A dechlorination agent and a method for preparing the same

Abstract

The application relates to the technical field of dechlorination agents, in particular to a dechlorination agent and a preparation method thereof.The preparation method of the dechlorination agent comprises the following steps: 1) uniformly mixing quaternary ammonium salt and organic amine, then uniformly mixing with silicate, reacting for 2-6 hours, performing solid-liquid separation, washing the solid, and drying; 2) calcining the dried solid obtained in the step 1) at 550-650 DEG C for 5-10 hours, cooling, and obtaining a carrier; 3) uniformly mixing the carrier obtained in the step 2) with a calcium source and a zinc source in water, adjusting the pH value to 10-12, reacting, standing, performing 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, thereby obtaining the dechlorination agent. The dechlorination agent prepared by the application has uniform pore diameter, high chlorine penetration 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, alkali 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 a 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 will decrease 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:

[0008] A preparation method of a dechlorination agent, comprising the following steps:

[0009] 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;

[0010] 2) calcining the dried solid in step 1) at 550-650 ℃ for 5-10 h, and cooling to obtain a carrier;

[0011] 3) 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;

[0012] 4) calcining the dried solid in step 3) at 800-1000℃ for 10-24h, and cooling, to obtain the product.

[0013] The quaternary ammonium salt in step 1) is one or both of cetyltrimethylammonium bromide and trioctylmethylammonium bromide.

[0014] The organic amine in step 1) is any one of triethylamine, diethylamine, and aniline.

[0015] The mass ratio of the quaternary ammonium salt to the organic amine in step 1) is 2-5:1.

[0016] The temperature during the reaction in step 1) is 50-70℃.

[0017] The washing in step 1) uses anhydrous ethanol.

[0018] The calcium source in step 3) is one or a combination of several of calcium chloride, calcium sulfate, and calcium nitrate.

[0019] The zinc source in step 3) is one or a combination of several of zinc chloride, zinc sulfate, and zinc nitrate.

[0020] The sodium hydroxide solution used to adjust the pH in step 3) has a concentration of 0.1-2mol / L.

[0021] The mixing in step 3) is first mixing the calcium source and the zinc source in water, and then mixing the carrier, and the mixing with the carrier is stirring for 10-50min.

[0022] 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℃.

[0023] The reaction time in step 3) is 3-6h, and the standing time is 4-8h.

[0024] The drying in step 3) is drying at 50-65℃ under vacuum for 2-7h.

[0025] The application also provides a dechlorination agent prepared by the above preparation method.

[0026] In summary, the application has the following beneficial effects:

[0027] 1) The carrier prepared by the application has a small pore size and a uniform distribution, so that the active ingredients of the dechlorination agent can be uniformly distributed therein, and the loss of the active ingredients is reduced to a certain extent.

[0028] 2、The application further adopts the mode of mixing the carrier with the mixed solution of the calcium source and the zinc source in hot contact, which can not only make the calcium source and the zinc source fully contact with the carrier, but also is beneficial to the close combination of the calcium source and the zinc source on the inner wall of the carrier pores, and the calcium source and the zinc source are not easy to fall off in the subsequent reaction process, thereby reducing the loss of the active ingredients.

[0029] 3、The complex compound (calcium zincate) of calcium and zinc exists in the components obtained after the reaction of the application, so that the multiple oxides are fully and uniformly dispersed in the carrier in the product after calcination, and the product has higher chlorine penetration capacity than the physically mixed oxides. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The spherical formed product of the dechlorination agent prepared in Example 6 after molding;

[0031] Figure 2 The scanning electron microscope image of the dechlorination agent prepared in Example 6. DETAILED DESCRIPTION

[0032] The application will be further described in detail in combination with the preparation examples, examples and comparative examples. The raw materials involved in the application can be obtained by market purchase.

[0033] Example 1

[0034] The preparation method of the dechlorination agent of the present embodiment comprises the following steps:

[0035] (1) 1.12 g of tricaprylylmethyl ammonium bromide was added to 120 mL of water, and stirred to fully mix, and a small amount of triethylamine was added and mixed uniformly to obtain a mixed solution A;

[0036] 30 mL of tetraethyl orthosilicate was added to the above mixed solution A, and the temperature was raised to 55°C, and stirred for 5 h; centrifugal separation was performed, the solid was washed with anhydrous ethanol, and dried;

[0037] (2) The dried solid of step (1) was calcined at 650°C for 8 h, cooled, and crushed to obtain a carrier;

[0038] (3) Calcium chloride and zinc chloride were added to water according to a molar ratio of 1:2, and stirred to fully dissolve to obtain a mixed solution B;

[0039] The carrier prepared in step (2) was added to the above mixed solution B, and stirred for 0.5 h, then a 0.6 mol / L sodium hydroxide solution was added to adjust the pH of the solution to 12, and continued to stir for 2 h; standing for 5 h, solid-liquid separation was performed, and dried in a vacuum drying oven at 60°C for 6 h;

[0040] (4) The dried solid of step (3) was transferred to a muffle furnace, the temperature was raised to 900°C, and kept for 12 h, and then cooled to obtain the product.

[0041] Example 2

[0042] The preparation method of the dechlorination agent of the present example comprises the following steps:

[0043] (1) 3.64 g of CTAB (cetyltrimethylammonium bromide) was added to 120 mL of water, stirred to mix thoroughly, a small amount of triethylamine was added, and mixed uniformly to obtain a mixed solution A;

[0044] 30 mL of tetraethyl orthosilicate was added to the above mixed solution A, heated to 60°C, and stirred for 3 h; centrifugal separation was performed, the solid was washed with anhydrous ethanol, and dried;

[0045] (2) The dried solid of step (1) was calcined at 650°C for 8 h, cooled, and crushed to obtain a carrier;

[0046] (3) Calcium chloride and zinc chloride were added to water according to a molar ratio of 1:3, stirred to dissolve thoroughly, and a mixed solution B was obtained;

[0047] The carrier prepared in step (2) was added to the above mixed solution B, stirred for 0.5 h, and then a 0.8 mol / L sodium hydroxide solution was added to adjust the pH of the solution to 12, and stirring was continued for 2 h; standing for 5 h, solid-liquid separation was performed, and drying was performed in a vacuum drying oven at 55°C for 6 h;

[0048] (4) The dried solid of step (3) was transferred to a muffle furnace, heated to 850°C, and kept for 15 h, and then cooled to obtain the product.

[0049] Example 3

[0050] The preparation method of the dechlorination agent of the present example comprises the following steps:

[0051] (1) 3.64 g of CTAB (cetyltrimethylammonium bromide) was added to 120 mL of water, stirred to mix thoroughly, a small amount of triethylamine was added, and mixed uniformly to obtain a mixed solution A;

[0052] 30 mL of tetraethyl orthosilicate was added to the above mixed solution A, heated to 60°C, and stirred for 3 h; centrifugal separation was performed, the solid was washed with anhydrous ethanol, and dried;

[0053] (2) The dried solid of step (1) was calcined at 650°C for 8 h, cooled, and crushed to obtain a carrier;

[0054] (3) Calcium chloride and zinc chloride were added to water according to a molar ratio of 1:3, stirred to dissolve thoroughly, and a mixed solution B was obtained;

[0055] The carrier prepared in step (2) is added into the mixed solution B, stirred for 0.5 h, and then a 0.6 mol / L sodium hydroxide solution is added to adjust the pH of the solution to 12, and the stirring is continued for 2 h; after standing for 5 h, the solid-liquid separation is performed, and the carrier is dried in a vacuum drying box at 60℃ for 6 h;

[0056] (4) The dried solid in step (3) is transferred into a muffle furnace, heated to 950℃, and kept for 10 h, and then cooled to obtain the product.

[0057] Example 4

[0058] The preparation method of the dechlorination agent of the present example comprises the following steps:

[0059] (1) 3.64 g of CTAB (cetyltrimethylammonium bromide) is added into 120 mL of water, stirred to mix thoroughly, and a small amount of triethylamine is added and mixed uniformly to obtain a mixed solution A;

[0060] 30 mL of tetraethyl orthosilicate is added into the mixed solution A, heated to 60℃, and stirred for 3 h; the solid is separated by centrifugation, washed with anhydrous ethanol, and dried;

[0061] (2) The dried solid in step (1) is calcined at 650℃ for 8 h, cooled, and crushed to obtain a carrier;

[0062] (3) Calcium chloride and zinc chloride are added into water according to a molar ratio of 1:3, stirred to dissolve thoroughly, and a mixed solution B is obtained;

[0063] The carrier at 120℃ is added into a container, and the mixed solution B is added dropwise until the liquid surface covers the carrier, and then the container is stood for 30 min; a 0.6 mol / L sodium hydroxide solution is added to adjust the pH of the solution to 12, and the stirring is continued for 2 h; after standing for 5 h, the solid-liquid separation is performed, and the carrier is dried in a vacuum drying box at 60℃ for 6 h;

[0064] (4) The dried solid in step (3) is transferred into a muffle furnace, heated to 950℃, and kept for 10 h, and then cooled to obtain the product.

[0065] The carrier at 120℃ is specifically prepared as follows: the carrier is placed in a muffle furnace, heated to 120℃, and kept for 1 h.

[0066] Example 5

[0067] The preparation method of the dechlorination agent of the present example comprises the following steps:

[0068] (1) 3.64 g of CTAB (cetyltrimethylammonium bromide) is added into 120 mL of water, stirred to mix thoroughly, and a small amount of triethylamine is added and mixed uniformly to obtain a mixed solution A;

[0069] 30 mL of tetraethyl orthosilicate was added into the above mixed solution A, and the temperature was raised to 60°C, and stirred for 3 h; centrifugal separation was performed, and the solid was washed with anhydrous ethanol and dried;

[0070] (2) The dried solid of step (1) was calcined at 650°C for 8 h, cooled, and broken to obtain a carrier;

[0071] (3) Calcium chloride and zinc chloride were added into water according to a molar ratio of 1:3, and stirred to fully dissolve to obtain a mixed solution B;

[0072] The carrier at 150°C was added into a container, and the above mixed solution B was added dropwise until the liquid surface submerged the carrier, and was placed for 30 min; a sodium hydroxide solution with a concentration of 1 mol / L was added to adjust the pH of the solution to 12, and was continuously stirred for 2 h; it was placed for 5 h, and solid-liquid separation was performed, and was dried in a vacuum drying box at 60°C for 6 h;

[0073] (4) The dried solid of step (3) was transferred into a muffle furnace, and the temperature was raised to 950°C, and was kept for 10 h, and was cooled to obtain the product.

[0074] The carrier at 150°C is specifically as follows: the carrier was placed in a muffle furnace, and the temperature was raised to 150°C, and was kept for 1 h.

[0075] Example 6

[0076] The preparation method of the dechlorination agent of the embodiment comprises the following steps:

[0077] (1) 3.64 g of CTAB (cetyltrimethylammonium bromide) was added into 120 mL of water, and stirred to fully mix, and a small amount of triethylamine was added, and mixed uniformly to obtain a mixed solution A;

[0078] 30 mL of tetraethyl orthosilicate was added into the above mixed solution A, and the temperature was raised to 60°C, and stirred for 3 h; centrifugal separation was performed, and the solid was washed with anhydrous ethanol and dried;

[0079] (2) The dried solid of step (1) was calcined at 650°C for 8 h, cooled, and broken to obtain a carrier;

[0080] (3) Calcium chloride and zinc chloride were added into water according to a molar ratio of 1:3, and stirred to fully dissolve to obtain a mixed solution B;

[0081] The carrier at 150°C was added into a container, and the above mixed solution B was added dropwise until the liquid surface submerged the carrier, and was placed for 30 min; a sodium hydroxide solution with a concentration of 1 mol / L was added to adjust the pH of the solution to 12, and was continuously stirred for 2 h; it was placed for 5 h, and solid-liquid separation was performed, and was dried in a vacuum drying box at 60°C for 6 h;

[0082] (4) The dried solid of step (3) is transferred into a muffle furnace, heated to 180℃, and kept for 2h, then heated to 900℃, and kept for 12h, and cooled to obtain the product.

[0083] The carrier at 150℃ is obtained by placing the carrier in a muffle furnace, heating to 150℃, and keeping for 1h.

[0084] Comparative Example 1

[0085] Comparative Example 1 differs from Example 6 in that calcium chloride and zinc chloride are used in a molar ratio of 3:1, and the others are the same as in Example 6.

[0086] Comparative Example 2

[0087] Comparative Example 2 differs from Example 6 in that step (4) is: the dried solid of step (3) is transferred into a muffle furnace, heated to 180℃, and kept for 2h, then heated to 600℃, and kept for 12h, and cooled to obtain the product, and the others are the same as in Example 6.

[0088] Performance test method

[0089] The dechlorination agents prepared in Examples 1-6 are tested for specific surface area and average pore size, and the test results are shown in Table 1 below.

[0090] Table 1 Specific surface area and average pore size of the dechlorination agents prepared in Examples 1-6

[0091]

[0092] As can be seen from the above table, the dechlorination agent prepared in the present application has a relatively large specific surface area and small pore size, which can make the active ingredients more evenly distributed therein, and to some extent, reduce the loss of active ingredients.

[0093] 2. Penetration chlorine capacity test

[0094] The reformate with a chlorine content of about 4μg / L and a water content of about 25μg / L is loaded into the dechlorination agent for liquid phase dynamic dechlorination experiment under the conditions of 70℃, 1MPa, and liquid space velocity of 5h -1 . The chlorine content in the effluent from the dechlorination tank is determined, and when the chlorine content of the effluent is greater than 0.5μg / L, it is considered to be penetration. The penetration chlorine capacity of the dechlorination agent is calculated according to the following formula, and the test results are shown in Table 2 below.

[0095] Penetration chlorine capacity = (mass content of chlorine in the dechlorination agent after penetration) / (total mass of the dechlorination agent after penetration) x 100%

[0096] Table 2 Penetration chlorine capacity test data of Examples 1-6 and Comparative Examples 1-2

[0097]

[0098] From the above table, it can be seen that the chlorine breakthrough capacity of the dechlorination agent of the present application is high, and in particular, after the process of mixing the carrier with the mixed solution is adopted, the chlorine breakthrough capacity is obviously increased, which may be caused by the fact that the calcium and zinc can fully contact and closely combine at a higher temperature. It can be known from the combination of Example 6 and Comparative Example 1 that when the amount of zinc chloride is small, the chlorine breakthrough capacity is small, which may be related to the small amount of calcium-zinc compounds generated. It can be known from the combination of Example 6 and Comparative Example 2 that when the sintering temperature is low, the chlorine breakthrough capacity is obviously decreased, which may be related to the fact that only oxides can be generated at this temperature, and intermediate compounds cannot be generated.

[0099] Figure 1 The spherical product is the final form in industrial application after the subsequent molding treatment of the dechlorination agent prepared in Example 6.

[0100] Figure 2 The scanning electron microscope image is the micro-morphology of the original product prepared in Example 6, and the micro-morphology presents uniform micron-sized particle agglomerates with a size concentrated in the range of 2-8 μm. The agglomerates are irregularly accumulated in a loose form, and the surface is distributed with dense and uniform rough textures, and local concave-convex morphologies derived from fine pores can be seen.

[0101] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the present specification, and as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

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, separate the solid and liquid, wash the solid, and dry it. The quaternary ammonium salt is one or both of hexadecyltrimethylammonium bromide and trioctylmethylammonium bromide; the organic amine is any one of triethylamine, diethylamine, and aniline. 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 calcium chloride and zinc chloride in water until homogeneous. Add calcium chloride and zinc chloride to water at a molar ratio of 1:

3. Adjust the pH to 10-12, react, let stand, separate solid and liquid, and dry the solid. When mixing the carrier with the mixture of calcium chloride and zinc chloride in step 3), the temperature of the carrier is 100-150℃. 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 mass ratio of quaternary ammonium salt to organic amine is 2-5:

1.

3. 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.

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

5. A dechlorinating agent prepared by the method described in claim 1.

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