Chlorine treatment agent for reformate, method and application

Abstract

The invention relates to the technical field of organic chlorine treatment in reformate, in particular to a chlorine treatment agent and method for reformate and application. The chlorine treating agent is prepared by innovatively fusing various components such as a molecular sieve, zinc oxide, mesoporous silica and an MOFs material, supplementing with a titanium source and cerium source composite coating and carrying out mixing, molding, roasting and atomic layer deposition. The chlorine treatment agent can be used for dechlorinating reformate, solves the problems of poor organic chlorine removal performance and the like of the existing chlorine treatment agent, can effectively remove various organic chlorine and inorganic chlorine at the same time, has the advantages of high dechlorinating precision, large chlorine capacity, high active component utilization rate, good mechanical property and the like, prolongs the service life of the chlorine treatment agent, and meets the long-period operation requirement of a device.

Description

Technical Field

[0001] The present application relates to the technical field of organic chlorine treatment in reformed oil, and specifically to a chlorine treatment agent, method and application of reformed oil. Background Art

[0002] In the petrochemical industry, catalytic reforming is a key process in oil refining. Its primary reaction is the conversion of light petroleum fractions or naphtha-range products into refined oils and aromatics over a dual-functional catalyst. Currently, catalytic reforming units all use catalysts containing halogenated chlorine as the acidic component. To maintain catalyst activity and achieve an optimal water-chlorine balance, water and organic chlorides must be continuously injected. During this process, lost water and HCl accumulate in the reformate. Furthermore, the reforming reaction is accompanied by cracking reactions, which can lead to the formation of trace amounts of olefins in the reformate. These olefins react with hydrogen chloride to form organic chlorides. In large-scale, fourth-generation UOP reforming units, particularly those focused on aromatics production, the organic chloride content in the reformate is particularly high. Chlorides in the reformate can corrode and clog downstream equipment pipelines, shortening equipment life and increasing maintenance costs. They can also affect the quality of the reformate, reducing its market competitiveness and making it impossible to meet increasingly stringent product quality standards. Therefore, effective chlorine removal from the reformate is crucial to the refining industry, and the use of adsorbents for dechlorination is a common method used in refineries.

[0003] The chlorine content of currently used liquid chlorine treatment agents is usually below 2% in actual applications, which results in a short service life of the chlorine treatment agents. For example, the service life of some liquid dechlorination units is only 1-2 months.

[0004] In addition, since the reformed oil contains a small amount of water, for chlorine treatment agents with alkali metals as active components, water will react with dechlorinated calcium chloride, magnesium chloride, etc., causing damage to the structure of the chlorine treatment agent, clogging of the pores, and reducing the chlorine capacity.

[0005] Furthermore, conventional chlorine treatment agents struggle to efficiently adsorb or react with only organochlorines. They may also adsorb or react with other useful components in the reformate, impacting product quality and yield. Furthermore, organochlorine compounds with varying structures and properties interact differently with chlorine treatment agents, making it difficult to find a single chlorine treatment agent that effectively removes all organochlorine compounds.

[0006] The operating temperature of liquid-phase dechlorination of reforming oil generally cannot exceed 100°C, and preferably does not exceed 70°C. At low temperatures, the dechlorination reaction rate and equilibrium may be limited, affecting the dechlorination effect. Summary of the Invention

[0007] To this end, the present invention provides a chlorine treatment agent, method, and application for reforming oil to at least partially address one of the above-mentioned technical problems. To this end, the present invention discloses at least the following technical solutions:

[0008] In a first aspect, embodiments disclose a chlorine treatment agent for reformate oil, comprising a chlorine treatment agent precursor and a deposited layer deposited on the surface of the chlorine treatment agent precursor. The chlorine treatment agent precursor is prepared from molecular sieves, zinc oxide, mesoporous silica, a metal-organic framework material, a strength enhancer, and a binder. The deposited layer is a nano-thin layer formed by alternating deposition of a titanium source and a cerium source. The thickness of the deposited layer is 10 to 30 nanometers.

[0009] This chlorine treatment agent utilizes a quaternary active system consisting of "molecular sieve-ZnO-MOFs-TiO2 / CeO2," forming a multidimensional dechlorination network. The molecular sieve (30-50%) selectively captures small chlorine molecules through its 0.5-1.5 nm polar micropores, while surface acidic sites catalyze the cleavage of C-Cl bonds. Nano-zinc oxide (15-30%) chemically anchors inorganic chlorine through surface defect sites, transforming it into a stable zinc salt. The MOFs (5-15%) selectively adsorbs organochlorine containing π bonds through its tunable macroporous structure and functionalized ligands. The TiO2 / CeO2 coating, a nanoscale composite oxide layer deposited by ALD, combines the functions of catalyzing the conversion of organochlorine at acidic sites and fixing inorganic chlorine at alkaline sites. Furthermore, the active system exhibits significant synergistic effects. First, the synergistic effect of the active system creates a gradient adsorption-reaction network, significantly reducing the dissociation energy of C-Cl bonds at low temperatures, enabling efficient electron transfer and chemical bond activation. This effectively overcomes the technical bottleneck of conventional dechlorination agents, which suffer from insufficient activity at low temperatures. Secondly, the synergistic effect of the molecular sieve skeleton and the flexible framework of MOFs, combined with the controllable active sites formed by ALD deposition and the surface defect engineering of zinc oxide, formed a complementary multi-type active site, significantly improving the utilization rate of active components. Thirdly, the size screening effect of the molecular sieve, the hydrophobic adsorption characteristics of MOFs and the acid-base regulation of the zinc oxide surface formed a dynamic balance. The synergistic effect of the three achieved the differentiated capture and directional conversion of different chlorides, maintained stable adsorption selectivity in complex component systems, and ensured the dechlorination accuracy and capacity stability under different working conditions.

[0010] In some embodiments, the molecular sieve is selected from at least one of type A molecular sieve, 10X, 13X, NaY, and ZSM-5. Preferably, the molecular sieve is 13X or NaY.

[0011] In some embodiments, the zinc oxide is selected from at least one of nano zinc oxide, micron zinc oxide, basic zinc carbonate, and zinc acetate. Nano zinc oxide, due to its large specific surface area, unique quantum size effect, and crystal defects, provides abundant active sites and plays a key role in the removal of inorganic chlorine.

[0012] In some embodiments, the specific surface area of ​​the mesoporous silica carrier is 700 to 1300 m 2 / g, pore volume 0.7~2cm 3 / g, with an average pore size of 2 to 40 nm. Mesoporous silica, as an important carrier, provides a good mass transfer channel for the dechlorination reaction.

[0013] In some embodiments, the metal organic framework material is selected from at least one of MIL-101, MIL-53, UIO-66, ZIF-8, MOF-5, MOF-177, MOF-74, and MOF-808. Preferably, the MOFs material is MIL-101, UIO-66, or ZIF-8.

[0014] Metal-organic frameworks (MOFs) are porous materials formed by the self-assembly of metal ions or clusters with organic ligands through coordination bonds. They possess properties such as large pore volume, large specific surface area, controllable pore size, and modifiable surface chemical properties. By incorporating MOFs into the active ingredients of chlorine treatment agents, various functional groups can be introduced through chemical modification. These functional groups can enhance the interaction between MOFs and organic chlorides, promoting the chemical adsorption process, and exhibiting particularly strong adsorption selectivity for organic chlorides containing π bonds. Furthermore, their macroporous structure facilitates the diffusion of organic chloride molecules to the vicinity of the active sites, while also providing pathways for the diffusion of reaction intermediates, thereby improving the efficiency of the dechlorination reaction. Furthermore, the structure and composition of MOFs can be precisely controlled based on actual reaction conditions, such as the form and content of the organic chloride, enabling selective adsorption of different forms of organic chloride to adapt to the process operating conditions of various reforming units.

[0015] In some embodiments, the strength enhancer is selected from at least one of attapulgite, kaolin, halloysite, rectorite, bentonite, and diatomaceous earth, preferably attapulgite or rectorite.

[0016] During the chlorine treatment agent's molding process, the fibrous crystal structures of attapulgite and rectorite can be interspersed between the agent's molecular structure, acting as a reinforcing "nano-rebar" and significantly improving the agent's strength. During high-temperature calcination, they undergo a series of physical and chemical changes, including dehydration and crystallization transformations, and react with other components to form new chemical bonds and phases. These newly formed phases fill the pores and intergranular spaces of the chlorine treatment agent, further enhancing its strength while also improving its high-temperature and corrosion resistance.

[0017] In some embodiments, the binder is selected from at least one of sodium carboxymethyl cellulose powder, sesbania powder, ethyl cellulose, and clay, and plays an important role in bonding the components during the preparation of the chlorine treatment agent, thereby ensuring the structural stability of the chlorine treatment agent.

[0018] In some embodiments, the chlorine treatment agent precursor comprises, by weight, 20-80 parts of molecular sieve, 10-40 parts of zinc oxide, 5-15 parts of metal organic framework material, 5-30 parts of mesoporous silica, 5-20 parts of strength enhancer, and 1-5 parts of binder.

[0019] In some embodiments, the chlorine treatment agent precursor comprises, by weight, 40 parts of molecular sieve, 20 parts of zinc oxide, 10 parts of metal organic framework material, 15 parts of mesoporous silica, 13 parts of strength enhancer, and 2 parts of binder.

[0020] In some embodiments, the chlorine treatment agent precursor comprises, by weight, 45 parts molecular sieve, 20 parts zinc oxide, 10 parts metal organic framework material, 10 parts mesoporous silica, 13 parts strength enhancer, and 2 parts binder.

[0021] In some embodiments, the chlorine treatment agent precursor comprises, by weight, 45 parts molecular sieve, 15 parts zinc oxide, 10 parts metal organic framework material, 15 parts mesoporous silica, 13 parts strength enhancer, and 2 parts binder.

[0022] In some embodiments, the chlorine treatment agent precursor comprises, by weight, 40 parts of molecular sieve, 25 parts of zinc oxide, 10 parts of metal organic framework material, 10 parts of mesoporous silica, 13 parts of strength enhancer, and 2 parts of binder.

[0023] In some embodiments, the chlorine treatment agent precursor comprises, by weight, 45 parts molecular sieve, 20 parts zinc oxide, 5 parts metal organic framework material, 10 parts mesoporous silica, 18 parts strength enhancer, and 2 parts binder.

[0024] In a second aspect, the embodiment discloses a method for preparing the treatment agent described in the first aspect. The method comprises:

[0025] (1) mixing molecular sieve, zinc oxide, mesoporous silica, metal organic framework material, strength enhancer and binder according to the formula amount and ball milling to obtain a blended powder;

[0026] (2) forming the blended powder in a ball rolling machine, and then drying and calcining to obtain a treatment agent precursor;

[0027] (3) The titanium source and the cerium source are alternately deposited on the treating agent precursor by an atomic deposition method to obtain the chlorine treating agent.

[0028] In some embodiments, in step (2), the drying temperature is 100-120° C., and the drying time is 2-5 h; the calcination temperature is 400-550° C., and the calcination time is 2-6 h.

[0029] In some embodiments, in step (3), the number of deposition cycles of the titanium source and the cerium source is 1 to 50, so that the deposition thickness on the surface of the treating agent precursor is 10 to 30 nm. The deposition temperature is 250 to 300°C.

[0030] In some embodiments, the titanium source is one or more selected from titanium tetrachloride, titanium tetrakis(methylethylamino), titanium tetrakis(diethylamino), titanium tetrakis(dimethylamino), titanium tetrakis(titanium tetraisopropoxide), titanium tetrakis(dimethylamino), and titanium tetrakis(diethylamino).

[0031] In some embodiments, the cerium source is one or more selected from trimethylcerium, cerium acetylacetonate, tri(cyclopentadienyl)cerium, tricerocene, and aminopropyltrimethoxysilane cerium.

[0032] The present invention uses this atomic layer deposition method to form a composite metal oxide with a titanium source and a cerium source. During this process, the grain size is reduced, the specific surface area is significantly increased, and the amount of medium-strong L-acid is greatly increased, which greatly enriches the acid sites on the surface of the chlorine treatment agent. These acid sites can effectively adsorb and activate C-Cl bonds, promoting the reaction of organic chlorine to inorganic chlorine. At the same time, the basic sites of the composite metal oxide can adsorb the inorganic chlorine produced during the reaction, achieving the dual functions of conversion and absorption of the chlorine treatment agent, and significantly improving the chlorine capacity and dechlorination accuracy of the chlorine treatment agent. In addition, the synergistic effect of the bimetallic and the more electron transfer pathways provided by the rare earth metal cerium during the adsorption process make the chlorine treatment agent have a higher dechlorination reaction speed, further improving the capacity of the chlorine treatment agent. Moreover, atomic layer deposition loading technology can achieve precise control at the atomic level, so that the active components form a uniform single atomic layer and nanometer-level thickness on the surface of the chlorine treatment agent, exposing the active sites to the greatest extent, improving the reaction efficiency and dechlorination performance; at the same time, it enhances the interaction between the active components and the carrier, effectively improving the loss of active components, greatly improving the utilization rate of active components, and further improving the dechlorination activity and dechlorination efficiency; it can also prevent the agglomeration of metal ions, overcome the problem of uneven loading of active components, ensure that the active components are highly and stably dispersed on the surface of the chlorine treatment agent, and further improve the chlorine capacity of the chlorine treatment agent.

[0033] In a third aspect, embodiments disclose a method for treating chlorine in reformate oil. The method comprises loading the chlorine treatment agent described in the first aspect and the chlorine treatment agent produced by the method described in the second aspect into a fixed bed to form a fixed bed of chlorine treatment agent; passing the reformate oil through the fixed bed of chlorine treatment agent in a continuous flow manner; adsorbing and removing chlorine through solid-liquid contact; and collecting the dechlorinated reformate oil from the outlet of the fixed bed of chlorine treatment agent.

[0034] In a fourth aspect, the embodiments disclose the use of the chlorine treatment agent described in the first aspect and the chlorine treatment agent prepared by the method described in the second aspect in removing organic chlorine and inorganic chlorine from reformed oil.

[0035] The present invention uses molecular sieve, zinc oxide, titanium dioxide, cerium dioxide, and MOFs five active components and loads them on mesoporous silica to prepare a chlorine treatment agent. The chlorine treatment agent can treat organic chlorine and inorganic chlorine in reformed oil, achieve deep purification function, effectively improve dechlorination accuracy, avoid the occurrence of "chlorine spitting phenomenon", and thus extend the service life of the chlorine treatment agent. By constructing a molecular sieve-ZnO-MOFs-TiO2 / CeO2 quaternary active system and combining atomic layer deposition technology (ALD) to accurately load nano coatings, multi-component synergistic dechlorination is achieved. Molecular sieves capture small molecular chlorine, MOFs selectively adsorb large molecular organic chlorine, nano zinc oxide efficiently converts inorganic chlorine, and the nanoscale composite oxide layer formed by ALD deposition has both acidic sites catalyzing organic chlorine conversion and alkaline sites fixing inorganic chlorine, significantly improving dechlorination performance, and its service life is increased by 5-10 times compared to traditional chlorine treatment agents. At the same time, the multi-active ingredients construct a channel that is more conducive to electron transfer, improve the electron transfer efficiency of the entire adsorption process, and accelerate the reaction speed.

[0036] The chlorine treatment agent provided by this invention achieves step-by-step screening of chlorinated compounds (1-10 nm) through a three-level gradient pore system: micropores, mesopores, and macropores. The MOFs' open metal sites coordinate with chlorinated hydrocarbons, the molecular sieve's acidic sites catalyze hydrolysis, and the CeO2 redox reaction promotes electron transfer. This system achieves a removal rate of >99% for various organic chlorines, including allyl chloride and chlorobenzene, and an adsorption rate of <0.1% for aromatic hydrocarbons. This system combines high selectivity with broad spectrum, enabling precise removal of various forms of organic chlorine to adapt to the process operating conditions of different reforming units.

[0037] The present invention deposits titanium and cerium on the surface through an atomic deposition method, successfully overcoming the problems of active component agglomeration, loss, uneven loading and low utilization rate, and significantly improving the reaction efficiency and dechlorination performance.

[0038] The chlorine treatment agent provided by the present invention utilizes molecular sieves, mesoporous silica, and macroporous MOFs to construct a multi-level microporous-mesoporous-macroporous structure. This unique structure effectively accelerates the mass transfer efficiency of organic and inorganic chlorine molecules within the pores, improving the liquid-solid mass transfer process and making the adsorption process more efficient. The extensive through-pores formed by high-temperature calcination and the large pore structure of the chlorine treatment agent enhance the diffusion of trace chlorides within the chlorine treatment agent, further improving dechlorination activity and precision.

[0039] The chlorine treatment agent provided by this invention utilizes a non-alkali metal active component (ZnO) to effectively prevent the formation of water-soluble substances. A superhydrophobic surface is formed by depositing TiO2 / CeO2 via ALD, and the three-dimensional framework is reinforced by the introduction of attapulgite and rectorite. This technology ensures that the chlorine treatment agent maintains its pore structure even in water-containing conditions, with a compressive strength exceeding 60N / particle. This completely solves the problem of conventional chlorine treatment agents pulverizing in water and ensures the agent's service life. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is further described in detail below with reference to the following examples. It should be understood that the specific examples described herein are merely for the purpose of explaining this application and are not intended to limit this application. Reagents not described in detail in this application are all conventional reagents and can be obtained from commercial channels; methods not specifically described in detail are all conventional experimental methods and can be obtained from the prior art.

[0041] Preparation of chlorine treatment agent for reforming oil

[0042] The examples and comparative examples of the present application respectively provide specific preparation processes of the chlorine treatment agent for reformed oil.

[0043] Example 1 provides a preparation process for a chlorine treatment agent for reforming oil. The process includes: accurately weighing 40g of 13X molecular sieve, 20g of nano zinc oxide, 10g of MIL-101 material, 15g of mesoporous silica, 13g of attapulgite, and 2g of sodium carboxymethyl cellulose powder in a powerful mixer and mixing at a speed of 500r / min for 1 hour to ensure that the components are fully and evenly mixed to obtain a blended powder. The blended powder is placed in a ball mill and granulated at a speed of 30r / min for 1 hour. Subsequently, the formed particles are placed in an oven, dried at 120°C for 2 hours, then placed in a muffle furnace and calcined at 550°C for 3 hours to obtain a chlorine treatment agent precursor. The atomic layer deposition method is adopted, with titanium tetrachloride as the titanium source and tri(cyclopentadienyl)cerium as the cerium source. At a deposition temperature of 280°C, one circle of titanium source is first deposited and then one circle of cerium source is deposited. This cycle is repeated multiple times until the thickness of the modified coating layer reaches 10nm, and a finished chlorine treatment agent is obtained.

[0044] Example 2 provides a preparation process for a chlorine treatment agent for reforming oil. The process comprises: accurately weighing 45g13X molecular sieve, 20g nano zinc oxide, 10g UIO-66 material, 10g mesoporous silica, 13g rectorite and 2g Tianqing powder and placing them in a powerful mixer, mixing them at a speed of 500r / min for 1h, ensuring that each component is fully and evenly mixed to obtain a blended powder. The blended powder is placed in a ball rolling machine and ball granulation is performed at a speed of 30r / min for 1h. Subsequently, the formed particles are placed in an oven, dried at 100°C for 3h, then placed in a muffle furnace, and roasted at 550°C for 4h to obtain a chlorine treatment agent precursor. The atomic layer deposition method is adopted, with tetrakis(diethylammonium)titanium as the titanium source and tri(cyclopentadienyl)cerium as the cerium source. At a deposition temperature of 270°C, one circle of titanium source is first deposited and then one circle of cerium source is deposited. This cycle is repeated many times to make the thickness of the modified coating layer reach 13nm, and a finished chlorine treatment agent is obtained.

[0045] Example 3 provides a preparation process for a chlorine treatment agent for reformed oil. The process comprises: accurately weighing 45g NaY molecular sieve, 15g nano zinc oxide, 10g UIO-66 material, 15g mesoporous silica, 13g attapulgite and 2g white clay and placing them in a powerful mixer, mixing them at a speed of 500r / min for 1h, ensuring that the components are fully and evenly mixed to obtain a blended powder. The blended powder is placed in a ball rolling machine and granulated at a speed of 30r / min for 1h. Subsequently, the formed particles are placed in an oven, dried at 150°C for 2h, then placed in a muffle furnace and calcined at 600°C for 2h to obtain a chlorine treatment agent precursor. The atomic layer deposition method is adopted, with tetrakis(dimethylamino)titanium as the titanium source and cerium acetylacetonate as the cerium source. At a deposition temperature of 280°C, one circle of titanium source is first deposited and then one circle of cerium source is deposited. This cycle is repeated many times to make the thickness of the modified coating layer reach 20nm, and a finished chlorine treatment agent is obtained.

[0046] Example 4 provides a preparation process for a chlorine treatment agent for reforming oil. The process comprises: accurately weighing 40g NaY molecular sieve, 25g nano zinc oxide, 10g ZIF-8 material, 10g mesoporous silica, 13g rectorite and 2g ethyl cellulose and placing them in a powerful mixer. Mixing at a speed of 500r / min for 1h ensures that the components are fully and evenly mixed to obtain a blended powder. The blended powder is placed in a ball mill and granulated at a speed of 30r / min for 1h. Subsequently, the formed particles are placed in an oven, dried at 120°C for 2h, then placed in a muffle furnace and calcined at 600°C for 2h to obtain a chlorine treatment agent precursor. Atomic layer deposition is used, with tetrakis(diethylamino)titanium as the titanium source and trimethylcerium as the cerium source. At a deposition temperature of 260°C, one circle of titanium source is first deposited followed by one circle of cerium source. This cycle is repeated multiple times to achieve a modified coating thickness of 10nm, thus obtaining a finished chlorine treatment agent.

[0047] Example 5 provides a preparation process for a chlorine treatment agent for reformed oil. The process comprises: accurately weighing 45g of 13X molecular sieve, 20g of nano zinc oxide, 5g of MIL-101 material, 10g of mesoporous silica, 18g of attapulgite, and 2g of sodium carboxymethyl cellulose powder in a powerful mixer and mixing at 500r / min for 1 hour to ensure that all components are fully and evenly mixed to obtain a blended powder. The blended powder is placed in a ball mill and granulated at 30r / min for 1 hour. Subsequently, the formed particles are placed in an oven, dried at 120°C for 3 hours, and then placed in a muffle furnace and calcined at 550°C for 3 hours to obtain a chlorine treatment agent precursor. The atomic layer deposition method is adopted, with titanium tetraisopropoxide as the titanium source and aminopropyltrimethoxysilane cerium as the cerium source. At a deposition temperature of 280°C, one circle of titanium source is first deposited and then one circle of cerium source is deposited. This cycle is repeated many times to make the thickness of the modified coating layer reach 16nm, and a finished chlorine treatment agent is obtained.

[0048] Comparative Example 1 provides a preparation process for a chlorine treatment agent for reforming oil. The process comprises: accurately weighing 50g of 13X molecular sieve, 20g of nano zinc oxide, 15g of mesoporous silica, 13g of attapulgite, and 2g of sodium carboxymethyl cellulose powder in a powerful mixer and mixing at a speed of 500r / min for 1 hour to ensure that the components are fully and evenly mixed to obtain a blended powder (the total powder weight is consistent with that in Example 1). The blended powder is placed in a ball mill and granulated at a speed of 30r / min for 1 hour. Subsequently, the formed particles are placed in an oven, dried at 120°C for 2 hours, then placed in a muffle furnace and calcined at 550°C for 3 hours to obtain a chlorine treatment agent precursor. The atomic layer deposition method is adopted, with titanium tetrachloride as the titanium source and tri(cyclopentadienyl)cerium as the cerium source. At a deposition temperature of 280°C, one circle of titanium source is first deposited and then one circle of cerium source is deposited. This cycle is repeated many times to make the thickness of the modified coating layer reach 10nm, and a finished chlorine treatment agent is obtained.

[0049] Comparative Example 2 provides a preparation process for a chlorine treatment agent for reformed oil. The process comprises: accurately weighing 50g of nano zinc oxide, 20g of MIL-101 material, 15g of mesoporous silica, 13g of attapulgite, and 2g of sodium carboxymethyl cellulose powder in a powerful mixer and mixing at a speed of 500r / min for 1 hour to ensure that the components are fully and evenly mixed to obtain a blended powder (the total powder weight is consistent with that in Example 1). The blended powder is placed in a ball mill and granulated at a speed of 30r / min for 1 hour. Subsequently, the formed particles are placed in an oven, dried at 120°C for 2 hours, then placed in a muffle furnace and calcined at 550°C for 3 hours to obtain a chlorine treatment agent precursor. The atomic layer deposition method is adopted, with titanium tetrachloride as the titanium source and tri(cyclopentadienyl)cerium as the cerium source. At a deposition temperature of 280°C, one circle of titanium source is first deposited and then one circle of cerium source is deposited. This cycle is repeated many times to make the thickness of the modified coating layer reach 10nm, and a finished chlorine treatment agent is obtained.

[0050] Comparative Example 3 provides a preparation process for a chlorine treatment agent for reforming oil. The process comprises: accurately weighing 50g of 13X molecular sieve, 20g of MIL-101 material, 15g of mesoporous silica, 13g of attapulgite, and 2g of sodium carboxymethyl cellulose powder in a powerful mixer and mixing at a speed of 500r / min for 1 hour to ensure that the components are fully and evenly mixed to obtain a blended powder (the total powder weight is consistent with that in Example 1). The blended powder is placed in a ball mill and granulated at a speed of 30r / min for 1 hour. Subsequently, the formed particles are placed in an oven, dried at 120°C for 2 hours, then placed in a muffle furnace and calcined at 550°C for 3 hours to obtain a chlorine treatment agent precursor. The atomic layer deposition method is adopted, with titanium tetrachloride as the titanium source and tri(cyclopentadienyl)cerium as the cerium source. At a deposition temperature of 280°C, one circle of titanium source is first deposited and then one circle of cerium source is deposited. This cycle is repeated many times to make the thickness of the modified coating layer reach 10nm, and a finished chlorine treatment agent is obtained.

[0051] Comparative Example 4 provides a process for preparing a chlorine treatment agent for reforming oil. The process involves accurately weighing 40g of 13X molecular sieve, 20g of nano-zinc oxide, 10g of MIL-101 material, 15g of mesoporous silica, 13g of attapulgite, and 2g of sodium carboxymethyl cellulose powder, placing them in a briquette mixer and mixing them at 500 rpm for 1 hour to ensure thorough and uniform mixing of the components to obtain a blended powder. The blended powder is then placed in a ball mill and granulated at 30 rpm for 1 hour. The granules are then dried in an oven at 120°C for 2 hours, then placed in a muffle furnace and calcined at 550°C for 3 hours to obtain a chlorine treatment agent precursor. The titanium and cerium source deposition steps are omitted.

[0052] Comparative Example 5 provides a process for preparing a chlorine treatment agent for reformed oil. The process involves accurately weighing 40g of 13X molecular sieve, 20g of nano-zinc oxide, 10g of MIL-101 material, 15g of mesoporous silica, 13g of attapulgite, and 2g of sodium carboxymethyl cellulose powder in a intensive mixer and mixing at 500 rpm for 1 hour to ensure thorough and uniform mixing of the components to obtain a blended powder. The blended powder is then placed in a ball mill and granulated at 30 rpm for 1 hour. The granules are then dried in an oven at 120°C for 2 hours, then placed in a muffle furnace and calcined at 550°C for 3 hours to produce a chlorine treatment agent precursor. The atomic layer deposition method is adopted, with titanium tetrachloride as the titanium source and tri(cyclopentadienyl)cerium as the cerium source. At a deposition temperature of 280°C, one circle of titanium source is first deposited and then one circle of cerium source is deposited. This cycle is repeated many times to make the thickness of the modified coating layer reach 5nm, and a finished chlorine treatment agent is obtained.

[0053] Comparative Example 6 provides a process for preparing a chlorine treatment agent for reformed oil. The process involves accurately weighing 40g of 13X molecular sieve, 20g of nano-zinc oxide, 10g of MIL-101 material, 15g of mesoporous silica, 13g of attapulgite, and 2g of sodium carboxymethyl cellulose powder in a intensive mixer and mixing at 500 rpm for 1 hour to ensure thorough and uniform mixing of the components to obtain a blended powder. The blended powder is then placed in a ball mill and granulated at 30 rpm for 1 hour. The granules are then dried in an oven at 120°C for 2 hours, then placed in a muffle furnace and calcined at 550°C for 3 hours to produce a chlorine treatment agent precursor. The atomic layer deposition method is adopted, with titanium tetrachloride as the titanium source and tri(cyclopentadienyl)cerium as the cerium source. At a deposition temperature of 280°C, one circle of titanium source is first deposited and then one circle of cerium source is deposited. This cycle is repeated many times to make the thickness of the modified coating layer reach 50nm, and a finished chlorine treatment agent is obtained.

[0054] Processing of reforming oil

[0055] 1. Test samples

[0056] Examples 1 to 5 and Comparative Examples 1 to 6 respectively provide chlorine treatment agents.

[0057] 2. Testing process

[0058] Reformed oil containing 5 ppm 1-chloropentane, 5 ppm trichloroethane, 5 ppm tetrachloroethylene, 5 ppm chlorobenzene, and 50 ppm hydrogen chloride was prepared as the simulated oil to be treated.

[0059] At atmospheric pressure, reaction temperature 30℃, and reforming oil volume space velocity 5h -1 Under the conditions of , 20 ml of the above-mentioned chlorine treatment agent was measured and evenly loaded into a reactor with an inner diameter of 20 mm. The simulated raw oil was passed through the reactor containing the chlorine treatment agent at a stable flow rate to conduct a dynamic dechlorination experiment. During the experiment, the LC-8 coulometric analyzer was used to conduct real-time and accurate testing of the chlorine content in the oil after the reaction. When the total chlorine content in the exported oil exceeded 0.2 ppm for three consecutive times, it was considered to be breakthrough, and the chlorine treatment agent was assumed to be inactivated. The chlorine capacity at this time is called the breakthrough chlorine capacity. Dechlorination accuracy refers to the ability of the chlorine treatment agent to remove chlorine elements, which is specifically manifested as the concentration value of the residual total chlorine content in the medium after treatment. It is usually expressed in mass concentration (such as ppm, μg / L) or molar concentration. This indicator is the core parameter for measuring the performance of the chlorine treatment agent. The smaller the value, the higher the accuracy. Dechlorination accuracy is measured by the chlorine content of the exported oil. In the experiment, the dechlorination accuracy is based on the penetration standard of the total chlorine content of 0.2 ppm at the outlet. Under the above test conditions, the chlorine treatment agents prepared in Examples 1-5 and Comparative Examples 1-6 were subjected to dechlorination evaluation as shown in Table 1. The strength test of the prepared chlorine treatment agents was also conducted in accordance with HG / T 2782-2024. The test results are shown in Tables 1 and 2.

[0060] Table 1 Test results of Examples 1-5

[0061] Sample number Example 1 Example 2 Example 3 Example 4 Example 5 Export inorganic chlorine content / ppm ＜0.1 ＜0.1 ＜0.1 ＜0.1 ＜0.1 Export 1-chloropentane content / ppm ＜0.1 ＜0.1 ＜0.1 ＜0.1 ＜0.1 Export trichloroethane content / ppm ＜0.1 ＜0.1 ＜0.1 ＜0.1 ＜0.1 Export tetrachloroethylene content / ppm ＜0.1 ＜0.1 ＜0.1 ＜0.1 ＜0.1 Export chlorobenzene content / ppm ＜0.1 ＜0.1 ＜0.1 ＜0.1 ＜0.1 Export organic chlorine content / ppm ＜0.1 ＜0.1 ＜0.1 ＜0.1 ＜0.1 Total chlorine content at outlet / ppm ＜0.2 ＜0.2 ＜0.2 ＜0.2 ＜0.2 Inorganic chlorine removal rate / % >99 >99 >99 >99 >99 Organic chlorine removal rate / % >99 >99 >99 >99 >99 Removal rate / % >99 >99 >99 >99 >99 Chlorine content / % 19.52 18.72 18.84 19.01 17.95 Strength / (N / particle) 62.3 66.8 55.6 58.7 71.3

[0062] As shown in Table 1, the dechlorinating agents provided in Examples 1-5 are significantly superior to Comparative Examples 1-6 in terms of dechlorination accuracy, chlorine capacity and strength. The key reason is that the multi-level collaborative system constructed by molecular sieve, MOFs material and zinc oxide: the micropores of the molecular sieve efficiently capture HCl and small molecule organic chlorine by polar adsorption; the mesopores of MOFs selectively adsorb large-volume chlorinated aromatic hydrocarbons by means of adjustable surface chemical properties, and activate C-Cl bonds by open metal sites; zinc oxide forms a heterojunction with the Ce-Ti composite coating deposited by atomic layer deposition, promoting the catalytic oxidation and stable storage of Cl-. The three realize the functional coupling of adsorption-catalysis-storage through a gradient pore mass transfer network, wherein the interface electronic reconstruction of the molecular sieve and MOFs reduces the organic chlorine adsorption energy barrier, the oxygen vacancies of the zinc oxide and the deposited layer enhance the low-temperature reaction activity, and the multi-level pore structure (micropore-mesopore-macroporous) synergistically optimizes the mass transfer path, breaks through the low-temperature diffusion kinetics limitation, and ultimately achieves high chlorine capacity and deep dechlorination. Thus, it is shown that the dechlorinating agent prepared by the preparation method provided in the embodiment of the present application has high dechlorination performance.

[0063] Specifically, compared to Example 1, the chlorine treatment agent in Comparative Example 1, which did not include MOFs, showed significant decreases in the removal rates of tetrachloroethylene and chlorobenzene (export contents were 3.8 ppm and 1 ppm, respectively), with the total organochlorine removal rate dropping to 75.5% and the chlorine capacity being only 1%. This indicates that the absence of MOFs prevents the selective adsorption of large molecular organochlorines through their unique surface properties and modifiable pores, while also disrupting the micropore-mesopore-macroporous multi-stage mass transfer system, causing the chlorine treatment agent to lose its adsorption capacity for complex organochlorines. This validates the key role of MOFs in the targeted capture of π-bonded compounds and the optimization of pore structure.

[0064] As shown in Table 2, specifically, compared with Example 1, no molecular sieve was added to the chlorine treatment agent in Comparative Example 2, and the test found that the removal rate of small molecule organic chlorine (such as 1-chloropentane and trichloroethane) was greatly reduced (the outlet contents were 1.1ppm and 0.5ppm, respectively), and the organic chlorine removal rate dropped to 91.5%, with a chlorine capacity of less than 1%. The lack of molecular sieves leads to a reduction in microporous polar adsorption sites, and the specific adsorption capacity for small molecule chlorinated compounds is relatively weak, making it impossible to effectively capture polar small molecule chlorinated compounds, and the loss of the molecular sieve acidic site's ability to catalyze the cleavage of the C-Cl bond further proves the irreplaceability of molecular sieves in improving adsorption selectivity and promoting organochlorine reactions.

[0065] Table 2 Test results of comparative examples 1-6

[0066] Sample number Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Export inorganic chlorine content / ppm ＜0.1 ＜0.1 ＜0.1 ＜0.1 ＜0.1 ＜0.1 Export 1-chloropentane content / ppm ＜0.1 1.1 ＜0.1 ＜0.1 ＜0.1 ＜0.1 Export trichloroethane content / ppm ＜0.1 0.5 ＜0.1 ＜0.1 ＜0.1 ＜0.1 Export tetrachloroethylene content / ppm 3.8 ＜0.1 ＜0.1 ＜0.1 ＜0.1 ＜0.1 Export chlorobenzene content / ppm 1 ＜0.1 ＜0.1 ＜0.1 ＜0.1 ＜0.1 Export organic chlorine content / ppm 4.8 1.6 ＜0.1 ＜0.1 ＜0.1 ＜0.1 Total chlorine content at outlet / ppm ＜4.9 ＜1.7 ＜0.2 ＜0.2 ＜0.2 ＜0.2 Inorganic chlorine removal rate / % >99 >99 >99 >99 >99 >99 Organic chlorine removal rate / % >75.5 >91.5 >99 >99 >99 >99 Removal rate / % >93.1 >97.6 >99 >99 >99 >99 Chlorine content / % <1 <1 8.56 11.38 13.64 15.98 Strength / (N / particle) 74.6 58.6 65.9 50.6 53.4 73.6

[0067] Specifically, compared to Example 1, the chlorine treatment agent in Comparative Example 3 did not contain nano-zinc oxide. The results showed that although the chlorine removal rate remained >99%, maintaining a high dechlorination accuracy, the chlorine capacity dropped sharply to 8.56% (compared to 19.52% in Example 1). The absence of nano-zinc oxide reduced the active site density, providing fewer active sites for contact reaction with hydrogen chloride. This prevented the rapid and efficient conversion of inorganic chlorine through the ZnO + HCl → ZnCl2 reaction, significantly reducing the amount of inorganic chlorine adsorbed and further reducing the dechlorination performance. This highlights the key role of nano-zinc oxide in improving chlorine capacity.

[0068] Specifically, compared to Example 1, the chlorine treatment agent provided in Comparative Example 4 did not undergo deposition of titanium and cerium sources; instead, it lacked a deposition layer and used an unmodified dechlorinating agent precursor. While dechlorination accuracy met the target, the chlorine capacity (11.23%) decreased by 41.5% compared to Example 1 (19.52%), and the strength (50.6 N / pellet) decreased by 18.8% compared to Example 1 (62.3 N / pellet). The lack of a coating exposed the active components directly to the oil phase, leading to component agglomeration and a reduction in surface acid sites. This demonstrates the key role of the TiO2 / CeO2 coating in inhibiting active component loss, enhancing surface acidity, and preventing agglomeration.

[0069] Specifically, compared with Example 1, the deposited layer of the chlorine treatment agent provided in Comparative Example 5 is thinner, while the deposited layer of the chlorine treatment agent provided in Comparative Example 6 is thicker. The results show that the chlorine capacity of Comparative Example 5 is 13.64%, a decrease of 30% compared with Example 1, and the mechanical strength is reduced by 14.3%; the chlorine capacity of Comparative Example 6 (15.98%) is higher than that of Comparative Example 5, but still lower than that of Example 1. The overly thin deposited layer cannot fully cover and protect the active components, causing them to be exposed to the reaction environment and poisoned and inactivated; at the same time, the titanium-cerium bimetallic cannot form a continuous synergistic catalytic interface, weakening the conversion ability of chlorides; the thin layer also causes the microcracks at the material interface to be not effectively filled, and the structure is prone to breakage under fluid erosion. These factors together lead to a decrease in chlorine capacity and mechanical strength. An overly thick deposition layer covers the pore structure of the support material, hindering the diffusion of organochlorine molecules to the active sites. At the same time, a dense coating obscures the surface active sites of zinc oxide and MOFs, weakening their adsorption and catalytic conversion capabilities for chlorine species. Furthermore, an overly thick layer disrupts the nanoscale dispersion of the titanium-cerium bimetallic, resulting in a decrease in electron transfer efficiency and further deterioration in dechlorination performance. This demonstrates that a coating thickness of 10-30 nm is the optimal range.

[0070] The above is only a preferred specific implementation method of the present application, but the scope of protection of the present application is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed in this application should be covered by the scope of protection of the present application.

Claims

1. A chlorine treatment agent for reforming oil, comprising a chlorine treatment agent precursor and a deposition layer deposited on the surface of the chlorine treatment agent precursor; the chlorine treatment agent precursor is prepared from molecular sieves, zinc oxide, mesoporous silica, a metal organic framework material, a strength enhancer, and a binder; the deposition layer is a nano-thin layer formed by alternating deposition of a titanium source and a cerium source; the thickness of the deposition layer is 10 to 30 nanometers.

2. The chlorine treatment agent according to claim 1, wherein the molecular sieve is selected from at least one of type A molecular sieve, 10X, 13X, NaY and ZSM-5, and the molecular sieve is 13X or NaY; Optionally, the zinc oxide is selected from at least one of nano zinc oxide, micron zinc oxide, basic zinc carbonate, and zinc acetate; Optionally, the metal organic framework material is selected from at least one of MIL-101, MIL-53, UIO-66, ZIF-8, MOF-5, MOF-177, MOF-74, and MOF-808. Optionally, the MOFs material is MIL-101, UIO-66, or ZIF-8. Optionally, the strength enhancer is selected from at least one of attapulgite, kaolin, halloysite, rectorite, bentonite, and diatomaceous earth. Optionally, the strength enhancer is attapulgite or rectorite; Optionally, the binder is selected from at least one of sodium carboxymethyl cellulose powder, sesbania powder, ethyl cellulose and white clay; Optionally, the titanium source is one or more selected from titanium tetrachloride, tetrakis(methylethylamino)titanium, tetrakis(diethylamino)titanium, tetrakis(dimethylamino)titanium, titanium tetraisopropoxide, tetrakis(dimethylamino)titanium, and tetrakis(diethylamino)titanium; Optionally, the cerium source is one or more selected from trimethylcerium, cerium acetylacetonate, tri(cyclopentadienyl)cerium, tricerocene, and aminopropyltrimethoxysilane cerium.

3. The chlorine treatment agent according to claim 1, wherein the specific surface area of ​​the mesoporous silica carrier is 700 to 1300 m 2 / g, pore volume 0.7~2cm 3 / g, average pore size 2~40nm.

4. The chlorine treatment agent according to claim 1, wherein the chlorine treatment agent precursor comprises, by weight, 20 to 80 parts of molecular sieve, 10 to 40 parts of zinc oxide, 5 to 15 parts of metal organic framework material, 5 to 30 parts of mesoporous silica, 5 to 20 parts of strength enhancer and 1 to 5 parts of binder.

5. The chlorine treatment agent according to claim 4, wherein the chlorine treatment agent precursor comprises, by weight, 40 parts of molecular sieve, 20 parts of zinc oxide, 10 parts of metal organic framework material, 15 parts of mesoporous silica, 13 parts of strength enhancer and 2 parts of binder; Optionally, the chlorine treatment agent precursor comprises, by weight, 45 parts of molecular sieve, 20 parts of zinc oxide, 10 parts of metal organic framework material, 10 parts of mesoporous silica, 13 parts of strength enhancer and 2 parts of binder; Optionally, the chlorine treatment agent precursor comprises, by weight, 45 parts of molecular sieve, 15 parts of zinc oxide, 10 parts of metal organic framework material, 15 parts of mesoporous silica, 13 parts of strength enhancer and 2 parts of binder; Optionally, the chlorine treatment agent precursor comprises, by weight, 40 parts of molecular sieve, 25 parts of zinc oxide, 10 parts of metal organic framework material, 10 parts of mesoporous silica, 13 parts of strength enhancer and 2 parts of binder; Optionally, the chlorine treatment agent precursor comprises, by weight, 45 parts of molecular sieve, 20 parts of zinc oxide, 5 parts of metal organic framework material, 10 parts of mesoporous silica, 18 parts of strength enhancer and 2 parts of binder.

6. The method for preparing the chlorine treatment agent according to any one of claims 1 to 5, comprising: (1) mixing molecular sieve, zinc oxide, mesoporous silica, metal organic framework material, strength enhancer and binder according to the formula amount and ball milling to obtain a blended powder; (2) forming the blended powder in a ball rolling machine, and then drying and calcining to obtain a treatment agent precursor; (3) The titanium source and the cerium source are alternately deposited on the treating agent precursor by an atomic deposition method to obtain the chlorine treating agent.

7. The preparation method according to claim 6, wherein in step (2), the drying temperature is 100-120°C, and the drying time is 2-5 hours; the roasting temperature is 400-550°C, and the roasting time is 2-6 hours.

8. The preparation method according to claim 6, wherein in step (3), the number of deposition cycles of the titanium source and the cerium source is 1 to 50, so that the deposition thickness on the surface of the treatment agent precursor is 10 to 30 nm, and the deposition temperature is 250 to 300°C.

9. A method for treating chlorine in reformed oil, comprising: The chlorine treatment agent according to any one of claims 1 to 5 or the chlorine treatment agent prepared by the method according to any one of claims 6 to 8 is loaded in a fixed bed manner to form a chlorine treatment agent fixed bed layer; passing the reformate through the fixed bed of chlorine treatment agent in a continuous flow manner; and The reformed oil after dechlorination treatment is collected from the outlet end of the fixed bed layer of the chlorine treatment agent.

10. Use of the chlorine treatment agent according to any one of claims 1 to 5 or the chlorine treatment agent prepared by the method according to any one of claims 6 to 8 for removing organic chlorine and inorganic chlorine from reformate oil.