Dechlorinating agent and preparation method thereof

Abstract

The invention relates to the technical field of dechlorinating agents, in particular to a dechlorinating agent and a preparation method thereof. The preparation method of the dechlorinating agent comprises the following steps: 1) uniformly mixing quaternary ammonium salt and organic amine, then adding silicate ester, uniformly mixing, reacting for 2-6 hours, carrying out solid-liquid separation, washing a solid, and drying; 2) roasting the solid dried in the step 1) at 550-650 DEG C for 5-10 hours, and cooling to obtain a carrier; 3) uniformly mixing the carrier prepared in the step 2) with a calcium source and a zinc source in water, adjusting the pH value to 10-12, reacting, standing, carrying out solid-liquid separation, and drying the solid, and 4) calcining the dried solid in the step 3) at 800-1000 DEG C for 10-24 hours, and cooling to obtain the dechlorinating agent. The prepared dechlorinating agent is uniform in pore diameter and high in penetrating chlorine capacity, and can effectively reduce the loss of active ingredients.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of dechlorination agents, and more particularly to a dechlorination agent and a preparation method thereof. BACKGROUND

[0002] In the petroleum industry, in order to achieve smooth reaction and ensure reaction effect, water, chloride and the like are usually added, which causes HCl generated in the reaction process to enter the product, thereby affecting reaction efficiency and yield and causing an impact on product performance. Dechlorination agents are very common reagents for removing chlorine elements, and the most commonly used one is a solid dechlorination agent.

[0003] The working principle of the solid dechlorination agent is to remove Cl - The active components fixed in the dechlorination agent include alkali metals, alkaline earth metals and oxides of other elements. Generally, the solid dechlorination agent needs to be loaded on a carrier, and the commonly used carrier is activated carbon. However, activated carbon itself has low strength and is easy to pulverize in the use process, resulting in loss of active components, especially under liquid phase reaction conditions.

[0004] In order to overcome the above-mentioned shortcomings, a molecular sieve can be used as a carrier, for example, a desulfurization oxide is loaded on a porous carrier of the molecular sieve by impregnation or the like, which can improve the strength of the dechlorination agent. However, the active components of the dechlorination agent prepared by this method are only combined on the surface of the carrier by surface adsorption. In the liquid phase reaction, the dechlorination efficiency is reduced due to high pressure, and the active components adsorbed on the surface are also easy to lose.

[0005] Therefore, it is of great significance to develop a new dechlorination agent to improve dechlorination efficiency and reduce loss of active components. SUMMARY

[0006] In order to improve dechlorination efficiency and reduce loss of active components during use of the dechlorination agent, the present application provides a dechlorination agent and a preparation method thereof.

[0007] The present application provides a dechlorination agent and a preparation method thereof, which specifically adopts the following technical scheme: A preparation method of a dechlorination agent, comprising the following steps: 1) uniformly mixing quaternary ammonium salt and organic amine, then uniformly mixing with silicate, reacting for 2-6 h, solid-liquid separation, washing the solid, and drying; 2) calcining the dried solid of step 1) at 550-650 ℃ for 5-10 h, and cooling to obtain a carrier; 3) uniformly mixing the carrier prepared in step 2) with a calcium source and a zinc source in water, adjusting the pH to 10-12, reacting, standing, solid-liquid separation, and drying the solid; 4) calcining the dried solid in step 3) at 800-1000℃ for 10-24h, and cooling, to obtain the dechlorination agent.

[0008] The quaternary ammonium salt in step 1) is one or both of cetyltrimethylammonium bromide and trioctylmethylammonium bromide.

[0009] The organic amine in step 1) is any one of triethylamine, diethylamine, and aniline.

[0010] The mass ratio of the quaternary ammonium salt to the organic amine in step 1) is 2-5:1.

[0011] The temperature during the reaction in step 1) is 50-70℃.

[0012] The washing in step 1) uses anhydrous ethanol.

[0013] The calcium source in step 3) is one or a combination of several of calcium chloride, calcium sulfate, and calcium nitrate.

[0014] The zinc source in step 3) is one or a combination of several of zinc chloride, zinc sulfate, and zinc nitrate.

[0015] The sodium hydroxide solution used to adjust the pH in step 3) has a concentration of 0.1-2mol / L.

[0016] The mixing in step 3) is first mixing the calcium source and the zinc source in water, and then mixing with the carrier, and when mixing with the carrier, stirring for 10-50min.

[0017] The temperature of the carrier when mixing the carrier with the mixture of the calcium source and the zinc source in step 3) is 100-150℃.

[0018] The reaction time in step 3) is 3-6h, and the standing time is 4-8h.

[0019] The drying in step 3) is drying at 50-65℃ under vacuum for 2-7h.

[0020] The application also provides a dechlorination agent prepared by the above preparation method.

[0021] In summary, the application has the following beneficial effects: 1) The carrier prepared by the application has a small pore size and a uniform distribution, which allows the active ingredients of the dechlorination agent to be uniformly distributed therein, and to some extent reduces the loss of active ingredients.

[0022] 2) The application further uses a method of mixing the carrier with the mixture of the calcium source and the zinc source by heat contact, which not only allows the calcium source and the zinc source to fully contact the carrier, but also facilitates the close combination of the calcium source and the zinc source on the inner wall of the carrier pores, and in the subsequent reaction process, the active ingredients are also less likely to fall off, thereby reducing the loss of active ingredients.

[0023] 3. The components obtained after the reaction of this application contain complex compounds of calcium and zinc (calcium zincate), which makes the various oxides in the calcined product fully and uniformly dispersed in the carrier, and has a higher chlorine penetration capacity compared with physically mixed oxides. Attached Figure Description

[0024] Figure 1 The dechlorination agent prepared in Example 6 is a spherical product formed by molding. Figure 2 This is a scanning electron microscope image of the dechlorination agent prepared in Example 6. Detailed Implementation

[0025] The present application will be further described in detail below with reference to preparation examples, embodiments and comparative examples. All raw materials involved in the present application are commercially available.

[0026] Example 1 The preparation method of the dechlorination agent in this embodiment includes the following steps: (1) Add 1.12g of trioctylmethylammonium bromide to 120mL of water, stir to mix thoroughly, add a small amount of triethylamine, and mix evenly to obtain mixture A; Add 30 mL of tetraethyl orthosilicate to the above mixture A, heat to 55 °C, stir for 5 h; centrifuge, wash the solid with anhydrous ethanol, and dry; (2) The solid dried in step (1) was calcined at 650°C for 8 hours, cooled, and crushed to obtain the carrier; (3) Add calcium chloride and zinc chloride to water at a molar ratio of 1:2 and stir until fully dissolved to obtain mixture B; Take the carrier prepared in step (2), add it to the above mixture B, stir for 0.5 h, add sodium hydroxide solution with a concentration of 0.6 mol / L to adjust the pH of the solution to 12, continue stirring for 2 h; let stand for 5 h, separate the solid and liquid, and dry in a vacuum drying oven at 60 ℃ for 6 h; (4) Transfer the solid dried in step (3) to a muffle furnace, heat it to 900°C, keep it at that temperature for 12 hours, and then cool it to obtain the product.

[0027] Example 2 The preparation method of the dechlorination agent in this embodiment includes the following steps: (1) Add 3.64g of CTAB (hexadecyltrimethylammonium bromide) to 120mL of water, stir to mix thoroughly, add a small amount of triethylamine, and mix evenly to obtain mixture A; Add 30 mL of tetraethyl orthosilicate to the above mixture A, heat to 60 °C, stir for 3 h; centrifuge, wash the solid with anhydrous ethanol, and dry; (2) The solid dried in step (1) was calcined at 650°C for 8 hours, cooled, and crushed to obtain the carrier; (3) Add calcium chloride and zinc chloride to water at a molar ratio of 1:3, stir to dissolve them completely, and obtain mixture B; Take the carrier prepared in step (2), add it to the above mixture B, stir for 0.5 h, add sodium hydroxide solution with a concentration of 0.8 mol / L to adjust the pH of the solution to 12, continue stirring for 2 h; let stand for 5 h, separate the solid and liquid, and dry in a vacuum drying oven at 55 ℃ for 6 h; (4) Transfer the solid dried in step (3) to a muffle furnace, heat it to 850°C, keep it at that temperature for 15 hours, and then cool it to obtain the product.

[0028] Example 3 The preparation method of the dechlorination agent in this embodiment includes the following steps: (1) Add 3.64g of CTAB (hexadecyltrimethylammonium bromide) to 120mL of water, stir to mix thoroughly, add a small amount of triethylamine, and mix evenly to obtain mixture A; Add 30 mL of tetraethyl orthosilicate to the above mixture A, heat to 60 °C, stir for 3 h; centrifuge, wash the solid with anhydrous ethanol, and dry; (2) The solid dried in step (1) was calcined at 650°C for 8 hours, cooled, and crushed to obtain the carrier; (3) Add calcium chloride and zinc chloride to water at a molar ratio of 1:3, stir to dissolve them completely, and obtain mixture B; Take the carrier prepared in step (2), add it to the above mixture B, stir for 0.5 h, add sodium hydroxide solution with a concentration of 0.6 mol / L to adjust the pH of the solution to 12, continue stirring for 2 h; let stand for 5 h, separate the solid and liquid, and dry in a vacuum drying oven at 60 ℃ for 6 h; (4) Transfer the solid dried in step (3) to a muffle furnace, heat it to 950°C, keep it at that temperature for 10 hours, and then cool it to obtain the product.

[0029] Example 4 The preparation method of the dechlorination agent in this embodiment includes the following steps: (1) Add 3.64g of CTAB (hexadecyltrimethylammonium bromide) to 120mL of water, stir to mix thoroughly, add a small amount of triethylamine, and mix evenly to obtain mixture A; Add 30 mL of tetraethyl orthosilicate to the above mixture A, heat to 60 °C, stir for 3 h; centrifuge, wash the solid with anhydrous ethanol, and dry; (2) The solid dried in step (1) was calcined at 650°C for 8 hours, cooled, and crushed to obtain the carrier; (3) Add calcium chloride and zinc chloride to water at a molar ratio of 1:3, stir to dissolve them completely, and obtain mixture B; Add the carrier at 120℃ into the container, add the above mixture B dropwise until the carrier is submerged, let stand for 30 minutes, add 0.6 mol / L sodium hydroxide solution to adjust the pH of the solution to 12, continue stirring for 2 hours; let stand for 5 hours, separate the solid and liquid, and dry in a vacuum drying oven at 60℃ for 6 hours; (4) Transfer the solid dried in step (3) to a muffle furnace, heat it to 950°C, keep it at that temperature for 10 hours, and then cool it to obtain the product.

[0030] Specifically, the 120℃ carrier is placed in a muffle furnace, heated to 120℃, and held for 1 hour.

[0031] Example 5 The preparation method of the dechlorination agent in this embodiment includes the following steps: (1) Add 3.64g of CTAB (hexadecyltrimethylammonium bromide) to 120mL of water, stir to mix thoroughly, add a small amount of triethylamine, and mix evenly to obtain mixture A; Add 30 mL of tetraethyl orthosilicate to the above mixture A, heat to 60 °C, stir for 3 h; centrifuge, wash the solid with anhydrous ethanol, and dry; (2) The solid dried in step (1) was calcined at 650°C for 8 hours, cooled, and crushed to obtain the carrier; (3) Add calcium chloride and zinc chloride to water at a molar ratio of 1:3, stir to dissolve them completely, and obtain mixture B; Add the carrier at 150℃ into the container, add the above mixture B dropwise until the carrier is submerged, let stand for 30 minutes, add 1 mol / L sodium hydroxide solution to adjust the pH of the solution to 12, continue stirring for 2 hours; let stand for 5 hours, separate the solid and liquid, and dry in a vacuum drying oven at 60℃ for 6 hours; (4) Transfer the solid dried in step (3) to a muffle furnace, heat it to 950°C, keep it at that temperature for 10 hours, and then cool it to obtain the product.

[0032] Specifically, the 150℃ carrier is placed in a muffle furnace, heated to 150℃, and held for 1 hour.

[0033] Example 6 The preparation method of the dechlorination agent in this embodiment includes the following steps: (1) Add 3.64g of CTAB (hexadecyltrimethylammonium bromide) to 120mL of water, stir to mix thoroughly, add a small amount of triethylamine, and mix evenly to obtain mixture A; Add 30 mL of tetraethyl orthosilicate to the above mixture A, heat to 60 °C, stir for 3 h; centrifuge, wash the solid with anhydrous ethanol, and dry; (2) The solid dried in step (1) was calcined at 650°C for 8 hours, cooled, and crushed to obtain the carrier; (3) Add calcium chloride and zinc chloride to water at a molar ratio of 1:3, stir to dissolve them completely, and obtain mixture B; Add the carrier at 150℃ into the container, add the above mixture B dropwise until the carrier is submerged, let stand for 30 minutes, add 1 mol / L sodium hydroxide solution to adjust the pH of the solution to 12, continue stirring for 2 hours; let stand for 5 hours, separate the solid and liquid, and dry in a vacuum drying oven at 60℃ for 6 hours; (4) Transfer the solid dried in step (3) to a muffle furnace, heat it to 180°C, keep it at that temperature for 2 hours, then heat it to 900°C, keep it at that temperature for 12 hours, and then cool it to obtain the product.

[0034] Specifically, the 150℃ carrier is placed in a muffle furnace, heated to 150℃, and held for 1 hour.

[0035] Comparative Example 1 The difference between Comparative Example 1 and Example 6 is that calcium chloride and zinc chloride are in a molar ratio of 3:1, while the other components are the same as in Example 6.

[0036] Comparative Example 2 The difference between Comparative Example 2 and Example 6 is that step (4) is: the solid dried in step (3) is transferred to a muffle furnace, heated to 180°C, kept at that temperature for 2 hours, then heated to 600°C, kept at that temperature for 12 hours, and then cooled to obtain the solid. The rest are the same as in Example 6.

[0037] Performance testing methods Physicochemical properties were tested using the dechlorinating agents prepared in Examples 1-6. Their specific surface area and average pore size were tested, and the test results are shown in Table 1 below.

[0038] Table 1. Specific surface area and average pore size of the dechlorinating agents prepared in Examples 1-6

[0039] As can be seen from the table above, the dechlorinating agent prepared in this application has a relatively large specific surface area and small pore size, which enables the active ingredients to be distributed more evenly and reduces the loss of active ingredients to a certain extent.

[0040] 2. Chlorine penetration tolerance test The reformed oil with a chlorine content of approximately 4 μg / L and a water content of approximately 25 μg / L was subjected to a reaction at 70℃, 1 MPa, and a liquid hourly space velocity of 5 h⁻¹. -1Under the specified conditions, a liquid-phase dynamic dechlorination experiment was conducted by loading the dechlorinating agent. The chlorine content in the reformate flowing out of the dechlorination tank was measured. When the chlorine content of the effluent was greater than 0.5 μg / L, it was considered to have penetrated. The penetration chlorine capacity of the dechlorinating agent was calculated according to the following formula. The test results are shown in Table 2 below.

[0041] Breakthrough chlorine capacity = (mass content of chlorine in the dechlorinating agent after breakthrough) / (total mass of the dechlorinating agent after breakthrough) × 100% Table 2. Data on chlorine penetration detection of Examples 1-6 and Comparative Examples 1-2

[0042] As can be seen from the table above, the dechlorinating agent of the present invention has a high chlorine penetration capacity. In particular, after adopting the process of hot mixing of the carrier and the mixed liquid, the chlorine penetration capacity increases significantly. This may be due to the fact that the calcium and zinc sources can fully contact and bind tightly on the surface of the carrier at a higher temperature. Referring to Example 6 and Comparative Example 1, it can be seen that when the amount of zinc chloride is low, the chlorine penetration capacity is low, which may be related to the low amount of calcium-zinc compounds generated. Referring to Example 6 and Comparative Example 2, it can be seen that when the sintering temperature is low, the chlorine penetration capacity decreases significantly. This may be related to the fact that only oxides can be generated at this temperature, and intermediate compounds cannot be generated.

[0043] Figure 1 The product shown is a spherical product formed from the dechlorinating agent prepared in Example 6 after subsequent molding treatment, which is the final form for industrial application.

[0044] Figure 2 The scanning electron microscope image shows the microstructure of the original product prepared in Example 6. The microstructure is a uniform micron-sized particle agglomerate with a size concentrated in the range of 2~8μm. The agglomerate has a loose and irregular stacking configuration, with dense and uniform rough texture distributed on the surface, and local fine pores showing uneven morphology.

[0045] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing a dechlorination agent, characterized in that, Includes the following steps: 1) Mix the quaternary ammonium salt and organic amine evenly, then add the silicate ester and mix evenly. React for 2-6 hours, then separate the solid and liquid, wash the solid, and dry it. 2) The solid dried in step 1) is calcined at 550-650℃ for 5-10 hours and then cooled to obtain the carrier; 3) Mix the carrier obtained in step 2) with the calcium source and zinc source in water until homogeneous, adjust the pH to 10-12, react, let stand, separate the solid and liquid, and dry the solid. 4) Calcine the dried solid from step 3) at 800-1000℃ for 10-24 hours, then cool to obtain the final product.

2. The method for preparing the dechlorinating agent according to claim 1, characterized in that, In step 1), the quaternary ammonium salt is one or both of hexadecyltrimethylammonium bromide and trioctylmethylammonium bromide.

3. The method for preparing the dechlorinating agent according to claim 1, characterized in that, In step 1), the organic amine is any one of triethylamine, diethylamine, or aniline.

4. The method for preparing the dechlorinating agent according to claim 1, characterized in that, In step 1), the mass ratio of quaternary ammonium salt to organic amine is 2-5:

1.

5. The method for preparing the dechlorinating agent according to claim 1, characterized in that, In step 3), the calcium source is one or a combination of calcium chloride, calcium sulfate, and calcium nitrate.

6. The method for preparing the dechlorinating agent according to claim 1, characterized in that, In step 3), the zinc source is one or a combination of zinc chloride, zinc sulfate, and zinc nitrate.

7. The method for preparing the dechlorinating agent according to claim 1, characterized in that, In step 3), sodium hydroxide solution is used to adjust the pH. The concentration of sodium hydroxide solution is 0.1-2 mol / L.

8. The method for preparing the dechlorinating agent according to any one of claims 1-7, characterized in that, In step 3), the calcium source and zinc source are first mixed evenly in water, and then mixed evenly with the carrier.

9. The method for preparing the dechlorinating agent according to claim 8, characterized in that, In step 3), when the carrier is mixed with the mixture of calcium and zinc sources, the temperature of the carrier is 100-150℃.

10. A dechlorinating agent prepared by the method of preparation of the dechlorinating agent as described in claim 1.

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