CN113736507B

CN113736507B - Liquid phase dechlorinating agent, preparation method and application thereof

Info

Publication number: CN113736507B
Application number: CN202010463290.9A
Authority: CN
Inventors: 曹志涛; 王健; 张晓琳; 张元礼; 程光剑; 桂建舟; 解洪新; 李凤生; 王洪星; 吕洁; 李民; 张英杰; 董大清; 莫娅南; 李�学; 高原; 黄集钺; 刘丹; 刘成伟; 彭海龙
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2020-05-27
Filing date: 2020-05-27
Publication date: 2023-08-22
Anticipated expiration: 2040-05-27
Also published as: CN113736507A

Abstract

The application provides a liquid-phase dechlorinating agent, a preparation method and application thereof. The liquid phase dechlorinating agent comprises: the active component is selected from at least one of an A molecular sieve, a 13X molecular sieve and a NaY molecular sieve, and the weight content of the active component in the liquid-phase dechlorinating agent is 20-40%; the auxiliary agent component is selected from at least three of copper oxide, sodium oxide, potassium oxide, barium oxide, calcium oxide, magnesium oxide, zinc oxide and ferric oxide, and the weight content of the auxiliary agent component in the liquid-phase dechlorinating agent is 3-10%; the carrier is carbon powder, and the weight content of the carbon powder in the liquid-phase dechlorinating agent is 10% -33%; and the balance of binder. The carbon powder has more adsorption sites and large pore volume and specific surface area, and meanwhile, the surface of the activated carbon powder has a plurality of oxygen-containing functional groups, so that the polarity of the carrier is improved, the bonding strength between the carrier and the active components is enhanced, and the loss of the active components is reduced so as to keep higher chlorine volume.

Description

Liquid phase dechlorinating agent, preparation method and application thereof

Technical Field

The application relates to the technical field of liquid phase purification, in particular to a liquid phase dechlorinating agent, a preparation method and application thereof.

Background

Chlorine source and hazard in catalytic reforming process: firstly, chlorides (mostly organic chlorides) are often added to improve the oil recovery rate when crude oil is extracted. While the oil recovery rate is improved, the chlorine content in the crude oil is also increased. Under the high temperature condition, the organic chlorine can be converted into inorganic hydrogen chloride, the pipeline has great corrosion effect, and if ammonia exists at the downstream, the ammonia can react to generate ammonium chloride, so that equipment is blocked, and the operation of the device is influenced. In the reforming reaction process, chlorine on the reforming catalyst is continuously lost, and the reforming catalyst needs to have certain acidity in order to maintain higher reaction activity, so that water and organic chloride are required to be continuously added, further the chlorine content in crude oil is increased, and the corrosion of pipelines and the blockage of equipment are accelerated. Therefore, it is highly desirable to prepare a highly effective dechlorinating agent.

The use of a dechlorinating agent is the main method for removing hydrogen chloride in the material. Currently, dechlorinating agents are mainly divided into two categories: one is a gas phase dechlorinating agent, and CN105617853A discloses a high-temperature gas phase dechlorinating agent which is prepared from calcium carbonate, magnesium carbonate, calcium oxide and aluminate cement, and has low strength, short service period and improved chlorine capacity. The other is a liquid-phase dechlorinating agent, namely a dechlorinating agent for liquid-phase materials, and because the mass transfer rate in a liquid-phase system is lower, the dechlorinating effect of the liquid-phase dechlorinating agent is poorer than that of a meteorological dechlorinating agent, and CN105542836A discloses a liquid-phase dechlorinating agent, wherein the chlorine capacity of the dechlorinating agent is only 16% when the dechlorinating agent is prepared from CuO, caO, KOH and active carbon.

As previously mentioned, the chlorine content of the reformate is relatively low, and the chlorine content of the dechlorinating agent is generally relatively low when liquid phase dechlorination is employed. The reforming process belongs to the water-chlorine balance operation process, the reformed oil also contains a small amount of water, the water has a larger influence on the dechlorination agent which takes alkali metal as an active component, the water can carry out a coordination reaction with dechlorinated substances (such as calcium chloride, magnesium chloride and the like), the structure of the dechlorination agent is damaged, the internal pore canal is blocked, and finally the chlorine capacity is reduced. Although the physical and chemical parameters (such as specific surface area, pore volume, pore distribution and the like) of some liquid-phase dechlorinating agents are ideal, the chlorine volume of the dechlorinating agent is still low during application, and particularly the water resistance of the dechlorinating agent taking alkaline earth metal compounds as active components is poor. The chlorine content control standard of the liquid-phase dechlorinating agent developed at home at present is in the range of 8% -15%, but according to practical conditions, the chlorine content of the existing liquid-phase dechlorinating agent in practical application is below 2%, long-term operation and use of the device cannot be met, the service period is only 1-2 months, and more, the condition that the content of outlet chlorine is higher than that of inlet chlorine is caused because chlorine is desorbed from the dechlorinating agent occurs.

The chlorine content is closely related to the operating temperature, in addition to the nature of the dechlorinating agent itself. Studies have shown that: for liquid phase dechlorination, the higher the temperature, the greater the chlorine capacity. For the dechlorination of the reforming oil phase, the operation temperature is limited, generally, the temperature cannot exceed 100 ℃, preferably not exceed 70 ℃, and the chlorine capacity is less than 12% when the liquid phase dechlorination agent is operated at 50 ℃ in the engineering design and application conditions of the liquid phase dechlorination technology of the catalytic reforming device of 60 ten thousand t/a of Qingyang petrochemical company introduced by the design and application of the reforming oil phase dechlorination technology of Landrace and the like; when operated at 75 ℃, the chlorine content is about 20%; the chlorine content was about 30% when operated at 100 ℃. Meanwhile, the chlorine content in the reforming oil is low, and the raw material contains a small amount of water, so that when the conventional liquid-phase dechlorinating agent is used for dechlorinating the reforming oil, the general effect is poor, and the main characteristics are low chlorine content, short operation period and the like. For example, the chlorine capacity of the liquid-phase dechlorinating agent developed by foreign companies adopted by the fowls refinery can only reach 3%, which is far lower than the control index; the PCL-100 molecular sieve adsorbent developed by UOP company is used for dechlorination of reforming generated oil in a liquid phase state, and the service life is only 3 months.

CN103830996a discloses a highly efficient dechlorinating agent. The dechlorinating agent is prepared from glucose and Cano ₃ 、Mg(NO ₃ ) ₂ 、Zn(NO ₃ ) ₂ 、NaHCO ₃ More than one of the active components are mixed, the carrier and the auxiliary agent are ZSM-5 molecular sieve, methyl cellulose is used as a binder, active component salt is dripped on the treated carrier and the treated auxiliary agent, and then the carrier and the auxiliary agent are subjected to rotation, heating, drying, roasting, forming and granulating to obtain the composite material. CN1088388C discloses a dechlorinating agent. The dechlorinating agent is prepared by taking sodium, calcium and zinc compounds as active components, taking kaolin or montmorillonite, bentonite and diatomite as carriers, kneading, extruding, shaping and roasting at 350-400 ℃. However, none of the dechlorinating agents described above are equally suitable for use in liquid phase dechlorination of reformate.

Generally, the acting force of the carbonaceous carrier (such as activated carbon and the like) and the active metal component is weaker, and the reaction performance of the active metal component can be improved, but the disadvantage is that the metal active component is easy to run off, especially under the condition of liquid phase reaction, and the running off is more serious, and if water exists in the liquid phase material, the running off is further aggravated. When the carrier is used for a dechlorinating agent, the carrier is characterized by reduced chlorine capacity and shortened service life.

Disclosure of Invention

The application mainly aims to provide a liquid-phase dechlorinating agent, a preparation method and application thereof, so as to solve the problem of low chlorine capacity of the liquid-phase dechlorinating agent in the prior art.

In order to achieve the above object, according to one aspect of the present application, there is provided a liquid-phase dechlorinating agent comprising: the active component is selected from at least one of an A molecular sieve, a 13X molecular sieve and a NaY molecular sieve, and the weight content of the active component in the liquid-phase dechlorinating agent is 20-40%; the auxiliary agent component is selected from at least three of copper oxide, sodium oxide, potassium oxide, barium oxide, calcium oxide, magnesium oxide, zinc oxide and ferric oxide, and the weight content of the auxiliary agent component in the liquid-phase dechlorinating agent is 3-10%; the carrier is carbon powder, and the weight content of the carbon powder in the liquid-phase dechlorinating agent is 10% -33%; and the balance of binder.

Further, the binder is silica sol and/or alumina sol; preferably, the weight content of the binder in the liquid-phase dechlorinating agent is 30-55%.

Further, the carbon powder is carbon powder with the average pore diameter less than or equal to 50 nm; preferably, the average pore diameter of the carbon powder is 4-15 nm, more preferably, the specific surface area of the carbon powder is 200-300 m ² /g。

According to a second aspect of the present application, there is also provided a process for preparing a liquid phase dechlorinating agent, the process comprising: dipping a solution prepared from a precursor of an auxiliary component on carbon powder to obtain a first mixture; drying the first mixture, and mixing the dried first mixture with an active component and a binder to obtain a second mixture; extruding the second mixture to obtain a dechlorination agent precursor; roasting the dechlorination agent precursor to obtain a liquid-phase dechlorination agent; wherein the auxiliary component is at least one of copper oxide, zinc oxide and ferric oxide, and the active component is at least one of A-type molecular sieve, 13X molecular sieve and NaY molecular sieve.

Further, the precursor of the adjunct component is a soluble salt, preferably a soluble nitrate or a soluble acetate.

Further, the step of calcining the dechlorination agent precursor to obtain the liquid-phase dechlorination agent comprises the following steps: drying the dechlorination agent precursor to obtain a dried precursor; and roasting the dried precursor to obtain the liquid-phase dechlorinating agent.

Further, the dechlorination agent precursor is dried at 80-120 ℃ to obtain a dried precursor, preferably for 3-5 hours.

Further, roasting the dried precursor in a nitrogen atmosphere to obtain a liquid-phase dechlorinating agent; preferably, the roasting temperature is 350-650 ℃, and the roasting time is 1-6 h.

Further, the roasting temperature is 450-600 ℃, and the roasting time is 3-5 h.

According to a third aspect of the present application there is also provided the use of any of the liquid phase dechlorinating agents described above in dechlorinating a reformate.

Further, the application is to perform dechlorination under the condition that the reformate is in a liquid phase, and it is preferable that the reformate is directly subjected to dechlorination without dehydration.

Further, the temperature of dechlorination treatment is 30-80 ℃, and the mass airspeed is 2-10h ^-1 Preferably 3 to 6 hours ^-1 The method comprises the steps of carrying out a first treatment on the surface of the Preferably, the dechlorination treatment is carried out at a pressure of 0.1 to 3 MPa; the height-diameter ratio of the reactor is 2-8: 1, preferably 3 to 5:1.

by adopting the technical scheme of the application, the carbon powder is adopted as the carrier, the carbon powder has more adsorption sites and large pore volume and specific surface area, which is beneficial to the loading of the auxiliary agent component and the active component on the active carbon powder, and meanwhile, the surface of the active carbon powder has a plurality of oxygen-containing functional groups, so that the polarity of the active carbon powder carrier is improved, the bonding strength between the carrier and the active component can be increased, and the loss of the active component is reduced so as to maintain higher chlorine capacity. Meanwhile, the hydrogen chloride is polar molecules, and is easier to be firmly adsorbed in the pore canal structure of the high-efficiency active carbon powder carrier with larger polarity, thereby being beneficial to improving the dechlorination precision of the dechlorination agent.

Detailed Description

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The present application will be described in detail with reference to examples.

Term interpretation:

chlorine content: chlorine capacity is the chlorine bearing capacity of the dechlorinating agent.

Dechlorination precision: namely, the dechlorination effect of the dechlorination agent is reflected, and the lower the chlorine content of the oil product after dechlorination is, the higher the dechlorination precision of the dechlorination agent is.

In response to the problem of low chlorine content of the liquid phase dechlorinating agent in the prior art, in one exemplary embodiment of the present application, a liquid phase dechlorinating agent is provided, including: the liquid phase dechlorinating agent comprises an active component, an auxiliary component, a carrier for loading the active component and the auxiliary component and a binder, wherein the carrier is carbon powder, and the mass content of the carbon powder in the liquid phase dechlorinating agent is 10% -33%; the active component is at least one of an A-type molecular sieve, a 13X molecular sieve and a NaY molecular sieve, and the mass ratio of the active component in the liquid-phase dechlorinating agent is 20-40%; the auxiliary component is at least three selected from copper oxide, sodium oxide, potassium oxide, barium oxide, calcium oxide, magnesium oxide, zinc oxide and ferric oxide, and the mass content of the auxiliary component in the liquid-phase dechlorinating agent is 3-10%; the balance being binder.

The liquid phase dechlorinating agent provided by the application has a large number of adsorption sites and large pore volume (such as 0.5-1.2 cm) ³ Per g) and a large specific surface area (which may be 150 to 600m, for example ² The carbon powder of/g) is used as a carrier, is favorable for loading auxiliary components and active components on the active carbon powder, and meanwhile, the surface of the active carbon powder is provided with a plurality of oxygen-containing functional groups, so that the polarity of the active carbon powder carrier is improved, the bonding strength between the carrier and the active components can be increased, and the loss of the active components is reduced so as to keep higher chlorine capacity. Meanwhile, the hydrogen chloride is a polar molecule, and is easier to be firmly adsorbed in the pore canal structure of the high-efficiency active carbon powder carrier with larger polarity, thereby being beneficial to improving the dechlorination precision of the dechlorination agent (the dechlorination precision of the dechlorination agent can reach below 0.5 ppm).

The liquid-phase dechlorinating agent has good effect on removing tetrachloroethane and methylene dichloride in oil products and organic chlorine, is particularly suitable for removing hydrogen chloride in reforming generated oil, and is also suitable for fine dechlorination in chemical production of synthetic ammonia, methanol and the like, and the application range is wide.

In the liquid-phase dechlorinating agent provided by the application, the active component is selected from the molecular sieves in the category as the active component, and the liquid-phase dechlorinating agent has the beneficial effect of effectively removing the organic chloride. On the basis of the active components, at least one of copper oxide, zinc oxide and ferric oxide is selected as an auxiliary component, which is helpful for improving the performance of the active components. The binder is used for molding. The components are mixed in reasonable amount, so that the performances of the components are matched in a synergistic way, and the liquid phase dechlorinating agent has higher chlorine capacity.

In the liquid-phase dechlorinating agent, the binder is used for binding each component and forming the product, and the specific type and the dosage of the binder can be reasonably adjusted on the basis of the existing binder. In a preferred embodiment, the binder is a silica sol or an alumina sol; preferably, the mass content of the binder in the liquid-phase dechlorinating agent is 30-55%. The silica sol or the alumina sol is selected as the binder, so that the method has the advantages of low cost and simple forming process. Preferably, the silica sol is a silica sol formed by dissolving silica in a nitric acid solution. Preferably, the alumina sol is an alumina sol formed by dissolving pseudoboehmite in a nitric acid solution. The specific concentration can be reasonably adjusted according to actual needs.

The carbon powder is preferably used as an adsorption carrier of the active component and the auxiliary component, and has a higher pore volume and a larger specific surface area for better loading of the active component and the auxiliary component. In a preferred embodiment, the carbon powder is carbon powder with an average pore size less than or equal to 50 nm; preferably, the average pore diameter of the carbon powder is 4-15 nm, more preferably, the specific surface area of the carbon powder is 200-300 m ² And/g. The carbon powder with the pore structure of microporous structure and mesoporous structure is preferable, and has the larger pore volume and specific surface area, so that the adsorption capacity of active components and auxiliary components is improved, the binding force between the carbon powder and a carrier is stronger, the carbon powder is not easy to run off, and the higher chlorine volume is maintained.

In a second exemplary embodiment of the present application, there is provided a method for preparing any one of the liquid-phase dechlorinating agents described above, including: dipping a solution prepared from a precursor of an auxiliary component on carbon powder to obtain a first mixture; drying the first mixture, and mixing the dried first mixture with an active component and a binder to obtain a second mixture; extruding the second mixture to obtain a dechlorination agent precursor; roasting the dechlorination agent precursor to obtain a liquid-phase dechlorination agent; wherein the auxiliary component is at least one of copper oxide, zinc oxide and ferric oxide, and the active component is at least one of A-type molecular sieve, 13X molecular sieve and NaY molecular sieve.

Aiming at the difference of gas-liquid phase molecular diffusion rates and the special molecular structure of macromolecular hydrocarbon, the preparation method of the liquid phase dechlorinating agent of the application comprises the steps of immersing carbon powder in soluble salt of an auxiliary agent component precursor, mixing the dried carbon powder with an active component A type molecular sieve, a 13X molecular sieve or a NaY molecular sieve, kneading and forming by a binder, and roasting to obtain the dechlorinating agent, wherein the specific surface area and pore volume are large, and the influence of molecular diffusion resistance on dechlorination is reduced.

In addition, during the roasting treatment, the part of the auxiliary component contacted with the carrier can be subjected to partial reduction reaction with carbon element, and the reduced auxiliary component and carbon powder of the carrier have stronger combination action, which is similar to the alloy structure of metal and carbon, and the mechanism of the auxiliary component and the carbon powder is likely to be similar to carburization in the field of metal materials. The acting force between the structure and the carrier is strong, so that the bonding strength between the carrier and the active component is enhanced, and the loss of the active component in the using process is reduced. The non-loss of active ingredient is one of the most important factors for increasing chlorine capacity.

In a preferred embodiment, the precursor of the adjunct component is a soluble salt, preferably a soluble nitrate or a soluble acetate. The soluble salts of copper oxide, zinc oxide and iron oxide precursors are soluble copper salts, soluble zinc salts and soluble iron salts, respectively. And reasonably selecting according to actual needs.

In the preparation method, the roasting step can be obtained by properly adjusting roasting conditions based on the existing roasting step. In a preferred embodiment, the step of calcining the dechlorination agent precursor to obtain the liquid phase dechlorination agent comprises: drying the dechlorination agent precursor to obtain a dried precursor; and roasting the dried precursor to obtain the liquid-phase dechlorinating agent. Drying and then roasting are carried out, so that the roasting structure is uniform.

In the step of drying before baking, the drying method is not limited. In a preferred embodiment, the dechlorinating agent precursor is dried at 80-120 ℃ to obtain a dried precursor, preferably for a period of 3-5 hours.

In the step of roasting, the specific temperature of the roasting can be reasonably adjusted to obtain the optimal roasting temperature. In a preferred embodiment, the dried precursor is calcined under a nitrogen atmosphere to provide a liquid phase dechlorinating agent; preferably, the roasting temperature is 350-650 ℃, and the roasting time is 1-6 h. In a more preferred embodiment, the firing temperature is 450-600℃and the firing time is 3-5 hours.

In a third exemplary embodiment of the present application, there is provided the use of any of the liquid phase dechlorinating agents described above for dechlorinating reformate. The liquid-phase dechlorinating agent has good removal effect on inorganic chlorine and organic chlorine in liquid-phase oil products of reformed oil, and can remove the chlorine content in the oil products to be less than or equal to 0.5mg/L.

In a preferred embodiment, the application is to subject the reformate to dechlorination under conditions where the reformate is in the liquid phase, preferably the reformate is subjected to dechlorination directly without dehydration. The liquid-phase dechlorinating agent has good removal effect on inorganic chlorine and organic chlorine in liquid-phase oil products of reformed oil, and can remove the chlorine content in the oil products to be less than or equal to 0.5mg/L. Thus, the dechlorination treatment of the reformed oil can be directly carried out without dehydration.

The specific parameter conditions of the dechlorination treatment can be determined according to the specific process and process requirements of the reforming process. In a preferred embodiment, the temperature of the dechlorination treatment is 30-80 ℃ and the mass space velocity is 2-10h ^-1 Preferably 3 to 6 hours ^-1 The method comprises the steps of carrying out a first treatment on the surface of the Preferably, the dechlorination treatment is carried out at a pressure of 0.1 to 3 MPa; the height-diameter ratio of the reactor is 2-8: 1, preferably 3 to 5:1. under certain other conditions, the larger the height-diameter ratio is, the longer the contact time between the dechlorinating agent and the oil product is, meanwhile, the fluid is distributed more uniformly in the bed layer, the more obvious the dechlorinating effect is, and the dechlorinating efficiency is high.

The advantageous effects of the present application will be further described below in connection with specific examples.

Example 1

6.0g of pseudo-boehmite (SB) powder was added to a nitric acid solution of a concentration of 2mol/L and a volume of 60mL, and stirred at room temperature for 1 hour to serve as a binder for standby.

Carbon powder (12%) having a mass of 10.0g was added to 5.14g of Mg (NO) ₃ ) ₂ ·6H ₂ O (0.80 g as MgO) (auxiliary 5.2%), ca (NO) 3.5g ₃ ) ₂ ·4H ₂ O (0.84 g in terms of CaO) and 5.0g Cu (NO) ₃ ) ₂ ·3H ₂ O (1.70 g in terms of CuO) is fully immersed and mixed by stirring in an aqueous solution, wherein the carbon powder has the following properties: average pore diameter of 12.8nm and specific surface area of 200m ² /g。

45g of binder (54%), carbon powder mixture and 25g (30%) of 13X molecular sieve are stirred and mixed, then the mixture is kneaded and molded, and then the sample is placed in a drying oven to be dried for 4 hours at 120 ℃, and then the sample is stabilized for 4 hours in a tube furnace under the nitrogen atmosphere at 550 ℃ to obtain the finished product dechlorination agent A.

Example 2

The polymer silica particles with the mass of 35.0g are added into nitric acid solution with the concentration of 5mol/L and the volume of 60mL, and stirred for 1h at room temperature to be used as a binder for standby.

15.0g (13.4%) carbon powder was added to 7.5g NaNO ₃ (in Na) ₂ O was 2.74g (auxiliary 6.25%), ca (NO) 3g ₃ ) ₂ ·4H ₂ O (0.72 g as CaO), 5.0g Cu (NO) ₃ ) ₂ ·3H ₂ O (1.70 g in terms of CuO) and 3.5g KNO ₃ (in K) ₂ O is 1.90 g) in the mixed aqueous solution, and the mixture was sufficiently impregnated by stirring. The carbon powder has the following properties: average pore diameter of 10.3nm and specific surface area of 220m ² /g。

After removing the excess liquid, the carbon powder mixture was mixed with a mixture of 65g (58%) nitric acid solution and polymeric silica particles and 25g (22%) 13X molecular sieve with stirring. And then, after kneading and forming the mixture, placing the sample in a drying oven to dry for 4 hours at 80 ℃, and then stabilizing the sample in a tube furnace under the nitrogen atmosphere at 550 ℃ for 4 hours to obtain the finished product dechlorinating agent B.

Example 3

The kaolin with the mass of 20g is added into nitric acid aqueous solution with the concentration of 3mol/L and the volume of 60mL, and stirred for 45min at room temperature to be used as a binder for standby.

Carbon powder with a mass of 10.0g (13.7%) was added to 6.5g of Cu (NO) ₃ ) ₂ ·3H ₂ O (2.21 g in terms of CuO) (auxiliary 6.7%), ca (NO) 5.5g ₃ ) ₂ ·4H ₂ O (1.32 g in terms of CaO), 2.3g of Ba (NO) ₃ ) ₂ (1.35 g in terms of BaO) was stirred in the mixed aqueous solution to be sufficiently impregnated. The carbon powder has the following properties: average pore diameter of 8.5nm and specific surface area of 240m ² /g。

After removing the excess liquid, the carbon powder mixture was mixed with a mixture of 30g nitric acid solution and kaolin and 28g (38.4%) NaY molecular sieve with stirring. And then, after kneading and forming the mixture, placing the sample in a drying oven to dry for 4 hours at 120 ℃, and then, stabilizing the sample in a tube furnace under the nitrogen atmosphere at 550 ℃ for 3 hours to obtain the finished product dechlorinating agent C.

Example 4

30g of SB powder is added into aqueous solution of nitric acid with the concentration of 3mol/L and the volume of 60mL, and the mixture is stirred for 45min at room temperature to be used as a binder.

MgSO 3.5g ₄ ·7H ₂ O (1.16 g as MgO) (auxiliary 7.4%), ca (NO) 5.5g ₃ ) ₂ ·4H ₂ O (1.32 g in terms of CaO), 7.0g Cu (NO) ₃ ) ₂ ·3H ₂ O (2.38 g in terms of CuO), 5.2g NaNO ₃ (in Na) ₂ 1.90g of O) was added to the mixture to prepare a mixed aqueous solution, and 30.0g of carbon powder (33%), 34g of the binder (37.5%) and 20g (22%) of the type A molecular sieve were added and stirred to sufficiently impregnate the carbon powder with the salt. The carbon powder has the following properties: average pore diameter of 7.8nm and specific surface area of 255m ² /g。

After filtration, the sample was dried in a drying oven at 120℃for 4 hours, and then was subjected to stabilization treatment in a tube furnace under nitrogen atmosphere at 550℃for 4 hours to obtain the final dechlorination agent D.

Example 5

Fe (NO) with a mass of 3.6g ₃ ) ₃ ·9H ₂ O (in Fe) ₂ O ₃ 0.70g (auxiliary 5.2%), 3.5g Ca (NO) ₃ ) ₂ ·4H ₂ O (0.84 g based on CaO), KNO of 2.8g ₃ (in K) ₂ 1.30g of O and 5.0g of Cu (NO) ₃ ) ₂ ·3H ₂ O (1.70 g in terms of CuO) was prepared as an aqueous solution, 15.6g of carbon powder (17.7%), 48g of the binder (54.5%) and 20g of 13X molecular sieve (22.7%) were added, and the mixture was stirred to sufficiently impregnate the carbon powder with the salt. The carbon powder has the following properties: an average pore diameter of 6.6nm and a specific surface area of 268m ² /g。

After filtration, the sample is dried in a drying oven at 90 ℃ for 5 hours, and then is stabilized in a tube furnace under the nitrogen atmosphere at 600 ℃ for 2 hours, so that the finished product dechlorinating agent E is obtained.

Example 6

Fe (NO) with a mass of 3.6g ₃ ) ₃ ·9H ₂ O (in Fe) ₂ O ₃ 0.70g (5.2%), 4.5g NaNO ₃ (in Na) ₂ O1.64 g), 6.0g Cu (NO) ₃ ) ₂ ·3H ₂ O (2.04 g in terms of CuO), 3.5g of Mg (NO) ₃ ) ₂ ·6H ₂ O (0.55 g based on MgO) was prepared as a mixed aqueous solution, and 22.0g of carbon powder (23.4%), 43g (45.8%) of the binder and 24g of NaY molecular sieve (25.6%) were added thereto by stirring to sufficiently impregnate the carbon powder with the salt. The carbon powder has the following properties: average pore diameter of 6nm and specific surface area of 270m ² /g。

After filtration, the sample is placed in a drying oven to be dried for 5 hours at 85 ℃, and then the sample is stabilized for 5 hours in a tube furnace under the nitrogen atmosphere at 450 ℃ to obtain the finished product dechlorination agent F.

Example 7

Fe (NO) with a mass of 3.6g ₃ ) ₃ ·9H ₂ O (in Fe) ₂ O ₃ 0.70g (10.7%), 4.5g NaNO ₃ (in Na) ₂ 1.64g O), 4.5g KNO ₃ (in K) ₂ 2.09g of O), 6.0g of Cu (NO) ₃ ) ₂ ·3H ₂ O (2.04 g in terms of CuO) was prepared as a mixed aqueous solution, and 6.0g (10%) of carbon powder, 30g (50%) of the binder and 18g (30%) of the type A molecular sieve were added thereto and stirred to sufficiently impregnate the carbon powder with the salt thereof. The carbon powder has the following properties: average pore diameter of 5.5nm and specific surface area of 280m ² /g。

After filtration, the sample is placed in a drying oven to be dried for 4 hours at 95 ℃, and then the sample is baked for 1 hour in a tube furnace under the nitrogen atmosphere at 650 ℃ to obtain the finished product antichlor G.

Example 8

30g of SB powder and polymer silica particles were added to a nitric acid solution having a concentration of 1mol/L and a volume of 90mL, and stirred at room temperature for 50 minutes.

15.0g of carbon powder was added to a mixture of Mg (NO) having a mass of 7.5g ₃ ) ₂ ·9H ₂ O (1.18 g as MgO), 2.3g Ba (NO) ₃ ) ₂ (1.35 g in terms of BaO), 6.5g Cu (NO) ₃ ) ₂ ·3H ₂ O (2.21 g in terms of CuO) was immersed in a 30ml aqueous solution with stirring. The carbon powder has the following properties: average pore diameter of 4.3nm and specific surface area of 300m ² /g。

After removing the excess liquid, the carbon powder mixture and 15g of X-type molecular sieve were added to 30g of nitric acid solution and mixed with the mixture of SB powder and polymeric silica particles under stirring. And (3) kneading and forming the pretreated mixture in a kneader, drying the sample in a drying oven at 120 ℃ for 3 hours, and then stabilizing the sample in a tube furnace at 350 ℃ under nitrogen atmosphere for 6 hours to obtain the finished product dechlorinating agent H.

Example 9

This example shows the results of testing the HCl performance of dechlorinating agents A-H in removal of reformate. Reforming the generated oil with chlorine content of 5 mug/L and water content of 20 mug/L at 30-80 ℃, 0.1-3MPa and airspeed of 2-10h ^-1 And (3) filling a dechlorinating agent for a liquid-phase dynamic dechlorinating experiment, measuring the chlorine content in the reformed oil flowing out of the dechlorinating tank, and analyzing the penetration chlorine content of the dechlorinating agent when the chlorine content is more than 0.5 mug/L. The chlorine capacity of the penetrated sample was measured after the sample was removed from the dechlorination apparatus, and the results are shown in Table 1.

The chlorine capacity measuring method and the calculation formula are as follows:

penetration chlorine capacity = mass content of chlorine in the post penetration dechlorinating agent/total mass of post penetration dechlorinating agent 100%.

Table 1: chlorine capacity of sample

As can be seen from table 1 above: the dechlorinating agents A-H all have good chlorine capacity. The chlorine capacity of the dechlorinating agent is not changed greatly under the same conditions, the pressure is from 0.1 to 3MPa and the temperature is from 30 to 80 ℃, which indicates that the influence of the pressure and the temperature on dechlorination is small; the airspeed is in the range of 2-10, when the airspeed is more than 7, the chlorine capacity is quickly reduced from 30.8% at 6 to 27.3%, and the chlorine capacity is obviously reduced, which indicates that the preferred airspeed range is 3-6; the ratio of high diameter is in the range of 2:1-8:1, the chlorine capacity is increased along with the increase of the ratio of high diameter, when the ratio of high diameter is 2, the chlorine capacity is 25.1%, when the ratio of high diameter is 3, the chlorine capacity is 31.3%, the increase is very high, when the ratio of high diameter is increased to 8, the chlorine capacity is 32.8%, and the increase is no longer obvious. The higher the ratio is, the better the ratio is, and the higher the ratio is, the greater the pressure drop of the bed layer is, so that the more preferable ratio is between 3:1 and 5:1.

Comparative example 1

Referring to the method of example 1 of CN1088388C, caCO is added in weight percent ₃ 35％、ZnCO ₃ 20％Mixing the above three materials together, adding 25% Na into the mixture ₂ CO ₃ And extruding the mixture into strips with the diameter of 0.45-0.9mm after uniformly mixing, and drying and roasting for 1 hour to obtain a dechlorination agent sample.

Comparative example 2

Referring to the method of example 2 of CN103127903A, 25g of ferrous sulfate, 40g of calcium oxide and 15g of active attapulgite clay were weighed and mixed, followed by kneading for 45 minutes; adding 35g of silica sol into the uniform dry material, wet-mixing the materials for 30min until the materials are mixed and ground into paste, putting the paste on a small-sized strip extruder, and extruding phi 4 strips; the strips were dried at 180℃for 2 hours to prepare dechlorination agent samples.

Comparative example 3

The procedure and procedure of example 8 was followed, with the stabilization treatment being changed to a conventional calcination treatment, i.e., calcination at 400℃for 3 hours, to give the final dechlorinating agent.

Sample H was subjected to dechlorination test under the same conditions as those of the samples obtained in comparative examples 1, 2 and 3, respectively, on reformate having a water content of 20. Mu.g/L and a chlorine content of 5. Mu.g/L and reformate having a chlorine content of 5. Mu.g/L and a water content of 0.5. Mu.g/L. The temperature is 30 ℃, the high diameter ratio is 4:1, and the liquid space velocity is 4h ^-1 The chlorine capacity data obtained at a pressure of 3MPa are shown in Table 2.

TABLE 2 chlorine content of the dechlorinating agent of example 8 and comparative examples 1-3 as a function of water content

It can be seen from Table 2 that the higher the water content in the oil, the smaller the chlorine content of the dechlorinating agent; the increase in trace water content from 0.5 to 25 μg/L compared to other dechlorinating agents reduced the chlorine capacity of the dechlorinating agent of example 8 from 35.7 to 31.8%, by about 4 percent, while the chlorine capacity of the comparative dechlorinating agent was reduced by more than 10 percent, indicating that the optimized dechlorinating agent of the present application has good water resistance.

From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects: the liquid phase dechlorinating agent has the advantages of low cost of raw materials, simple preparation method, long service life, high mechanical strength, stability of each component under the liquid phase dechlorinating condition, difficult loss, and certain desulfurization and denitrification effects, and is beneficial to the subsequent treatment process of dechlorinated materials.

The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A liquid phase dechlorinating agent, characterized in that the liquid phase dechlorinating agent comprises:

the active component is selected from at least one of an A-type molecular sieve, a 13X molecular sieve and a NaY molecular sieve, and the weight content of the active component in the liquid-phase dechlorinating agent is 20% -40%;

the auxiliary agent component is selected from at least three of copper oxide, sodium oxide, potassium oxide, barium oxide, calcium oxide, magnesium oxide, zinc oxide and ferric oxide, and the weight content of the auxiliary agent component in the liquid-phase dechlorinating agent is 3% -10%;

the carrier is used for loading the active component and the auxiliary component, the carrier is carbon powder, and the weight content of the carbon powder in the liquid-phase dechlorinating agent is 10% -33%; the average pore diameter of the carbon powder is 4-15 nm, and the specific surface area of the carbon powder is 200-300 m ² /g; and

the balance of binder;

the preparation method of the liquid-phase dechlorinating agent comprises the following steps:

dipping a solution prepared from a precursor of the auxiliary component on carbon powder to obtain a first mixture;

drying the first mixture, and mixing the first mixture with the active component and the binder to obtain a second mixture;

extruding the second mixture to form strips to obtain a dechlorination agent precursor;

roasting the dechlorination agent precursor to obtain the liquid-phase dechlorination agent;

roasting the dechlorination agent precursor to obtain the liquid-phase dechlorination agent, wherein the step of obtaining the liquid-phase dechlorination agent comprises the following steps of:

drying the dechlorination agent precursor to obtain a dried precursor;

roasting the dried precursor to obtain the liquid-phase dechlorinating agent;

roasting the dried precursor in nitrogen atmosphere to obtain the liquid-phase dechlorinating agent;

the roasting temperature is 350-650 ℃, and the roasting time is 1-6 h.

2. The liquid phase dechlorinating agent according to claim 1, characterized in that the binder is a silica sol and/or an aluminium sol.

3. The liquid-phase dechlorinating agent according to claim 1, wherein a weight content of the binder in the liquid-phase dechlorinating agent is 30% -55%.

4. A process for the preparation of a liquid-phase dechlorinating agent as claimed in any one of claims 1 to 3, characterised in that the preparation process comprises:

dipping a solution prepared from a precursor of an auxiliary component on carbon powder to obtain a first mixture;

drying the first mixture, and mixing the first mixture with an active component and a binder to obtain a second mixture;

drying the dechlorination agent precursor to obtain a dried precursor;

roasting the dried precursor to obtain the liquid-phase dechlorinating agent;

the roasting temperature is 350-650 ℃, and the roasting time is 1-6 h.

5. The method of claim 4, wherein the precursor of the adjuvant component is a soluble salt.

6. The method of claim 5, wherein the precursor of the adjunct component is a soluble nitrate or soluble acetate.

7. The method according to claim 4, wherein the dechlorinating agent precursor is dried at 80-120 ℃ to obtain the dried precursor.

8. The method according to claim 7, wherein the drying time is 3 to 5 hours.

9. The method according to claim 4, wherein the baking temperature is 450-600 ℃, and the baking time is 3-5 hours.

10. Use of a liquid phase dechlorinating agent as claimed in any one of claims 1 to 3 for dechlorinating a reformate.

11. The use according to claim 10, characterized in that the dechlorination treatment is carried out under conditions in which the reformate is in the liquid phase.

12. The use according to claim 11, wherein the reformate is subjected to the dechlorination treatment directly without dehydration.

13. The use according to claim 10, characterized in thatThe temperature of the dechlorination treatment is 30-80 ℃, and the mass airspeed is 2-10h ^-1 。

14. The use according to claim 13, wherein the mass space velocity is 3-6h ^-1 。

15. The use according to claim 13, wherein the dechlorination treatment is carried out at a pressure of 0.1-3 mpa; the height-diameter ratio of the reactor is 2-8: 1.

16. the use according to claim 15, wherein the reactor height to diameter ratio is 3-5: 1.