Rosin-based activated carbon and preparation method thereof

Abstract

The invention relates to the field of activated carbon, in particular to rosin-based activated carbon and a preparation method thereof. The active carbon provided by the invention is obtained by carrying out stress refining on the rosin serving as a substrate material and belongs to biomass-based active carbon, but the active carbon prepared from the rosin is larger in specific surface area and stronger in adsorption capacity compared with common active carbon, the raw materials are renewable, and environmental pollution is reduced. The preparation method of the rosin-based activated carbon comprises the following three steps of S1 raw material purification, S2 carbonization and S3 activation, in the S2 carbonization step, an acid solution and a metal oxide are added, the carbonization temperature can be reduced, rosin decomposition can be enhanced, and generation of functional groups with high specific surface area is effectively promoted; the metal oxide can increase the porosity of the rosin-based activated carbon.

Description

Technical Field

[0001] The invention relates to the field of activated carbon, and in particular to rosin-based activated carbon and a preparation method thereof. Background Art

[0002] Activated carbon has a wide range of applications in environmental protection, chemical industry, food processing, medicine and energy storage due to its excellent adsorption performance, high specific surface area and chemical stability. Traditional raw materials for the preparation of activated carbon mainly include wood materials, coal and petroleum coke. However, with the deepening of the concept of sustainable development, finding renewable and environmentally friendly raw materials for the preparation of activated carbon has become a research hotspot. Pine is one of the most common log species in China, with a wide distribution, mainly in the northeast, northwest and south China. Pine is a coniferous tree and one of the important wood resources in my country. The annual demand is very large. Rosin is a natural resin secreted by pine and other plants, so it is rich in source and is a potential high-quality raw material for the preparation of activated carbon. At present, there are few studies on the preparation of rosin-based activated carbon, and most of the preparation methods have problems such as complex process, high energy consumption and unstable product performance.

[0003] Therefore, it is very valuable to invent a rosin-based activated carbon with simple process, low energy consumption and excellent product performance. Summary of the invention

[0004] In view of the above-mentioned existing technical problems, the present invention aims to provide a rosin-based activated carbon and a preparation method thereof. The rosin-based activated carbon prepared by this method has a very high specific surface area and a good pore structure, which greatly improves the adsorption capacity of the activated carbon and has broad application prospects.

[0005] The invention discloses a method for preparing rosin-based activated carbon, comprising the following steps:

[0006] S1 Raw material purification: Add the collected rosin to the melter, add turpentine oil conditioning liquid, then add washing water, stir and mix, heat and melt, cool and clarify after melting, remove fine impurities and water after clarification, and obtain pure rosin liquid;

[0007] S2 carbonization: adding the purified rosin liquid obtained in step S1 to a reactor, introducing an inert gas into the reactor to replace the air, then adding deionized water, an acidic solution and a metal oxide into the reactor filled with the inert gas, and then heating, pressurizing and stirring, cooling after the reaction is completed to obtain a solid-liquid mixture, centrifuging the solid-liquid mixture, collecting solid matter, combining the collected solid matter and washing it with a washing liquid, and drying it after washing to obtain rosin carbide;

[0008] S3 activation: add the rosin carbide obtained in step S2 to an activation reactor, introduce water vapor, increase the temperature and pressurize the activation reactor to react for 2 to 4 hours, and after the reaction is completed, take out the reactants in the activation reactor and dry them to obtain rosin-based activated carbon.

[0009] Preferably, in the S1 raw material purification step, the oil content of the turpentine oil conditioning liquid is 20-30%.

[0010] Preferably, in the S1 raw material purification step, the volume ratio of the rosin to the washing water is 1:(4-5).

[0011] Preferably, in the S1 raw material purification step, the temperature required for the heating and melting process is 100-120°C.

[0012] Preferably, in the S2 carbonization step, the inert gas is helium, argon or nitrogen.

[0013] Preferably, in the S2 carbonization step, the acidic solution is an acetic acid solution with a mass fraction of 30 to 50%; and the metal oxide is calcium oxide.

[0014] Preferably, in the S2 carbonization step, the mass ratio of the acid solution to the rosin liquid is (0.5-1.5):1; the mass ratio of the metal oxide to the rosin liquid is (0.8-1.2):1.

[0015] Preferably, in the S2 carbonization step, the reaction temperature of the reactor during the heating, pressurizing and stirring process is 220-250° C.; the pressure of the reactor is 3-5 MPa.

[0016] Preferably, in the S3 activation step, the temperature of the activation reactor is 300-350° C.; the pressure of the activation reactor is 10-14 MPa.

[0017] A rosin-based activated carbon is prepared by any of the above-mentioned methods for preparing rosin-based activated carbon.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention provides a method for preparing rosin-based activated carbon. The rosin-based activated carbon prepared by the method has a high specific surface area. Rosin is used as a raw material. After pyrolysis and activation treatment, the specific surface area of ​​the activated carbon obtained is ≥1800m2 / g, which greatly improves its adsorption capacity; the method has a good pore structure and can adjust the activation conditions to form a rich microporous structure, so that the activated carbon exhibits superior performance in gas and liquid adsorption; the method is environmentally friendly and uses renewable resource rosin as a raw material, which reduces dependence on traditional wood and coal resources. At the same time, inert gas protection is used in the production process to reduce environmental pollution; the method has a broad application prospect. The rosin-based activated carbon can be widely used in water treatment, air purification, waste gas treatment and other environmental protection fields, and has high commercial value and social benefits.

[0020] In the preparation method of a rosin-based activated carbon provided by the present invention, in the S2 carbonization step, adding an acidic solution and a metal oxide can reduce the carbonization temperature, enhance the decomposition of the rosin, and effectively promote the formation of functional groups with a high specific surface area; the metal oxide can increase the porosity of the rosin-based activated carbon. DETAILED DESCRIPTION

[0021] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0022] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0023] Embodiment 1: A method for preparing rosin-based activated carbon, comprising the following steps:

[0024] S1 Raw material purification: Add the collected rosin to the melter, add turpentine oil with an oil content of 20%, and then add washing water, wherein the volume ratio of rosin to washing water is 1:4; stir and mix, heat to 100°C for melting, dissolve for 1 hour, cool to the reaction liquid after melting, remove fine impurities and water after clarification, and obtain pure rosin liquid.

[0025] S2 carbonization: add the purified rosin liquid obtained in step S1 to a reactor, introduce nitrogen into the reactor to replace the air, then add deionized water, 30% acetic acid solution and calcium oxide to the reactor filled with inert gas, wherein the mass ratio of acetic acid solution to rosin liquid is 0.5:1, and the mass ratio of calcium oxide to rosin liquid is 0.8:1; then raise the temperature of the reactor to 220°C, pressurize to 3MPa and start stirring for 2h, after the reaction is completed, cool to 25°C to obtain a solid-liquid mixture, set the centrifugal speed of the centrifuge to 1500rpm, place the solid-liquid mixture in a centrifuge for centrifugal separation, collect solid matter, combine the collected solid matter and wash it with washing liquid, wash it 2 to 3 times in total, wherein the washing liquid is ethanol solution, dry it after washing, set the drying temperature of the dryer to 80°C, and obtain rosin carbonization.

[0026] S3 activation: add the rosin carbide obtained in step S2 to the activation reactor, introduce water vapor, raise the temperature of the activation reactor to 300°C, pressurize it to 10MPa and start the activation reaction. The reaction time is 2h. After the reaction is completed, take out the reactants in the activation reactor and dry them. Set the drying temperature of the dryer to 50°C to obtain rosin-based activated carbon.

[0027] Embodiment 2: A method for preparing rosin-based activated carbon, comprising the following steps:

[0028] S1 Raw material purification: Add the collected rosin to the melter, add turpentine oil with an oil content of 25%, and then add washing water, wherein the volume ratio of rosin to washing water is 1:4.5; stir and mix, heat to 110°C for melting, dissolve for 2 hours, cool to the end of melting until the reaction liquid is clear, remove fine impurities and water after clarification, and obtain pure rosin liquid.

[0029] S2 carbonization: add the purified rosin liquid obtained in step S1 to a reactor, introduce nitrogen into the reactor to replace the air, then add deionized water, 40% acetic acid solution and calcium oxide to the reactor filled with inert gas, wherein the mass ratio of acetic acid solution to rosin liquid is 1:1, and the mass ratio of calcium oxide to rosin liquid is 1:1; then raise the temperature of the reactor to 235°C, pressurize to 4MPa and start stirring for 3.5h, cool to 25°C after the reaction is completed, obtain a solid-liquid mixture, set the centrifugal speed of the centrifuge to 1500rpm, place the solid-liquid mixture in a centrifuge for centrifugal separation, collect solid matter, combine the collected solid matter and wash it with washing liquid, wash it 2 to 3 times in total, wherein the washing liquid is ethanol solution, dry it after washing, set the drying temperature of the dryer to 80°C, and obtain rosin carbonization.

[0030] S3 activation: add the rosin carbide obtained in step S2 to the activation reactor, introduce water vapor, raise the temperature of the activation reactor to 330°C, pressurize it to 12MPa and start the activation reaction. The reaction time is 3h. After the reaction is completed, take out the reactants in the activation reactor and dry them. Set the drying temperature of the dryer to 50°C to obtain rosin-based activated carbon.

[0031] Embodiment 3: A method for preparing rosin-based activated carbon, comprising the following steps:

[0032] S1 Raw material purification: Add the collected rosin to the melter, add turpentine oil with an oil content of 30%, and then add washing water, wherein the volume ratio of rosin to washing water is 1:5; stir and mix, heat to 120℃ for melting, after dissolving for 3h, cool down until the reaction liquid is clear, remove fine impurities and water after clarification, and obtain pure rosin liquid.

[0033] S2 carbonization: add the purified rosin liquid obtained in step S1 to a reactor, introduce nitrogen into the reactor to replace the air, then add deionized water, 50% acetic acid solution and calcium oxide to the reactor filled with inert gas, wherein the mass ratio of acetic acid solution to rosin liquid is 1.5:1, and the mass ratio of calcium oxide to rosin liquid is 1.2:1; then raise the temperature of the reactor to 250°C, pressurize to 5MPa and start stirring for 5h, after the reaction is completed, cool to 25°C to obtain a solid-liquid mixture, set the centrifugal speed of the centrifuge to 1500rpm, place the solid-liquid mixture in a centrifuge for centrifugal separation, collect solid matter, combine the collected solid matter and wash it with washing liquid, wash it 2 to 3 times in total, wherein the washing liquid is ethanol solution, dry it after washing, set the drying temperature of the dryer to 80°C, and obtain rosin carbonization.

[0034] S3 activation: add the rosin carbide obtained in step S2 to the activation reactor, introduce water vapor, raise the temperature of the activation reactor to 350°C, pressurize it to 14MPa and start the activation reaction. The reaction time is 4h. After the reaction is completed, take out the reactants in the activation reactor and dry them. Set the drying temperature of the dryer to 50°C to obtain rosin-based activated carbon.

[0035] Embodiment 4: A method for preparing rosin-based activated carbon, comprising the following steps:

[0036] S1 Raw material purification: Add the collected rosin to the melter, add turpentine oil with an oil content of 23.4%, and then add washing water, wherein the volume ratio of rosin to washing water is 1:4.3; stir and mix, heat to 120°C for melting, dissolve for 1.7 hours, cool to the end of melting until the reaction liquid is clear, remove fine impurities and water after clarification, and obtain pure rosin liquid.

[0037] S2 carbonization: add the purified rosin liquid obtained in step S1 to a reactor, introduce argon gas into the reactor to replace the air, then add deionized water, 35% acetic acid solution and calcium oxide to the reactor filled with inert gas, wherein the mass ratio of acetic acid solution to rosin liquid is 1.3:1, and the mass ratio of calcium oxide to rosin liquid is 0.9:1; then raise the temperature of the reactor to 235°C, pressurize to 3.5MPa and start stirring for 2.2h, after the reaction is completed, cool to 25°C to obtain a solid-liquid mixture, set the centrifugal speed of the centrifuge to 1500rpm, place the solid-liquid mixture in a centrifuge for centrifugal separation, collect solid matter, combine the collected solid matter and wash it with washing liquid, wash it 2 to 3 times in total, wherein the washing liquid is ethanol solution, dry it after washing, set the drying temperature of the dryer to 80°C, and obtain rosin carbonization.

[0038] S3 activation: add the rosin carbide obtained in step S2 to the activation reactor, introduce water vapor, raise the temperature of the activation reactor to 328°C, pressurize it to 12.6MPa and start the activation reaction. The reaction time is 2.7h. After the reaction is completed, take out the reactants in the activation reactor and dry them. Set the drying temperature of the dryer to 50°C to obtain rosin-based activated carbon.

[0039] Example 5: A method for preparing rosin-based activated carbon, comprising the following steps:

[0040] S1 Raw material purification: Add the collected rosin to the melter, add turpentine oil with an oil content of 26.9%, and then add washing water, wherein the volume ratio of rosin to washing water is 1:4.7; stir and mix, heat to 120°C for melting, dissolve for 2.6 hours, cool to the end of melting until the reaction liquid is clear, remove fine impurities and water after clarification, and obtain pure rosin liquid.

[0041] S2 carbonization: add the purified rosin liquid obtained in step S1 to a reactor, introduce helium into the reactor to replace the air, then add deionized water, 44% acetic acid solution and calcium oxide to the reactor filled with inert gas, wherein the mass ratio of acetic acid solution to rosin liquid is 0.7:1, and the mass ratio of calcium oxide to rosin liquid is 1.1:1; then raise the temperature of the reactor to 242°C, pressurize to 4.3MPa and start stirring for 3.6h, cool to 25°C after the reaction is completed, obtain a solid-liquid mixture, set the centrifugal speed of the centrifuge to 1500rpm, place the solid-liquid mixture in a centrifuge for centrifugal separation, collect solid matter, combine the collected solid matter and wash it with washing liquid, wash it 2 to 3 times in total, wherein the washing liquid is ethanol solution, dry it after washing, set the drying temperature of the dryer to 80°C, and obtain rosin carbonization.

[0042] S3 activation: add the rosin carbide obtained in step S2 to the activation reactor, introduce water vapor, raise the temperature of the activation reactor to 343°C, pressurize it to 13.2MPa and start the activation reaction. The reaction time is 2.7h. After the reaction is completed, take out the reactants in the activation reactor and dry them. Set the drying temperature of the dryer to 50°C to obtain rosin-based activated carbon.

[0043] Example 6: A method for preparing rosin-based activated carbon, comprising the following steps:

[0044] S1 Raw material purification: Add the collected rosin to the melter, add turpentine oil with an oil content of 25%, and then add washing water, wherein the volume ratio of rosin to washing water is 1:4.5; stir and mix, heat to 110°C for melting, dissolve for 2 hours, cool to the end of melting until the reaction liquid is clear, remove fine impurities and water after clarification, and obtain pure rosin liquid.

[0045] S2 carbonization: add the purified rosin liquid obtained in step S1 to a reactor, introduce nitrogen into the reactor to replace the air, then add deionized water and 40% acetic acid solution by mass to the reactor filled with inert gas, wherein the mass ratio of acetic acid solution to rosin liquid is 1:1; then raise the temperature of the reactor to 235°C, pressurize to 4MPa and start stirring for 3.5h, after the reaction is completed, cool to 25°C to obtain a solid-liquid mixture, set the centrifugal speed of the centrifuge to 1500rpm, place the solid-liquid mixture in a centrifuge for centrifugal separation, collect solid matter, combine the collected solid matter and wash it with washing liquid, wash it 2 to 3 times in total, wherein the washing liquid is ethanol solution, dry it after washing, set the drying temperature of the dryer to 80°C, and obtain rosin carbonization.

[0046] S3 activation: add the rosin carbide obtained in step S2 to the activation reactor, introduce water vapor, raise the temperature of the activation reactor to 330°C, pressurize it to 12MPa and start the activation reaction. The reaction time is 3h. After the reaction is completed, take out the reactants in the activation reactor and dry them. Set the drying temperature of the dryer to 50°C to obtain rosin-based activated carbon.

[0047] Embodiment 7: A method for preparing rosin-based activated carbon, comprising the following steps:

[0048] S1 Raw material purification: Add the collected rosin to the melter, add turpentine oil with an oil content of 25%, and then add washing water, wherein the volume ratio of rosin to washing water is 1:4.5; stir and mix, heat to 110°C for melting, dissolve for 2 hours, cool to the end of melting until the reaction liquid is clear, remove fine impurities and water after clarification, and obtain pure rosin liquid.

[0049] S2 carbonization: add the purified rosin liquid obtained in step S1 to a reactor, introduce nitrogen into the reactor to replace the air, then add deionized water and calcium oxide to the reactor filled with inert gas, the mass ratio of calcium oxide to rosin liquid is 1:1; then raise the temperature of the reactor to 235°C, pressurize to 4MPa and start stirring for 3.5h, after the reaction is completed, cool to 25°C to obtain a solid-liquid mixture, set the centrifugal speed of the centrifuge to 1500rpm, place the solid-liquid mixture in a centrifuge for centrifugal separation, collect solid matter, combine the collected solid matter and wash it with washing liquid, wash it 2 to 3 times in total, wherein the washing liquid is ethanol solution, dry it after washing, set the drying temperature of the dryer to 80°C, and obtain rosin carbonization.

[0050] S3 activation: add the rosin carbide obtained in step S2 to the activation reactor, introduce water vapor, raise the temperature of the activation reactor to 330°C, pressurize it to 12MPa and start the activation reaction. The reaction time is 3h. After the reaction is completed, take out the reactants in the activation reactor and dry them. Set the drying temperature of the dryer to 50°C to obtain rosin-based activated carbon.

[0051] Embodiment 8: A method for preparing rosin-based activated carbon, comprising the following steps:

[0052] S1 Raw material purification: Add the collected rosin to the melter, add turpentine oil with an oil content of 25%, and then add washing water, wherein the volume ratio of rosin to washing water is 1:4.5; stir and mix, heat to 110°C for melting, dissolve for 2 hours, cool to the end of melting until the reaction liquid is clear, remove fine impurities and water after clarification, and obtain pure rosin liquid.

[0053] S2 carbonization: add the purified rosin liquid obtained in step S1 to a reactor, introduce nitrogen into the reactor to replace the air, then add deionized water to the reactor filled with inert gas, then raise the temperature of the reactor to 235°C, pressurize to 4MPa and start stirring for 3.5h, after the reaction is completed, cool to 25°C to obtain a solid-liquid mixture, set the centrifugal speed of the centrifuge to 1500rpm, place the solid-liquid mixture in a centrifuge for centrifugal separation, collect the solid matter, combine the collected solid matter and wash it with washing liquid, wash it 2 to 3 times in total, wherein the washing liquid is ethanol solution, dry it after washing, set the drying temperature of the dryer to 80°C, and obtain rosin carbonization.

[0054] S3 activation: add the rosin carbide obtained in step S2 to the activation reactor, introduce water vapor, raise the temperature of the activation reactor to 330°C, pressurize it to 12MPa and start the activation reaction. The reaction time is 3h. After the reaction is completed, take out the reactants in the activation reactor and dry them. Set the drying temperature of the dryer to 50°C to obtain rosin-based activated carbon.

[0055] The performance of the rosin-based activated carbon prepared in Examples 1 to 8 was tested, and the test results are shown in the following table:

[0056] Example <![CDATA[Specific surface area (m 2 / g)]]> Pore ​​diameter (nm) <![CDATA[Density (g / cm 3 )]]> Adsorption capacity (mg / g) 1 1800 2 0.3 200 2 1900 1.59 0.2 260 3 1860 1.85 0.23 240 4 1832 1.93 0.28 220 5 1875 1.65 0.26 243 6 1750 2.31 0.35 180 7 1610 2.51 0.46 175 8 1450 5.61 0.53 150

[0057] It can be seen from the test data in the above table that the specific surface area of ​​Examples 1 to 5 is not less than 1800m2 / g, the pore diameter is not greater than 2nm, the density is not higher than 0.3g / cm3, and the adsorption capacity is not less than 200mg / g. Examples 1 to 5 are screenings of various parameters in the preparation conditions of rosin-based activated carbon, among which the rosin-based activated carbon prepared in Example 2 has the best performance. Example 6 is an activated carbon without adding metal oxides in the S2 carbonization step, Example 7 is an acetic acid solution without adding the S2 carbonization step, and Example 8 is an activated carbon with both metal oxides and acetic acid solution added in the S2 carbonization step. The performance of the rosin-based activated carbon prepared in Examples 6 to 8 is much worse than that in Examples 1 to 5, because the addition of acidic solution and metal oxide can reduce the carbonization temperature, enhance the decomposition of rosin, and effectively promote the formation of functional groups with high specific surface area; metal oxides can increase the porosity of rosin-based activated carbon.

[0058] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the invention.

Claims

1. A method for preparing rosin-based activated carbon, characterized in that: The following steps are involved: S1 Raw material purification: Add the collected rosin to the melter, add turpentine oil conditioning liquid, then add washing water, stir and mix, heat and melt, cool and clarify after melting, remove fine impurities and water after clarification, and obtain pure rosin liquid; S2 carbonization: adding the purified rosin liquid obtained in step S1 to a reactor, introducing an inert gas into the reactor to replace the air, then adding deionized water, an acidic solution and a metal oxide into the reactor filled with the inert gas, and then heating, pressurizing and stirring, cooling after the reaction is completed to obtain a solid-liquid mixture, centrifuging the solid-liquid mixture, collecting solid matter, combining the collected solid matter and washing it with a washing liquid, and drying it after washing to obtain rosin carbide; S3 activation: add the rosin carbide obtained in step S2 to an activation reactor, introduce water vapor, increase the temperature and pressurize the activation reactor to react for 2 to 4 hours, and after the reaction is completed, take out the reactants in the activation reactor and dry them to obtain rosin-based activated carbon.

2. The method for preparing rosin-based activated carbon according to claim 1, characterized in that: In the S1 raw material purification step, the oil content of the turpentine oil conditioning liquid is 20-30%.

3. The method for preparing rosin-based activated carbon according to claim 1, characterized in that: In the S1 raw material purification step, the volume ratio of the rosin to the washing water is 1:(4-5).

4. The method for preparing rosin-based activated carbon according to claim 1, characterized in that: In the S1 raw material purification step, the temperature required for the heating and melting process is 100-120°C.

5. The method for preparing rosin-based activated carbon according to claim 1, characterized in that: In the S2 carbonization step, the inert gas is helium, argon or nitrogen.

6. The method for preparing rosin-based activated carbon according to claim 1, characterized in that: In the S2 carbonization step, the acidic solution is an acetic acid solution with a mass fraction of 30 to 50%; and the metal oxide is calcium oxide.

7. The method for preparing rosin-based activated carbon according to claim 1, characterized in that: In the S2 carbonization step, the mass ratio of the acid solution to the rosin liquid is (0.5-1.5):1; the mass ratio of the metal oxide to the rosin liquid is (0.8-1.2):

1.

8. The method for preparing rosin-based activated carbon according to claim 1, characterized in that: In the S2 carbonization step, the reaction temperature of the reactor during the heating, pressurizing and stirring process is 220-250° C.; the pressure of the reactor is 3-5 MPa.

9. The method for preparing rosin-based activated carbon according to claim 1, characterized in that: In the S3 activation step, the temperature of the activation reactor is 300-350° C.; the pressure of the activation reactor is 10-14 MPa.

10. Rosin-based activated carbon prepared by the method for preparing rosin-based activated carbon according to any one of claims 1 to 9.