阅读说明：本技术 一种多孔泡沫状液相脱氯剂、其制备方法和用途 (Porous foam emulsion phase dechlorinating agent, preparation method and application thereof ) 是由 张海洪 于群 辛靖 侯章贵 王文辰 王宁 陈松 刘剑 杨国明 张博 于 2020-06-03 设计创作，主要内容包括：本发明公开了一种多孔泡沫状液相脱氯剂、其制备方法和用途。所述液相脱氯剂包括多孔泡沫陶瓷载体和形成于所述多孔泡沫陶瓷载体上的复合涂层,所述复合涂层包含粘结剂和纳米氧化物。本发明所述的液相脱氯剂具有氯容高、机械强度高、耐水性强、易制备等优点,脱氯剂的压碎强度＞100N/cm,在50℃时的穿透氯容量可达到60％以上。(The invention discloses a porous foam emulsion phase dechlorinating agent, a preparation method and application thereof. The liquid-phase dechlorination agent comprises a porous ceramic foam carrier and a composite coating formed on the porous ceramic foam carrier, wherein the composite coating comprises a binder and a nano-oxide. The liquid phase dechlorinating agent has the advantages of high chlorine capacity, high mechanical strength, strong water resistance, easy preparation and the like, the crushing strength of the dechlorinating agent is more than 100N/cm, and the chlorine penetration capacity at 50 ℃ can reach more than 60 percent.)

1. A liquid phase dechlorination agent, which is characterized by comprising a porous foamed ceramic carrier and a composite coating formed in the pores and on the surface of the porous foamed ceramic carrier, wherein the composite coating comprises a binder and a nano-oxide.

2. The liquid-phase dechlorination agent according to claim 1, wherein the porous ceramic foam support has a three-dimensional network structure inside, and comprises a mixture of silica and alumina;

preferably, in the porous foamed ceramic carrier, the mass percentages of the silicon oxide and the aluminum oxide are respectively 10-20% and 80-90% based on the total mass of the silicon oxide and the aluminum oxide as 100%.

3. The liquid-phase dechlorination agent according to claim 1 or 2, characterised in that the thickness of the composite coating is between 5 μ ι η and 500 μ ι η, preferably between 50 μ ι η and 100 μ ι η.

4. The liquid phase dechlorination agent of any one of claims 1 to 3 wherein the binder comprises at least one of silica sol and water glass;

preferably, the nano-oxide comprises at least one of nano-zinc oxide, nano-calcium oxide and nano-magnesium oxide;

preferably, the average particle size of the nano-oxide is 1nm to 200nm, preferably 1nm to 100 nm;

preferably, the mass of the nano oxide is 5-70%, preferably 5-40% of the mass of the porous foamed ceramic carrier.

5. A process for the preparation of a liquid phase dechlorination agent according to any one of claims 1 to 4, wherein the process comprises the steps of:

(1) preparing a gel comprising a binder and a nano-oxide;

(2) soaking the porous foamed ceramic carrier in the gel obtained in the step (1), taking out the porous foamed ceramic carrier after soaking, blowing out residual gel in pore channels and drying;

(3) and (4) roasting to obtain the liquid-phase dechlorinating agent.

6. The method of claim 5, wherein step (1) further comprises a surfactant in the gel;

preferably, the surfactant comprises at least one of polyethylene glycol, tween-80 and cetyltrimethylammonium bromide;

preferably, the mass concentration of the surfactant in the gel is 1-3%;

preferably, the binder comprises at least one of silica sol and water glass (i.e., liquid sodium silicate);

preferably, step (1) comprises: mixing the binder, the nano oxide, the surfactant and the water, and stirring to obtain the gel.

7. The method according to claim 5 or 6, wherein the time for the impregnation in step (2) is 1 to 2 hours;

preferably, the porous ceramic foam carrier of step (2) is subjected to step (1') before use, and specifically comprises: carrying out alkali washing on the porous foamed ceramic carrier, then washing the porous foamed ceramic carrier to be neutral by water, and drying the porous foamed ceramic carrier for later use;

preferably, the drying temperature in the step (1') is 100-120 ℃, and the time is 1-3 h;

preferably, step (2) further comprises repeating the following steps at least 1 time until the desired coating thickness is achieved: soaking the porous foamed ceramic carrier dried in the step (2) in gel, taking out the porous foamed ceramic carrier after soaking, blowing out residual gel in pore channels and drying;

preferably, the number of repetitions is 1 to 30, preferably 5 to 30.

8. The method according to any one of claims 5 to 7, wherein the roasting temperature in the step (3) is 300 ℃ to 500 ℃;

preferably, the calcination of step (3) is carried out in an air atmosphere.

9. Method according to any of claims 5-8, characterized in that the method comprises the steps of:

(1) carrying out alkali washing on the porous foamed ceramic carrier to remove ash and impurities on the surface of the carrier, washing the carrier to be neutral by using deionized water, and drying the carrier for 1-3 h at the temperature of 100-120 ℃ for later use;

(2) adding a binder, a nano oxide and a surfactant into deionized water, and continuously stirring to obtain a milky white gel, wherein the mass concentration of the surfactant in the milky white gel is 1-3%;

(3) soaking the porous foamed ceramic carrier obtained in the step (1) in the milky white gel obtained in the step (2) for 1-2 h, taking out, blowing off residual gel in pore channels, and drying;

(4) repeating step (3) at least 1 time until the desired coating thickness is achieved;

(5) roasting at 300-500 deg.c in air atmosphere to obtain porous foam emulsion phase dechlorinating agent.

10. Use of a liquid phase dechlorination agent according to any one of claims 1 to 4 wherein the liquid phase dechlorination agent is used in a liquid phase dechlorination process for reforming produced oil.

Technical Field

The invention belongs to the field of dechlorinating agents, relates to a liquid-phase dechlorinating agent, a preparation method and application thereof, and particularly relates to a high-efficiency porous foam emulsion-phase dechlorinating agent, a preparation method and application thereof.

Background

Chlorine is a poison of catalysts and adsorbents which are common in industry, and causes pollution to the environment. Chlorine is reactive with metal ions due to its high electron affinity and mobility, and often migrates downward with the process fluid, causing permanent poisoning of the catalyst and often being full bed. For liquid phase dechlorination of reformate, the operating temperature is low, typically not exceeding 70 ℃. The reformed oil contains a small amount of water, and the water has a large influence on a dechlorinating agent which takes alkali metal as an active component because under the liquid-phase dechlorination condition, the water and dechlorinated substances such as calcium chloride, magnesium chloride and the like generate a complex reaction to cause the structural damage of the dechlorinating agent and the blockage of internal pore channels, and on the other hand, the liquid-phase mass transfer resistance of the reformed oil is large, and the adverse factors finally cause the reduction of chlorine capacity.

The active components of the antichlor prepared by the domestic blending method are mostly Na₂CO₃、NaOH、NaHCO₃、CaO、CaCO₃The dechlorinating agent is prepared by mixing, kneading, molding, drying and roasting the oxides, hydroxides and carbonates of alkali metals and alkaline earth metals, wherein part of products adopt organic amines as active components, and the carriers are mostly porous substances which are cheap and easy to obtain, such as alumina, diatomite, clay and the like, and organic and high-molecular additives are added.

The method for preparing dechlorinating agent from Na is proposed by the people of the Rou Jiu Ming (CN101773768A)₂CO₃、CaCO₃CaO and MgO are active components, cross-linked bentonite is a porous auxiliary agent, methyl cellulose is a foaming agent and an auxiliary agent, and the active components are kneaded, extruded and dried and roasted to obtain the porous material with the pore volume of 0.3-0.4 mL/g and the specific surface area of 70m²/g～90m²A dechlorinating agent with chlorine capacity of 12.3 to 19.1 percent.

Xiaotiansu et al (CN103386244B) developed a dechlorinating agent, which comprises calcium carbonate, zinc carbonate, manganese carbonate or oxide as active component, weak acid salt, kaolin, pseudo-boehmite or alumina as carrier, organic pore-forming agent and assistant, and is prepared through mixing with water, kneading, shaping, drying and calcining to obtain the dechlorinating agent with 30% chlorine capacity.

CN105542836A provides a high-precision liquid-phase dechlorinating agent, which consists of the following components: 5-20% of CuO, 5-10% of CaO, 4-8% of KOH and the balance of modified activated carbon; the modified activated carbon is activated carbon which is treated by acidification and oxidation. The dechlorinating agent adopts the modified activated carbon as the carrier, so that the pore channel structure of the activated carbon can be optimized, the pore volume and the specific surface area are improved, the content of oxygen-containing functional groups on the surface of the activated carbon can be increased, the polarity of the carrier is improved, the combination degree between the carrier and the active components is enhanced, the loss of the active components is reduced, and hydrogen chloride is a polar molecule, so that the dechlorinating agent is easier to be stably adsorbed on the surface of the modified activated carbon with the same larger polarity, and the dechlorinating precision is improved. Meanwhile, the synergistic effect of the three active substances in the dechlorinating agent increases the reactivity of the dechlorinating agent and hydrogen chloride, the maximization of the chlorine capacity of the dechlorinating agent is effectively realized, the chlorine capacity of the liquid-phase dechlorinating agent is up to 16%, and the dechlorination precision is as low as below 0.5 ppm. However, the chlorine capacity of the dechlorinating agent is low, the service cycle is short, and the long-cycle operation of the device cannot be met.

CN1724119A discloses a preparation method of a dechlorinating agent, which comprises the steps of carrying out slurry synthesis reaction on polyhexenol, bentonite and alkyl ammonium salt with an aqueous solution containing sodium hydroxide, magnesium hydroxide and copper hydroxide at the temperature of 40-80 ℃, carrying out extrusion forming on a reaction product after the reaction is finished, drying for 4h at the temperature of 80-100 ℃, and then roasting for 10h at the temperature of 650 ℃ to obtain the dechlorinating agent. Although the dechlorination agent in the above technology is 823K, 0.1mg/m³The penetrating chlorine capacity of the catalyst is 55.3%, but the penetrating chlorine capacity of the catalyst at normal temperature is very small and is less than 20%.

CN104437342A provides a high-chlorine-capacity liquid-phase dechlorinating agent, a preparation method and application thereof, which are suitable for removing inorganic chlorine in oil products, and are particularly suitable for removing hydrogen chloride in reformed oil. The carrier of the dechlorinating agent is a carbon molecular sieve, the active component is an oxide of alkali metal and alkaline earth metal, and the auxiliary agent component is copper oxide, iron oxide or zinc oxide. The preparation method comprises soaking soluble copper salt, calcium salt, magnesium salt, barium salt, etc. onto cylindrical carbon molecular sieve, drying, and stabilizing. The dechlorinating agent has the advantages of high chlorine capacity, cheap and easily-obtained raw materials, uniform distribution of active components on a carrier, good thermal stability, strong water resistance, high mechanical strength and the like, and simultaneously has the effects of desulfurization and denitrification. However, the dechlorinating agent adopts a carbon molecular sieve as a carrier, so that the cost is too high to meet the industrial requirements.

The dechlorinating agent disclosed in CN103386244 is prepared from the following materials: 15-70% of a carrier; 15-60% of active component; 1-10% of pore-forming agent; 1-5% of extrusion aid; 2-10% of a binder; the carrier is weak acid salt, kaolin, pseudoboehmite or Al₂O₃At least one of; mixing the above materials, adding water, kneading, extruding, drying, and roasting. The dechlorination agent has high adsorption efficiency on high-concentration or low-concentration HCl at normal temperature, high dechlorination precision and chlorine capacity of more than 30 percent, and has a certain adsorption effect on organic chloride. The dechlorinating agent is in the gasThe phase dechlorination process has higher chlorine capacity, but the dechlorination agent has smaller chlorine capacity when used for liquid-phase dechlorination.

CN 102357354 discloses a high-chlorine-capacity dechlorinating agent which is composed of 30-60% of aluminum hydroxide and 30-50% of sodium hydroxide by weight, and is prepared by precipitating and mixing the aluminum hydroxide and the sodium hydroxide to form gel, crystallizing, washing, drying and roasting the gel. The dechlorination agent has high pore volume, good mechanical strength, wear resistance, less dust and no blockage of equipment pipelines, and is widely used in dechlorination industrial towers. However, the chlorine capacity of the liquid phase dechlorination process is smaller.

CN 109453735A (a honeycomb liquid phase dechlorinating agent, a preparation method and application thereof) provides a high-precision liquid phase dechlorinating agent, which comprises the following components: 3-28% of nano calcium oxide and the balance of titanium dioxide carrier; the dechlorinating agent adopts titanium dioxide as a carrier, silica sol and nano calcium oxide as a composite coating, and the chlorine capacity of the liquid-phase dechlorinating agent is 20-30%.

In summary, the dechlorinating agent developed at home and abroad at present is mainly used in the gas-phase dechlorinating process, the chlorine capacity for liquid-phase dechlorinating is only about 8-16%, the chlorine capacity is low, the water resistance is poor, the mechanical strength is poor, the dechlorinating agent is easy to pulverize and harden and the like, and the requirements of long-period (more than 12 months) operation of the device cannot be met. Therefore, how to improve the liquid-phase dechlorinating agent and the preparation method thereof to overcome the defects of the prior art still remains a problem to be solved in the field.

Disclosure of Invention

In order to overcome the defects of low chlorine capacity, low mechanical strength and the like of a liquid-phase dechlorinating agent in the prior art, the invention aims to provide a liquid-phase dechlorinating agent, a preparation method and application thereof, and particularly relates to a high-efficiency porous foam emulsion-phase dechlorinating agent, a preparation method and application thereof. The liquid-phase dechlorinating agent has the advantages of high chlorine capacity, high mechanical strength, good water resistance and long service cycle, and can meet the requirement of long-term (12 months and more) operation of the device.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a liquid phase dechlorination agent comprising a porous ceramic foam support and a composite coating formed within and on the pores of the porous ceramic foam support, the composite coating comprising a binder and a nano-oxide.

The liquid phase dechlorinating agent has the characteristics of high strength, high porosity and good mass transfer capacity of the porous foamed ceramic carrier, the composite coating containing the binder and the nano oxide is arranged on the porous foamed ceramic carrier, the composite coating is a gel coating, the composite coating exists on the surface and in pores of the carrier in the dipping process but mainly exists in the pores of the carrier, the binder promotes better dispersion and dipping, the nano oxide with the superfine particle size can ensure that the oxide is uniformly dispersed in the carrier, and the factors are comprehensively matched, so that the dechlorinating agent has the advantages of high chlorine capacity, high mechanical strength, good water resistance and long service cycle.

The following is a preferred technical solution of the present invention, but not a limitation to the technical solution provided by the present invention, and the technical objects and advantageous effects of the present invention can be better achieved and achieved by the following preferred technical solution.

The external shape of the porous ceramic foam support is not limited in the present invention, and is preferably an oblate cylindrical shape.

Preferably, the interior of the porous ceramic foam support is a three-dimensional network structure comprising a mixture of silica and alumina.

Preferably, the porous ceramic foam support contains 10 to 20 mass% (e.g., 10%, 12%, 15%, 18%, 20%, etc.) and 80 to 90 mass% (e.g., 80%, 82%, 85%, 88%, 90%, etc.) of silica and alumina, respectively, based on 100 mass% of the total mass of silica and alumina. Partial silica is used to replace alumina, which helps to increase hardness, increase silica content, and improve strength of the dechlorination agent, but too much is not beneficial to carrier formation.

Preferably, the thickness of the composite coating is 5 μm to 500 μm, such as 5 μm, 10 μm, 20 μm, 35 μm, 50 μm, 60 μm, 70 μm, 85 μm, 100 μm, 120 μm, 130 μm, 150 μm, 170 μm, 180 μm, 200 μm, 220 μm, 245 μm, 270 μm, 300 μm, 330 μm, 360 μm, 400 μm, 430 μm, 455 μm, 470 μm or 500 μm, etc., preferably 50 μm to 100 μm. The thickness can be measured by a thickness gauge.

Preferably, the binder comprises at least one of silica sol and water glass (i.e. liquid sodium silicate).

Preferably, the nano-oxide includes at least one of nano-zinc oxide, nano-calcium oxide and nano-magnesium oxide.

Preferably, the average particle size of the nano-oxide is 1nm to 200nm, for example, 1nm, 3nm, 5nm, 8nm, 10nm, 15nm, 20nm, 30nm, 35nm, 50nm, 60nm, 80nm, 100nm, 115nm, 130nm, 150nm, 170nm, 180nm, or 200nm, and the like, preferably … ….

Preferably, the mass of the nano-oxide is 5% to 70% of the mass of the porous foamed ceramic support, such as 5%, 10%, 15%, 18%, 20%, 25%, 30%, 34%, 38%, 42%, 46%, 50%, 55%, 60%, 65%, 70%, etc., preferably 5% to 40%.

The thickness of the composite coating and the content of the nano-oxide affect the chlorine capacity and the strength of the dechlorinating agent, and the thickness and content ranges are preferred in order to obtain better comprehensive performance.

The porous foam emulsion phase dechlorinating agent has high bonding degree between the adhesive and the nano oxide composite coating and the porous foam ceramic carrier, and the coating has smooth surface and no crack; the thickness of the composite coating can be controlled between 5 mu m and 500 mu m, preferably between 50 mu m and 100 mu m, the mass transfer resistance in the liquid-phase dechlorination process is very small, the chlorine capacity can reach more than 60 percent, and the service cycle is long.

In a second aspect, the present invention provides a process for the preparation of a liquid phase dechlorination agent according to the first aspect, the process comprising the steps of:

(1) preparing a gel comprising a binder and a nano-oxide;

(2) soaking the porous foamed ceramic carrier in the gel obtained in the step (1), taking out the porous foamed ceramic carrier after soaking, blowing out residual gel in pore channels and drying;

(3) and (4) roasting to obtain the liquid-phase dechlorinating agent.

The method is simple, and the gel containing the adhesive and the nano oxide can be loaded on the surface of the porous foamed ceramic carrier and in the three-dimensional network structure by impregnation, so that the liquid-phase dechlorinating agent with excellent performance is obtained.

In the present invention, the preparation method of the porous ceramic foam carrier is the prior art, and the preparation method can be performed by referring to the methods disclosed in the prior art by those skilled in the art, and an exemplary preparation method comprises the following steps:

selecting a polyurethane foam plastic mould with a three-dimensional porous structure, dipping the polyurethane foam plastic mould into prepared raw material (the manufacturer generally adopts materials such as alumina, silicon oxide, silicon carbide, zirconia and the like) mixed slurry, fully feeding the mixed slurry into the plastic mould, drying, roasting at a certain temperature, burning the plastic mould, and obtaining the porous foam ceramic with the shape corresponding to the foam plastic mould.

As a preferable technical scheme of the method, the gel in the step (1) further comprises a surfactant. The addition of the surfactant can ensure that the surface of the gel coating is smooth and does not crack in the subsequent drying process, thereby effectively improving the thermal stability of the coating.

Preferably, the surfactant comprises at least one of polyethylene glycol, tween-80 and cetyltrimethylammonium bromide.

Preferably, the mass concentration of the surfactant in the gel is 1% to 3%, such as 1%, 1.3%, 1.5%, 1.7%, 2%, 2.2%, 2.5%, 2.8%, or 3%. If the mass concentration is less than 1%, the dispersion of the nano oxide is not uniform, and the impregnation effect is affected; if the mass concentration is more than 3%, the cost of the dechlorinating agent increases.

Preferably, the binder comprises at least one of silica sol and water glass (i.e. liquid sodium silicate).

The choice of binder and surfactant will affect the performance of the product, and the aforementioned classes of binders and surfactants are preferred in order to further improve the smoothness, stability and compactness of the product.

Preferably, step (1) comprises: mixing the binder, the nano oxide, the surfactant and the water, and stirring to obtain the gel.

Preferably, the impregnation time in step (2) is 1h to 2h, such as 1h, 1.2h, 1.5h, 1.8h or 2h, etc.

As a preferred technical scheme of the method of the invention, the porous foamed ceramic carrier in the step (2) is subjected to the step (1') before use, and the method specifically comprises the following steps: and (3) carrying out alkali washing on the porous foamed ceramic carrier, then washing the porous foamed ceramic carrier to be neutral by using water, and drying the porous foamed ceramic carrier for later use.

According to the preferred technical scheme, ash and impurities on the surface of the carrier are removed through alkaline washing, so that the combination degree of the gel and the surface of the porous foamed ceramic carrier is improved. The alkaline solution used for alkaline washing may be, for example, a 40% by mass sodium hydroxide solution.

Preferably, the drying temperature in step (1') is 100 ℃ to 120 ℃, such as 100 ℃, 105 ℃, 110 ℃, 115 ℃ or 120 ℃ and the like; the time is 1h to 3h, such as 1h, 1.5h, 2h or 3 h.

As another preferred embodiment of the method of the present invention, the step (2) further comprises repeating the following steps at least 1 time until the desired coating thickness is reached: and (3) soaking the porous foamed ceramic carrier dried in the step (2) in gel, taking out the porous foamed ceramic carrier after soaking, blowing out residual gel in pore channels, and drying.

In the invention, the target nano oxide content is difficult to achieve by adopting a single long-time dipping mode. Preferably, the steps are repeated according to this preferred embodiment, and more preferably, the first layer is quickly dried and then dipped before the second layer is hung, and so on.

Because the porous foamed ceramic carrier is compact, the thickness of the composite coating can be controlled by controlling the times of soaking gel, and the mass transfer resistance in the liquid-phase dechlorination process is reduced.

Preferably, the number of repetitions is 1 to 30, such as 1, 2, 3, 5, 6, 8, 10, 12, 15, 17, 19, 20, 22, 24, 25, 28, or 30, and the like.

In order to further ensure the chlorine capacity of the product, the number of repetition is preferably 1 to 30, and more preferably 5 to 30.

Preferably, the temperature of the calcination in step (3) is 300 ℃ to 500 ℃, such as 300 ℃, 325 ℃, 350 ℃, 370 ℃, 380 ℃, 400 ℃, 425 ℃, 440 ℃, 460 ℃, 480 ℃, or 500 ℃, etc.

Preferably, the calcination of step (3) is carried out in an air atmosphere.

As a further preferred technical solution of the method of the present invention, the method comprises the steps of:

(1) carrying out alkali washing on the porous foamed ceramic carrier to remove ash and impurities on the surface of the carrier, washing the carrier to be neutral by using deionized water, and drying the carrier for 1-3 h at the temperature of 100-120 ℃ for later use;

(2) adding a binder, a nano oxide and a surfactant into deionized water, and continuously stirring to obtain a milky white gel, wherein the mass concentration of the surfactant in the milky white gel is 1-3%;

(3) soaking the porous foamed ceramic carrier obtained in the step (1) in the milky white gel obtained in the step (2) for 1-2 h, taking out, blowing off residual gel in pore channels, and drying;

(4) repeating step (3) at least 1 time until the desired coating thickness is achieved;

(5) roasting at 300-500 deg.c in air atmosphere to obtain porous foam emulsion phase dechlorinating agent.

In a third aspect, the present invention provides a use of a liquid phase dechlorination agent according to the first aspect in a liquid phase dechlorination process for reforming produced oil. For example for HCl removal from the liquid phase product in a catalytic reforming section.

The prior art is referred to in the art for techniques not mentioned in the present invention.

Compared with the prior art, the invention has the following beneficial effects:

the porous foam emulsion phase dechlorinating agent has high bonding degree between the adhesive and the nano oxide composite coating and the porous foam ceramic carrier, and the coating has smooth surface and no crack; the thickness of the composite coating can be controlled between 5 mu m and 500 mu m, preferably between 50 mu m and 100 mu m, the crushing strength of the dechlorinating agent is more than 100N/cm, the mass transfer resistance in the liquid phase dechlorinating process is very small, the penetrating chlorine capacity at 50 ℃ can reach more than 60 percent, and the service cycle is long.

The liquid-phase dechlorinating agent has the advantages of high chlorine capacity, high mechanical strength, strong water resistance, easy preparation and the like, and has wide application prospect.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments.

In order to better understand the present invention, the following examples are further provided to illustrate the present invention, but the present invention is not limited to the following examples. The purpose of this is only to better understand the content of the invention, not to limit the scope of protection of the invention.