Method for purifying asphalt flue gas and device for purifying asphalt flue gas

Abstract

The invention relates to the technical field of asphalt flue gas treatment, and discloses a method for purifying asphalt flue gas and a device for purifying the asphalt flue gas. The method is carried out in a device containing an adsorption-desorption unit and a catalytic oxidation unit, and comprises the following steps: (1) introducing the asphalt flue gas into the adsorption-desorption unit to be in contact with an adsorbent for adsorption treatment, and then carrying out desorption treatment on the adsorbent to obtain enriched asphalt flue gas; and (2) introducing the asphalt-enriched flue gas into a catalytic oxidation unit filled with a catalyst for catalytic oxidation treatment. By adopting the method provided by the invention, purification can be realized under the normal-pressure working condition, the purified asphalt flue gas can meet the emission standard, the environmental pollution is reduced, and meanwhile, the operation cost is relatively low.

Description

Technical Field

[0001] The invention relates to the technical field of asphalt fume treatment, and in particular to a method for purifying asphalt fume and a device for purifying asphalt fume. Background Art

[0002] Asphalt flue gas contains a variety of harmful substances such as H2S, SO2, non-methane hydrocarbons, benzo(a)pyrene, benzene and its derivatives, polycyclic aromatic hydrocarbons, and a small amount of heterocyclic compounds of O2, N2, and SO4.

[0003] At present, the treatment methods of asphalt flue gas mainly refer to the mature technology of volatile organic compounds (VOCs) treatment in refineries. However, due to the complex environment in which asphalt flue gas is generated, the existing technology is not applicable to all occasions. The more mature treatment technologies currently include combustion method, absorption method, adsorption method, plasma method, etc.

[0004] Incineration is to convert asphalt fume components into harmless substances through chemical reactions and then purify them; absorption and adsorption are to separate pollutants from exhaust gas by physical methods; electrostatic capture and plasma dust removal technology is to charge asphalt fume particles first and then separate them by electric field. However, the above asphalt fume treatment methods have problems such as complex process and high cost to varying degrees, and it is difficult to achieve ideal flue gas treatment effects.

[0005] At present, the more common asphalt fume treatment methods are mainly divided into two categories: one is to control from the source of production, suppress the formation of asphalt fume in the production and processing stage or replace asphalt with other production materials, but this method is more difficult. The other is to collect and treat the asphalt fume generated during the production and processing of asphalt. From the perspective of treatment methods, it is divided into two types: recycling treatment and oxidation treatment. Among them, recycling treatment is suitable for gases with high concentrations or high value, and oxidation treatment is suitable for organic gases that are easily oxidized. The existing research on asphalt fume is not large in scale and is small and scattered. The treatment process and detection methods for asphalt fume also need to be further improved.

[0006] The current asphalt flue gas treatment technology has greatly increased the asphalt cost. Asphalt is the end product of the refinery, the added value is low. If the environmental protection cost is added, it is difficult for asphalt manufacturers to make a profit, which also makes the promotion of asphalt flue gas treatment technology difficult. Therefore, accelerating the research on asphalt flue gas treatment and developing a complete asphalt flue gas treatment method with appropriate investment and operating costs has great development space and practical significance. Summary of the invention

[0007] The purpose of the present invention is to overcome the defects of the existing asphalt fume treatment technology, such as poor treatment effect and high cost.

[0008] In order to achieve the above object, the first aspect of the present invention provides a method for purifying asphalt flue gas, which is carried out in a device containing an adsorption-desorption unit and a catalytic oxidation unit, comprising:

[0009] (1) introducing the asphalt flue gas into the adsorption-desorption unit to contact the asphalt flue gas with the adsorbent for adsorption treatment, and then desorbing the adsorbent to obtain asphalt-enriched flue gas;

[0010] (2) introducing the asphalt-enriched flue gas into the catalytic oxidation unit filled with catalyst for catalytic oxidation treatment;

[0011] The catalyst contains cordierite honeycomb ceramics and active metal components supported on the cordierite honeycomb ceramics; the active metal components contain copper, vanadium and chromium, and the molar ratio of the copper, vanadium and chromium is 1.8-2.2:1:0.5-1.

[0012] A second aspect of the present invention provides a device for purifying asphalt fume, the device comprising:

[0013] An adsorption-desorption unit and a catalytic oxidation unit connected in sequence;

[0014] The adsorption-desorption unit comprises an adsorption tower, and the adsorption tower is provided with an adsorption bed;

[0015] The catalytic oxidation unit contains a catalytic oxidation reactor.

[0016] The present invention obtains pretreated asphalt flue gas by preferably pretreating the asphalt flue gas so that the sulfide content in the pretreated asphalt flue gas is less than 100 ppm and the total content of colloid and asphaltene is less than 20 ppm, and then sequentially performs adsorption treatment and desorption treatment to obtain enriched asphalt flue gas. The enriched asphalt flue gas is then subjected to catalytic oxidation treatment in the presence of a specific type of catalyst to meet emission standards, reduce environmental pollution, and achieve low-cost operation.

[0017] The device provided by the present invention can realize heat recovery, which is used to maintain self-heating operation, reduce external heating, and reduce energy consumption.

[0018] The remaining features and advantages of the present invention will be described in detail through the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a diagram of a preferred device for purifying asphalt fume provided by the present invention.

[0020] Description of Reference Numerals

[0021] E-101-Oil cooling unit, T-101-Absorption tower, V-101-Diesel circulating tank, P-101-Diesel circulating pump, T-102-Alkaline washing tower, V-102-Alkaline solution circulating box, P-102-Alkaline solution circulating pump, F101-Alkaline solution filter

[0022] T-103-water washing tower, V-103-water circulation box, P-103-water circulation pump, F-102 water filter

[0023] C-101- fan, V-201- gas-liquid separation tank, F-103- oil mist collector

[0024] V-202-adsorption tower, V-203-concentration adjustment tank

[0025] E-202-electric heater, E-201-heat exchanger, R-201-catalytic oxidation reactor

[0026] S-201-Exhaust pipe DETAILED DESCRIPTION

[0027] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0028] The sulfide in the present invention refers to hydrogen sulfide, methyl mercaptan, methyl sulfide, dimethyl disulfide and sulfur dioxide.

[0029] In the present invention, the content of sulfide is determined by adopting the GB / T-14678 gas chromatography standard for the determination of hydrogen sulfide, methyl mercaptan, methyl sulfide and dimethyl disulfide in air quality and the HJ / T-56 iodine titration standard for the determination of sulfur dioxide in exhaust gas from stationary pollution sources.

[0030] In the present invention, the total content of asphaltene and colloid is determined by using the SY / T-7550 method for determining the content of wax, colloid and asphaltene in crude oil.

[0031] The content of non-methane total hydrocarbons is determined using the HJ / T-38 gas chromatography standard for the determination of non-methane total hydrocarbons in exhaust gas from stationary pollution sources.

[0032] The content of asphalt smoke is determined using the HJ / T-45 gravimetric method for the determination of asphalt smoke in exhaust gas from stationary pollution sources.

[0033] The contents of benzene, toluene and xylene were determined using the HJ-734 solid phase adsorption-thermal desorption / gas chromatography-mass spectrometry standard for the determination of volatile organic compounds in waste gas from stationary pollution sources.

[0034] As mentioned above, the first aspect of the present invention provides a method for purifying asphalt flue gas, which is carried out in a device containing an adsorption-desorption unit and a catalytic oxidation unit, comprising:

[0035] (1) introducing the asphalt flue gas into the adsorption-desorption unit to contact the asphalt flue gas with the adsorbent for adsorption treatment, and then desorbing the adsorbent to obtain asphalt-enriched flue gas;

[0036] (2) introducing the asphalt-enriched flue gas into the catalytic oxidation unit filled with catalyst for catalytic oxidation treatment;

[0037] The catalyst contains cordierite honeycomb ceramics and active metal components supported on the cordierite honeycomb ceramics; the active metal components contain copper, vanadium and chromium, and the molar ratio of the copper, vanadium and chromium is 1.8-2.2:1:0.5-1.

[0038] Preferably, in step (2), the specific surface area of ​​the catalyst is not less than 8 m 2 / g, preferably 9-15m 2 / g.

[0039] Preferably, in step (2), the average pore size of the catalyst is no greater than 10 nm, preferably 5-10 nm.

[0040] Preferably, in step (2), the pore volume of the catalyst is not less than 0.008 cm 3 / g, preferably 0.009-0.020cm 3 / g. The inventors of the present invention have found that the catalyst prepared under this preferred condition has a better asphalt fume purification effect.

[0041] It should be noted that the present invention has no particular limitation on the preparation method of the catalyst, but in order to obtain a better purification effect of asphalt flue gas, the present invention provides a preferred specific implementation method:

[0042] In step (2), the catalyst is prepared by a method comprising the following steps:

[0043] (a) subjecting an aqueous solution containing copper, vanadium and chromium to a precipitation reaction at a pH value of 10-12 to obtain a solid product I; the molar ratio of the copper, vanadium and chromium is 2:1:0.5-1;

[0044] (b) subjecting the solid product I to a roasting treatment I to obtain a solid product II;

[0045] (c) coating the solution containing the solid product II onto a cordierite honeycomb ceramic to obtain a primary product;

[0046] (d) subjecting the primary product to a drying treatment and a calcination treatment II in sequence.

[0047] Preferably, in step (c), the solid content of the solution containing the solid product II is 20-30 wt%. The inventors of the present invention have found that the catalyst prepared under this preferred condition has a better asphalt fume purification effect.

[0048] Preferably, in step (c), the coating amount of the solution containing the solid product II is 10-20% of the weight of the cordierite honeycomb ceramic.

[0049] Preferably, in step (b) and step (d), the conditions of the calcination treatment I and the calcination treatment II independently include: a heating rate of 5-15°C / min, a termination temperature of 350-400°C, and a constant temperature time of 1-4h.

[0050] Preferably, in step (c), the drying treatment conditions include: temperature of 110-130° C. and time of 1-4 h.

[0051] It should be noted that the present invention has no particular limitation on the method for obtaining the solid product I in step (a), and those skilled in the art can make a selection based on technical means known in the art. A preferred specific implementation method is exemplified in the following text of the present invention, which should not be construed as a limitation on the present invention by those skilled in the art.

[0052] Preferably, in step (1), the content of non-methane total hydrocarbons in the asphalt fume is 1000-2500 mg / m 3 , the sulfur dioxide content is 15-60mg / m 3 , the content of hydrogen sulfide is 400-3600mg / m 3 , the benzene content is 5-35mg / m 3 .

[0053] According to a preferred embodiment, the method further comprises: in step (1), before introducing the asphalt flue gas into the adsorption-desorption unit, first introducing the asphalt flue gas into a pretreatment unit for pretreatment to obtain pretreated asphalt flue gas;

[0054] The pretreatment conditions are controlled so that the sulfide content in the pretreated asphalt fume is less than 100 mg / m3 The total content of asphaltene and resin is less than 20 mg / m 3 .

[0055] The inventors of the present invention have found that under this preferred condition, not only can the risk of adsorbent clogging and catalyst clogging and poisoning be reduced, but also the number of recycling times of the absorption liquid can be increased while ensuring the purification effect, thereby reducing the processing cost.

[0056] According to a particularly preferred embodiment, in step (1), the pretreatment unit comprises an absorption unit, an alkali washing unit, a water washing unit and a gas-liquid separation unit;

[0057] The pretreatment method comprises: introducing the asphalt fume into the absorption unit, the alkali washing unit, the water washing unit and the gas-liquid separation unit in sequence for pretreatment.

[0058] Preferably, in step (1), the absorption unit contains diesel, and the treatment conditions in the absorption unit include: temperature of -5°C to 20°C, pressure of 5-20 kPa, liquid-to-gas ratio of 5-30 L / m 3 .

[0059] Preferably, in step (1), the alkali washing unit contains an alkaline solution, and the treatment conditions in the alkali washing unit include: the concentration of the alkaline solution is 3-13wt%, the temperature is 15-30°C, the pressure is 5-20kPa, and the liquid-gas ratio is 5-25L / m 3 .

[0060] More preferably, the solute in the alkaline solution is selected from at least one of sodium hydroxide and potassium hydroxide.

[0061] Preferably, in step (1), the water washing unit contains water, and the treatment conditions in the water washing unit include: a temperature of 15-30°C, a pressure of 5-20 kPa, a liquid-gas ratio of 5-25 L / m 3 .

[0062] It should be noted that the above-mentioned liquid-to-gas ratio in the present invention refers to the ratio of the liquid phase volume to the gas phase volume.

[0063] According to another preferred embodiment, in step (2), the conditions of the catalytic oxidation treatment include: the ignition temperature is not less than 250°C, the pressure is 5-17 kPa, and the volume space velocity is 10000-24000h -1 The inventors of the present invention have found that this preferred case has a better asphalt fume purification effect.

[0064] Preferably, in step (1), the adsorbent is selected from at least one of activated carbon and molecular sieve.

[0065] More preferably, the adsorbent is activated carbon, and the CTC value of the activated carbon is greater than 80wt%, the iodine value is not less than 1100mg / g, and the total pore volume is greater than 0.52m 3 / g. The inventors of the present invention have found that under the preferred condition, organic matter with complex components in asphalt fume can be adsorbed, and the adsorption saturation capacity of VOCs can be as high as 20%. It can be regenerated and reused after multiple uses, and can still maintain good adsorption performance after regeneration, so that the purification cost of asphalt fume is lower.

[0066] In the present invention, the CTC value refers to the carbon tetrachloride adsorption rate value.

[0067] Preferably, in step (2), the conditions of the adsorption treatment include: a temperature of 30-40° C. and a pressure of 5-17 kPa.

[0068] Preferably, in step (2), the conditions for the desorption treatment include: a temperature of 80-100°C, a pressure of 5-15 kPa, and a desorption air volume of 0.1-0.5 times the air volume of the asphalt flue gas to be purified.

[0069] The inventors of the present invention have found that adsorbing asphalt flue gas with an adsorbent and then desorbing the adsorbent can reduce the standby time of the device in the catalytic oxidation unit, reduce energy consumption and extend the service life of the device in the catalytic oxidation unit.

[0070] As mentioned above, the second aspect of the present invention provides a device for purifying asphalt fume, the device comprising:

[0071] An adsorption-desorption unit and a catalytic oxidation unit connected in sequence;

[0072] The adsorption-desorption unit comprises an adsorption tower, and the adsorption tower is provided with an adsorption bed;

[0073] The catalytic oxidation unit contains a catalytic oxidation reactor.

[0074] Preferably, the device further comprises:

[0075] a pretreatment unit disposed upstream of the adsorption-desorption unit;

[0076] The pre-processing unit contains a pre-processing device.

[0077] Preferably, the pretreatment device comprises an absorption unit, an alkali washing unit, a water washing unit and a gas-liquid separation unit which are connected in sequence.

[0078] Further preferably, the absorption unit contains an absorption tower; the alkali washing unit contains an alkali washing tower; the water washing unit contains a water washing tower; and the gas-liquid separation unit contains a gas-liquid separation tank and an oil mist collector.

[0079] The following combination Figure 1 The device for purifying asphalt fume of the present invention is exemplified.

[0080] The diesel oil stored in the diesel oil circulation tank V-101 is pressurized by the diesel oil circulation pump P-101 and sent to the top of the absorption tower T-101 after being cooled by the oil cooling unit E-101; the asphalt fume to be purified is introduced from the bottom of the tower into the absorption tower T-101 to contact with the diesel oil in reverse direction, and the liquid phase after contact returns to the bottom of the absorption tower T-101 by gravity and enters the diesel oil circulation tank V-101, and the gas phase is drawn out from the top of the absorption tower T-101;

[0081] The alkaline solution stored in the alkaline solution circulation box V-102 is pressurized by the alkaline solution circulation pump P-102 and sent to the top of the alkaline washing tower T-102 for spraying and atomization after passing through the alkaline solution filter F101, so as to contact with the gas phase drawn out from the top of the absorption tower T-101 and introduced from the bottom of the alkaline washing tower T-102. The liquid phase after contact returns to the bottom of the alkaline washing tower T-102 by gravity and enters the alkaline solution circulation box V-102, and the gas phase is drawn out from the top of the alkaline washing tower T-102;

[0082] The water stored in the water circulation tank V-103 is pressurized by the circulating water pump P-103 and sent to the top of the water washing tower T-103 after passing through the water filter F102 for spraying and atomization, so as to contact with the gas phase drawn out from the top of the alkali washing tower T-102 and introduced from the bottom of the water washing tower T-103. The liquid phase after contact returns to the bottom of the water washing tower T-103 by gravity and enters the water circulation tank V-103, and the gas phase is drawn out from the top of the water washing tower T-103;

[0083] The gas phase drawn out from the top of the water washing tower T-103 is introduced into the oil mist collector F-103 by the fan C-101, and then introduced into the gas-liquid separation tank V-201 to complete pretreatment after passing through the filter plate provided inside the oil mist collector F-103, and the pretreated asphalt fume is obtained, and then drawn out from the top of the gas-liquid separation tank V-201;

[0084] The gas phase drawn out from the top of the gas-liquid separation tank V-201 is introduced into the adsorption tower V-202 from the top of the adsorption tower V-202, and flows through the adsorption bed filled with adsorbent provided inside the adsorption tower V-202 for adsorption treatment until the adsorption amount of the adsorbent is close to saturation, and the adsorbent is heated for desorption treatment. The gas phase obtained by the desorption treatment is adjusted in the concentration adjustment tank V-203 and then introduced into the catalytic oxidation reactor R-201;

[0085] The electric heater E-202 is turned on in advance to preheat the catalytic oxidation reactor R-201, and the temperature in the catalytic oxidation reactor R-201 can maintain the temperature required for catalytic oxidation treatment; the gas phase obtained after adjustment by the concentration adjustment tank V-203 is introduced into the catalytic oxidation reactor R-201 filled with the catalyst for catalytic oxidation treatment, and discharged through the exhaust pipe S-201 after the test meets the standard;

[0086] After reaching the standard, part of the gas phase discharged is introduced into the heat exchanger E-201 for heat exchange with the gas phase drawn out from the concentration adjustment tank V-203 to recover heat for subsequent catalytic oxidation treatment; part of it is introduced into the adsorption tower V-202 for desorption and regeneration of the adsorbent.

[0087] The present invention will be described in detail below by way of examples.

[0088] In the following examples, unless otherwise specified, all raw materials used were commercially available.

[0089] Cordierite honeycomb ceramics: purchased from Jiangsu Yixing Non-metallic Chemical Machinery Factory Co., Ltd.

[0090] The diesel fuel was all 0# diesel fuel, and the solute of the alkaline solution was all sodium hydroxide.

[0091] Adsorbent:

[0092] Activated carbon I: CTC value is 83wt%, iodine value is 1100mg / g, total pore volume is 0.55m 3 / g;

[0093] Activated carbon II: CTC value is 66wt%, iodine value is 800mg / g, total pore volume is 0.48m 3 / g;

[0094] Molecular sieve: The molar ratio of silicon to aluminum is 300:1, and the specific surface area is 360m 2 / g.

[0095] Preparation Example 1: Preparation of Catalyst CAT-1

[0096] (a) Under the condition of pH 10, an aqueous solution containing copper, vanadium and chromium is subjected to precipitation reaction until no more precipitation is produced, and then centrifugation and washing are performed in sequence to obtain a solid, and then dried at 120° C. for 4 h to obtain a solid product I;

[0097] The total molar concentration of copper, vanadium and chromium is 1 mol / L, and the molar ratio of copper, vanadium and chromium is 2:1:1.

[0098] (b) subjecting the solid product I to a calcination treatment I to obtain a solid product II;

[0099] The conditions of calcination treatment I are: carried out in a muffle furnace, with a heating rate of 10°C / min, a termination temperature of 380°C, and a constant temperature time of 2h;

[0100] (c) mixing the solid product II with water to obtain a solution containing the solid product II; and coating the solution containing the solid product II on a cordierite honeycomb ceramic to obtain a primary product; the coating amount of the solution containing the solid product II is 15% of the weight of the cordierite honeycomb ceramic;

[0101] The mixing conditions are: stirring at a speed of 800 rpm for 90 min; the solid content of the solution containing the solid product II is 25 wt%;

[0102] (d) subjecting the primary product to a drying treatment and a calcination treatment II in sequence;

[0103] The conditions for the drying treatment are: temperature of 120°C and time of 2h; the conditions for the calcination treatment II are: carried out in a muffle furnace with a heating rate of 10°C / min, an end temperature of 380°C, and a constant temperature time of 2h.

[0104] Preparation Example 2: Preparation of Catalyst CAT-2

[0105] This preparation example was carried out in the same manner as in Preparation Example 1, except that in this preparation example:

[0106] The molar ratio of copper, vanadium and chromium is 2:1:0.7;

[0107] The remaining conditions are the same as those in Preparation Example 1.

[0108] Preparation Example 3: Preparation of Catalyst CAT-3

[0109] This preparation example was carried out in the same manner as in Preparation Example 1, except that in this preparation example:

[0110] The molar ratio of copper, vanadium and chromium is 2:1:0.5;

[0111] The remaining conditions are the same as those in Preparation Example 1.

[0112] Comparative Preparation Example 1: Preparation of Catalyst CAT-D1

[0113] This comparative preparation example was carried out in the same manner as Preparation Example 1, except that in this comparative preparation example:

[0114] The molar ratio of copper, vanadium and chromium is 2:1:0.1;

[0115] The remaining conditions are the same as those in Preparation Example 1.

[0116] Comparative Preparation Example 2: Preparation of Catalyst CAT-D2

[0117] This comparative preparation example was carried out in the same manner as Preparation Example 1, except that in this comparative preparation example:

[0118] The molar ratio of copper, vanadium and chromium is 2:1:2;

[0119] The remaining conditions are the same as those in Preparation Example 1.

[0120] The relevant parameter information of the catalyst prepared above is shown in Table 1, and the relevant parameters are obtained by BET test.

[0121] Table 1

[0122] Catalyst type <![CDATA[Specific surface area (m 2 / g)]]> Average pore size (nm) <![CDATA[Pore volume (cm 3 / g) <!-- 6 -->]]> CAT-1 10.55 7.36 0.0153 CAT-2 9.35 9.05 0.0095 CAT-3 8.24 9.10 0.0081 CAT-D1 7.55 10.35 0.0077 CAT-D2 7.87 10.46 0.0080

[0123] In the present invention, some indicators of asphalt fume in Example 1 and Example 2 are shown in Table 2.

[0124] Table 2

[0125]

[0126]

[0127] Example 1

[0128] (1) introducing the asphalt fume into a pretreatment unit and sequentially passing through an absorption unit, an alkali washing unit, a water washing unit and a gas-liquid separation unit for pretreatment to obtain pretreated asphalt fume;

[0129] The pretreated asphalt flue gas is introduced into an adsorption-desorption unit to contact with an adsorbent for adsorption treatment, and then the adsorbent adsorbed with the asphalt flue gas is desorbed to obtain asphalt-enriched flue gas;

[0130] (2) introducing the asphalt-enriched flue gas into a catalytic oxidation unit loaded with a catalyst for catalytic oxidation treatment;

[0131] The specific process condition parameters are shown in Table 3, and the relevant indicators of the purified asphalt flue gas are shown in Table 4.

[0132] Example 2

[0133] (1) introducing the asphalt fume into a pretreatment unit and sequentially passing through an absorption unit, an alkali washing unit, a water washing unit and a gas-liquid separation unit for pretreatment to obtain pretreated asphalt fume;

[0134] The pretreated asphalt flue gas is introduced into an adsorption-desorption unit to contact with an adsorbent for adsorption treatment, and then the adsorbent adsorbed with the asphalt flue gas is desorbed to obtain asphalt-enriched flue gas;

[0135] (2) introducing the asphalt-enriched flue gas into a catalytic oxidation unit loaded with a catalyst for catalytic oxidation treatment;

[0136] The specific process condition parameters are shown in Table 3, and the relevant indicators of the purified asphalt flue gas are shown in Table 4.

[0137] Example 3

[0138] This embodiment is carried out in the same manner as in Embodiment 1, except that in this embodiment:

[0139] Replace the catalyst CAT-1 with an equal volume of catalyst CAT-3;

[0140] The remaining process parameters are the same as those in Example 1.

[0141] The relevant indicators of the purified asphalt flue gas are shown in Table 4.

[0142] Example 4

[0143] This embodiment is carried out in the same manner as in Embodiment 1, except that in this embodiment:

[0144] Without pretreatment, that is, directly introducing the asphalt flue gas into the adsorption-desorption unit for adsorption treatment with the adsorbent, and then desorbing the adsorbent adsorbed with the asphalt flue gas to obtain asphalt-enriched flue gas;

[0145] The remaining process parameters are the same as those in Example 1.

[0146] The relevant indicators of the purified asphalt flue gas are shown in Table 4.

[0147] Example 5

[0148] This embodiment is carried out in the same manner as in Embodiment 1, except that in this embodiment:

[0149] Activated carbon I was replaced with activated carbon II, and the packing density was 450±80g / L;

[0150] The remaining process parameters are the same as those in Example 1.

[0151] The relevant indicators of the purified asphalt flue gas are shown in Table 4.

[0152] Example 6

[0153] This embodiment is carried out in the same manner as in Embodiment 1, except that in this embodiment:

[0154] The activated carbon I was replaced by molecular sieve, and the bulk density was 700±30g / L;

[0155] The remaining process parameters are the same as those in Example 1.

[0156] The relevant indicators of the purified asphalt flue gas are shown in Table 4.

[0157] Example 7

[0158] This embodiment is carried out in the same manner as in Embodiment 1, except that in this embodiment:

[0159] The ignition temperature of catalytic oxidation treatment is 200°C;

[0160] The remaining process parameters are the same as those in Example 1.

[0161] The relevant indicators of the purified asphalt flue gas are shown in Table 4.

[0162] Comparative Example 1

[0163] This comparative example was carried out in the same manner as in Example 1, except that in this comparative example:

[0164] Replace the catalyst CAT-1 with an equal volume of catalyst CAT-D1;

[0165] The remaining process parameters are the same as those in Example 1.

[0166] The relevant indicators of the purified asphalt flue gas are shown in Table 4.

[0167] Comparative Example 2

[0168] This comparative example was carried out in the same manner as in Example 1, except that in this comparative example:

[0169] Replace the catalyst CAT-1 with an equal volume of catalyst CAT-D2;

[0170] The remaining process parameters are the same as those in Example 1.

[0171] The relevant indicators of the purified asphalt flue gas are shown in Table 4.

[0172] Comparative Example 3

[0173] This comparative example was carried out in the same manner as in Example 1, except that in this comparative example:

[0174] Without pretreatment, adsorption treatment and desorption treatment, the asphalt flue gas is directly introduced into a catalytic oxidation unit filled with a catalyst for catalytic oxidation treatment;

[0175] The remaining process parameters are the same as those in Example 1.

[0176] The relevant indicators of the purified asphalt flue gas are shown in Table 4.

[0177] The purification air volume of asphalt fume in the embodiments of the present invention and the comparative examples is 100m 3 / h.

[0178] Table 3

[0179]

[0180]

[0181] Table 4

[0182]

[0183] Note: In Table 4, the results corresponding to the non-incineration method column in the non-methane total hydrocarbon detection index are the non-methane total hydrocarbon content in the asphalt flue gas after adsorption treatment in the adsorption bed; the results corresponding to the incineration method column are the non-methane total hydrocarbon content in the asphalt flue gas after catalytic oxidation treatment in the catalytic oxidation reactor, and the remaining detection indicators are the contents of various indicators in the asphalt flue gas after catalytic oxidation treatment in the catalytic oxidation reactor;

[0184] / - means not detected.

[0185] It can be seen from Tables 2 to 4 that the method provided by the present invention can achieve purification under normal pressure conditions, and the purified asphalt fume can meet emission standards, reduce environmental pollution, and have lower operating costs.

[0186] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for purifying asphalt fume, characterized in that: The method is carried out in a device containing an adsorption-desorption unit and a catalytic oxidation unit, comprising: (1) introducing the asphalt flue gas into the adsorption-desorption unit to contact the asphalt flue gas with the adsorbent for adsorption treatment, and then desorbing the adsorbent to obtain asphalt-enriched flue gas; (2) introducing the asphalt-enriched flue gas into the catalytic oxidation unit filled with catalyst for catalytic oxidation treatment; The catalyst contains cordierite honeycomb ceramics and active metal components supported on the cordierite honeycomb ceramics; the active metal components contain copper, vanadium and chromium, and the molar ratio of the copper, vanadium and chromium is 1.8-2.2:1:0.5-1.

2. The method according to claim 1, wherein: In step (2), the specific surface area of ​​the catalyst is not less than 8m 2 / g, preferably 9-15m 2 / g; Preferably, in step (2), the average pore size of the catalyst is no greater than 10 nm, preferably 5-10 nm; Preferably, in step (2), the pore volume of the catalyst is not less than 0.008 cm 3 / g, preferably 0.009-0.020cm 3 / g.

3. The method according to claim 1 or 2, wherein: In step (2), the catalyst is prepared by a method comprising the following steps: (a) subjecting an aqueous solution containing copper, vanadium and chromium to a precipitation reaction at a pH of 10-12 to obtain a solid product I; the molar ratio of the copper, vanadium and chromium is 2:1:0.5-1; (b) subjecting the solid product I to a roasting treatment I to obtain a solid product II; (c) coating the solution containing the solid product II onto a cordierite honeycomb ceramic to obtain a primary product; (d) subjecting the primary product to a drying treatment and a calcination treatment II in sequence.

4. The method according to claim 3, wherein: In step (c), the solid content of the solution containing the solid product II is 20-30 wt %; Preferably, in step (c), the coating amount of the solution containing the solid product II is 10-20% of the weight of the cordierite honeycomb ceramic.

5. The method according to any one of claims 1 to 4, wherein: In step (1), the content of non-methane total hydrocarbons in the asphalt fume is 1000-2500 mg / m 3 , the sulfur dioxide content is 15-60mg / m 3 , the content of hydrogen sulfide is 400-3600mg / m 3 , the benzene content is 5-35mg / m 3 .

6. The method according to any one of claims 1 to 5, wherein: The method further comprises: in step (1), before introducing the asphalt flue gas into the adsorption-desorption unit, first introducing the asphalt flue gas into a pretreatment unit for pretreatment to obtain pretreated asphalt flue gas; The pretreatment conditions are controlled so that the sulfide content in the pretreated asphalt fume is less than 100 mg / m 3 The total content of asphaltene and resin is less than 20 mg / m 3 .

7. The method according to claim 6, wherein: In step (1), the pretreatment unit comprises an absorption unit, an alkali washing unit, a water washing unit and a gas-liquid separation unit; The pretreatment method comprises: introducing the asphalt fume into the absorption unit, the alkali washing unit, the water washing unit and the gas-liquid separation unit in sequence for pretreatment.

8. The method according to claim 7, wherein: In step (1), the absorption unit contains diesel, and the treatment conditions in the absorption unit include: temperature of -5°C to 20°C, pressure of 5-20 kPa, liquid-to-gas ratio of 5-30 L / m 3 .

9. The method according to claim 7 or 8, wherein: In step (1), the alkali washing unit contains an alkaline solution, and the treatment conditions in the alkali washing unit include: the concentration of the alkaline solution is 3-13wt%, the temperature is 15-30°C, the pressure is 5-20kPa, and the liquid-gas ratio is 5-25L / m 3 .

10. The method according to any one of claims 7 to 9, wherein: In step (1), the water washing unit contains water, and the treatment conditions in the water washing unit include: temperature of 15-30°C, pressure of 5-20 kPa, liquid-gas ratio of 5-25 L / m 3 .

11. The method according to any one of claims 1 to 10, wherein: In step (2), the conditions of the catalytic oxidation treatment include: the ignition temperature is not less than 250°C, the pressure is 5-17 kPa, and the volume space velocity is 10000-24000h -1 .

12. The method according to any one of claims 1 to 11, wherein: In step (1), the adsorbent is selected from at least one of activated carbon and molecular sieve; Preferably, the adsorbent is activated carbon, and the CTC value of the activated carbon is greater than 80wt%, the iodine value is not less than 1100mg / g, and the total pore volume is greater than 0.52m 3 / g.

13. The method according to any one of claims 1 to 12, wherein: In step (2), the conditions of the adsorption treatment include: a temperature of 30-40°C and a pressure of 5-17 kPa; Preferably, in step (2), the conditions for the desorption treatment include: a temperature of 80-100°C, a pressure of 5-15 kPa, and a desorption air volume of 0.1-0.5 times the air volume of the asphalt flue gas to be purified.

14. A device for purifying asphalt fume, characterized in that: The device includes: An adsorption-desorption unit and a catalytic oxidation unit connected in sequence; The adsorption-desorption unit comprises an adsorption tower, and the adsorption tower is provided with an adsorption bed; The catalytic oxidation unit contains a catalytic oxidation reactor.

15. The device according to claim 14, wherein: The device also includes: a pretreatment unit disposed upstream of the adsorption-desorption unit; The pre-processing unit contains a pre-processing device.

16. The device according to claim 14 or 15, wherein: The pretreatment device comprises an absorption unit, an alkali washing unit, a water washing unit and a gas-liquid separation unit which are connected in sequence; Preferably, the absorption unit contains an absorption tower; the alkali washing unit contains an alkali washing tower; the water washing unit contains a water washing tower; and the gas-liquid separation unit contains a gas-liquid separation tank and an oil mist collector.

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