat material is cut, pleated, and assembled with metal parts to form a high-temperature filter element.

[0022] Specifically, on the basis of traditional inorganic binder silica sol and aluminum sol, organic silicon resin and coupling agent amino silane are added. During the low-temperature curing stage after the filter element is formed, the organic silicon resin is cross-linked and cured to form a strong and flexible bond at the fiber intersection points, and the coupling agent plays a bridging role to establish a firm molecular bridge between the organic-inorganic phases. During the high-temperature sintering stage, the organic groups in the organic silicon resin are decomposed and burned off, and the main chain Si-O-Si structure is converted into amorphous silicon dioxide, which is integrated with the silica sol network to form a continuous, strong and nano-porous ceramic bonding phase. Compared with the high-temperature filter using pure inorganic binder, the flexible bond formed by the organic phase in the filter during the low-temperature stage significantly improves the mechanical strength and thermal shock resistance, and can withstand severe pulse blowing and cleaning without breaking, thereby prolonging the service life.

[0023] Preferably, in step S4, the set value of the filter pressure difference is 1500 Pa.

[0024] Preferably, in step S4, the opening and closing interval time of the pneumatic high-temperature ball valve (11) is 3 seconds.

[0025] Preferably, in step S4, the high-temperature nitrogen gas enters the nitrogen blowing system (5) through the gas pocket (6) and the pneumatic high-temperature ball valve (11), and the blowing high-temperature nitrogen gas temperature for pulse blowing of the high-temperature filter is 300-350℃.

[0026] Preferably, in step S5, the unloading air lock valve (10) adopts an intermittent operation mode.

[0027] Preferably, the integrated high-temperature filtration process for porous carbon precursor low-temperature carbonization pyrolysis gas adopts two high-temperature filters to alternately perform filtration and blowing operations.

[0028] Preferably, in the integrated high-temperature filtration process for porous carbon precursor low-temperature carbonization pyrolysis gas, when a single filter is blowing, the inlet pneumatic valve (2) and the outlet pneumatic valve (7) are in a closed state.

[0029] Preferably, in the integrated high-temperature filtration process for porous carbon precursor low-temperature carbonization pyrolysis gas, the electric tracing maintains the medium temperature at 800-850℃ during the entire process.

[0030] Thanks to the above technical solutions, the present application has the following advantages compared with the prior art:

[0031] 1. The present application realizes a breakthrough in filtration precision, with a dust removal efficiency of up to 99.5%, far exceeding the traditional 50% filtration level, ensuring that the ultra-fine dust in the pyrolysis gas is effectively trapped; secondly, through the innovative dust closed-loop recycling design, the filtered material can be directly returned to the discharge hood and enter the product system, greatly improving the material yield and overall capacity.

[0032] 2、The application solves the long-standing clogging problem in the industry in terms of system reliability. By maintaining a working temperature of 850 DEG C, combined with a specially modified high-temperature-resistant filter element, it ensures that the tar is always in a gaseous state during the filtration process, effectively preventing the complex coking phenomenon of tar and dust, and ensuring long-term stable operation of the system. At the same time, the entire process does not produce waste water, waste residue and other secondary pollutants, achieving clean production;

[0033] 3、The application also has excellent operation stability, fully meeting the needs of continuous production of low-temperature carbonization rotary kiln; the integrated compact design greatly reduces the equipment floor area, and can save more than 40% of the space requirement compared with the traditional multi-stage treatment system; these advantages together constitute an efficient, environmentally friendly and stable pyrolysis gas treatment solution, providing reliable technical support for the production of porous carbon precursors. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, some of the drawings described below are some embodiments of the present application, and those skilled in the art can also make other drawings according to these drawings without creative labor.

[0035] Figure 1 is an integrated high-temperature filter device for porous carbon precursor low-temperature carbonization pyrolysis gas according to Embodiment 1 of the present application;

[0036] Among them, 1-pyrolysis gas inlet pipeline; 2-inlet pneumatic valve; 3-electric heat tracing system; 4-high-temperature filter element; 5-nitrogen blowing system; 6-gas pocket; 7-outlet pneumatic valve; 8-pyrolysis gas outlet pipeline; 9-nitrogen heater; 10-unloading airlock valve; 11-pneumatic high-temperature ball valve; 12-high-temperature filter housing; 13-high-temperature-resistant metal expansion joint. DETAILED DESCRIPTION

[0037] In order to have a clearer understanding of the technical features, objectives and effects of the present application, the specific implementation schemes will be described in detail.

[0038] The present application will be further described below in conjunction with the embodiments, but the present application is not limited to the following embodiments. The implementation conditions used in the embodiments can be further adjusted according to different requirements of specific use, and the implementation conditions indicated are the conventional conditions in the industry. The technical features involved in each embodiment of the present application can be combined with each other as long as there is no conflict.

[0039] Embodiment 1

[0040] Referring to the drawings Figure 1The embodiment provides a kind of porous carbon precursor low-temperature carbonization pyrolysis gas integrated high temperature filtration process, comprising the following steps:

[0041] S1, system startup phase: first start electric heat tracing system 3, preheat high temperature filter to 850 DEG C working temperature, the volume expansion of high temperature filter shell 12 in this process is absorbed by high temperature resistant metal expansion joint 13;

[0042] S2, pyrolysis gas input stage: pyrolysis gas is from the discharge cover of low-temperature carbonization rotary kiln and enters the inside of high temperature filter shell 12 through pyrolysis gas inlet pipeline 1 and inlet pneumatic valve 2;

[0043] S3, filtration separation stage: when the filtration wind speed of pyrolysis gas through high temperature filter core 4 is controlled at 0.82 m / min, gaseous tar passes through high temperature filter core (the high temperature filter core uses high-temperature-resistant 850 DEG C alkali earth silicate glass fiber filter core, and the filtration accuracy thereof is ≤5 um;The specific material of the high temperature filter core is alkali earth silicate glass fiber composed of CaO+MgO+SiO2 component, and a special modified organic+inorganic composite adhesive is used), enters the rear-end incineration system through outlet pneumatic valve 7 and pyrolysis gas outlet pipeline 8, and dust is intercepted by the filter core and adheres to the surface of the filter core;

[0044] S4, filter core regeneration stage: when the differential pressure of the filter core reaches the set value 1500 Pa, start nitrogen heater 9 to heat nitrogen to 350 DEG C, high-temperature nitrogen enters nitrogen blowing system 5 through gas pocket 6 and pneumatic high-temperature ball valve 11 (the opening and closing interval time of the pneumatic high-temperature ball valve 11 is 3 seconds) to pulse spray the high-temperature filter core;

[0045] S5, dust recovery stage: the dust sprayed off falls to the bottom of high temperature filter shell 12, returns to the discharge cover through the discharge airlock valve 10, and enters the product system;

[0046] S6, circulating operation stage: repeat steps S2-S5 to realize continuous and stable operation of the system;

[0047] Further, the special modified organic+inorganic composite adhesive is a composite adhesive composed of methyl organosilicon resin+silica sol+alumina sol;

[0048] Further, the high-temperature filter core comprises, by weight:

[0049] Alkali earth silicate glass fiber (CaO+MgO+SiO2 system): 80 parts;

[0050] Polypropylene fiber: 5 parts;

[0051] Composite adhesive: 20 parts (organosilicon resin 5 parts, silica sol 14.25 parts, and alumina sol 0.75 parts);

[0052] Amino silane coupling agent (KH-550): 0.4 parts;

[0053] Dispersant (non-ionic polyacrylamide): 0.2 parts;

[0054] Deionized water: appropriate amount, adjust the slurry concentration to 0.3%;

[0055] The preparation method of the high-temperature filter element comprises the following steps:

[0056] a. Slurry preparation and dispersion: Dissolve the dispersant in water, start stirring at a speed of about 200 rpm, slowly and uniformly add the alkali earth silicate glass fiber and polypropylene fiber under stirring, continue stirring for 25 min; increase the stirring speed to 600 rpm, stir for 25 min to completely disperse the fiber bundles; slowly add the coupling agent after pre-hydrolysis to the slurry, continue stirring at a speed of 300 rpm for 20 min; sequentially add the inorganic binder and the organic binder, stir for 20 min; reduce the stirring speed to 80 rpm, stir for 20 min to remove excess air bubbles;

[0057] b. Wet forming and dewatering: The uniformly dispersed slurry is introduced into the inclined screen former through the pumping system, and the slurry is filtered and taken up on the inclined screen former under the action of gravity and vacuum suction to form a wet mat blank; then, the wet mat blank passes through the vacuum dewatering zone to remove most of the free water and form a wet mat with certain wet strength;

[0058] c. Drying and pre-curing: The dewatered wet mat is sent to a program-controlled temperature drying box; first, heat treatment is carried out at 120℃ for 60 min to slowly and completely remove the physically combined free water in the mat; then, the temperature is raised to 250℃, and heat preservation is carried out at this temperature for 90 min for low-temperature curing; at this stage, the organic silicon resin is preliminarily crosslinked and cured, and cooperates with the amino silane coupling agent to form a bonding bridge with certain strength at the fiber intersection points, so as to give the mat blank sufficient dry strength for subsequent processing;

[0059] d. Organic matter decomposition and pore forming: the pre-cured mat blank is transferred to a high-temperature sintering furnace, the furnace temperature is raised to 500℃ at a heating rate of 5℃ / min, and heat preservation is carried out at this temperature for 1.5 hours; this process aims to completely decompose, oxidize and burn out the organic polyester and residual dispersant, etc., so as to leave a large number of additional micrometer-level pores with good permeability in the mat body;

[0060] e. High-temperature sintering and ceramic phase formation: continue to raise the furnace temperature from 500℃ to 930℃ at a heating rate of 3℃ / min, and heat preservation is carried out at 930℃ for 2 hours for high-temperature heat treatment;

[0061] f. Post-processing and finished product assembly: After sintering, the ceramic fiber felt is cooled to room temperature in the furnace; then, it is precisely cut according to the design dimensions and pleated into a wave shape using special equipment to significantly increase the filtration area; finally, the pleated filter felt is assembled with metal end caps and support components and sealed and fixed with high-temperature resistant ceramic adhesive to obtain the final high-temperature filter element product.

[0062] Example 2

[0063] This embodiment provides an integrated high-temperature filtration process for the low-temperature carbonization pyrolysis gas of porous carbon precursors, including the following steps:

[0064] S1. System startup phase: First, start the electric heat tracing system 3 to preheat the high temperature filter to the working temperature of 850℃. During this process, the volume expansion generated by the high temperature filter housing 12 is absorbed by the high temperature resistant metal expansion joint 13.

[0065] S2, Pyrolysis gas introduction stage: Pyrolysis gas enters the high temperature filter housing 12 from the discharge hood of the low temperature carbonization rotary kiln through the pyrolysis gas inlet pipe 1 and the inlet pneumatic valve 2;

[0066] S3, Filtration and Separation Stage: When the filtration velocity of the pyrolysis gas through the high-temperature filter element 4 is controlled at 0.80 m / min, the gaseous tar passes through the high-temperature filter element (the high-temperature filter element is an alkaline earth silicate glass fiber filter element that is resistant to high temperature of 850℃ and has a filtration accuracy of ≤5um), and enters the downstream incineration system through the outlet pneumatic valve 7 and the pyrolysis gas outlet pipe 8. The dust is intercepted by the filter element and adheres to the surface of the filter element.

[0067] S4, Filter element regeneration stage: When the filter element pressure difference reaches the set value of 1500Pa, the nitrogen heater 9 is started to heat the nitrogen to 300℃. The high-temperature nitrogen enters the nitrogen injection system 5 through the air tank 6 and the pneumatic high-temperature ball valve 11 (the opening and closing interval is 3 seconds) to perform pulse injection on the high-temperature filter element.

[0068] S5. Dust recovery stage: The dust that falls off during the blowing process falls to the bottom of the high-temperature filter housing 12, returns to the discharge hood through the unloading airlock valve 10, and enters the product system.

[0069] S6. Cyclic Operation Phase: Repeat steps S2 to S5 to achieve continuous and stable operation of the system;

[0070] The preparation method of the high-temperature filter element is the same as that in Example 1.

[0071] Example 3

[0072] This embodiment provides an integrated high-temperature filtration process for the low-temperature carbonization pyrolysis gas of porous carbon precursors, including the following steps:

[0073] S1, system starting stage: first start the electric heat tracing system 3, preheat the high-temperature filter to the working temperature of 850 DEG C, the volume expansion of the high-temperature filter shell 12 in this process is absorbed by the high-temperature resistant metal expansion joint 13;

[0074] S2, pyrolysis gas input stage: the pyrolysis gas from the discharge cover of the low-temperature carbonization rotary kiln enters the inside of the high-temperature filter shell 12 through the pyrolysis gas inlet pipeline 1 and the inlet pneumatic valve 2;

[0075] S3, filtration and separation stage: when the filtration air speed of the pyrolysis gas through the high-temperature filter core 4 is controlled at 0.85 m / min, the gaseous tar passes through the high-temperature filter core, enters the rear-end incineration system through the outlet pneumatic valve 7 and the pyrolysis gas outlet pipeline 8, and the dust is intercepted by the filter core and adheres to the surface of the filter core;

[0076] S4, filter core regeneration stage: when the filter core differential pressure reaches the set value 1500 Pa, the nitrogen gas is heated to 400 DEG C by starting the nitrogen gas heater 9, the high-temperature nitrogen gas enters the nitrogen gas blowing system 5 through the gas pocket 6 and the pneumatic high-temperature ball valve 11 (the opening and closing interval time is 3 seconds) to pulse spray the high-temperature filter core;

[0077] S5, dust recovery stage: the sprayed dust falls to the bottom of the high-temperature filter shell 12, returns to the discharge cover through the discharge airlock valve 10, and enters the product system;

[0078] S6, circulating operation stage: repeat steps S2-S5 to realize the continuous and stable operation of the system;

[0079] The preparation method of the high-temperature filter core is the same as that of embodiment 1.

[0080] Embodiment 4

[0081] The embodiment provides a kind of porous carbon precursor low-temperature carbonization pyrolysis gas integrated high-temperature filtering process, and two high-temperature filters are alternately filtered and sprayed operation;When a single filter is operated, the following steps are included:

[0082] S1, system starting stage: first start the electric heat tracing system 3, preheat the high-temperature filter to the working temperature of 850 DEG C, the volume expansion of the high-temperature filter shell 12 in this process is absorbed by the high-temperature resistant metal expansion joint 13;

[0083] S2, pyrolysis gas input stage: the pyrolysis gas from the discharge cover of the low-temperature carbonization rotary kiln enters the inside of the high-temperature filter shell 12 through the pyrolysis gas inlet pipeline 1 and the inlet pneumatic valve 2;

[0084] S3, filtration separation stage: when the filtration wind speed of the pyrolysis gas through the high-temperature filter core 4 is controlled at 0.83 m / min, the gaseous tar passes through the high-temperature filter core, enters the outlet pneumatic valve 7 and the pyrolysis gas outlet pipeline 8, and enters the rear-end incineration system, and the dust is intercepted by the filter core;

[0085] S4, filter core regeneration stage: when the differential pressure of the filter core during operation reaches the set value 1500 Pa, the inlet pneumatic valve 2 and the outlet pneumatic valve 7 are closed, the nitrogen gas heater 9 is started to heat the nitrogen gas to 350℃, the high-temperature nitrogen gas enters the nitrogen gas blowing system 5 through the gas pocket 6 and the pneumatic high-temperature ball valve 11 (the opening and closing interval time is 3 seconds) to pulse blow the high-temperature filter core of the filter; at the same time, the pyrolysis gas is switched to another filter for filtration;

[0086] S5, dust recovery stage: the dust blown off falls to the bottom of the high-temperature filter shell 12, returns to the discharge cover through the discharge airlock valve 10, and enters the product system;

[0087] S6, cyclic operation stage: the two filters are alternately repeated steps S2-S5 to realize continuous and stable operation of the system.

[0088] The preparation method of the high-temperature filter core is the same as that of embodiment 1.

[0089] Comparative example 1

[0090] This comparative example is based on the above-mentioned embodiment 1, and the same parts as the above-mentioned embodiment 1 will not be repeated.

[0091] In this comparative example, the filtration wind speed in step S3 is controlled at 1.20 m / min.

[0092] Comparative example 2

[0093] This comparative example is based on the above-mentioned embodiment 1, and the same parts as the above-mentioned embodiment 1 will not be repeated.

[0094] In this comparative example, the nitrogen gas is heated to 250℃ in step S4.

[0095] Comparative example 3

[0096] This comparative example is based on the above-mentioned embodiment 1, and the same parts as the above-mentioned embodiment 1 will not be repeated.

[0097] In this comparative example, the high-temperature filter core in step S3 uses a common high-temperature ceramic fiber filter core (Tianya Environmental Protection CF1T0406N), which has a nominal temperature resistance of 800℃ and a filtration accuracy of ≤10um.

[0098] The detection data of the examples and comparative examples are listed in Table 1 below.

[0099] Table 1

[0100]

[0101] From Table 1, it can be seen that the filtration efficiency and dust emission: all the schemes using high-precision alkaline earth silicate filter element (Examples 1-4) have very high filtration efficiency, and the dust emission concentration is much lower than that of Comparative Example 1. The dust emission concentration of Comparative Example 1 exceeds the standard due to the increase of dust penetration rate caused by the excessively high filtration wind speed, which shows that controlling the filtration wind speed at 0.8-0.85 m / min is the key to ensure ultra-high filtration precision; the filter element material (Comparative Example 3) has little effect on this index.

[0102] Tar coking and system stability: this is the key to measure the success of high-temperature filtration. In Examples 1, 2 and 4, gaseous tar passes through the filter element smoothly at a stable high temperature of 850°C, without coking at all. In Comparative Example 2, the nitrogen blowing temperature (250°C) is too low, which causes the local temperature of the high-temperature filter element to drop suddenly during purging, resulting in a small amount of tar condensation and carbonization, causing "coking" and plugging the filter element. This is manifested as a slow and irreversible rise in system pressure drop, ultimately leading to a significant reduction in operating time. In Comparative Example 1, the actual operating temperature may be lower than 850°C due to the excessively high pressure drop, which also causes serious tar coking. This proves that maintaining a stable high temperature (800-850°C) and sufficient blowing temperature (300-400°C) is the lifeline to avoid tar coking and ensure long-term operation.

[0103] Continuous operating time and material recovery rate: this directly reflects the reliability and economy of the process; the continuous operating time of Example 4 (double-machine switching) has obvious advantages; the filter element of Comparative Example 3 fails quickly due to the material's inability to withstand 850°C high temperature, resulting in the shortest operating time and a large amount of dust entering the downstream system when the filter element fails, causing a sharp drop in material recovery rate. Comparative Examples 1 and 2 are forced to shut down prematurely due to coking or pressure drop problems. This shows that the appropriate filter element material and optimized operating parameters together determine the effective operation rate of the system.

[0104] System pressure drop and energy consumption: the system pressure drop is a direct reflection of the operating resistance, and is positively correlated with energy consumption. The system pressure drop of Example 2 (low filtration wind speed) and Example 4 (double-machine rotation regeneration) is the lowest, the operation is the most stable, and the energy consumption is also relatively low. In Comparative Examples 1 (high wind speed) and 2 (incomplete regeneration), the pressure drop is too high, resulting in a significant increase in the energy consumption of the main fan. Although the nitrogen gas heating energy consumption of Comparative Example 2 is slightly lower, the overall energy consumption has no advantage due to the high system resistance.

[0105] Environment and by-products: all schemes are treated at high temperature, and the tar enters the incinerator in gaseous form, without producing wastewater, which reflects the environmental advantage of high-temperature dry treatment.

[0106] The test data of the above examples and comparative examples were tested by the following method:

[0107] Filtering efficiency: artificial gravimetric analysis method is used to measure the dust mass concentration at the inlet and outlet of the filter, and the appropriate sampling points are selected on the flue before and after the filter;

[0108] Dust emission concentration: artificial gravimetric analysis method is used to collect dust with filter membrane, and the change of flue gas flow is monitored synchronously, and the emission concentration is calculated by the weight gain of the filter membrane;

[0109] Tar coking condition: observe regularly;

[0110] Continuous running time: increase the tar content in the medium to 2 times of the actual working condition, accelerate the aging and calculate the normal working life;

[0111] System pressure drop: pressure sensors are installed at the inlet and outlet of the high-temperature filter to measure the static pressure and calculate the difference;

[0112] Material recovery rate: direct metering method is used for calculation;

[0113] Energy consumption: directly read from the electric energy meter.

[0114] The integrated high-temperature filtration process disclosed by the application is a system with closely coupled parameters. Embodiments 1 to 4 are all operated within the parameter range defined in the claims, and all show excellent comprehensive performance. Among them, embodiment 2 (low filtration wind speed + moderate spraying temperature) has the best balance in single machine operation, and embodiment 4 (double machine alternation) has incomparable advantages in continuity and reliability. The comparative example clearly shows by the control variable method that any deviation of the key parameters (such as filtration wind speed, spraying temperature, filter core material) will destroy the high-temperature balance of the system, mainly causing two major problems of tar coking and premature failure of the filter core, thereby causing the system pressure drop to soar, the running time to be shortened, the emission to be exceeded and the recovery rate to be decreased. This in turn proves the scientificity and necessity of the setting of each parameter in the claims of the application.

[0115] In conclusion, the application realizes a breakthrough in filtering accuracy, with a dust removal efficiency of 99.5%, far exceeding the 50% filtering level of traditional technologies, ensuring that the ultra-fine dust in the pyrolysis gas is effectively intercepted; secondly, through the innovative dust closed-loop recycling design, the filtered material can be directly returned to the discharge cover and enter the product system, greatly improving the material yield and overall production capacity; the application solves the long-standing plugging problem in the industry in terms of system reliability, effectively preventing the complex coking phenomenon of tar and dust by maintaining a working temperature of 850 DEG C and cooperating with specially modified ceramic filter cartridges; at the same time, the entire process does not produce secondary pollutants such as wastewater and waste residue, achieving clean production; the application also has excellent running stability, fully meeting the needs of continuous production of low-temperature carbonization rotary kiln; its integrated compact design greatly reduces the equipment floor space, saving more than 40% of the space requirement compared with traditional multi-stage processing systems; these advantages together constitute an efficient, environmentally friendly and stable pyrolysis gas treatment solution, providing reliable technical support for porous carbon precursor production.

[0116] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0117] The above-described embodiments only express several embodiments of the present application, which are described in detail and specifically, but should not be understood as a limitation on the scope of the patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the scope of protection of the present application should be subject to the appended claims.

Claims

1. An integrated high-temperature filtration process for low-temperature carbonization and pyrolysis gas of porous carbon precursors, characterized in that, Includes the following steps: S1, System Start-up Stage: First, start the electric heat tracing system (3) to preheat the high temperature filter to the working temperature of 850℃. During this process, the volume expansion generated by the high temperature filter housing (12) is absorbed by the high temperature resistant metal expansion joint (13). S2, Pyrolysis gas introduction stage: Pyrolysis gas enters the high temperature filter housing (12) from the discharge hood of the low temperature carbonization rotary kiln through the pyrolysis gas inlet pipe (1) and the inlet pneumatic valve (2); S3, Filtration and Separation Stage: When the pyrolysis gas passes through the high-temperature filter element (4), the gaseous tar passes through the high-temperature filter element and enters the downstream incineration system through the outlet pneumatic valve (7) and the pyrolysis gas outlet pipe (8). The dust is intercepted by the filter element and adheres to the surface of the filter element. S4, Filter element regeneration stage: When the filter element pressure difference reaches the set value, start the nitrogen heater (9) to heat the nitrogen to 300~400℃. The high temperature nitrogen enters the nitrogen injection system (5) through the air bag (6) and the pneumatic high temperature ball valve (11) to pulse-purge the high temperature filter element; S5, Dust recovery stage: The dust that falls off during the blowing process falls to the bottom of the high-temperature filter housing (12), returns to the discharge hood through the unloading airlock valve (10), and enters the product system; S6. Cyclic Operation Phase: Repeat steps S2 to S5 to achieve continuous and stable operation of the system; In step S1, the high-temperature filter housing (12) is cylindrical and made of 310S stainless steel; In step S3, the filtration velocity of the pyrolysis gas through the high-temperature filter element (4) is controlled at 0.8~0.85m / min; the high-temperature filter element (4) is an alkaline earth silicate glass fiber filter element that is resistant to high temperature of 850℃ and has a filtration accuracy of ≤5um; the specific material of the high-temperature filter element is an alkaline earth silicate glass fiber composed of CaO+MgO+SiO2, and a modified organic + inorganic composite binder is used. The modified organic + inorganic composite adhesive is a composite adhesive composed of organosilicon resin, silica sol, and aluminum sol. The preparation method of the high-temperature filter element includes the following steps: Alkaline earth silicate glass fiber, organic polyester or polypropylene fiber, composite binder, coupling agent, and dispersant are added to a slurry tank and mechanically stirred to form a uniform slurry. The slurry is then fed into an inclined wire forming machine to form a wet felt blank, which is then vacuum dried and dehydrated. The wet felt is placed in a drying oven and the physically bound free water is slowly removed at 100~150℃; then it is cured at a low temperature of 200~300℃. Then raise the temperature to 400~600℃ and keep it at that temperature for 1~2 hours; continue to raise the temperature to 900~950℃ for high-temperature heat treatment; After sintering, the felt material is cut, pleated, and assembled with metal parts to form a high-temperature filter element; Throughout the entire process of the integrated high-temperature filtration process for low-temperature carbonization and pyrolysis gas of the porous carbon precursor, the electric heat tracing is configured to maintain the medium temperature at 800~850℃.

2. The integrated high-temperature filtration process for low-temperature carbonization pyrolysis gas of porous carbon precursor according to claim 1, characterized in that, In step S1, the high-temperature filter is preheated to an operating temperature of 850°C.

3. The integrated high-temperature filtration process for low-temperature carbonization pyrolysis gas of porous carbon precursor according to claim 1, characterized in that, In step S4, the filter element pressure differential is set to 1500 Pa; the opening and closing interval of the pneumatic high-temperature ball valve (11) is 3 seconds.

4. The integrated high-temperature filtration process for low-temperature carbonization pyrolysis gas of porous carbon precursor according to claim 1, characterized in that, In step S4, the high-temperature nitrogen gas enters the nitrogen injection system (5) through the gas bag (6) and the pneumatic high-temperature ball valve (11) to pulse-purge the high-temperature filter element. The temperature of the high-temperature nitrogen gas is 300~350℃.

5. The integrated high-temperature filtration process for low-temperature carbonization pyrolysis gas of porous carbon precursor according to claim 1, characterized in that, In step S5, the unloading airlock valve (10) operates in an intermittent mode.

6. The integrated high-temperature filtration process for low-temperature carbonization pyrolysis gas of porous carbon precursor according to claim 1, characterized in that, Two high-temperature filters are used to perform filtration and blowing operations alternately; when a single filter is being blown, its inlet pneumatic valve (2) and outlet pneumatic valve (7) are in the closed state.

Images