阅读说明：本技术 一种无机脱氯剂、制备方法及应用 (Inorganic dechlorinating agent, preparation method and application ) 是由 张青 卓润生 施宗波 刘新生 何俊潼 周立旻 于 2021-08-11 设计创作，主要内容包括：本发明公开了一种无机脱氯剂、制备方法及应用,无机脱氯剂包括基础载体,基础载体外包覆有稀土氧化物层形成复合载体,复合载体外包覆有活性组分层,其中基础载体为Al-(2)O-(3),活性组分为碱金属氧化物；以占无机脱氯剂总量计各组分的摩尔分数为：1～50％的碱金属氧化物、0.5～5％的稀土氧化物,余量为Al-(2)O-(3)；稀土氧化物与Al-(2)O-(3)表面作用,在其表面形成了碱稳定结构,抑制碱金属与Al-(2)O-(3)作用生成铝酸钠,更好地保留氧化铝的孔道结构,同时稀土氧化物和氧化钠相互作用,稳定氧化钠,防止活性组分的流失,使氧化钠更多以氢氧化钠的形式存在,更好地和HCl反应,从而提高氯容。(The invention discloses an inorganic dechlorinating agent, a preparation method and application thereof 2 O 3 The active component is alkali metal oxide; the mole fraction of each component in the total amount of the inorganic dechlorinating agent is as follows: 1-50% of alkali metal oxide, 0.5-5% of rare earth oxide and the balance of Al 2 O 3 (ii) a Rare earth oxide and Al 2 O 3 Surface reaction to form alkali stable structure on the surface to inhibit alkali metal and Al 2 O 3 Sodium aluminate is generated by action, the pore structure of alumina is better reserved, meanwhile, the rare earth oxide and the sodium oxide interact with each other, the sodium oxide is stabilized, the loss of active components is prevented, the sodium oxide exists in a sodium hydroxide form more, and the sodium oxide better reacts with HCl, so that the chlorine capacity is improved.)

1. The inorganic dechlorinating agent is characterized by comprising a basic carrier, wherein the basic carrier is coated with a rare earth oxide layer to form a composite carrier, the composite carrier is coated with an active component layer, and the basic carrier is Al₂O₃The active component is alkali metal oxide;

the mole fraction of each component in the total amount of the inorganic dechlorinating agent is as follows: 1-50% of alkali metal oxide, 0.5-5% of rare earth oxide and the balance of Al₂O₃。

2. The inorganic dechlorination agent according to claim 1, wherein the rare earth element in the rare earth oxide layer is derived from a salt containing a rare earth element.

3. The inorganic dechlorination agent according to claim 2, wherein the rare earth element in the rare earth oxide layer is derived from lanthanum nitrate or lanthanum chloride.

4. The inorganic dechlorination agent according to claim 1, wherein the Al is selected from the group consisting of Al, and Al₂O₃The aluminum element in the aluminum-containing composite material is derived from one or more of aluminum sol, aluminum nitrate, aluminum sulfate and aluminum chloride.

5. The inorganic dechlorination agent according to claim 1, wherein the alkali metal in the alkali metal oxide is derived from an alkali metal salt or an alkali metal containing base.

6. A process for the preparation of an inorganic dechlorinating agent according to claim 1, comprising the steps of:

mixing an aluminum source and an acidified solution of a rare earth element, adding an alkaline precipitator, precipitating, filtering, and roasting for 1-10h to obtain a composite carrier, wherein the roasting temperature is 500-1000 ℃;

molding the composite carrier;

the composite carrier is dried after being dipped in alkali metal alkaline solution, then the steps of dipping and drying are alternately repeated for 1 to 5 times, and roasting activation is carried out after the last drying is finished, wherein the activation time is 0.5 to 15 hours, and the activation temperature is 300-750 ℃.

7. The method of claim 6, wherein the alkaline precipitant is ammonia water.

8. The preparation method of the inorganic dechlorinating agent according to claim 6, wherein the composite carrier is formed by rolling ball forming;

or;

the composite carrier molding specifically comprises the steps of extruding the composite carrier, cutting into granules and molding.

9. The method as claimed in claim 6, wherein the activation temperature is 300-500 ℃ and the activation time is 1-5 hours; the dipping and drying steps are alternately repeated 1-2 times.

10. Use of an inorganic dechlorinating agent according to any one of claims 1 to 5 or obtained by a process according to any one of claims 6 to 9 in the field of petrochemical industry.

Technical Field

The invention belongs to the technical field of petrochemical industry, and particularly relates to an inorganic dechlorinating agent, a preparation method and application thereof.

Background

The inorganic dechlorinating agent in the current market is mainly prepared by loading active components such as alkali metal, alkaline earth metal compound and the like on a carrier in a certain form, wherein the carrier comprises active Al₂O₃Activated carbon, inorganic clay or diatomaceous earth, and the like. The preparation process of the carbonaceous carrier is complex, the cost is high, the carbonaceous carrier has flammable and explosive risks in the high-temperature roasting process, and active components are easy to lose, such as the carbonaceous carrier with patent application numbers or patent numbers of CN201410776492.3, CN201511020457.X and CN 201711151914.8; the dechlorinating agent prepared by taking inorganic clay or diatomite as a carrier has the defect of small specific surface area, such as patent application numbers or patent numbers CN1064099A and CN 1088388C;

active Al₂O₃The advantages of the dechlorinating agent are Al₂O₃The internal pore canal of (2) is high-polarity, the carrier can absorb a certain amount of HCl gas, the active component can also react with HCl, and the chlorine capacity is high. U.S. patent application No. 4,4639259 discloses a catalyst containing Al₂O₃The alkaline earth metal dechlorinating agent as carrier can reduce HCl to 1ppm at normal temperature, and the penetrating chlorine content is 20%. Chinese patent application CN1079415A discloses a gamma-Al alloy₂O₃The active component is alkali metal and alkaline earth metal carbonate as carrier, and can reduce HCl to 0.5ppm and reach penetrating chlorine capacity of 25%.

In addition, the carrier disclosed in the Chinese patent application CN201410776492.3 is a carbon molecular sieve, and the Chinese patent publication No. CN97116288 uses inorganic clay, bentonite, kaolin or diatomite as the carrier, and improves the chlorine capacity of the dechlorinating agent by modifying the carrier and adding an auxiliary agent.

However, the chlorine capacity, dechlorination accuracy and chlorine capacity at high temperature of the existing inorganic dechlorinating agents on the market need to be further improved.

Disclosure of Invention

Aiming at the problems that the chlorine capacity, the dechlorination precision and the chlorine capacity at high temperature of the existing inorganic dechlorinating agent need to be further improved; the invention provides an inorganic dechlorinating agent.

The invention adopts the following technical scheme: an inorganic dechlorinating agent comprises a basic carrier and a basic carrierCoating rare earth oxide layer to form composite carrier, coating active component layer outside the composite carrier, wherein the base carrier is Al₂O₃The active component is alkali metal oxide;

the mole fraction of each component in the total amount of the inorganic dechlorinating agent is as follows: 1-50% of alkali metal oxide, 0.5-5% of rare earth oxide and the balance of Al₂O₃。

Further defined, the rare earth element in the rare earth oxide layer is derived from a salt containing the rare earth element.

Further defined, the rare earth element in the rare earth oxide layer is derived from lanthanum nitrate or lanthanum chloride.

In a further definition, the Al₂O₃The aluminum element in the aluminum-containing composite material is derived from one or more of aluminum sol, aluminum nitrate, aluminum sulfate and aluminum chloride.

Further defined, the alkali metal in the alkali metal oxide is derived from an alkali metal salt or an alkali containing alkali metal.

The invention also discloses a preparation method of the inorganic dechlorinating agent, which comprises the following steps:

mixing an aluminum source and an acidified solution of a rare earth element, adding an alkaline precipitator, precipitating, filtering, and roasting for 1-10h to obtain a composite carrier, wherein the roasting temperature is 500-1000 ℃;

molding the composite carrier;

the composite carrier is dried after being dipped in alkali metal alkaline solution, then the steps of dipping and drying are alternately repeated for 1 to 5 times, and roasting activation is carried out after the last drying is finished, wherein the activation time is 0.5 to 15 hours, and the activation temperature is 300-750 ℃.

The aluminum source is one or more of aluminum sol, aluminum nitrate, aluminum sulfate and aluminum chloride.

The rare earth element is from lanthanum nitrate or lanthanum chloride; the alkali metal is derived from an alkali metal salt or an alkali containing alkali metal.

Further limited, the alkaline precipitant is ammonia water.

Further limiting, the composite carrier molding is specifically to mold the composite carrier in a rolling ball manner;

or;

the composite carrier molding specifically comprises the steps of extruding the composite carrier, cutting into granules and molding.

Further limiting, the activation temperature is 300-500 ℃, and the activation time is 1-5 hours; the dipping and drying steps are alternately repeated 1-2 times.

The invention has the beneficial effects that: the inorganic dechlorinating agent disclosed above can be applied to the field of petrochemical industry; rare earth oxide and Al₂O₃Surface reaction to form alkali stable structure on the surface to inhibit alkali metal and Al₂O₃Sodium aluminate is generated under the action, the pore structure of alumina is better reserved, meanwhile, the rare earth oxide and the sodium oxide interact with each other, the sodium oxide is stabilized, the loss of active components is prevented, the sodium oxide exists in a sodium hydroxide form more, and the sodium oxide better reacts with HCl, so that the chlorine capacity is improved, and the final dechlorination precision is high.

The carrier has adjustable pore size distribution (different pore size changes caused by different raw material compositions, nucleation conditions, nano-particle sizes and different accumulation modes), stable structure, and large and modifiable inner surface of the pore channel. The carrier is a mesoporous material, so that on one hand, a larger inner surface of a pore channel and a larger pore diameter diffusion channel can be provided, active components are uniformly dispersed, and meanwhile, the transmission performance is improved; on the other hand, the structure can be kept stable at high temperature, the method is suitable for preparing dechlorinating agents used under the conditions of normal temperature and high temperature, the use temperature range is expanded, the use conditions are more loose, the dechlorinating cost is saved, and the method can be applied to the fields of petrochemical industry or other fields needing dechlorination, such as crude oil dechlorination and oil product dechlorination.

Detailed Description

Example 1

Mixing 500g of alumina sol, 0.6g of lanthanum nitrate and deionized water, dropwise adding 4mol/L ammonia water solution, adjusting the pH value to 8, precipitating, carrying out suction filtration, kneading by a small kneader, rolling on a small turntable ball rolling machine to form a ball shape with phi of 3 mm, drying for 8 hours at 120 ℃ in an industrial oven, soaking in 15g of NaOH, drying for 2 hours at 120 ℃ in the industrial oven, and roasting for 2 hours at high temperature at 300 ℃ in an industrial muffle furnace.

Example 2

Mixing 500g of alumina sol, 0.35g of lanthanum chloride and deionized water, dropwise adding 4mol/L ammonia water solution, adjusting the pH value to 8, precipitating, carrying out suction filtration, kneading by a small kneader, rolling on a small turntable ball rolling machine to form a ball shape with phi of 3 mm, drying for 8 hours at 120 ℃ in an industrial oven, soaking in 15g of NaOH, drying for 2 hours at 120 ℃ in the industrial oven, and roasting for 2 hours at high temperature at 300 ℃ in an industrial muffle furnace.

Example 3

Mixing 500g of aluminum nitrate, 0.6g of lanthanum nitrate and deionized water, dropwise adding 4mol/L ammonia water solution, adjusting the pH value to 8, precipitating, filtering, kneading by a small kneader, rolling on a small turntable ball rolling machine to form a ball with a diameter of phi 3 mm, drying for 8 hours at 120 ℃ in an industrial oven, soaking in 15g of NaOH, drying for 2 hours at 120 ℃ in the industrial oven, and roasting for 2 hours at a high temperature of 300 ℃ in an industrial muffle furnace.

Comparative example 1

Dropwise adding 4mol/L ammonia water solution into 500g of alumina sol, adjusting the pH value to 8, precipitating, filtering, kneading by a small kneader, rolling into a sphere with a diameter of 3 mm on a small turntable ball rolling machine, drying for 8 hours at 120 ℃ in an industrial oven, soaking in 15g of NaOH, drying for 2 hours at 120 ℃ in the industrial oven, and roasting for 2 hours at a high temperature of 300 ℃ in an industrial muffle furnace.

Comparative example 2

15g of NaOH is dipped on 120g of alumina balls, dried for 2 hours at 120 ℃ in an industrial oven, and then roasted for 2 hours at a high temperature of 300 ℃ in an industrial muffle furnace.

The dechlorinating agents prepared in examples 1 to 3 and the dechlorinating agents prepared in comparative examples 1 and 2 were measured for their chlorine capacity, and the results are shown in Table 1.

TABLE 1

Item	Example 1	Example 2	Example 3	Comparative example 1	Comparative example 2
						Chlorine capacity (m%) used at normal temperature	30	34	32	25	23
Chlorine capacity (m%) at 800 ℃	24	27	26	13	12

As can be seen from Table 1, the rate capacity at normal temperature of the inorganic dechlorinating agents prepared in examples 1 to 3 (in which the rare earth element is impregnated on the support) can reach 30 m%, which is higher than that of the inorganic dechlorinating agents not impregnated with the rare earth element (comparative examples 1 to 2), and the chlorine capacity of the inorganic dechlorinating agents prepared in examples 1 to 3 is reduced at high temperature, so that the dechlorination requirements can be satisfied.

Finally, it should be noted that: the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.