Magnetic activated carbon for removing chloride ions in amine liquid

Abstract

The invention relates to magnetic activated carbon for removing chloride ions in amine liquid. The adsorption characteristic of the activated carbon and the response capability of the magnetic material are combined, so that an efficient, rapid and reusable chloride ion removal process is realized. The preparation method comprises carbonization of the activated carbon substrate, water vapor activation treatment and chemical precipitation preparation of the magnetic material (iron oxide). The magnetic activated carbon has a high specific surface area, a porous structure and good magnetic response capability, and magnetic separation and recovery can be realized through an external magnetic field. Compared with the prior art, the method has the advantages of simplicity and convenience in operation, lower cost, high efficiency, good selectivity and the like. Therefore, the magnetic activated carbon has a wide application prospect in the field of amine liquid treatment, and an innovative solution is provided for environmental protection and equipment protection.

Description

Technical Field

[0001] The invention relates to the field of amine solution treatment, in particular to a magnetic activated carbon used for removing chloride ions from amine solution. Background Art

[0002] In the fields of industrial production and petroleum refining, amine liquid is widely used to absorb and remove gases, acidic substances or other harmful components. However, the chloride ion content in amine liquid often becomes a problem because it causes environmental pollution, equipment corrosion and reduced production efficiency. Therefore, it is very important to find a method to effectively remove chloride ions from amine liquid.

[0003] There are several methods available for removing chloride ions from amine solutions, including ion exchange, electrochemical methods, chemical precipitation, and adsorption. However, these methods have some problems in practical applications. For example, although the ion exchange method can remove chloride ions, it is complicated, time-consuming, and costly to operate. Although the electrochemical method has high selectivity, it requires a long processing time. The chemical precipitation method has limited effect in removing chloride ions and may produce other harmful wastes. Therefore, an efficient, economical, and easy-to-operate method is needed to remove chloride ions from amine solutions. Summary of the invention

[0004] The purpose of the present invention is to provide a magnetic activated carbon for removing chloride ions from amine solution in view of the above problems. By combining the adsorption characteristics of activated carbon and the magnetic response ability of magnetic materials, the magnetic activated carbon can achieve efficient, rapid and reusable chloride ion removal. Compared with the prior art, the magnetic activated carbon has the advantages of simple operation, low cost and good removal effect.

[0005] The main technical scheme of the present invention is: a magnetic activated carbon for removing chloride ions from amine solution, characterized in that the magnetic activated carbon comprises an activated carbon substrate and a magnetic material, the specific surface area of ​​the activated carbon is ≥1500m² / g, it has a porous structure, and the pore size range is 2-5nm; the magnetic material is Fe2O3 magnetic particles, and the average particle size range is between 10-200nm.

[0006] The preparation method of magnetic activated carbon of the present invention comprises: Step a: Activated carbon substrate preparation Raw material selection: Coconut shell is used as raw material, and good quality, clean and impurity-free coconut shell is strictly selected as the starting material of activated carbon. Ensure that the coconut shell has sufficient carbon content and appropriate physical properties.

[0007] Carbonization: The coconut shell raw material is placed in a high temperature furnace and carbonized in an inert atmosphere (such as nitrogen or argon). The temperature range of the carbonization treatment is controlled to be 500°C to 900°C to convert the coconut shell raw material into a high specific surface area activated carbon substrate at high temperature. The carbonization process needs to ensure complete pyrolysis of the coconut shell to obtain uniform activated carbon.

[0008] Cooling and atmosphere conditioning: After carbonization is complete, the activated carbon substrate is removed from the high-temperature furnace and quickly cooled to prevent unnecessary oxidation. It is then stored in a dry and oxygen-free environment to ensure the quality and purity of the substrate.

[0009] Step b: Preparation of magnetic materials Reaction conditions: Under alkaline conditions, FeCl2 or FeCl3 reacts with water or other solvents to generate Fe2O3 magnetic particles. Ensure that the pH value of the reaction is between 8 and 12 to maintain the alkaline reaction environment.

[0010] Reaction temperature and time: The reaction temperature is controlled between 50 and 100°C and the reaction time is maintained between 4 and 6 hours to ensure sufficient generation of Fe2O3 magnetic particles.

[0011] Particle dispersion and uniformity: Ensure that the Fe2O3 magnetic particles are uniformly dispersed in the reaction solution and have the desired particle size range (10 to 200 nm) through proper stirring and control of reaction conditions.

[0012] Step c: Preparation of magnetic activated carbon Impregnation process: Impregnate the activated carbon substrate prepared in advance into the magnetic material solution. The concentration of the magnetic material solution is controlled between 0.1 and 1 mol / L to ensure that enough material can be impregnated into the activated carbon substrate.

[0013] Impregnation time and pH adjustment: The impregnation time is usually controlled between 10 minutes and 2 hours to ensure sufficient material adsorption onto the activated carbon substrate. At the same time, the pH value during the impregnation process is kept between 8 and 12 to maintain an alkaline environment.

[0014] Washing and Drying: The impregnated activated carbon substrate needs to be washed to remove unadsorbed magnetic materials and then dried to ensure that the prepared magnetic activated carbon has the required purity and performance.

[0015] Step d: Magnetic activated carbon treatment and conditioning Heat treatment: The prepared magnetic activated carbon is heat treated in a nitrogen atmosphere, and the calcination temperature is controlled between 200 and 400 °C to improve its stability and adsorption performance.

[0016] Activation treatment: physical activation or chemical activation, where physical activation includes steam activation and carbon dioxide activation. The temperature range of steam activation is between 800 and 1000°C, the activation time is between 1 hour and 3 hours, and the steam flow rate is between 0.1 mL / min and 5 mL / min.

[0017] Surface modification: By introducing free radicals (-COOH) or free radicals (-NH2), the adsorption capacity of magnetic activated carbon for chloride ions is enhanced, thereby improving its efficiency in removing chloride ions from amine solution.

[0018] The magnetic activated carbon of the present invention comprises an activated carbon substrate and a magnetic material. The activated carbon substrate has a high specific surface area and a porous structure, providing abundant adsorption sites. The magnetic material gives the magnetic activated carbon a magnetic response capability, enabling it to respond to an external magnetic field.

[0019] Therefore, the magnetic activated carbon of the present invention provides an innovative method for solving the problem of removing chloride ions in amine solution. The magnetic activated carbon realizes an efficient, rapid and reusable removal process of chloride ions by combining the adsorption characteristics of activated carbon and the magnetic response ability of magnetic materials. Its efficient removal performance and easy operation make it have a wide range of application prospects, and it is expected to play an important role in the fields of industrial production and petroleum refining, and can be applied to the fields of industrial production and petroleum refining, providing an innovative solution for environmental protection and equipment protection. Implementation

[0020] The present invention is described in detail below with reference to the embodiments.

[0021] Example A magnetic activated carbon for removing chloride ions from amine solution, the preparation method of which comprises: Step 1: Prepare the activated carbon substrate 1.1 Select coconut shell as activated carbon raw material. Make sure that the selected coconut shell raw material has sufficient purity and appropriate physical and chemical properties to ensure that the final prepared activated carbon substrate has good adsorption performance.

[0022] 1.2 Carbonization treatment. The coconut shell raw material is pyrolyzed at high temperature, usually in a carbonization furnace. The carbonization temperature range is generally 500℃ to 900℃, and the specific carbonization temperature can be determined according to the characteristics of the raw material and the required activated carbon properties.

[0023] 1.3 Activation treatment is performed to increase the porosity and specific surface area of ​​the carbon substrate. Activation treatment can be performed by physical activation or chemical activation methods. Among them, physical activation methods include water vapor activation and carbon dioxide activation. The water vapor activation method is adopted. The activation temperature is generally between 800°C and 1000°C, and higher temperatures help to increase the porosity and specific surface area. The activation time is generally between 1 hour and 3 hours. The water vapor flow rate can be adjusted according to the size of the activation reactor and the reaction conditions, between 0.1mL / min and 5mL / min. The concentration of the activator can be controlled by adjusting the water vapor flow rate and the contact time of the water vapor with the carbon substrate.

[0024] Step 2: Prepare magnetic materials 2.1 Iron oxide (Fe2O3) was selected as the magnetic material because it has good magnetic properties and chemical stability and is suitable for the preparation of magnetic activated carbon.

[0025] 2.2 Preparation of magnetic particles by chemical precipitation. First, add an appropriate amount of metal salt, such as FeCl2 and FeCl3, to an appropriate solution. During the reaction, the metal salt undergoes reduction and precipitation reactions to generate magnetic particles. The specific reaction equation is as follows: 2FeCl3+3NaOH→Fe2O3+6NaCl+3H2O.

[0026] 2.3 Control the size, shape and magnetic properties of magnetic particles. This can be achieved by adjusting the reaction conditions. For example, the growth process of the particles can be controlled by controlling the pH value, temperature and reaction time of the solution. Higher pH values ​​and longer reaction times can promote the growth of particles, thereby obtaining larger particle sizes. Temperature regulation can also affect the shape and size distribution of the particles. In addition, the morphology of the particles can be regulated by adding surfactants or templates.

[0027] In step 2, the size, shape and magnetic properties of the magnetic particles can be controlled by adjusting the following reaction conditions: pH: Adjusting the pH of the solution can affect the morphology and size of the particles. Higher pH values ​​generally help produce larger particles. The specific pH range can be determined based on laboratory testing and research, and the reaction is usually carried out under alkaline conditions. Temperature: The reaction temperature can affect the shape and size distribution of the particles. Generally, higher temperatures can promote particle growth and produce larger particle sizes. However, too high a temperature may cause particle aggregation or uneven crystal growth. The specific temperature range can be determined based on laboratory testing and preliminary research. Reaction time: Reaction time is also a key factor in controlling particle size. Longer reaction times generally help particle growth and morphology regulation. The specific reaction time can be determined based on laboratory testing and research.

[0028] The pH value of the present invention is in the range of 8-12, the temperature is in the range of 50° C. to 100° C., and the reaction time is preferably in the range of 4 hours to 6 hours.

[0029] Step 3: Combine the magnetic material with the activated carbon substrate 3.1 Choose a suitable method to combine the magnetic material with the activated carbon substrate. Immerse the activated carbon substrate in the magnetic material solution so that it can fully adsorb the magnetic material particles. Control the loading amount of the magnetic particles by adjusting the immersion time, solution concentration and pH value. The following are the specific steps: Prepare the magnetic material solution: Disperse the magnetic material (such as Fe2O3) in an appropriate solvent, such as water or an organic solvent. Ensure that the concentration of the magnetic material in the solution is appropriate. Prepare the activated carbon substrate: Place the activated carbon substrate in dry conditions and ensure that its surface is clean and free of impurities. Impregnation process: Immerse the activated carbon substrate in the magnetic material solution so that it can fully contact and adsorb the magnetic material particles.

[0030] This can be regulated by the following steps: a. Impregnation time: Based on laboratory testing and research, the impregnation time can be adjusted to control the loading of magnetic particles. Generally speaking, longer impregnation time can achieve higher loading. The range is 10 minutes to 2 hours.

[0031] b. Solution concentration: According to the concentration of magnetic material and the adsorption capacity of activated carbon substrate, adjust the solution concentration to control the loading amount of magnetic particles. Generally speaking, higher solution concentration will lead to higher loading amount. The range is 0.1-1mol / L.

[0032] c. pH value: Based on laboratory tests and research, the pH value of the solution is adjusted to affect the adsorption performance of the magnetic particles, ranging from 8-12.

[0033] Washing and drying: The impregnated activated carbon substrate is washed to remove unabsorbed magnetic material particles and solvent residues. It is then placed under appropriate conditions for drying to ensure that the magnetic activated carbon is completely dry.

[0034] Step 4: Treatment and adjustment of the prepared magnetic activated carbon 4.1 Heat treatment is performed at high temperature, such as calcination in a nitrogen atmosphere at a temperature of 200°C to 400°C, to promote structural adjustment and pore development of magnetic activated carbon and improve adsorption performance.

[0035] 4.2 Activate or modify the surface to improve the adsorption selectivity and magnetic response of magnetic activated carbon. For example, the magnetic activated carbon can be treated with a chemical activator, such as an alkaline agent, an activation temperature of 500°C to 900°C, and an activation time of 1 hour to 3 hours. Or its surface can be functionalized to introduce specific functional groups and enhance the adsorption capacity, for example, by introducing free radicals (-COOH) or free radicals (-NH2), its adsorption capacity for chloride ions can be enhanced. Comparative Example 1

[0036] Traditional method: Ion exchange method to remove chloride ions. It requires complicated operation, takes a lot of time and cost. The chloride ion removal rate is only 70%, which cannot meet the requirements of efficient chloride ion removal. Example 1

[0037] Magnetic activated carbon removes chloride ions. The specific surface area of ​​the activated carbon substrate is required to be above 1500m² / g, and the particle size of the magnetic material is between 10-200nm. Within this range, magnetic activated carbon can efficiently remove chloride ions, and its chloride ion removal rate reaches more than 90%. Comparative Example 2

[0038] Traditional method: Chemical precipitation method to remove chloride ions. The reaction is carried out in a wide pH range, but the effect is limited and the waste generated may pollute the environment. Example 2

[0039] Magnetic activated carbon removes chloride ions. The preparation reaction of magnetic materials is required to be carried out under alkaline conditions, with a pH range of 8-12. Within this range, magnetic activated carbon has a good removal effect while avoiding waste generation. Comparative Example 3

[0040] Traditional method: electrochemical method to remove chloride ions. Although it has high selectivity, it takes a long time to process and has high requirements on equipment. Example 3

[0041] Magnetic activated carbon removes chloride ions. The magnetic activated carbon is required to be heat treated, and the calcination temperature range is between 200℃ and 400℃. Within this range, the adsorption performance and stability of the magnetic activated carbon are improved, achieving rapid and efficient chloride ion removal. Comparative Example 4

[0042] Traditional method: chemical activation to remove chloride ions. Although it can increase porosity and specific surface area, the operation is complicated and easily produces waste. Example 4

[0043] Magnetic activated carbon removes chloride ions. The magnetic activated carbon is required to be activated, and the activator is an alkaline substance such as sodium hydroxide (NaOH). The activation temperature ranges from 500°C to 900°C, and the activation time ranges from 1 hour to 5 hours. Within this range, the porosity and specific surface area of ​​the magnetic activated carbon are moderately improved, achieving efficient chloride ion removal while avoiding waste generation. Comparative Example 5

[0044] Traditional method: Use traditional activated carbon to remove chloride ions. Its adsorption capacity and selectivity are low and cannot meet the requirements of efficient removal of chloride ions. Example 5

[0045] Magnetic activated carbon removes chloride ions. It is required that the magnetic activated carbon is surface modified and specific functional groups (such as carboxyl or amino groups) are introduced. Under this condition, the selective adsorption capacity of magnetic activated carbon for chloride ions is enhanced, and efficient and selective chloride ion removal is achieved. To enhance the selective adsorption capacity of magnetic activated carbon for chloride ions, the surface can be modified by soaking the activated carbon in a solution containing carboxyl (-COOH) or amino (-NH2) precursors. For carboxyl introduction, an acidic solution, such as chloroacetic acid, can be used for treatment, followed by washing and drying. For amino introduction, an amino precursor solution, such as ethylenediamine, can be used for treatment, followed by washing and drying. The surface of the magnetic activated carbon treated in this way will have specific functional groups, which will enhance its adsorption selectivity for chloride ions and achieve efficient and selective chloride ion removal.

[0046] From the above comparison, it can be seen that the magnetic activated carbon provided by the present invention realizes an efficient, rapid and reusable chloride ion removal process by reasonably limiting the range of various parameters. Within the parameter range, the magnetic activated carbon can efficiently remove chloride ions while avoiding some problems existing in traditional methods, such as complex operation, time-consuming and waste generation. However, outside the range and conditions, the removal effect of the magnetic activated carbon may be affected and the required chloride ion removal rate cannot be achieved. Therefore, within the limited range, the embodiments of the present invention demonstrate its characteristics of high efficiency, economy and ease of operation, providing an innovative solution for the field of amine liquid treatment.

Claims

1. A magnetic activated carbon for removing chloride ions from amine solution, characterized in that: The magnetic activated carbon comprises an activated carbon substrate and a magnetic material. The activated carbon has a specific surface area of ​​≥1500m² / g, a porous structure, and a pore size range of 2-5nm. The magnetic material is Fe2O3 magnetic particles, and the average particle size range is between 10-200nm.

2. The magnetic activated carbon according to claim 1, characterized in that The preparation method of magnetic activated carbon comprises: a: Preparation of activated carbon substrate: Coconut shell is used as the activated carbon raw material, and the activated carbon substrate is prepared by carbonization and activation treatment; b: Preparation of magnetic material: Fe2O3 magnetic particles are prepared by reacting FeCl2 or FeCl3 to generate Fe2O3 under alkaline conditions, controlling the pH value, reaction temperature and reaction time of the reaction; Fe2O3 magnetic particles are prepared by reacting FeCl2 or FeCl3 to generate Fe2O3 magnetic particles, controlling the pH value of the reaction to be between 8 and 12, maintaining the reaction temperature at 50 to 100° C., and reacting for 4 to 6 hours; c: Preparation of magnetic activated carbon: The activated carbon substrate is immersed in a magnetic material solution, and the magnetic activated carbon is obtained by adjusting the concentration, immersion time and pH value of the magnetic material solution; the dry, impurity-free activated carbon substrate is immersed in the magnetic material solution, the concentration of the magnetic material solution is controlled to be between 0.1 and 1 mol / L, the immersion time is between 10 minutes and 2 hours, and the pH value is maintained between 8 and 12. The activated carbon substrate after immersion is washed and dried to prepare magnetic activated carbon; d: Magnetic activated carbon treatment and adjustment: including heat treatment, activation or surface modification.

3. The magnetic activated carbon according to claim 2, characterized in that In step a, the carbonization treatment is to pyrolyze the coconut shell raw material at high temperature.

4. The magnetic activated carbon according to claim 2 or 3, characterized in that In step a, the carbonization treatment temperature ranges from 500°C to 900°C.

5. The magnetic activated carbon according to claim 2, characterized in that In step a, the activation treatment adopts physical activation or chemical activation, and physical activation includes water vapor activation and carbon dioxide activation.

6. The magnetic activated carbon according to claim 5, characterized in that The water vapor activation has an activation temperature between 800° C. and 1000° C., an activation time between 1 hour and 3 hours, and a water vapor flow rate between 0.1 mL / min and 5 mL / min.

7. The magnetic activated carbon according to claim 2, characterized in that In step b, the pH value is controlled to be 8-12, the temperature is 50° C. to 100° C., and the reaction time is 4 to 6 hours.

8. The magnetic activated carbon according to claim 2, characterized in that In step c, Fe2O3 magnetic particles are dispersed in water or an organic solvent to form a magnetic material solution, a dry, clean, impurity-free activated carbon substrate is immersed in the magnetic material solution, and the immersed activated carbon substrate is washed and dried to obtain magnetic activated carbon.

9. The magnetic activated carbon according to claim 2 or 8, characterized in that In step c, the concentration of the magnetic solution is controlled to be 0.1-1 mol / L, the immersion time is 10 minutes to 2 hours, and the pH value is 8-12.

10. The magnetic activated carbon according to claim 2, characterized in that In step d, the heat treatment has a calcination temperature of 200°C to 400°C; the activation treatment has an activator of an alkaline reagent, an activation temperature of 500°C to 900°C, and an activation time of 1 hour to 5 hours; the surface modification is performed by introducing free radicals (-COOH) or free radicals (-NH2) to enhance its adsorption capacity for chloride ions.