TWI373364B - Method for adsorbing mercury vapor - Google Patents

Description

1373364 IX. INSTRUCTIONS OF THE INVENTION: TECHNICAL FIELD OF THE INVENTION The present invention relates to a method of adsorbing mercury vapor, and more particularly to a pore-stranded adsorbent material thereof. [Prior Art] Mercury is a highly toxic heavy metal with a melting point of _38 83t: and a boiling point of 356.73T: its volatility is the crown of all metals, easily invading the internal organs through the respiratory or digestive tract and accumulating in the body. Inside. The degree of toxicity varies depending on its type of presence. The most toxic one is organic mercury, which has a half-life of about 75 days, while the half-life of inorganic mercury in humans is about 42 days. According to the Global Mercury Assessment completed by the United Nations Environment Agency in 2002 and the US Environmental Protection Agency's Mercury Study Report to Congress, which was completed in 1997 and submitted to Congress, both indicate that mercury has a significant negative impact on the environment. And has global circulation characteristics. Most of the mercury in the exhaust gas is in the elemental state (HgG), and the other part is inorganic mercury. When mercury is released into the atmosphere, it is adsorbed on the particles and can be transported in the range of 1 〇〇 to 1 〇〇〇 km. Once the mercury settles to the surface, elemental mercury is converted to mercapto-mercury, which is bioconcentrated and becomes a strong carcinogen that harms the human body. In summary, the content of mercury in the environment and in the living body has received considerable international attention in recent years. The types of pollutants collected from flue gas from solid waste sources are mainly classified into elemental mercury (Hg0), oxidized mercury (Hg2+) and granular combined mercury (Hg(p)). Different types of mercury compounds have different chemical properties and also affect their capture strategies. Conventional dust removal equipment such as electrostatic precipitator (ESP) or bag filter (BF) can remove the granular knot 5 1373364 mercury (Hg(p)). The oxidized mercury (Hg2+) in the gas phase is soluble in water and removed by flue gas desulfurization (FGD). Only elemental mercury (HgG) is emitted into the atmosphere through exhaust gas treatment equipment and is the most difficult type of mercury species to handle. Domestic heavy metal mercury fixed pollution sources include cement kiln, municipal waste incineration plant, electric arc furnace, coal-fired power generation furnace and coal-fired steam-fired symbiotic steel furnace, etc. The emission concentration is as low as ppb, and there is no specific mercury Add pollution prevention equipment to the pollution discharge. According to foreign experience, the most feasible mercury pollution control system at present is the sorbent injection method, which is the treatment method that does not need to change the current pollution prevention equipment on a large scale. At present, the adsorbent widely used in coal-fired power plants is FGD activated carbon (FGD AC, available from Norit Americas Inc.) having a density of about 51.51 g/cm3, a specific surface area of about 600 m2/g, and a particle size of 9-ΐ5 μιη.

Carey (J. Air Waste Manage. Assoc·, 48, 1166-1174, 1998) The adsorption capacity of § FGD activated carbon was measured by 1 Opg/m water. The average adsorption capacity of HgG was about 2 〇(^g/g, and the adsorption efficiency φ rate for oxidized mercury is higher than elemental mercury. Therefore, Carey suggests that FGD activated carbon is more suitable for capturing gaseous oxidized mercury (Hg2+).

Miller (Fuel Processing Technology, 65-66, 343.353 2000) tested the activity-carbon adsorption capacity at a concentration of mercury ranging from n to 16 jLlg/m3. In the case where the adsorption temperature is 1〇7.0, the average volume of mercury adsorption is about 57 to 614 pg/g. Yang (Combustion Science and Technology, 12, 486-490, 2006) tested two activated carbons, PAC-1 and PAC-2, from China. The surface area of PAC-1 is 735 m2/g 'the average particle size is 150 μιη, and the amount of adsorption capacity of 1373364 for & rc is 67 (^g/g, penetration time is 228 minutes. Surface area of PAC-2 at 14 rc. The average particle diameter of 928 m 2 /g was 250 μm, the adsorption capacity for HgG at 140 ° C was 1040 pg / g, and the breakthrough time was 336 minutes.

Hsi (Environ. Sci. Technol., 25, 2785-2791, 2000) prepared an activated carbon fiber having a specific surface area of 1886 m 2 /g. When the mercury inlet concentration was 50 pg/m 3 , the above activated carbon fiber adsorbed Hg0 at 135 ° C. The amount is 350 pg / g. The biggest problem with the above unmodified activated carbon is that it is less effective in treating low-gas coals, so further modification may be required. Sun (China Environ. Sci., 26, 257-261, 2006) treated brominated activated carbon (bromine content 0.33%)' to increase the adsorption rate of mercury and increase the adsorption capacity by 80 times.

Hsi (Environ. Sci. Technol., 25, 2785-2791, 2000) prepares activated carbon fibers impregnated with sulfur. When the inlet concentration of mercury is 5 (^g/m3, the adsorption amount of the above activated carbon fibers to HgG at 135 °C It is 35 (^g/g.

Lee (Environ. Sci. Technol., 40, 2714-2720, 2006) was doped with sodium sulphide to montmorillonite to prepare an adsorbent. The above non-carbon adsorbent has a very low mercury adsorption capacity at a temperature lower than 140 ° C, and a mercury adsorption capacity of 283 pg / g at 7 〇 t. Lee further diluted sodium polysulfide into montmorillonite with an adsorption capacity of only 157 pg/g at 70 °C.

Carey (Environ. Prog) 19,167-174, 2000) The fly ash produced after burning bituminous coal is used as an adsorbent material, and its adsorption capacity for mercury is only 10 pg/g. Carey further uses fly ash produced by burning lignite as an adsorbent. Its adsorption capacity for mercury is only 30 pg/g. 7 1373364 In summary, there is still a need for a new method for preparing adsorbent materials to prevent mercury contamination. SUMMARY OF THE INVENTION The present invention provides a method for adsorbing mercury vapor, including The pore size ruthenium-based adsorption material is placed in the mercury pollution source flue; and the medium-aperture ruthenium-based adsorption material adsorbs the mercury vapor in the mercury pollution source flue; wherein the medium-diameter ruthenium-based adsorption material has a surface area of 700 to 1500 m 2 /g, and the pore size is between [Embodiment] The present invention provides a method for adsorbing mercury vapor, comprising: placing a medium-aperture ruthenium-based adsorbent in a mercury-contaminated source flue, and adsorbing mercury vapor in a mercury-contaminated flue by a medium-aperture ruthenium-based adsorbent. The mercury source flue can be an incinerator, a cement rotary kiln, an electric arc furnace, a coal-fired power generation boiler, a coal-fired cogeneration plant, a sintering furnace, or a non-ferrous metal smelting industry.

The method for preparing the medium pore size ruthenium-based adsorbing material of the present invention is a spray gas gel method. First, 1 mole of tetraethoxy decane, 〇. 8 to 0.24 moles of cetyltridecyl ammonium bromide, 10 moles of ethanol, 40 moles of water, and 0.00 moles of hydrochloric acid, mixed to form a colloid. The colloid is then atomized by an ultrasonic sprayer and introduced into the two heating zones with high pressure dry air. The temperature of the first section of the heating zone is between 1 ° C and 200 ° C to evaporate the solvent in the mist to form adsorbent particles. The second stage heating zone has a temperature between 500 ° C and 600 ° C for calcining, condensing, and densifying the adsorbent particles. Then, the concentrated pore size ruthenium-based adsorbent material was filtered through a high-efficiency filter paper at 10 ° C to 200 ° C to avoid condensation of water and gas. Finally, at 500 ° C 8 1373364

The structure induced by the structure of 600UC is used to collect the medium-sized sulfhydryl-based adsorbent material to reduce the enthalpy-like shape, and the hole-like structure of the hole-based absorbing material is fused to the core, and the pores are arranged in a regular manner. 7 (f〇 is 0.769mL/g, far ': between 2" nm' and the total pores are higher than the commercially available activated carbon. In the adsorption performance of the recorded 蒗a 焉, the present invention ",, /MHg〇 )

Knowing the commercial activated carbon, on it,? The base and the attached materials are also for the purpose of the money and the water volume of the water is between 1〇〇〇3__ϋ(4). The middle of the hole is made of the material. = The attached special H can be adjusted by the ratio of raw materials and changing operating conditions. ° and. The diameter size 'reaches a specific homo-aperture, changing its adsorption capacity for different concentrations of gas. In addition, in the present invention, the pore size Shishiji adsorbs the characteristics of the dinan surface area and the uniform-middle pore structure distribution, and since the enemy is different, the pure stone eve 'genus is not easily affected by water and gas (4) and the money is reduced. Those skilled in the art will be able to clarify the features of the present invention, particularly by way of example. : Lower block [Examples] Example 1 (Preparation of medium pore size ruthenium-based adsorption material) 1 mole of tetraethoxy decane, 0.18 moles of hexamethylpyridyl triammonium bromide, 10 moles A portion of the ethanol, 4 moles of water, and 8 moles of hydrochloric acid 'mixed to form a colloid. The colloid is then atomized by an ultrasonic atomizer to carry high pressure dry air into the two heating zones in the reaction tube. The reaction tube was a tube having a length of 1 cm and an inner diameter of 1.27 cm. The flow rate of the high pressure dry air is approximately S. OLSTPmirT1. The temperature of 9 1373364 in the first section of the heating zone is 15 〇. The crucible is used to evaporate the solvent in the mist to form the adsorbent particles. The temperature of the second section of the heating zone is 550. (:, for calcination, condensation, and densification of adsorbent particles. Then, at 150: (by: high-efficiency filter paper filtration to collect the medium-diameter sulfhydryl-based adsorbate. Finally, at 55 〇. 〇 extra calcination collection of the pore diameter The ruthenium-based adsorbent was used for 4 hours. The specific surface area, micropore surface area, total pore volume, micropore volume, and pore size distribution of the above adsorbent were measured by a Beckman coulter SA3100Plus specific surface area meter, and all data were passed through 77Kn2, etc. The temperature adsorption curve was obtained (77K is & boiling point under lamat), and the sample was measured at 1〇-20μίοπ: vacuum and 150 before measurement. (: desorption for 1.5 hours to remove water vapor and organic adsorbed on the surface of the sample. Substance, followed by isothermal adsorption experiments to lamat, the specific surface area calculation is based on the BET equation recommended by STM D4820-96a; micropore surface area and micropore volume calculations are calculated according to the t-pl〇t method recommended by Lippens et al. J (Jura-Harkins equation) ° Statistical thickness t=[13.99/(0.〇34-log(p/p0))]0.°5 (The statistical thickness t in Equation 1 is applied to the range of linear regression Between 4.5 A and 8. 〇A The surface and pore volume of the remaining pores larger than 2 nm are obtained by subtracting the micropore value from the total pore value. The microporous pore distribution is obtained by using the three-dimensional mode. The non-micropore pore size distribution is obtained by using the BJH mode. Activated carbon CAC (China carbon mercury removal carbon S206) and its sulfur impregnant CAC-300S (sulfur impregnation temperature of 300 ° C), CAC-400S (sulfur impregnation temperature of 4 〇〇. 〇, and CAC-650S (sulfur impregnation) Compared with the temperature of 65 〇C), the hole hand Tt Shi Xiji adsorption material of the present invention has a high specific surface area and does not contain any micropores, whether it is higher than the commercially available activated carbon than the surface of the 1373364 area or the total pore volume. Further, in the present invention, the pore size distribution of the pore size ruthenium-based adsorption material is less than 1 〇 nm, as shown in Fig. 1. Table 1 BET surface area of the sample (m2/g) Micropore surface area (m2/g) Micropore/Total ▲ Area (%) Total pore volume (mL/g) Micropore volume (mL/g) Micropore volume / Total pore volume (%) Medium pore size 矽-based adsorption material 1293.6 0 0.769 0 0 CAC 915.7+ 5.7 363.0+5.9 39.4+0.9 CAC-300S 11.6+0.1 NDND u.497+0.OOQ 0.155+0.002 31.2+1.0 CAC-400S 327.9+3.6 17.6+1.8 5.1+0.5, ^* 021 +0.000 NDND CAC-650S 796.7+3.8 344*3+17.3 43.2+2 0.199+0.004 0.001+0.001 0.5+0.4 ND is below the detection limit ~ υ.430+0.006 [〇_146土0.005 33.9+1.6 The pore structure of the medium-diameter Shixiji adsorption material was analyzed by Xenon Diffraction Diffractometer (XRD 'RigakuD/MAX-B). The dry material of the above analysis was a copper target with a voltage of 30k, a current of 20mA, and a scanning speed of 4 〇〇 deg / min. As shown in Fig. 2, in the present invention, the aperture bismuth-based adsorbing material has a significantly low diffraction peak at the diffraction angle of 3 〇 β, which is the spectral value of the (100) orientation, and the channel arrangement can be determined compared with the literature. The structure is similar to that of the MCM-41 and is a hexagonal inline. The surface observation of the above-mentioned medium-diameter Shishiji adsorption material was observed by a high-resolution field-fired gun-through electron microscope additional energy analyzer (feg_TEm & eds, JEOL, JEM-2010, Japan). As shown in Fig. 3, many white spots which are regularly arranged and have similar sizes, that is, hole openings, can be observed on the surface of the adsorbent. The structure of the holes is hexagonal, and the rules are arranged in a three-dimensional direction, and the shape is spherical. Example 2 (Simulated flue gas mercury vapor adsorption experiment) Figure 4 is a schematic diagram of the steaming and gas adsorption device of Carey (EPRI WO3453-07, 1998). The device of this embodiment is roughly based on the system. Detailed revision. The system can be divided into three parts: a standard gas (fruit steaming 1373364 gas Hg0) generating part; (2) containing the above-mentioned mesoporous weighing stone bed; and (3) adsorption monitoring and data, the adsorption of the adsorbent material The standard permeation tube is produced and the concentration is set to 5 ,. The system uses VICI as lL/min (25. 〇. The gas pipeline part is Τ ', and the gas flow is set to cover the heating belt to maintain the pipeline temperature at the second and second s = the fixed inner diameter is 0-5 吋. In the adsorption bed. Fixed type: Attached: The adsorbent in the inside (the medium-diameter Shi Xiji suction of Example i)

2 Sulfur impregnation butterfly is used in an amount of (4) to and uniformly mixed with 5 g of fine quartz sand to completely heat the adsorbent. The temperature of the suction bed is set to 15 〇. The outflow gas passes through the heating line and passes through two sets of impingers, respectively containing a SnCl2 solution and a Na2C〇3 solution. The function of the SnCU solution is to reduce the Hg oxime oxidized by the adsorbent, and the Na2C 〇 3 solution serves to protect the downstream detection system from acid gas corrosion. Finally, the gas enters the cold vapor atomic fluorescence spectrometer (CVAFS) to obtain the adsorption breakthrough curve to estimate the total adsorption of the HgQ vapor by the medium pore size ruthenium-based adsorbent. The pore size ruthenium-based adsorbent in the first embodiment and the commercially available activated carbon are used. The adsorption capacity is compared as shown in Table 2. The adsorption breakthrough curve is shown in Figure 5. In the present invention, the pore size ruthenium-based adsorbent material is at least three times more adsorbed to mercury vapor (Hg 〇) than the commercially available activated carbon or its sulfur impregnated product, and the penetration time of the pore size ruthenium-based adsorbent material in the present invention is higher. Long, it is shown that the pore size Shishiji adsorption material of the present invention has an excellent adsorption capacity for low concentration mercury vapor (HgQ). 12 1373364 Table 2 Adsorbent Adsorption Capacity (# g/g) Example 1 of the pore size ruthenium-based adsorbent material 1129.94 CAC 166.87 CAC-300S 263.13 CAC-400S 227.66 CAC-650S 158.32 Although the present invention has been disclosed in several embodiments as above However, it is not intended to limit the invention, and any one of ordinary skill in the art can make any changes and refinements without departing from the spirit and scope of the invention, so that the scope of protection of the present invention is attached. The scope of the patent application is subject to change.

13 1373364 BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a pore size distribution diagram of a pore size ruthenium-based adsorption material in Example 1 of the present invention; and Fig. 2 is an XRD pattern of an aperture ruthenium-based adsorption material in Example 1 of the present invention; 3 is a TEM spectrum of the pore size ruthenium-based adsorption material in the first embodiment of the present invention; FIG. 4 is a schematic diagram of the mercury vapor adsorption apparatus according to the second embodiment of the present invention; and FIG. 5 is an aperture 矽 in the first embodiment of the present invention. Comparison of adsorption breakthrough curves of base adsorbent materials with commercially available activated carbon and sulfur-impregnated products. [Main component symbol description] None 14

Claims (1)

1373364 Revised period: 101.8.7 Amendment No. 97146216-J: X. Application for patent garden: 1. A method for adsorbing mercury vapor, comprising: placing a medium-porosity-controlled stone-based adsorbent material in a mercury-contaminated source In the middle of the channel, the mercury vapor in the mercury source flue is adsorbed by the medium-diameter Shishiji adsorption material; ', wherein the surface area of the pore-sized sulfhydryl-absorbing material is 7〇〇 to 1500m2/g, and the pore size is between 2 -3nm, wherein the preparation method of the medium pore size ruthenium-based adsorption material comprises: mixing 1 mole of tetraethoxy decane, 0.08 to 0 24 moles of cetyltridecyl ammonium bromide, 10 moles a portion of ethanol, 4 parts of water, and 0.008 parts of hydrochloric acid to form a mixture; and atomizing and heating the mixture in two stages to form a medium-diameter Shishiji adsorption material, the first stage of heating The temperature is between 100. (: to 2〇〇t, and the temperature of the second stage heating is between 500. 〇 and 000t. 1) The method of adsorbing mercury vapor according to the first item of the patent scope, the smear source flue Including incinerator, cement rotary, electric arc furnace 'burning power generation, (4) steam and electricity symbiosis plant, sintering furnace, or non-ferrous metal refining 3 · as in the patent application scope item i, the mesoporous tree base 3000μ§/§ The water of the door is between 1 OOOpg/g to 15