Liquid-phase dechlorinating agent and preparation method thereof

Abstract

The invention provides a liquid-phase dechlorinating agent and a preparation method thereof. The preparation method comprises the following steps: carrying out a neutralization reaction on a sodium metaaluminate solution and carbon dioxide-containing gas to obtain a solid-phase system containing pseudo-boehmite and sodium carbonate; the method comprises the following steps: dehydrating a solid-phase system containing pseudo-boehmite and sodium carbonate to obtain an active component; the active component and the binder are adopted as raw materials for roasting treatment, and the liquid-phase dechlorinating agent is prepared. The liquid-phase dechlorinating agent prepared by the invention has the characteristics of high dechlorinating activity and large chlorine capacity, and is suitable for removing inorganic chlorine in oil products, especially hydrogen chloride in reformate.

Description

Technical Field

[0001] The invention relates to the field of preparation of dechlorinating agents, and in particular to a liquid phase dechlorinating agent and a preparation method thereof. Background Art

[0002] Catalytic reforming is one of the important production processes in oil refining and petrochemical industry. The main reaction is the process of converting cycloalkanes and alkanes into aromatics or isoalkanes under the action of bifunctional catalysts. At present, catalysts with chlorine as the acidic component are used in catalytic reforming reactions. In actual production operations, the chlorine content in the catalyst is gradually lost due to the influence of water and other factors in the reaction system. In order to ensure the activity of the catalyst and achieve the best water-chlorine balance, water and organic chlorides need to be continuously injected. The water and chlorine lost in this process are partially accumulated in the reforming oil. After the reforming oil is fractionated in the stabilization tower (or depentanizer), C3 and C4 components are obtained at the top of the tower, and reforming gasoline (or depentanized oil) is obtained at the bottom of the tower. The presence of a small amount of chlorine in the reforming oil will not only affect the quality of the top product, but also cause corrosion of the downstream stabilization system and extraction device. Therefore, it is very necessary to dechlorinate the reforming oil.

[0003] At present, solid dechlorinating agents are generally used in industrial devices to remove hydrogen chloride from reforming oil. The dechlorination mechanism is that the active components in the dechlorinating agent react with HCl to generate stable metal chlorides and are fixed, thereby achieving the purpose of removing HCl. The active components are usually selected from alkali metals or alkaline earth metal oxides that can react with HCl, and then the active components and binders are prepared by kneading to form a dechlorinating agent, or the active components are loaded on a carrier by an impregnation method. For example: Chinese patent CN105542836A discloses a high-precision liquid phase dechlorinating agent for liquid phase dechlorination of reforming oil, which is composed of the following components: 5-20% CuO, 5-10% CaO, 4-8% KOH, and the remainder is modified activated carbon. The preparation method is to immerse the modified activated carbon in a Cu-Ca composite solution, then filter, drain, and roast, and immerse the roasted product in a KOH aqueous solution and filter and dry to obtain a dechlorinating agent. The chlorine content of the obtained dechlorinating agent is above 16%, and the dechlorination accuracy is below 0.5 mg / kg.

[0004] CN110885699 A discloses a dechlorinating agent with large pore volume and pore diameter, and its preparation method and application. The dechlorinating agent is composed of sodium carbonate and aluminum oxide; wherein the weight percentage of sodium carbonate is 5-30wt%, and the weight percentage of aluminum oxide is 70-95wt%; the pore volume of the dechlorinating agent is 0.5-1.5cm 3 / g, and the average pore size is 5-30nm. The dechlorination agent has a stable pore structure, large pore volume and pore size, and can achieve high dechlorination efficiency and dechlorination accuracy when used for liquid phase dechlorination of reforming oil.

[0005] CN105749855A discloses a liquid-phase dechlorinating agent, which is composed of a composite crystal structure of an active component and an auxiliary component, wherein the active component is at least one of magnesium oxide, calcium oxide, magnesium carbonate and calcium carbonate, and the auxiliary component is aluminum oxide or iron oxide, and comprises the following steps: (a) preparing a reaction mixture material by preparing an active component precursor, an auxiliary component precursor and a precipitant; (b) placing the mixture obtained in step (a) in an autoclave, and crystallizing the mixture for 3 to 8 hours under closed stirring at 130 to 190° C.; (c) filtering, washing, drying and molding the reaction product obtained in step (b); and (d) roasting the molded material in step (c) to obtain a finished dechlorinating agent.

[0006] CN106268832A discloses a novel high-efficiency dechlorinating agent and a preparation method thereof. The dechlorinating agent uses one or more of Na2CO3, CaCO3, CaO, MgO, CuO, ZnO and their derivatives as active components, NH4HCO3 as a porosity aid, at least one of Al2O3, diaspore, kaolin or white clay as a carrier and an aid, and partially modified Zn salt and Ca salt as synergistic aids. After adding appropriate amount of water in corresponding proportions and mixing, the mixture is extruded into strips, and then dried and roasted to prepare the dechlorinating agent.

[0007] The above preparation method requires a large amount of ethanol aqueous solution to wash the reaction product when preparing the synergist. The washing liquid containing ethanol is difficult to recover and difficult to industrialize. At the same time, the active components Na2CO3, CaCO3, ZnO, MgO, etc. are mixed into the dechlorination agent carrier by mechanical force, and the active components are easily unevenly dispersed, which reduces the utilization rate of the active components.

[0008] Therefore, simplifying the dechlorination agent preparation process and improving the dispersibility and utilization rate of active components such as Na2CO3, thereby ensuring the dechlorination activity of the reforming oil liquid phase dechlorination agent, are problems that need to be solved in this field. Summary of the invention

[0009] The main purpose of the present invention is to provide a liquid phase dechlorinating agent and a preparation method thereof, so as to solve the problem of low dechlorination activity of the reformed oil liquid phase dechlorinating agent caused by the complex preparation process of the dechlorinating agent in the prior art, low dispersibility and utilization rate of the active components.

[0010] In order to solve the above problems, the present invention provides a method for preparing a liquid-phase dechlorinating agent, which comprises: neutralizing a sodium aluminate solution with a neutralizing gas containing carbon dioxide to obtain a solid phase system containing pseudo-boehmite and sodium carbonate; dehydrating the solid phase system containing pseudo-boehmite and sodium carbonate to obtain an active component; and roasting the active component and a binder as raw materials to obtain a liquid-phase dechlorinating agent.

[0011] Furthermore, during the neutralization reaction of the sodium aluminate solution and the neutralizing gas, the content of sodium aluminate in the sodium aluminate solution is 8-18wt%, the volume fraction of carbon dioxide in the neutralizing gas is 30-100%, the reaction temperature is ≤50°C, and the endpoint pH of the reaction is 9.2-11.0.

[0012] Furthermore, after the neutralization reaction, the preparation method of the liquid phase dechlorinating agent further comprises: subjecting the product of the neutralization reaction to an aging reaction to obtain a solid phase system containing pseudo-boehmite and sodium carbonate; preferably, the temperature of the aging reaction is 75 to 95°C.

[0013] Furthermore, before the neutralization reaction, the preparation method of the liquid-phase dechlorinating agent further comprises: subjecting the sodium aluminate solution to a coprecipitation reaction with a coprecipitant to obtain a coprecipitation product system, wherein the coprecipitant is selected from magnesium nitrate and / or zinc nitrate; subjecting the coprecipitation product system to a neutralization reaction with a neutralizing gas containing carbon dioxide; preferably, when the coprecipitant is zinc nitrate, the molar ratio of sodium aluminate to the coprecipitant in the sodium aluminate solution is 1:0.04 to 0.16; when the coprecipitant is magnesium nitrate, the molar ratio of sodium aluminate to the coprecipitant in the sodium aluminate solution is 1:0.05 to 0.27.

[0014] Furthermore, the preparation method of the liquid phase dechlorinating agent further comprises: adding activated carbon during the neutralization reaction; preferably, the amount of activated carbon used is 1-3% by weight of the active component.

[0015] Furthermore, the particle size of the activated carbon added in the neutralization reaction is 300 mesh, the iodine value is ≥800, and the methylene blue, mL / 0.1g is ≥11.

[0016] Furthermore, the dehydration treatment in the preparation method of the liquid phase dechlorinating agent includes: drying and dehydrating the solid phase system containing pseudo-boehmite and sodium carbonate, and then roasting and dehydrating; preferably, the drying and dehydration temperature is 105-120°C; preferably, the roasting and dehydration temperature is 350-550°C, and more preferably 400-500°C.

[0017] Furthermore, the temperature of the calcination treatment during the preparation process is 260-450°C, preferably 300-400°C.

[0018] Furthermore, the binder used for the calcination treatment is sodium bentonite and / or calcium bentonite. Preferably, the binder has a blue absorption amount ≥28%, a colloid value ≥300ml / 15g, a water absorption rate ≥150%, a 325-mesh particle content ≥80%, and a moisture content ≤11%; preferably, the raw material also includes water-soluble starch. Preferably, the amount of water-soluble starch accounts for 3 to 5wt% of the total weight of the raw material.

[0019] Another aspect of the present invention further provides a liquid phase dechlorinating agent, which is prepared by the preparation method provided in the present application.

[0020] By applying the technical solution of the present invention, the liquid phase dechlorination agent provided by the present application uses a sodium aluminate solution carbonation method to prepare pseudo-boehmite and sodium carbonate, and directly disperses sodium carbonate in situ in the pseudo-boehmite, which makes the active components of the dechlorination agent obtained by the present invention evenly distributed, has a higher pore volume, and has a higher dechlorination activity in the liquid phase dechlorination process. At the same time, Mg is introduced into the carbonation reaction. 2+ and / or Zn 2+ , the chlorine capacity of the prepared dechlorinating agent is improved, so that it has the function of removing trace hydrogen sulfide in oil products. In addition, activated carbon is added during the roasting process, so that the uniformity and firmness of the alkaline components loaded on the carrier are improved. On this basis, the liquid phase dechlorinating agent prepared by the present invention has the characteristics of high dechlorination activity and large chlorine capacity, and is suitable for removing inorganic chlorine in oil products, especially removing hydrogen chloride in reformed oil. DETAILED DESCRIPTION

[0021] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below in conjunction with the embodiments.

[0022] As described in the background technology, the existing dechlorinating agent preparation technology has the problems of complex process, low dispersibility and utilization rate of active components, resulting in low dechlorination activity of the reforming oil liquid phase dechlorinating agent. In order to solve the above technical problems, the present application provides a method for preparing a liquid phase dechlorinating agent, which comprises: neutralizing a sodium aluminate solution with a neutralizing gas containing carbon dioxide to obtain a solid phase system containing pseudo-boehmite and sodium carbonate; dehydrating the solid phase system containing pseudo-boehmite and sodium carbonate to obtain an active component; using the active component and a binder as raw materials for kneading, granulation, drying and roasting to obtain a liquid phase dechlorinating agent. The preparation method of the liquid phase dechlorinating agent provided in the present application simplifies the existing production process steps and is easy to realize industrial production.

[0023] The present invention utilizes a carbonation method to prepare pseudo-boehmite, that is, an industrial liquid sodium aluminate solution (preferably an Al2O3 content of 95±5%; the causticity coefficient of the sodium aluminate solution is 1.5-1.7) is used with a neutralizing gas containing carbon dioxide (preferably a CO2 content of 30-100%, by volume) for a neutralization reaction to prepare pseudo-boehmite and sodium carbonate. After the neutralization reaction is completed, the sodium carbonate is not separated, and the product system is sequentially dehydrated and roasted to generate γ-Al2O3, while the sodium carbonate is in-situ dispersed in the γ-Al2O3. The roasted product is mixed with a binder as an active component and then roasted to obtain the desired liquid phase dechlorination agent.

[0024] In order to further improve the efficiency and conversion rate of the neutralization reaction, preferably, carbon dioxide is introduced into the sodium aluminate solution to carry out a gelation reaction (or neutralization reaction), wherein the content of sodium aluminate in the sodium aluminate solution is 8-18wt%, the volume fraction of carbon dioxide in the neutralization gas is 30-80%, the reaction temperature is ≤50°C, and the endpoint pH of the reaction is 9.2-11.0.

[0025] In order to further improve the chlorine capacity of the dechlorinating agent and increase its desulfurization function, preferably, before the sodium aluminate solution is subjected to the neutralization reaction with carbon dioxide, the preparation method of the liquid phase dechlorinating agent further comprises: subjecting the sodium aluminate solution to a coprecipitation reaction with a coprecipitant (selected from magnesium nitrate and / or zinc nitrate) to obtain a coprecipitation product system, and then subjecting the coprecipitation product system to a subsequent neutralization reaction with a neutralizing gas containing carbon dioxide. 2+ or Zn 2+ After the coprecipitant is added, carbon dioxide gas is introduced to react. The prepared precursor has a stable hydrotalcite structure. After high-temperature calcination, a magnesium-aluminum or zinc-aluminum composite can be obtained. + Mg 2+ 、Zn 2+ As alkaline active components, they are evenly distributed. This type of composite not only has strong alkalinity, but also has a large specific surface area and pore volume. 2+ The ions have good desulfurization function, so that the dechlorination agent prepared subsequently can remove trace amounts of hydrogen sulfide in oil products. In a preferred embodiment, when the coprecipitant is zinc nitrate, the molar ratio of sodium aluminate to the coprecipitant in the sodium aluminate solution is 1:0.04-0.16; when the coprecipitant is magnesium nitrate, the molar ratio of sodium aluminate to the coprecipitant in the sodium aluminate solution is 1:0.05-0.27.

[0026] In order to further increase the above alkaline active component Na + Mg 2+ 、Zn 2+ The uniformity and firmness of the load on the carrier, in the step of preparing pseudo-boehmite by gelling reaction of carbon dioxide and sodium aluminate solution, activated carbon is added to the reaction liquid. In a preferred embodiment, the amount of activated carbon is 1-3% in terms of the weight percentage of the active component. The added activated carbon not only has a capacity expansion effect during the roasting process, but also can react with part of the sodium nitrate to form sodium carbonate, further improving the dechlorination activity of the subsequent dechlorination agent. Preferably, the particle size of the activated carbon added is 300 mesh, the iodine value is ≥800, and the methylene blue, mL / 0.1g ≥11 (see GB / T12496-2015 for the industry test standard activated carbon standard).

[0027] After the neutralization reaction is completed, the product obtained by the neutralization reaction is subjected to an aging reaction to obtain a solid phase system containing pseudo-boehmite and sodium carbonate. In a preferred embodiment, the temperature of the aging reaction is 75-95°C and the time is 1-2 hours. The aging reaction under the above conditions promotes the reaction of the reaction raw materials to fully react, thereby improving the conversion rate of the reaction raw materials. After the aging reaction is completed, the filter cake is obtained by filtering, and the sodium carbonate content in the filter cake is achieved by adjusting the concentration of each reactant solution.

[0028] After the neutralization reaction, the solid phase system containing pseudo-boehmite and sodium carbonate is filtered to obtain a solid phase system, which needs to be dehydrated. The dehydration treatment is preferably to dry and dehydrate the solid phase system containing pseudo-boehmite and sodium carbonate, and then to roast and dehydrate; preferably, the drying and dehydration time is 2 to 4 hours, and the temperature is 105 to 120°C to remove physically adsorbed water; preferably, the roasting and dehydration time is 1.5 to 2.5 hours, and the temperature is 350 to 550°C, more preferably 400 to 500°C, to remove the chemically bound water therein. Finally, an aluminum oxide-sodium carbonate mixture, an optional aluminum oxide-sodium carbonate-magnesium oxide mixture, and an optional aluminum oxide-sodium carbonate-zinc oxide mixture are generated.

[0029] The magnesium oxide content in the magnesium-aluminum composite oxide generated by calcination is 5 to 20% (weight); the zinc oxide content in the zinc-aluminum composite oxide is 5 to 20% (weight).

[0030] In a preferred embodiment, the mixture of the active component (metal composite oxide) obtained by dehydration treatment and the binder is calcined at 260-450°C to obtain a calcined product with more uniform dispersion of alkaline active sites, which is conducive to further improving the removal effect of the dechlorinating agent on the chlorine element. The calcination temperature is further preferably 300-400°C.

[0031] The binder used in the preparation of the dechlorinating agent in this application can be a commonly used type in the art. Sodium bentonite and / or calcium bentonite, which preferably accounts for 15 to 35% of the total material mass, are used as a binder, and the mixture is obtained by uniformly mixing it with the above-mentioned composite oxide powder. In a preferred embodiment, the selected binder has a blue absorption amount ≥28%, a colloid value ≥300ml / 15g, a water absorption rate ≥150%, a 325-mesh particle content ≥80%, and a moisture content ≤11%. The national standard for bentonite is specifically shown in GB / T20973-2020.

[0032] In order to meet the requirements of the dechlorinating agent for shape and application performance, the dechlorinating agent also includes kneading, extrusion molding and drying and subsequent roasting steps during the preparation process. Preferably, the drying temperature is 120°C. In order to further improve the extrusion performance of the dechlorinating agent, water-soluble starch is added in the kneading step of the above-mentioned bentonite binder and the composite oxide powder. In a preferred embodiment, the amount of water-soluble starch accounts for 3 to 5wt% of the total weight of the raw materials.

[0033] Another aspect of the present invention further provides a liquid phase dechlorinating agent, which is prepared by the preparation method provided by the present application. The production process steps of the liquid phase dechlorinating agent provided by the present invention are simple, and it is easy to realize industrial production; and the active components of the obtained dechlorinating agent are evenly distributed, have a high pore volume, and have a high dechlorination activity during the liquid phase dechlorination process, which solves the problem of low dechlorination activity of the reforming oil liquid phase dechlorinating agent caused by the complex preparation process of the dechlorinating agent, low dispersibility and utilization rate of the active components in the prior art.

[0034] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0035] The reforming oil used in the following examples and comparative examples is from PetroChina Urumqi Petrochemical Company.

[0036] The raw materials used in the following examples and comparative examples are all commercially available.

[0037] The specific surface area and pore size of the dechlorinating agents obtained in the following examples and comparative examples were tested according to the BET method.

[0038] The chlorine content of the reforming oil used in the following examples and comparative examples before and after dechlorination was determined in accordance with SH / T0977-2019.

[0039] The whole process is described in detail below by way of examples, but the scope of the claims of the present invention is not limited by these examples. Meanwhile, the examples only provide some conditions for achieving this purpose, but do not mean that these conditions must be met to achieve this purpose.

[0040] Example 1

[0041] Industrial liquid sodium aluminate solution (Al2O3 content 95±5%; causticity coefficient of sodium aluminate solution is 1.5-1.7) is diluted to a solution with Al2O3 content of 10% for standby use. Weigh 1000g of the above solution into a three-necked flask with stirring, cool the flask with a water bath to keep warm, stir and introduce 40vol% carbon dioxide at 40℃ for gelation reaction, the pH value of the reaction solution is 9.8-10.2, and the reaction is completed. Heat to 85-90℃ for aging for 3h, cool to 50℃ for suction filtration. Dry the filter cake at 120℃ for 2h, roast in a muffle furnace at 450℃ for 4h, and cool to obtain 128.0g of alumina powder with a Na2O content of 21.3wt%. 35.0g of the above alumina powder; 15.0g of sodium bentonite, add deionized water dropwise to knead and extrude. Dry at 120℃ for 2h; roast at 360℃ for 2h to obtain dechlorinating agent 1.

[0042] Example 2

[0043] The difference from Example 1 is as follows: before the gelling reaction in Example 1, 5.1 g of 300 mesh activated carbon was added to the reaction solution, and the filter cake was dried at 120°C for 2 h in a muffle furnace, heated to 450°C and roasted for 4 h and cooled to obtain alumina powder. 37.5 g of the above alumina powder and 12.5 g of sodium bentonite were added dropwise with deionized water to knead and extrude. The mixture was dried at 120°C for 2 h and roasted at 360°C for 2 h to obtain dechlorinating agent 2.

[0044] Example 3

[0045] The difference from Example 1 is that the industrial liquid sodium aluminate solution in Example 1 is diluted to a 5% Al2O3 solution for standby use. 1000g of the above solution is weighed and poured into a three-necked flask with stirring. The flask is cooled and kept warm with a water bath. At 40°C, it is stirred and 30vol% carbon dioxide is introduced for gelation reaction. The pH value of the reaction liquid is 9.8-10.2, and the reaction is completed. The temperature is raised to 85-90°C for aging for 3h, and the temperature is lowered to 50°C for suction filtration. The filter cake is dried at 120°C for 2h, roasted in a muffle furnace at 450°C for 4h, and cooled to obtain 65.0g of alumina powder with a Na2O content of 14.4wt%. 35.0g of the above alumina powder; 15.0g of sodium bentonite, deionized water is added dropwise to knead and extrude. Dry at 120°C for 2h; roast at 360°C for 2h to obtain dechlorinating agent 3.

[0046] Example 4

[0047] Example 1 Industrial liquid sodium aluminate solution is diluted to a 10% solution of Al2O3 content for standby use. Weigh 1000g of the above solution into a three-necked flask with stirring, add 300 mesh activated carbon 3.0g to the reaction solution, and at 40°C, stir and drop 115g of magnesium nitrate solution (magnesium nitrate concentration 13wt%), the amount of sodium aluminate and coprecipitant (magnesium nitrate) in the sodium aluminate solution The ratio of the amount of substance is 1:0.05. After the dropwise addition is completed, 40vol% carbon dioxide is introduced for gelation reaction, the pH value of the reaction solution is 9.8-10.2, and the reaction is completed. Heating to 85-90°C for aging for 3h, cooling to 50°C for suction filtration. The filter cake is dried at 120°C for 2h, roasted in a muffle furnace at 450°C for 4h, and cooled to obtain 116.0g of alumina powder with a Na2O content of 13.4wt%. 40.0 g of the above-mentioned alumina powder, 10.0 g of sodium bentonite, and 1.5 g of water-soluble starch were added dropwise with deionized water to knead and extrude into strips, dried at 120° C. for 2 h, and calcined at 360° C. for 2 h to obtain a dechlorinating agent 4.

[0048] Example 5

[0049] Example 1 Industrial liquid sodium aluminate solution is diluted to a 10% solution containing Al2O3 for standby use. Weigh 1000g of the above solution and pour it into a three-necked flask with stirring. Add 5.0g of 300-mesh activated carbon to the reaction solution. At 40°C, stir and drip 200g of zinc nitrate solution (zinc nitrate concentration 10wt%). The ratio of the amount of sodium aluminate to the coprecipitant (zinc nitrate) in the sodium aluminate solution is 1:0.07. After the addition is completed, 40vol% carbon dioxide is introduced for gelation reaction. The pH value of the reaction solution is 9.8-10.2, and the reaction is completed. Heat to 85-90°C for aging for 3h, cool to 50°C for suction filtration. Dry the filter cake at 120°C for 2h, roast it in a muffle furnace at 450°C for 4h, and cool it to obtain 122.0g of aluminum oxide zinc oxide powder with a Na2O content of 11.2wt%. 40.0 g of the above-mentioned alumina powder, 10.0 g of sodium bentonite, and 1.5 g of water-soluble starch were added dropwise with deionized water to knead and extrude into strips, dried at 120° C. for 2 h, and calcined at 360° C. for 2 h to obtain a dechlorinating agent 5.

[0050] Comparative Example 1

[0051] The dechlorinating agent was prepared according to the method provided in CN106268832A, and specifically, the dechlorinating agent, namely Comparative Example 1, was prepared according to the method of Example 5 therein.

[0052] Evaluation method of dechlorination activity of liquid phase dechlorination agent: 20-40 mesh liquid phase dechlorination agent is loaded into an adsorption column with inner diameter of Φ8mm, the height-to-diameter ratio is selected as 8:1, the temperature is 75℃, the pressure is selected as 0.8MPa, and the chlorine content is about 5mg / kg and the reforming product oil is heated at a liquid space velocity of 4h -1(volume) into the adsorption column (up in and out from the bottom), measure the chlorine content in the outflowing reforming oil, when the chlorine content is greater than 0.5mg / kg, it can be regarded as breakthrough, and record the reaction time. The longer the dechlorination agent is used, the better the dechlorination activity.

[0053] Evaluation method of chlorine content of liquid phase dechlorination agent: 20-40 mesh liquid phase dechlorination agent is loaded into an adsorption column with an inner diameter of Φ8mm, the height-to-diameter ratio is selected as 8:1, the temperature is room temperature, the pressure is normal pressure, the HCl content is 0.1%, and the flow rate of N2 is controlled by a flow meter, and the air velocity is 1000h -1 Entering the adsorption column, the raw gas passes through the bed from top to bottom, contacts and reacts with the filler, and the experiment is judged to be over when the outlet HCl concentration reaches 0.5 mg / kg. After the experiment, the dechlorinating agent in the reactor is taken out and the chlorine capacity is analyzed. The breakthrough chlorine capacity (Cl%) of the dechlorinating agent refers to the chlorine content contained in the unit mass of the dechlorinating agent when 0.5 mg / kg HCl is detected in the tail gas of the evaluation system. The calculation formula for breakthrough chlorine capacity is as follows:

[0054] Cl%=m 氯 / m 脱氯剂 ×100%.

[0055] Table 1 Performance of dechlorinating agent obtained in Example

[0056] Dechlorination agent <![CDATA[Pore volume, cm 3 / g]]> Pore ​​diameter, nm Breakthrough time, h Chlorine content, Cl% Example 1 0.22 8 32 20.1 Example 2 0.26 12 30 20.5 Example 3 0.35 14 36 18.9 Example 4 0.40 11 40 24.1 Example 5 0.32 9 29 16.3 Comparative Example 1 0.22 10 28 18.1

[0057] The dechlorination activity evaluation method of the liquid phase dechlorination agent of the present invention is as follows: 20 to 40 mesh of the dechlorination agent of Example 5 is loaded into an adsorption column with an inner diameter of Φ8 mm, the aspect ratio is selected to be 8:1, the temperature is 75°C, the pressure is selected to be 0.8 MPa, the hydrogen sulfide content is about 2 mg / kg, and the reforming pre-hydrogenation raw material is heated at a space velocity of 4 h -1 (volume) into the adsorption column (up in and out from the bottom), and the sulfur content in the outflowing oil was measured. Under the above conditions, the dechlorinating agent of Example 5 was operated for 100 hours, and the sulfur content in the outflowing oil was not detected.

[0058] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects: pseudo-boehmite and sodium carbonate are prepared by carbonation method of sodium aluminate solution, and sodium carbonate is directly dispersed in situ in pseudo-boehmite, which makes the active components of the dechlorination agent obtained by the present invention evenly distributed, has a higher pore volume, and has a higher dechlorination activity in the liquid phase dechlorination process. At the same time, Mg is introduced into the carbonation reaction. 2+ and / or Zn 2+, the chlorine capacity of the prepared dechlorinating agent is improved, so that it has the function of removing trace hydrogen sulfide in oil products. In addition, activated carbon is added during the roasting process, so that the uniformity and firmness of the alkaline components loaded on the carrier are improved. On this basis, the liquid phase dechlorinating agent prepared by the present invention has the characteristics of high dechlorination activity and large chlorine capacity, and is suitable for removing inorganic chlorine in oil products, especially removing hydrogen chloride in reformed oil.

[0059] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those described herein, for example.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a liquid phase dechlorinating agent, characterized in that: The preparation method of the liquid phase dechlorinating agent comprises: The sodium aluminate solution is subjected to a neutralization reaction with a neutralizing gas containing carbon dioxide to obtain a solid phase system containing pseudo-boehmite and sodium carbonate; Dehydrating the solid phase system containing pseudo-boehmite and sodium carbonate to obtain an active component; The active component and the binder are used as raw materials for kneading, granulation, drying and calcination to obtain the liquid phase dechlorination agent.

2. The method for preparing a liquid phase dechlorinating agent according to claim 1, characterized in that: During the neutralization reaction, the content of sodium aluminate in the sodium aluminate solution is 8-18wt%, the volume fraction of carbon dioxide in the neutralization gas is 30-100%, the reaction temperature is ≤50°C, and the end point pH of the reaction is 9.2-11.

0.

3. The method for preparing a liquid phase dechlorinating agent according to claim 1 or 2, characterized in that: After the neutralization reaction, the preparation method of the liquid phase dechlorinating agent further comprises: subjecting the product of the neutralization reaction to an aging reaction to obtain the solid phase system containing pseudo-boehmite and sodium carbonate; Preferably, the temperature of the aging reaction is 75-95°C.

4. The method for preparing a liquid phase dechlorinating agent according to any one of claims 1 to 3, characterized in that: Before carrying out the neutralization reaction, the preparation method of the liquid phase dechlorinating agent further comprises: The sodium aluminate solution is subjected to a coprecipitation reaction with a coprecipitant to obtain a coprecipitation product system, wherein the coprecipitant is selected from magnesium nitrate and / or zinc nitrate; Carrying out the neutralization reaction between the coprecipitation product system and the neutralization gas containing carbon dioxide; Preferably, when the coprecipitant is zinc nitrate, the molar ratio of sodium aluminate to the coprecipitant in the sodium aluminate solution is 1:0.04-0.16; When the coprecipitant is magnesium nitrate, the molar ratio of sodium aluminate to the coprecipitant in the sodium aluminate solution is 1:0.05-0.

27.

5. The method for preparing a liquid phase dechlorinating agent according to any one of claims 1 to 4, characterized in that: The preparation method of the liquid phase dechlorinating agent further comprises: adding activated carbon during the neutralization reaction; Preferably, the amount of the activated carbon is 1-3% by weight of the active component.

6. The method for preparing a liquid phase dechlorinating agent according to claim 5, characterized in that: The activated carbon has a particle size of 300 mesh, an iodine value of ≥800, and methylene blue, mL / 0.1 g ≥11.

7. The method for preparing a liquid phase dechlorinating agent according to claim 1, characterized in that: The dehydration treatment comprises: drying and dehydrating the solid phase system containing pseudo-boehmite and sodium carbonate, and then calcining and dehydrating the solid phase system; Preferably, the drying and dehydration temperature is 105-120°C; Preferably, the temperature of the calcination and dehydration is 350-550°C, more preferably 400-500°C.

8. The method for preparing a liquid phase dechlorinating agent according to claim 1 or 7, characterized in that: The calcination temperature is 260-450°C, preferably 300-400°C.

9. The method for preparing a liquid phase dechlorinating agent according to claim 8, characterized in that: The binder is sodium bentonite and / or calcium bentonite. Preferably, the binder has a blue absorption of ≥28%, a colloid value of ≥300ml / 15g, a water absorption rate of ≥150%, a 325-mesh particle content of ≥80%, and a moisture content of ≤11%; Preferably, the raw material further comprises water-soluble starch. Preferably, the amount of the water-soluble starch accounts for 3-5wt% of the total weight of the raw material.

10. A liquid phase dechlorinating agent, characterized in that: The liquid phase dechlorinating agent is prepared by the preparation method described in any one of claims 1 to 9.