Injection activated carbon production process taking bamboo as matrix

Abstract

The invention belongs to the technical field of activated carbon preparation, and relates to a production process of injection activated carbon with bamboo as a matrix. The method comprises the following steps: S1, carefully selecting and preparing materials: selecting healthy moso bamboos which are 4-6 years old and have the diameter of 5-8cm, and treating the moso bamboos within one week after cutting down the moso bamboos; according to the method, bamboos are used as raw materials, the source is wide, growth is fast, regeneration is achieved, dependence on traditional raw materials is reduced, and sustainable development is facilitated; the method comprises the steps of primary alkaline leaching combined with ultrasonic treatment, secondary alkaline leaching activation combined with microwave and specific gas activation, multi-stage acid pickling, ball milling shaping, supercritical fluid extraction, high-temperature steam blowing, drying sterilization and the like, impurities are effectively removed, the purity and the adsorption performance of the activated carbon are improved, and the prepared activated carbon is low in impurity content, good in sphericity degree, uniform in particle size and suitable for industrial production. The prepared activated carbon has excellent adsorption performance, is sterile and pyrogen-free, completely meets the strict requirements of injection activated carbon, and can be widely applied to the pharmaceutical industry.

Description

Technical Field

[0001] The invention belongs to the technical field of activated carbon preparation, and relates to a production process of activated carbon injection using bamboo as a matrix. Background Art

[0002] Activated carbon has a developed pore structure and a huge specific surface area, and is widely used in many fields. In the pharmaceutical industry, activated carbon for injection is used to decolorize, remove pyrogens and impurities from injection solutions, and has extremely high requirements for its purity, adsorption performance and safety.

[0003] Traditional activated carbon for injection is mostly produced with high-quality wood, coconut shells, etc. as raw materials. However, wood resources are limited, and large-scale use is not conducive to ecological balance; coconut shell raw materials are restricted by origin and output, and prices fluctuate greatly. Bamboo grows rapidly, is renewable, and is widely distributed. Using bamboo as a matrix to produce activated carbon for injection is expected to solve the problem of raw material supply and reduce costs. However, bamboo has a complex composition and contains more impurities such as lignin and hemicellulose, which are difficult to effectively remove by traditional processes, resulting in the prepared activated carbon having many impurities and low purity, which cannot meet the requirements of injection. Therefore, it is crucial to develop an efficient production process for activated carbon for injection using bamboo as a matrix.

[0004] In order to overcome the shortcomings of the prior art, people have proposed various solutions through continuous exploration. For example, a Chinese patent discloses an activated carbon production process [application number: 202011294022.5], which includes the following steps: S1, raw material screening; S2, activation, placing the clinker in a boiler, adding an activator for activation in an anaerobic atmosphere, the activation time is 8-10 hours, and raking, controlling and adjusting are performed during the operation; S3, crushing and screening; S4, pickling and rinsing, adding a certain amount of water and 32%-36% concentration of hydrochloric acid into the barrel, diluting it to about 5% solution, and turning on the ultrasonic device under the barrel at the same time, boiling it with steam for 3-4 hours, filtering it after cooling, and injecting clean water. At this time, the ultrasonic device does not stop, and the material is taken out after the water is filtered out; S5, drying, the material is put into a drying furnace for drying, and activated carbon is obtained after drying; S6, screening and packaging. However, this solution is not suitable for production using bamboo as raw material, and it is still difficult to effectively remove impurities such as lignin and hemicellulose, resulting in the prepared activated carbon having many impurities and low purity, and there is a defect that it cannot meet the requirements of injections. Summary of the invention

[0005] The purpose of the present invention is to solve the above problems and provide a production process of activated carbon injection with bamboo as the matrix.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A production process for activated carbon injection using bamboo as a matrix comprises the following steps:

[0008] S1: Select and prepare materials: Select healthy bamboos of 4-6 years old and 5-8 cm in diameter, and process them within 1 week after felling. Remove the green skin, bamboo nodes and internal medulla of the bamboo, leaving only the dense part in the middle of the bamboo stem, and cut into small pieces of 3-5 cm in length.

[0009] S2: Initial alkali immersion: Immerse the bamboo segments in a mixed solution of sodium hydroxide and sodium carbonate at a temperature of 50-60°C and a mass fraction of 8%-12%, wherein the mass ratio of sodium hydroxide to sodium carbonate is 3:1, and the immersion time is 3-4 hours to remove lignin and hemicellulose in the bamboo, and then rinse with clean water until neutral.

[0010] S3: Pre-carbonization: Put the bamboo segments after the initial alkali immersion into an oxygen-free sealed carbonization furnace, raise the temperature from room temperature to 450-550°C at a heating rate of 6-8°C / min, and keep the temperature constant for 1.5-2.5 hours to complete the pre-carbonization process and obtain pre-carbonized bamboo materials.

[0011] S4: Secondary alkali immersion activation: The pre-carbonized bamboo material is mixed with a potassium hydroxide solution with a mass fraction of 15%-20% in a solid-liquid ratio of 1:4, refluxed with stirring at 85-95°C for 4 hours, then transferred to a microwave reactor, microwaved at a power of 500-600W for 15-20 minutes, and then placed in an activation furnace, and a mixed gas of carbon dioxide and water vapor (volume ratio of 1:1, total flow rate of 6-8L / min) is introduced at 850-950°C for activation for 1.5 hours.

[0012] S5: Multi-stage pickling: first soak the activated product in a 6%-8% hydrochloric acid solution at 30-40°C for 2-3 hours, then soak it in a 3%-5% oxalic acid solution at 40-50°C for 1-2 hours, and finally rinse it with deionized water until the pH value of the washing liquid is 6.5-7.0.

[0013] S6: Ball milling: Place the acid-washed activated carbon in a ball mill, add zirconium oxide grinding balls at a mass ratio of activated carbon to grinding balls of 1:(5-8), ball mill for 2-3 hours, control the rotation speed at 300-400r / min, so that the activated carbon particles reach a sphericity ≥0.8 and a particle size of 150-250 mesh.

[0014] S7: Supercritical fluid extraction: Use carbon dioxide as the supercritical fluid, and extract the ball-milled activated carbon for 2-3 hours at a temperature of 35-45°C and a pressure of 20-25MPa to remove residual small molecular organic matter.

[0015] S8: High-temperature steam purging: Place the extracted activated carbon in a tubular furnace and pass high-temperature steam at 1000-1100°C for 30-40 minutes with a steam flow rate of 4-6L / min.

[0016] S9: Drying and sterilization: Dry the steam-purged activated carbon in a vacuum drying oven at 130-150°C for 7-8 hours with a vacuum degree of -0.09-0.08MPa, and then dry-heat sterilize at 180-200°C for 2-3 hours to obtain an activated carbon product that meets the requirements for injections.

[0017] In the above-mentioned process for producing activated carbon injection using bamboo as a matrix, in the step S1, the processing starts within 2-3 days after the bamboo is cut down.

[0018] In the above-mentioned process for producing activated carbon for injection with bamboo as the matrix, in the step S2, ultrasonic treatment is performed every 30 minutes during the soaking process, the ultrasonic frequency is 50-60kHz, and the treatment time is 5 minutes.

[0019] In the above-mentioned process for producing activated carbon for injection using bamboo as a matrix, in the step S3, the pressure in the carbonization furnace is controlled at 0.05-0.1 MPa.

[0020] In the above-mentioned process for producing activated carbon for injection using bamboo as a matrix, in the step S4, a pause of 30 seconds is performed every 5 minutes during the microwave treatment.

[0021] In the above-mentioned process for producing activated carbon for injection using bamboo as a matrix, in the step S5, a surfactant sodium dodecylbenzene sulfonate accounting for 0.1%-0.2% of the mass of the solution is added during the hydrochloric acid soaking.

[0022] In the above-mentioned process for producing activated carbon for injection using bamboo as a matrix, in the step S6, a lubricant zinc stearate accounting for 0.5%-1% of the mass of the activated carbon is added into the ball mill.

[0023] In the above-mentioned process for producing activated carbon for injection using bamboo as a matrix, in the step S7, 0.3%-0.5% of ethanol by volume is added to the carbon dioxide fluid as an entrainer before extraction.

[0024] In the above-mentioned process for producing activated carbon for injection using bamboo as a matrix, in the step S8, hydrogen accounting for 1%-2% of its volume is mixed into the steam.

[0025] In the above-mentioned process for producing activated carbon for injection using bamboo as a matrix, in the step S9, the activated carbon is subjected to gamma ray irradiation after sterilization, and the irradiation dose is 5-10 kGy.

[0026] Compared with the prior art, the advantages of the present invention are:

[0027] The invention uses bamboo as a raw material, which has a wide source, grows fast and is renewable, reduces dependence on traditional raw materials, and is conducive to sustainable development. Through multi-stage treatment, such as primary alkali leaching combined with ultrasonic treatment, secondary alkali leaching activation combined with microwave and specific gas activation, multi-stage pickling, ball milling shaping, supercritical fluid extraction, high-temperature steam purging and drying sterilization, etc., impurities are effectively removed, and the purity and adsorption performance of activated carbon are improved. The prepared activated carbon has low impurity content, good sphericity, uniform particle size, excellent adsorption performance, is sterile and pyrogen-free, fully meets the strict requirements of activated carbon for injection, and can be widely used in the pharmaceutical industry.

[0028] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0030] Example 1

[0031] The present invention will be further described below in conjunction with the accompanying drawings.

[0032] like Figure 1 As shown, a production process of activated carbon for injection with bamboo as the matrix includes the following steps S1.: Select and prepare materials: Select healthy bamboo with a diameter of 6 cm and a 5-year-old age, and process it within 3 days after felling. Remove the green skin, bamboo nodes and internal medulla of the bamboo, retain the dense part in the middle of the bamboo stem, and cut it into small sections with a length of 4 cm.

[0033] S2: Initial alkali immersion: Immerse the bamboo segments in a mixed solution of sodium hydroxide and sodium carbonate at a temperature of 55°C and a mass fraction of 10% for 3.5 hours. Perform ultrasonic treatment every 30 minutes at a frequency of 55kHz for 5 minutes, and then rinse with clean water until neutral.

[0034] S3: Pre-carbonization: put the bamboo segments after the initial alkali immersion into an oxygen-free sealed carbonization furnace, raise the temperature from room temperature to 500°C at a heating rate of 7°C / min, and keep the temperature constant for 2 hours. The pressure in the carbonization furnace is controlled at 0.07MPa.

[0035] S4: Secondary alkali leaching activation: The pre-carbonized bamboo material was mixed with a potassium hydroxide solution with a mass fraction of 18% at a solid-liquid ratio of 1:4, refluxed and stirred at 90°C for 4 hours, transferred to a microwave reactor, and microwaved at a power of 550W for 18 minutes, with a pause of 30 seconds every 5 minutes. Then placed in an activation furnace, a mixed gas of carbon dioxide and water vapor (volume ratio of 1:1, total flow rate of 7L / min) was introduced at 900°C for activation for 1.5 hours.

[0036] S5: Multi-stage pickling: First, soak the activated product in a 7% hydrochloric acid solution at 35°C for 2.5 hours, add 0.15% of the surfactant sodium dodecylbenzene sulfonate, then soak it in a 4% oxalic acid solution at 45°C for 1.5 hours, and finally rinse it with deionized water until the pH value of the washing solution is 6.8.

[0037] S6: Ball milling: Place the acid-washed activated carbon in a ball mill, add zirconium oxide grinding balls at a mass ratio of activated carbon to grinding balls of 1:6, ball mill for 2.5 hours, control the speed at 350r / min, and add lubricant zinc stearate accounting for 0.8% of the mass of the activated carbon.

[0038] S7: Supercritical fluid extraction: Carbon dioxide was used as the supercritical fluid, and the ball-milled activated carbon was extracted for 2.5 hours at a temperature of 40°C and a pressure of 22 MPa. Before the extraction, 0.4% of ethanol by volume was added to the carbon dioxide fluid as an entrainer.

[0039] S8: High-temperature steam purging: The activated carbon after extraction is placed in a tubular furnace and purged with high-temperature steam at 1050°C for 35 minutes at a steam flow rate of 5L / min. Hydrogen accounting for 1.5% of its volume is mixed into the steam.

[0040] S9: Drying and sterilization: The steam-purged activated carbon was dried in a vacuum drying oven at 140°C for 7.5 hours with a vacuum degree of -0.085MPa, then dry-heat sterilized at 190°C for 2.5 hours, and finally irradiated with gamma rays with an irradiation dose of 8kGy.

[0041] After testing, the specific surface area of ​​the activated carbon prepared in this embodiment is [X] m 2 / g, uniform pore size distribution, extremely low impurity content, sterile and pyrogen-free, meeting the standards for activated carbon for injection.

[0042] Example 2

[0043] Combination Figure 1 As shown, the difference from Example 1 is that:

[0044] S1: Select and prepare materials: Select healthy bamboos of 4 years old and 5 cm in diameter, and process them within 2 days after felling. Remove the green skin, bamboo nodes and internal medulla of the bamboo, keep the dense part in the middle of the bamboo stem, and cut into small pieces of 3 cm in length.

[0045] S2: Initial alkali immersion: Immerse the bamboo segments in a mixed solution of sodium hydroxide and sodium carbonate at a temperature of 50°C and a mass fraction of 8% for 3 hours. Perform ultrasonic treatment every 30 minutes at a frequency of 50kHz for 5 minutes, and then rinse with clean water until neutral.

[0046] S3: Pre-carbonization: put the bamboo segments after the initial alkali immersion into an oxygen-free sealed carbonization furnace, raise the temperature from room temperature to 450°C at a heating rate of 6°C / min, and keep the temperature constant for 1.5 hours. The pressure in the carbonization furnace is controlled at 0.05MPa.

[0047] S4: Secondary alkali leaching activation: The pre-carbonized bamboo material was mixed with a 15% potassium hydroxide solution at a solid-liquid ratio of 1:4, refluxed and stirred at 85°C for 4 hours, transferred to a microwave reactor, and microwaved at a power of 500W for 15 minutes, with a pause of 30 seconds every 5 minutes. Then placed in an activation furnace, a mixed gas of carbon dioxide and water vapor (volume ratio 1:1, total flow rate 6L / min) was introduced at 850°C for activation for 1.5 hours.

[0048] S5: Multi-stage pickling: First, soak the activated product in a 6% hydrochloric acid solution at 30°C for 2 hours, add 0.1% of the surfactant sodium dodecylbenzene sulfonate to the solution, then soak it in a 3% oxalic acid solution at 40°C for 1 hour, and finally rinse it with deionized water until the pH value of the washing solution is 6.5.

[0049] S6: Ball milling: Place the acid-washed activated carbon in a ball mill, add zirconium oxide grinding balls at a mass ratio of 1:5 between activated carbon and grinding balls, ball mill for 2 hours, control the speed at 300r / min, and add 0.5% of the activated carbon mass as lubricant zinc stearate.

[0050] S7: Supercritical fluid extraction: Carbon dioxide was used as a supercritical fluid, and the ball-milled activated carbon was extracted for 2 hours at a temperature of 35° C. and a pressure of 20 MPa. Before the extraction, 0.3% of ethanol by volume was added to the carbon dioxide fluid as an entrainer.

[0051] S8: High-temperature steam purging: The activated carbon after extraction is placed in a tubular furnace and purged with high-temperature steam at 1000°C for 30 minutes at a steam flow rate of 4L / min. Hydrogen accounting for 1% of its volume is mixed into the steam.

[0052] S9: Drying and sterilization: The steam-purged activated carbon was dried in a vacuum drying oven at 130°C for 7 hours with a vacuum degree of -0.09MPa, then dry-heat sterilized at 180°C for 2 hours, and finally irradiated with gamma rays with an irradiation dose of 5kGy.

[0053] After testing, all performance indicators of the activated carbon prepared in this embodiment meet the requirements of activated carbon for injection.

[0054] Comparative Example 1

[0055] Basically the same as Example 1, except that the ultrasonic treatment in the initial alkali leaching step is missing.

[0056] After testing, the specific surface area of ​​the activated carbon obtained is [X] m 2 / g, the impurity content is relatively high, and some performance indicators do not meet the standards for activated carbon injections.

[0057] Comparative Example 2

[0058] The method is basically the same as Example 1, except that microwave treatment is not performed in the secondary alkali leaching activation step.

[0059] After testing, it was found that the porosity of activated carbon was low and its adsorption performance was reduced, which could not fully meet the strict requirements of activated carbon for injection.

[0060] By comparing the examples and the comparative examples, it can be seen that the various steps of the production process of the present invention work synergistically to effectively improve the quality of the activated carbon injection with bamboo as the matrix.

[0061] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways without departing from the spirit of the present invention.

Claims

1. A production process for activated carbon injection using bamboo as a matrix, characterized in that: The following steps are involved: S1: Select and prepare materials: Select healthy bamboos of 4-6 years old and 5-8 cm in diameter, and process them within 1 week after felling. Remove the green skin, bamboo nodes and internal medulla of the bamboo, leaving only the dense part in the middle of the bamboo stem, and cut into small pieces of 3-5 cm in length. S2: Initial alkali immersion: Immerse the bamboo segments in a mixed solution of sodium hydroxide and sodium carbonate at a temperature of 50-60°C and a mass fraction of 8%-12%, wherein the mass ratio of sodium hydroxide to sodium carbonate is 3:1, and the immersion time is 3-4 hours to remove lignin and hemicellulose in the bamboo, and then rinse with clean water until neutral. S3: Pre-carbonization: Put the bamboo segments after the initial alkali immersion into an oxygen-free sealed carbonization furnace, raise the temperature from room temperature to 450-550°C at a heating rate of 6-8°C / min, and keep the temperature constant for 1.5-2.5 hours to complete the pre-carbonization process and obtain pre-carbonized bamboo materials. S4: Secondary alkali immersion activation: The pre-carbonized bamboo material is mixed with a potassium hydroxide solution with a mass fraction of 15%-20% in a solid-liquid ratio of 1:4, refluxed with stirring at 85-95°C for 4 hours, then transferred to a microwave reactor, microwaved at a power of 500-600W for 15-20 minutes, and then placed in an activation furnace, and a mixed gas of carbon dioxide and water vapor (volume ratio of 1:1, total flow rate of 6-8L / min) is introduced at 850-950°C for activation for 1.5 hours. S5: Multi-stage pickling: first soak the activated product in a 6%-8% hydrochloric acid solution at 30-40°C for 2-3 hours, then soak it in a 3%-5% oxalic acid solution at 40-50°C for 1-2 hours, and finally rinse it with deionized water until the pH value of the washing liquid is 6.5-7.

0. S6: Ball milling: Place the acid-washed activated carbon in a ball mill, add zirconium oxide grinding balls at a mass ratio of activated carbon to grinding balls of 1:(5-8), ball mill for 2-3 hours, control the rotation speed at 300-400r / min, so that the activated carbon particles reach a sphericity ≥0.8 and a particle size of 150-250 mesh. S7: Supercritical fluid extraction: Use carbon dioxide as the supercritical fluid, and extract the ball-milled activated carbon for 2-3 hours at a temperature of 35-45°C and a pressure of 20-25MPa to remove residual small molecular organic matter. S8: High-temperature steam purging: Place the extracted activated carbon in a tubular furnace and pass high-temperature steam at 1000-1100°C for 30-40 minutes with a steam flow rate of 4-6L / min. S9: Drying and sterilization: Dry the steam-purged activated carbon in a vacuum drying oven at 130-150°C for 7-8 hours with a vacuum degree of -0.09-0.08MPa, and then dry-heat sterilize at 180-200°C for 2-3 hours to obtain an activated carbon product that meets the requirements for injections.

2. The process for producing activated carbon for injection with bamboo as the matrix according to claim 1, characterized in that: In the S1 step, the bamboo is processed within 2-3 days after being cut down.

3. The process for producing activated carbon for injection using bamboo as a matrix according to claim 1, characterized in that: In the step S2, ultrasonic treatment is performed every 30 minutes during the immersion process, the ultrasonic frequency is 50-60 kHz, and the treatment time is 5 minutes.

4. The process for producing activated carbon for injection using bamboo as a matrix according to claim 1, characterized in that: In the step S3, the pressure in the carbonization furnace is controlled at 0.05-0.1 MPa.

5. The process for producing activated carbon for injection with bamboo as the matrix according to claim 1, characterized in that: In the step S4, the microwave treatment was paused for 30 seconds every 5 minutes.

6. The process for producing activated carbon for injection with bamboo as the matrix according to claim 1, characterized in that: In the step S5, a surfactant sodium dodecylbenzene sulfonate accounting for 0.1% to 0.2% of the solution mass is added during the hydrochloric acid soaking.

7. The process for producing activated carbon for injection with bamboo as the matrix according to claim 1, characterized in that: In the step S6, a lubricant zinc stearate accounting for 0.5% to 1% of the weight of the activated carbon is added into the ball mill.

8. The process for producing activated carbon for injection with bamboo as the matrix according to claim 1, characterized in that: In the step S7, 0.3% to 0.5% of ethanol by volume is added to the carbon dioxide fluid as an entrainer before extraction.

9. The process for producing activated carbon for injection using bamboo as a matrix according to claim 1, characterized in that: In the step S8, hydrogen accounting for 1% to 2% of the steam volume is mixed into the steam.

10. The process for producing activated carbon for injection with bamboo as the matrix according to claim 1, characterized in that: In the step S9, the activated carbon is subjected to gamma ray irradiation after sterilization, and the irradiation dose is 5-10 kGy.

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