Dechlorination agent composition, dechlorination agent, preparation method, application and recovery method thereof

Abstract

The present application relates to the technical field of dechlorination purification of reforming generated oil, and discloses a dechlorination agent composition, a dechlorination agent, a preparation method, application and recovery method thereof.The composition comprises a molecular sieve carrier, an active component precursor, a binder and an additive; wherein the pore size of the molecular sieve carrier is 0.3-0.5 nm; the active component precursor is a soluble salt of alkali metal and / or alkaline earth metal; the binder is selected from the group consisting of alumina, silica, titania, zirconia, magnesia, calcium oxide, magnesium oxide, calcium carbonate, calcium sulfate, calcium nitrate, calcium chloride, calcium bromide, calcium iodide, calcium fluoride, calcium phosphate, calcium aluminate, calcium silicate, calcium titanate, calcium zirconate, calcium ferrite, calcium molybdate, calcium tungstate, calcium vanadate, calcium borate, calcium carbonate, calcium sulfate, calcium nitrate, calcium chloride, calcium bromide, calcium iodide, calcium fluoride, calcium phosphate, calcium aluminate, calcium silicate, calcium titanate, calcium zirconate, calcium ferrite, calcium molybdate, calcium tungstate, calcium vanadate, calcium borate, calcium carbonate, calcium sulfate, calcium nitrate, calcium chloride, calcium bromide, calcium iodide, calcium fluoride, calcium phosphate, calcium aluminate, calcium silicate, calcium titanate, calcium zirconate, calcium ferrite, calcium molybdate, calcium tungstate, calcium vanadate, calcium borate, calcium carbonate, calcium sulfate, calcium nitrate, calcium chloride, calcium bromide, calcium iodide, calcium fluoride, calcium phosphate, calcium aluminate, calcium silicate, calcium titanate, calcium zirconate, calcium ferrite, calcium molybdate, calcium tungstate, calcium vanadate, calcium borate, calcium carbonate, calcium sulfate, calcium

Description

Technical Field

[0001] This invention relates to the field of dechlorination and purification technology for reformed oil, specifically to a dechlorination agent composition, a dechlorination agent, its preparation method, application, and recovery method. Background Technology

[0002] Chlorine in catalytic reforming comes from two sources: first, chlorides (mostly organic chlorides) are added during crude oil extraction to improve oil recovery; second, water and organic chlorides are added during the reforming reaction to maintain high catalyst activity. In actual reforming operations, chlorides in the feedstock can cause severe corrosion to aromatics units and lead to environmental pollution, posing a significant hazard. To mitigate equipment and pipeline corrosion and reduce the impact on downstream products, solid dechlorination technology is commonly used in reforming units, employing different dechlorinating agents depending on the feedstock and operating conditions of each section.

[0003] CN101269294A discloses a room-temperature zinc-calcium dechlorination agent and its preparation method. The dechlorination agent comprises an active component and a carrier. The active component is a mixture of active ZnO, Ca(OH)2, or light CaCO3, and the carrier is clay and aluminate cement. This invention solves the problems that dechlorination agents cannot achieve high chlorine capacity and high dechlorination efficiency at room temperature.

[0004] CN104437342A discloses a high-chlorine-capacity liquid-phase dechlorinating agent, its preparation method, and its application. This dechlorinating agent exhibits advantages such as high chlorine capacity, water resistance, and long service life in the liquid-phase dechlorination of reforming products at low temperatures and low chlorine levels. The liquid-phase dechlorinating agent uses carbon molecular sieves as a carrier and alkali metal or alkaline earth metal oxides as the active components.

[0005] CN103127903A discloses a room-temperature dechlorination agent, solving the problem of excessive energy consumption during the preparation of existing dechlorination agents due to calcination. Furthermore, it provides a room-temperature dechlorination agent that is simple to prepare, low-cost, and has high chlorine capacity. It is prepared using ferrous sulfate, calcium oxide, and attapulgite clay.

[0006] However, existing dechlorination agents have poor stability during long-term operation and have strict requirements for reaction temperature, pressure and operating space velocity, resulting in a narrow range of applications.

[0007] Furthermore, existing dechlorinating agents cannot be recycled and reused. When the dechlorinating agent reaches the end of its service life, it is necessary to reduce the production load, carry out process treatment, shut down the unit, and replace the agent. The entire process takes a long time, affecting normal production and causing production fluctuations. In addition, purchasing new agents also increases the cost of production operations.

[0008] Therefore, there is an urgent need to develop a dechlorination agent that is stable in long-term operation, has a wide range of applications, and has good recovery effect. Summary of the Invention

[0009] The purpose of this invention is to overcome the problems of poor long-term operational stability, narrow applicability, and poor recovery effect of existing dechlorinating agents, and to provide a dechlorinating agent composition, dechlorinating agent, its preparation method, application, and recovery method.

[0010] To achieve the above objectives, the first aspect of the present invention provides a dechlorination agent composition, wherein the composition comprises the following components in weight percentage: 30-80% molecular sieve carrier, 2-20% active component precursor, 15-45% binder, and 2-15% additives;

[0011] Wherein, the pore size of the molecular sieve support is

[0012] The precursor of the active component is a soluble salt of an alkali metal and / or an alkaline earth metal.

[0013] A second aspect of the present invention provides a dechlorinating agent prepared from the dechlorinating agent composition described in the first aspect.

[0014] The third aspect of the present invention provides a method for preparing a dechlorinating agent, wherein 30-80% by weight of a molecular sieve carrier, 2-20% by weight of an active component precursor, 15-45% by weight of a binder and 2-15% by weight of an additive are mixed, shaped, dried and calcined to obtain a dechlorinating agent.

[0015] Wherein, the pore size of the molecular sieve support is

[0016] The precursor of the active component is a soluble salt of an alkali metal and / or an alkaline earth metal.

[0017] The fourth aspect of the present invention provides a dechlorinating agent prepared by the preparation method described in the third aspect.

[0018] The fifth aspect of the present invention provides the application of the dechlorinating agent described in the second or fourth aspect in the dechlorination process of catalytic reforming.

[0019] The sixth aspect of the present invention provides a method for recovering the dechlorinating agent described in the second or fourth aspect, wherein the method includes: heating, holding and cooling the used dechlorinating agent under continuous purging conditions to obtain the recovered dechlorinating agent.

[0020] The beneficial technical effects achieved by the present invention through the above technical solution are as follows:

[0021] This invention provides a dechlorinating agent that is simple to prepare, requires readily available materials, is low in cost, operates stably over long periods, has a good dechlorination effect, is widely applicable, and has a simple recycling process with low energy consumption and good recovery effect. It can remove chlorides from oil at room temperature, thereby reducing equipment corrosion and has broad application prospects. Detailed Implementation

[0022] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0023] The first aspect of the present invention provides a dechlorination agent composition, wherein the composition comprises the following components in weight percentage: 30-80% molecular sieve carrier, 2-20% active component precursor, 15-45% binder and 2-15% additives;

[0024] Wherein, the pore size of the molecular sieve support is

[0025] The precursor of the active component is a soluble salt of an alkali metal and / or an alkaline earth metal.

[0026] In this invention, the dechlorination agent composition has a pore size of Using molecular sieves as carriers and soluble salts of alkali metals and / or alkaline earth metals as active component precursors, combined with binders and additives in specific amounts, the resulting dechlorinating agent can have high chlorine capacity and adsorption capacity, and can operate stably over a long period of time.

[0027] In this invention, the pore size of the molecular sieve carrier is suitable for the entry of chlorine molecules to be removed. If the pore size is too large, the chlorine will not be able to be fixed on the molecular sieve to achieve the removal effect, and if the pore size is too small, it will not be able to enter the molecular sieve channel.

[0028] Molecular sieves primarily utilize physical adsorption, while alkali metals and / or alkaline earth metals primarily utilize chemical adsorption. There is also a synergistic effect between the two. The molecular sieve selected in this invention possesses the characteristic of adsorbing polar compounds, allowing chlorine molecules to remain on its surface and subsequently react with metal salts, thereby achieving the purpose of removal.

[0029] The main sources of chlorine in reformed oil are twofold: firstly, chlorides injected during crude oil extraction, and secondly, chlorides injected to maintain the activity of the reforming catalyst. The reforming process is a water-chlorine equilibrium operation; the reformed oil contains a small amount of water, and the inorganic chlorine in the reformed oil is dissolved in this small amount of water.

[0030] The molecular sieve carrier described in this invention has the ability to adsorb and remove water. During the adsorption and removal process, water molecules and HCl molecules can enter the pores, thereby achieving the adsorption and removal of inorganic chlorine. The molecular sieve can adsorb and remove inorganic chlorine and water, and can be regenerated under certain conditions, thus achieving the purpose of regenerating the dechlorinating agent. In other words, the dechlorinating agent described in this invention has a good regeneration effect.

[0031] The weight percentage of the molecular sieve carrier can be selected as 30%, 40%, 50%, 60%, 70%, 80%, or any value within the range of any two of the above values.

[0032] The weight percentage of the active component precursor can be selected as 2%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, or any value within the range of any two of the above values.

[0033] The weight percentage of the adhesive can be selected as 15%, 20%, 25%, 30%, 35%, 40%, 45%, or any value within the range of any two of the above values.

[0034] The weight percentage of the adjuvant can be selected as 2%, 5%, 8%, 10%, 12%, 15%, or any value within the range of any two of the above values.

[0035] In this invention, the adjuvants can be selected by those skilled in the art according to actual needs. This invention does not impose specific limitations on them.

[0036] According to some embodiments of the present invention, the dechlorination agent composition comprises the following components in weight percentage: 50-70% molecular sieve carrier, 3-10% active component precursor, 20-40% binder, and 3-10% additives.

[0037] According to some embodiments of the present invention, the molecular sieve support is selected from at least one of 4A molecular sieve, 5A molecular sieve, ZSM-5 molecular sieve and NaY molecular sieve.

[0038] According to some preferred embodiments of the present invention, the pore size of the molecular sieve support is

[0039] According to some preferred embodiments of the present invention, the average particle size of the molecular sieve carrier particles is not less than 200 mesh.

[0040] In this invention, the pore size of the molecular sieve carrier is controlled within a specific range to adsorb and remove chlorine impurities; the average particle size of the molecular sieve carrier particles is controlled within a specific range to ensure that the bed pressure drop meets requirements, the dechlorinating agent particles are not easily crushed or caking, and have a better specific surface area to fully contact the oil and remove impurities. The silicon-aluminum molar ratio of the molecular sieve is approximately 2.

[0041] According to some preferred embodiments of the present invention, the specific surface area of ​​the molecular sieve support is not less than 200 m². 2 / g. In this invention, controlling the specific surface area of ​​the molecular sieve carrier within a specific range allows for greater contact between the dechlorinating agent and the oil, increasing the adsorption reaction rate and better removing impurities.

[0042] According to some preferred embodiments of the present invention, the active component precursor is selected from at least one of the following substances: a soluble nitrate or soluble carbonate of at least one of sodium, potassium, magnesium, calcium and barium, preferably sodium nitrate and / or potassium nitrate.

[0043] According to some preferred embodiments of the present invention, the binder is a silica sol and / or an alumina sol, preferably an alumina sol prepared from boehmite.

[0044] The binder can be prepared by adding boehmite to deionized water, mechanically stirring, and then gradually adding concentrated nitric acid to obtain a viscous aluminum sol, which is used as the binder.

[0045] According to some preferred embodiments of the present invention, the additive is selected from at least one of pore expanders, pore-forming agents, extrusion aids, and stabilizers. The extrusion aid may be guar gum powder.

[0046] According to a particularly preferred embodiment of the present invention, a dechlorination agent composition is provided, wherein the dechlorination agent composition comprises the following components in weight percentage: 50-70% molecular sieve carrier, 3-10% active component precursor, 20-40% binder, and 3-10% additives;

[0047] The pore size of the molecular sieve support is The average particle size of the molecular sieve carrier particles is not less than 200 mesh; the specific surface area of ​​the molecular sieve carrier is not less than 200 m². 2 / g;

[0048] The active component precursor is sodium nitrate and / or potassium nitrate;

[0049] The binder is an aluminum sol prepared from boehmite;

[0050] The additive is selected from at least one of pore expanders, pore-forming agents, extrusion aids, and stabilizers.

[0051] A second aspect of the present invention provides a dechlorinating agent prepared from the dechlorinating agent composition described in the first aspect.

[0052] The third aspect of the present invention provides a method for preparing a dechlorinating agent, wherein 30-80% by weight of a molecular sieve carrier, 2-20% by weight of an active component precursor, 15-45% by weight of a binder and 2-15% by weight of an additive are mixed, shaped, dried and calcined to obtain a dechlorinating agent.

[0053] Wherein, the pore size of the molecular sieve support is

[0054] The precursor of the active component is a soluble salt of an alkali metal and / or an alkaline earth metal.

[0055] The dechlorination agent preparation method of the present invention has the advantages of simple and readily available raw materials, low cost, and simple preparation process, and can obtain a dechlorination agent with high chlorine capacity and adsorption capacity, stable long-term operation and wide applicability.

[0056] According to some embodiments of the present invention, the drying temperature is 60-130℃, for example 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, and any value within the range of any two of the above values, preferably 80-120℃; the drying time is 0.5-3h, for example 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, and any value within the range of any two of the above values, preferably 1-2h. In the present invention, if the drying temperature is too low or the drying time is too short, the moisture contained therein will not evaporate completely, affecting the product performance, and the unevaporated moisture will be released into the oil during the reaction, becoming a new impurity. Since the drying chamber is not a vacuum or filled with inert gas, excessively high temperatures can lead to some oxidation reactions, and excessively long drying times will also increase costs.

[0057] According to some preferred embodiments of the present invention, the calcination temperature is 400-650℃, for example 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, and any value within the range of any two of the above values, preferably 500-600℃; the calcination time is 1-5h, for example 1h, 2h, 3h, 4h, 5h, and any value within the range of any two of the above values, preferably 2-4h. In the present invention, if the calcination temperature is too low or the calcination time is too short, the metal salt will decompose incompletely. If the calcination temperature is too high, the skeletal structure or molecular formula of the component will be damaged, and some side reactions will occur. If the calcination time is too long, the cost will increase.

[0058] According to some embodiments of the present invention, the molecular sieve support has a weight percentage of 50-70%, the active component precursor has a weight percentage of 3-10%, the binder has a weight percentage of 20-40%, and the additives have a weight percentage of 3-10%.

[0059] According to some preferred embodiments of the present invention, the molecular sieve support is selected from at least one of 4A molecular sieve, 5A molecular sieve, ZSM-5 molecular sieve and NaY molecular sieve.

[0060] According to some preferred embodiments of the present invention, the pore size of the molecular sieve support is

[0061] According to some preferred embodiments of the present invention, the average particle size of the molecular sieve carrier particles is not less than 200 mesh.

[0062] According to some preferred embodiments of the present invention, the specific surface area of ​​the molecular sieve support is not less than 200 m². 2 / g.

[0063] According to some preferred embodiments of the present invention, the active component precursor is selected from at least one of the following substances: a soluble nitrate or soluble carbonate of at least one of sodium, potassium, magnesium, calcium and barium, preferably sodium nitrate and / or potassium nitrate.

[0064] According to some preferred embodiments of the present invention, the binder is a silica sol and / or an alumina sol, preferably an alumina sol prepared from boehmite.

[0065] According to some preferred embodiments of the present invention, the additive is selected from at least one of pore expanders, pore-forming agents, extrusion aids, and stabilizers.

[0066] According to a particularly preferred embodiment of the present invention, a method for preparing a dechlorinating agent is provided, wherein 50-70% by weight of a molecular sieve carrier, 3-10% by weight of an active component precursor, 20-40% by weight of a binder, and 3-10% by weight of an additive are mixed, and after molding, dried at 80-120°C for 1-2 hours and calcined at 500-600°C for 2-4 hours to obtain the dechlorinating agent;

[0067] The pore size of the molecular sieve support is The average particle size of the molecular sieve carrier particles is not less than 200 mesh; the specific surface area of ​​the molecular sieve carrier is not less than 200 m². 2 / g;

[0068] The active component precursor is sodium nitrate and / or potassium nitrate;

[0069] The binder is an aluminum sol prepared from boehmite;

[0070] The additive is selected from at least one of pore expanders, pore-forming agents, extrusion aids, and stabilizers.

[0071] The fourth aspect of the present invention provides a dechlorinating agent prepared by the preparation method described in the third aspect.

[0072] The fifth aspect of the present invention provides the application of the dechlorinating agent described in the second or fourth aspect in the dechlorination process of catalytic reforming.

[0073] According to some embodiments of the present invention, the dechlorination operating conditions include: a dechlorination temperature of 15-45°C, preferably 30-40°C; a dechlorination pressure of 1-5 MPa, preferably 2-3 MPa; and a mass hourly space velocity of 2-10 h⁻¹. -1 Preferably 3-6h -1 .

[0074] According to some embodiments of the present invention, the height-to-diameter ratio of the reactor is 1-6:1, preferably 2-3:1.

[0075] The dechlorination temperature can be selected from 15℃, 20℃, 25℃, 30℃, 35℃, or any value within the range of any two of the above values.

[0076] The dechlorination pressure can be selected from 1MPa, 2MPa, 3MPa, 4MPa, 5MPa, or any value within the range of any two of the above values.

[0077] The mass air velocity can be selected as 2h. -1 3h -1 4h -1 5h -1 6h -1 7h -1 8h -1 9h -1 10h -1 , and any value within the range formed by any two of the above values.

[0078] The height-to-diameter ratio of the reactor can be selected as 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, or any value within the range of any two of the above values.

[0079] The sixth aspect of the present invention provides a method for recovering the dechlorinating agent described in the second or fourth aspect, wherein the method includes: heating, holding and cooling the used dechlorinating agent under continuous purging conditions to obtain the recovered dechlorinating agent.

[0080] The dechlorinating agent described in this invention can be recycled and reused using the above-mentioned recycling method, with good recycling effect.

[0081] According to some embodiments of the present invention, the method further includes: purging the used dechlorinating agent for 1-3 hours before heating. In the present invention, purging the used dechlorinating agent for a certain period of time before heating can remove residual oil from the dechlorinating agent and the dechlorination tank.

[0082] According to some preferred embodiments of the present invention, the used dechlorinating agent is heated to 200-300°C and held at that temperature for 2-4 hours before being cooled. Using these conditions, the used dechlorinating agent can achieve a better recovery effect.

[0083] According to some preferred embodiments of the present invention, the purging gas is selected from at least one of nitrogen, argon, helium and hydrogen.

[0084] According to a particularly preferred embodiment of the present invention, a method for recovering a dechlorinating agent is provided, wherein the method comprises: under continuous nitrogen purging conditions, first purging the used dechlorinating agent for 1-3 hours, then heating it to 200-300°C and holding it at that temperature for 2-4 hours, and then cooling it down to obtain the recovered dechlorinating agent.

[0085] This invention, while ensuring dechlorination effect and long-term stable operation, allows for simple recycling and reuse, thus reducing fluctuations and economic losses caused by unit shutdowns for reagent replacement, and also reducing issues such as load reduction during process treatment before and after reagent replacement.

[0086] The present invention will be described in detail below through embodiments.

[0087] Unless otherwise specified in the following examples and comparative examples, all conditions were performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available products.

[0088] Test method:

[0089] Chlorine content of oil: Tested according to Q / SY LYF0467-2009.

[0090] Saturated chlorine capacity of dechlorinating agent: According to Q-SY LYF 0985.1.2-2018, the chlorine content adsorbed by the dechlorinating agent is tested. When the chlorine content no longer increases, the saturated chlorine capacity is calculated using the following formula:

[0091] Saturated chlorine capacity (%) = a / x

[0092] Where x is the mass of fresh dechlorinating agent (mg); a is the mass of chlorine adsorbed by the dechlorinating agent when the chlorine content no longer increases (mg).

[0093] Preparation Example 1

[0094] This preparation example illustrates the preparation of a dechlorination agent.

[0095] Prepare the dechlorination agent composition according to the formula in Table 1.

[0096] 78g of boehmite was added to 90mL of deionized water and mechanically stirred for 30min. Then, 5mL of concentrated nitric acid was added dropwise to obtain a viscous aluminum sol, which was used as a binder.

[0097] The molecular sieve carrier active component precursor, binder and additives are mixed, molded and dried at 80°C for 2 hours, and then calcined at 500°C for 2 hours to obtain dechlorination agent A.

[0098] Preparation Example 2

[0099] This preparation example illustrates the preparation of a dechlorination agent.

[0100] Prepare the dechlorination agent composition according to the formula in Table 1.

[0101] 78g of boehmite was added to 90mL of deionized water and mechanically stirred for 30min. Then, 5mL of concentrated nitric acid was added dropwise to obtain a viscous aluminum sol, which was used as a binder.

[0102] The molecular sieve carrier active component precursor, binder and additives are mixed, molded and dried at 120℃ for 1 hour, and then calcined at 600℃ for 4 hours to obtain dechlorination agent B.

[0103] Preparation Example 3

[0104] This preparation example illustrates the preparation of a dechlorination agent.

[0105] Prepare the dechlorination agent composition according to the formula in Table 1.

[0106] 78g of boehmite was added to 90mL of deionized water and mechanically stirred for 30min. Then, 5mL of concentrated nitric acid was added dropwise to obtain a viscous aluminum sol, which was used as a binder.

[0107] The molecular sieve carrier active component precursor, binder and additives are mixed, molded and dried at 100℃ for 1.5h, and then calcined at 520℃ for 3h to obtain dechlorination agent C.

[0108] Preparation Example 4

[0109] This preparation example illustrates the preparation of a dechlorination agent.

[0110] Prepare the dechlorination agent composition according to the formula in Table 1.

[0111] 78g of boehmite was added to 90mL of deionized water and mechanically stirred for 30min. Then, 5mL of concentrated nitric acid was added dropwise to obtain a viscous aluminum sol, which was used as a binder.

[0112] The molecular sieve carrier active component precursor, binder and additives are mixed, molded and dried at 60°C for 3 hours, and then calcined at 400°C for 5 hours to obtain dechlorination agent D.

[0113] Preparation Example 5

[0114] This preparation example illustrates the preparation of a dechlorination agent.

[0115] Prepare the dechlorination agent composition according to the formula in Table 1.

[0116] 78g of boehmite was added to 90mL of deionized water and mechanically stirred for 30min. Then, 5mL of concentrated nitric acid was added dropwise to obtain a viscous aluminum sol, which was used as a binder.

[0117] The molecular sieve carrier active component precursor, binder and additives are mixed, molded and dried at 130℃ for 0.5h, and then calcined at 650℃ for 1h to obtain dechlorination agent E.

[0118] Comparative Preparation Example 1

[0119] The dechlorinating agent was prepared according to the method of Preparation Example 3, except that only NaY type molecular sieve was used and sodium nitrate was not added, resulting in dechlorinating agent F.

[0120] Comparative Preparation Example 2

[0121] The dechlorinating agent was prepared according to the method of Preparation Example 4, except that copper nitrate was used instead of potassium nitrate to obtain dechlorinating agent G.

[0122] Table 1

[0123]

[0124] Test Example 1

[0125] The dechlorinating agents AG from Preparation Examples 1-5 and Comparative Preparation Examples 1-2 were placed in reformed oil prepared with HCl for static adsorption. The chlorine content adsorbed by the dechlorinating agent was tested daily. When the chlorine content no longer increased, the dechlorinating agent was considered to have reached saturation. After the dechlorinating agent was removed, the surface oil was air-dried, and the saturated chlorine capacity of the dechlorinating agent was calculated. The results are shown in Table 2.

[0126] Table 2

[0127] Saturated chlorine capacity, % 32.2 32.0 31.8 22.2 20.5 15.3 18.5

[0128] Examples 1-5

[0129] Following the operating parameters in Table 3-4, the dechlorinating agent AE from Preparation Examples 1-5 was applied to the catalytic reforming process for dechlorination. The dechlorination results are shown in Table 3-4.

[0130] Comparative Examples 1-2

[0131] Following the operating parameters in Table 3-4, dechlorinating agents F and G from Comparative Preparation Examples 1-2 were applied to the catalytic reforming process for dechlorination. The dechlorination results are shown in Table 3-4.

[0132] Table 3

[0133] Filling amount, g 25.0 25.0 25.0 25.0 25.0 25.0 25.0 Dechlorination temperature, °C 20 30 25 15 35 25 25 Dechlorination pressure, MPa 2 3 2.3 1 5 2.3 2.3 <![CDATA[mass hourly space velocity, h -1 > 3 5 6 2 10 6 6 Chlorine content of raw materials, mg / l 1.37 1.37 1.37 1.37 1.37 1.37 1.37 Chlorine content of the product, mg / L 0.34 0.45 0.49 0.66 0.67 0.89 0.73 Average chlorine removal rate, mg / L 1.03 0.92 0.88 0.71 0.7 0.48 0.64 Removal rate, % 75.18 67.15 64.23 51.82 51.09 35.04 46.72

[0134] Table 4

[0135] Filling amount, g 25.0 25.0 25.0 25.0 25.0 25.0 25.0 Dechlorination temperature, °C 20 30 25 15 35 25 25 Dechlorination pressure, MPa 2 3 2.3 1 5 2.3 2.3 <![CDATA[mass hourly space velocity, h -1 > 3 5 6 2 10 6 6 Chlorine content of raw materials, mg / l 17.8 17.8 17.8 17.8 17.8 17.8 17.8 Chlorine content of the product, mg / L 0.97 1.01 1.05 2.33 3.57 4.87 3.89 Average chlorine removal rate, mg / L 16.83 16.79 16.75 15.47 14.23 12.93 13.91 Removal rate, % 94.55 94.33 94.10 86.91 79.94 72.64 78.15

[0136] Examples 6-10

[0137] Following the operating parameters in Table 5, the dechlorinating agent used in Examples 1-5 was recovered using the following method: Under continuous nitrogen purging, the used dechlorinating agent was first purged for a certain period of time, then heated, kept warm, and cooled to room temperature to obtain the recovered dechlorinating agent. The recovery results are shown in Table 5.

[0138] Comparative Examples 3-4

[0139] Following the operating parameters in Table 5, the dechlorinating agent used in Comparative Examples 1-2 was recovered using the methods described in Examples 6-10, resulting in recovered dechlorinating agent. The recovery results are shown in Table 5.

[0140] Table 5

[0141]

[0142]

[0143] Test Example 2

[0144] In a laboratory fixed-bed pilot-scale evaluation apparatus, 25 g of dechlorinating agent AG from Preparation Examples 1-5 and Comparative Preparation Examples 1-2 were each loaded for long-term (500 h) continuous evaluation. The reaction conditions are shown in the table below. The chlorine content of the tested products and the removal rate were calculated, as shown in Table 6.

[0145] Table 6

[0146] Filling amount, g 25.0 25.0 25.0 25.0 25.0 25.0 25.0 Dechlorination temperature, °C 40 40 40 40 40 40 40 Dechlorination pressure, MPa 3.0 3.0 3.0 3.0 3.0 3.0 3.0 <![CDATA[Mass hourly space velocity, h -1 > 3 3 3 3 3 3 3 Reaction time, h 500 500 500 500 500 500 500 Chlorine content of raw materials, mg / l 1.19 1.19 1.19 1.19 1.19 1.19 1.19 Chlorine content of the product, mg / L 0.40 0.48 0.52 0.71 0.75 0.88 0.78 Average chlorine removal rate, mg / L 0.79 0.71 0.67 0.48 0.44 0.31 0.41 Removal rate, % 66.39 59.66 56.30 40.34 36.97 26.05 34.45

[0147] Test Example 3

[0148] The dechlorinating agent AE from Preparation Examples 1-5 was evaluated using a pilot-scale side-line test.

[0149] Without insulation, the dechlorination reaction temperature is essentially the same as the outdoor temperature. With insulation, the dechlorination reaction temperature is approximately 40℃. Therefore, evaluation tests of the dechlorinating agent at different temperatures can be conducted. The side stream, via a flow meter and valve, allows for adjustment of the material mass hourly space velocity (MHV), enabling evaluation tests under different MHV conditions. The test results are shown in Table 7.

[0150] Table 7

[0151]

[0152]

[0153] As can be seen from the results in Tables 2-7, the dechlorinating agent AE prepared using Preparation Examples 1-5 of this invention exhibits excellent dechlorination performance and long-term operational stability. It achieves high removal rates under different dechlorination temperatures and mass hourly space velocities (MSVs), and after proper recovery treatment, it can continue operation, essentially maintaining the chlorine capacity and dechlorination effect of the new agent. This reduces the frequency of plant shutdowns for agent replacement and lowers production costs. In contrast, the dechlorinating agents prepared in the comparative preparation examples are inferior to those of this invention in terms of dechlorination effect, long-term operational stability, and recovery effect.

[0154] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a dechlorination agent, characterized in that, The molecular sieve carrier (30-80% by weight), the active component precursor (2-20% by weight), the binder (15-45% by weight), and the additives (2-15% by weight) are mixed, molded, dried, and calcined to obtain the dechlorinating agent. The molecular sieve support has a pore size of 4-8 Å. The molecular sieve support is selected from at least one of 4A molecular sieve, 5A molecular sieve, ZSM-5 molecular sieve and NaY molecular sieve; The active component precursor is sodium nitrate and / or potassium nitrate; The binder is an aluminum sol prepared from boehmite; The additive is selected from at least one of pore expanders, pore-forming agents, extrusion aids, and stabilizers.

2. The preparation method according to claim 1, wherein, The drying temperature is 60-130℃; the drying time is 0.5-3 hours. And / or, the roasting temperature is 400-650℃; the roasting time is 1-5h.

3. The preparation method according to claim 2, wherein, The drying temperature is 80-120℃; the drying time is 1-2 hours. And / or, the roasting temperature is 500-600℃; the roasting time is 2-4h.

4. The preparation method according to any one of claims 1-3, wherein, The molecular sieve support comprises 50-70% by weight, the active component precursor comprises 3-10% by weight, the binder comprises 20-40% by weight, and the additive comprises 3-10% by weight. And / or, the pore size of the molecular sieve support is 4-5 Å; And / or, the average particle size of the molecular sieve carrier particles is not less than 200 mesh; And / or, the specific surface area of ​​the molecular sieve support is not less than 200 m². 2 / g.

5. A dechlorinating agent prepared by the preparation method according to any one of claims 1-4.

6. The application of the dechlorinating agent according to claim 5 in the dechlorination process of catalytic reforming.

7. The application according to claim 6, wherein, The dechlorination operating conditions include: dechlorination temperature of 15-45℃; dechlorination pressure of 1-5MPa; and mass hourly space velocity of 2-10h. -1 .

8. The application according to claim 7, wherein, The dechlorination operating conditions include: dechlorination temperature of 30-40℃; dechlorination pressure of 2-3 MPa; and mass hourly space velocity of 3-6 h⁻¹. -1 .

9. A method for recovering the dechlorinating agent according to claim 5, characterized in that, The method includes: under continuous purging conditions, heating, heat preservation and cooling of the used dechlorinating agent to obtain the recovered dechlorinating agent.

10. The recycling method according to claim 9, wherein, The method further includes: purging the used dechlorinating agent for 1-3 hours before heating; And / or, heat the used dechlorinating agent to 200-300℃, keep it at that temperature for 2-4 hours, and then cool it down; And / or, the purging gas is selected from at least one of nitrogen, argon, helium and hydrogen.

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