Bio-based carbon black with high specific surface area as well as preparation method and application of bio-based carbon black
High specific surface area bio-based carbon black was prepared by processes such as DES dissolution, spray drying, zinc chloride catalysis and high temperature carbonization, which solved the problems of coarse particles in lignin-based carbon materials and pollution from traditional carbon black, and realized a green alternative to high-performance rubber composite materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI CHANGFA NEW MATERIAL CO LTD
- Filing Date
- 2026-02-03
- Publication Date
- 2026-05-19
AI Technical Summary
In existing technologies, carbon materials prepared from lignin have coarse particles and low specific surface area, which makes it difficult to meet the requirements of high-end applications. In addition, traditional carbon black production processes are highly polluting and costly.
High specific surface area bio-based carbon black was prepared by dissolving lignin with DES solvent, combined with spray drying, zinc chloride catalyst and high temperature carbonization treatment, acid washing and pure water washing, and finally air jet milling.
The prepared bio-based carbon black has a uniform particle size distribution, high specific surface area, and excellent mechanical properties. It is suitable for high-end rubber composite materials, conforms to sustainable manufacturing and carbon emission reduction policies, and has significant environmental benefits.
Smart Images
Figure CN122060348A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of fine chemical raw material preparation technology, and particularly relates to a high specific surface area bio-based carbon black, its preparation method and application. Background Technology
[0002] In recent years, the overuse of fossil resources has led to increasingly severe air pollution, greenhouse gas emissions, and climate change, making the replacement of traditional petrochemical resources with sustainable materials a global consensus. Carbon black, a widely used basic additive in various materials, currently mainly comes from the thermal cracking or partial combustion of fossil fuels. This process not only emits large amounts of carbon dioxide and pollutants but also incurs high raw material costs. Therefore, developing environmentally friendly, sustainable, and low-cost carbon black alternatives has become an urgent need for the industry.
[0003] Lignin, a natural polymer formed by the polymerization of aromatic alcohols, is widely found in plant cell walls and is abundant in nature. It is also produced in large quantities as a byproduct in the pulping industry and biorefining processes. Lignin's structure is rich in various functional groups and has a high carbon content, making it easy to chemically modify and suitable for producing various chemical materials, such as dispersants and cement water-reducing agents. Current research explores lignin as a substitute for or partial substitute for carbon black, but most studies are limited to simple blending or low-proportion substitution. Furthermore, the resulting carbon materials often have coarse particles and low specific surface area, significantly impacting mechanical properties when used as rubber reinforcing agents and failing to meet the requirements of high-end applications. Therefore, technological innovation to convert lignin into high-performance bio-based carbon black can not only achieve high-value utilization of lignin resources but also promote the development of green products such as bio-based rubber, aligning with the "dual carbon" goal and fostering the development of a circular economy. Summary of the Invention
[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high specific surface area bio-based carbon black, its preparation method, and its application. The prepared bio-based carbon black exhibits uniform particle size distribution and high specific surface area, demonstrating excellent mechanical properties (such as tensile strength, tear strength, and elongation) in rubber and other composite materials.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] This invention provides a method for preparing high specific surface area bio-based carbon black, which includes the following steps:
[0007] (1) Lignin was dissolved using DES solvent to obtain a homogenized colloidal solution;
[0008] (2) The homogenized colloidal solution is dried to obtain lignin microspheres;
[0009] (3) The lignin microspheres are pre-oxidized and then subjected to programmed temperature carbonization under an inert atmosphere with zinc chloride as a catalyst to obtain crude carbon black.
[0010] (4) The crude carbon black is subjected to acid washing and pure water washing until neutral, and solid-liquid separation is performed to obtain a solid product;
[0011] (5) The solid product is dried and then pulverized to obtain the high specific surface area bio-based carbon black.
[0012] Further, the lignin in step (1) includes one or more of alkali lignin, sulfate lignin, enzymatic hydrolyzed lignin, and ball-milled lignin, wherein the lignin has a moisture content of 5-10%, an effective content of 80-95%, and a pH of 2.0-7.0.
[0013] Further, the DES solvent in step (1) is a composite solvent of choline chloride, citric acid and water, the mass ratio of choline chloride, citric acid and water is 6:2:2, and the mass ratio of lignin to the DES solvent is 1:(2-6).
[0014] Furthermore, in step (2), the homogenized colloidal solution is dried using a pressure spray dryer, wherein the atomization pressure of the spray dryer is 0.5-2.0 MPa and the heat source temperature is 280-350℃.
[0015] Furthermore, the particle size of the lignin microspheres described in step (2) is 10-80 μm.
[0016] Furthermore, the amount of zinc chloride used in step (3) is 3%-30% of the lignin quality;
[0017] The pre-oxidation temperature is 150-250℃, and the holding time is 0.5-1.5 hours;
[0018] The programmed heating carbonization process involves heating to 600-800℃ at a rate of 5-10℃ / min and carbonizing for 1-3 hours.
[0019] Further, in step (4), the crude carbon black is acid-washed with hydrochloric acid, the concentration of which is 0.1-1M and the amount used is 3-10 times the mass of the crude carbon black;
[0020] The amount of pure water used is 3-10 times the amount of crude carbon black used.
[0021] The washing temperature is 40-60℃, and the washing time is 0.5-1.5 hours.
[0022] Furthermore, in step (5), an air jet mill is used for pulverization.
[0023] The drying temperature is 50-80℃.
[0024] The present invention also provides a high specific surface area bio-based carbon black, which is prepared by the preparation method of high specific surface area bio-based carbon black as described above.
[0025] The present invention also provides the application of the high specific surface area bio-based carbon black as described above in the preparation of rubber composite materials.
[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0027] (1) The present invention uses a low eutectic solvent (DES) composed of choline chloride, citric acid and water to dissolve lignin, thereby achieving full dispersion and homogenization of lignin molecules and avoiding particle coarsening and structural defects caused by lignin aggregation; and uses pressure spray drying to microsphere lignin, thereby achieving particle refinement and homogenization, and significantly increasing specific surface area and reactivity.
[0028] (2) This invention uses zinc chloride as a catalyst, combined with pre-oxidation and high-temperature carbonization under inert gas, to promote the orderly pyrolysis of lignin and significantly improve the specific surface area and structural stability of carbon black. Finally, residual zinc ions are effectively removed by acid washing, washed with pure water until neutral, and combined with vacuum drying and air jet milling to obtain pure, highly dispersible bio-based carbon black with a high specific surface area.
[0029] (3) This invention employs a combination of multiple processes, including DES dissolution and high-temperature carbonization, resulting in bio-based carbon black with uniform particle size distribution (PDI < 1.1) and large specific surface area (> 1000 m² / g). It can achieve a high proportion of replacement for traditional petroleum-based carbon black in rubber and other composite materials, exhibiting excellent mechanical properties. Furthermore, this process is entirely green and low-carbon, with a carbon emission equivalent of only 0.8–1.0 t / t, significantly lower than traditional carbon black production processes (approximately 3.2 t / t). This aligns with sustainable manufacturing and carbon reduction policies, making it suitable for high-performance composite materials such as high-end rubber products and battery electrode materials, demonstrating significant environmental benefits and application prospects. Attached Figure Description
[0030] Figure 1 This is a scanning electron microscope image of the bio-based carbon black obtained in Example 2 of the present invention. Detailed Implementation
[0031] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.
[0032] Example 1
[0033] Step 1: Use 100g of alkali lignin as raw material, with a moisture content of 5%, an effective content of 80%, and a pH of 2.0;
[0034] Step 2: Add 200g of DES solvent (120g of choline chloride, 40g of citric acid, and 40g of water) to dissolve the alkali lignin at a temperature of 30℃ for 0.5 hours to obtain a homogenized colloidal solution.
[0035] Step 3: Pour the homogenized colloidal solution into a pressure spray dryer, set the atomization pressure of spray drying to 0.5 MPa and the temperature to 280℃, and perform drying treatment to obtain lignin microspheres with a particle size of 10 μm.
[0036] Step 4: Place the lignin microspheres in a carbonization furnace, heat to 150℃, and hold for 0.5 hours for pre-oxidation. Under nitrogen protection, add 3g of zinc chloride and heat to 600℃ at a rate of 5℃ / min. Carbonize for 1 hour to obtain lignin carbon black.
[0037] Step 5: Add 0.1M hydrochloric acid (the amount of hydrochloric acid is 3 times the mass of lignin carbon black) to the lignin carbon black, heat to 40℃, keep warm and stir for 0.5h to fully wash away zinc ions, then add pure water to wash the lignin carbon black until neutral (the amount of pure water is 3 times the mass of lignin carbon black), and set the centrifuge speed to 1000r / min for deacidification and dehydration treatment;
[0038] Step 6: Dry the material under vacuum at 50°C and then process it with airflow milling to obtain bio-based carbon black.
[0039] Example 2
[0040] Step 1: Use 100g of sulfate lignin as raw material, with a moisture content of 7%, an effective content of 87%, and a pH of 4.0;
[0041] Step 2: Add 400g of DES solvent (240g of choline chloride, 80g of citric acid, and 80g of water) to dissolve the sulfate lignin at a temperature of 50℃ for 1 hour to obtain a homogenized colloidal solution.
[0042] Step 3: Pour the homogenized colloidal solution into a pressure spray dryer, set the atomization pressure of spray drying to 1.0 MPa and the temperature to 300℃, and perform drying treatment to obtain lignin microspheres with a particle size of 40 μm.
[0043] Step 4: Place the lignin microspheres in a carbonization furnace, heat to 200℃, and hold for 1.0 hour for pre-oxidation. Under nitrogen protection, add 15g of zinc chloride and heat to 700℃ at a rate of 7℃ / min. Carbonize for 2 hours to obtain lignin carbon black.
[0044] Step 5: Add 0.5M hydrochloric acid (the amount of hydrochloric acid is 6 times the mass of lignin carbon black) to the lignin carbon black, heat to 50℃, keep warm and stir for 1 hour to fully wash away zinc ions, then add pure water to wash the lignin carbon black until neutral (the amount of pure water is 6 times the mass of lignin carbon black), and set the centrifuge speed to 2000 r / min for deacidification and dehydration treatment;
[0045] Step 6: Dry the material under vacuum at 65°C and then process it with airflow milling to obtain bio-based carbon black.
[0046] Example 3
[0047] Step 1: Use 100g of enzymatically hydrolyzed lignin as raw material, with a moisture content of 10%, an effective content of 95%, and a pH of 7.0;
[0048] Step 2: Add 600g of DES solvent (360g of choline chloride, 120g of citric acid, and 120g of water) to dissolve the enzymatically hydrolyzed lignin at a temperature of 80℃ for 2 hours to obtain a homogenized colloidal solution.
[0049] Step 3: Pour the homogenized colloidal solution into a pressure spray dryer, set the atomization pressure of spray drying to 2.0 MPa and the temperature to 350℃, and perform drying treatment to obtain lignin microspheres with a particle size of 80 μm;
[0050] Step 4: Place the lignin microspheres in a carbonization furnace, heat to 250℃, and hold for 1.5 hours for pre-oxidation. Under nitrogen protection, add 30g of zinc chloride and heat to 800℃ at a rate of 10℃ / min. Carbonize for 3 hours to obtain lignin carbon black.
[0051] Step 5: Add 1M hydrochloric acid to the lignin carbon black (the amount of hydrochloric acid is 10 times the mass of lignin carbon black), heat to 60℃, keep warm and stir for 1.5h to fully wash away zinc ions, then add pure water to wash the lignin carbon black until neutral (the amount of pure water is 10 times the mass of lignin carbon black), and set the centrifuge speed to 3000r / min for deacidification and dehydration treatment;
[0052] Step 6: Dry the material under vacuum at 80°C and then process it with airflow milling to obtain bio-based carbon black.
[0053] Comparative Example 1
[0054] The only difference from Example 1 is that DES is not used to dissolve lignin in step 1; instead, water under the same conditions is used to disperse lignin.
[0055] Comparative Example 2
[0056] The only difference from Example 1 is that step 3 does not use spray drying to treat the homogenized colloidal solution, but uses an oven drying process at a temperature of 150°C for 2 hours.
[0057] Comparative Example 3
[0058] The only difference from Example 1 is that zinc chloride catalytic treatment is not used.
[0059] Comparative Example 4
[0060] The only difference from Example 1 is that: in step 4, no pre-oxidation treatment is performed. Instead, 3g of zinc chloride is added directly under nitrogen protection, and the temperature is raised to 600°C at a rate of 5°C / min. The mixture is then carbonized for 1 hour to obtain lignin carbon black.
[0061] Comparative Example 5
[0062] The only difference from Example 1 is that the carbonization temperature in step 4 is adjusted from 600°C to 450°C.
[0063] Comparative Example 6
[0064] The only difference from Example 1 is that hydrochloric acid cleaning is not performed in step 5.
[0065] Comparative Example 7
[0066] The only difference from Example 1 is that there is no pure water cleaning process after the hydrochloric acid cleaning treatment in step 5.
[0067] Comparative Example 8
[0068] The only difference from Example 1 is that there is no airflow pulverization process after drying in step 6.
[0069] Comparative Example 9
[0070] Carbon black products were prepared using the preparation method described in Example 2 of patent CN115322590A.
[0071] Comparative Example 10
[0072] The only difference from Example 1 is that the 200g DES solvent in step 1 is replaced with a composite solvent of 50g choline chloride and 150g ethylene glycol.
[0073] Finished product performance testing
[0074] The performance of the bio-based carbon black prepared in the above examples and comparative examples was tested using the following methods or standards.
[0075] I. PDI: The particle size of carbon black was measured using a powder particle size analyzer. 90 D 10 D 50 PDI = (D 90 -D 10 ) / D 50 ;
[0076] II. Specific surface area: BET nitrogen adsorption method (GB / T 10722-2021);
[0077] III. CO2 Emission Equivalent: CO2 emission equivalent = (direct CO2 emissions + indirect CO2 emissions) / qualified carbon black production.
[0078] The results of the performance test of bio-based carbon black are shown in Table 1.
[0079] Table 1
[0080]
[0081] Note: The carbon black in Comparative Example 8 was not pulverized after drying and was in block form, so PDI and specific surface area were not measured.
[0082] The test results show that, compared with the carbon black obtained in Comparative Examples 1-10 and commercially available carbon black N330, the bio-based carbon black prepared by the process of this invention has a lower PDI, a larger specific surface area, and a significantly lower CO2 emission equivalent during production than that of traditional carbon black production processes.
[0083] Effect Example
[0084] Rubber products were prepared using carbon black obtained from the above examples and comparative examples, as well as commercially available carbon black N330. The tensile strength, tear strength, elongation, and hardness of the resulting rubber products were tested.
[0085] The raw material formula for rubber preparation is as follows: 100 parts of natural rubber, 50 parts of carbon black / commercially available carbon black N330 prepared in the examples or comparative examples, 1.5 parts of stearic acid, and 1 part of accelerator TBBS.
[0086] The rubber preparation method is as follows: (1) Prepare experimental raw materials; (2) Plasticize and process natural rubber using an open mill; (3) Add the processed natural rubber and various additives to a mixer for mixing; (4) Use a flat vulcanizing machine to vulcanize the rubber to obtain the corresponding rubber products.
[0087] The testing methods or standards are as follows.
[0088] I. Tensile Strength: GB / T 528-2009
[0089] II. Tear Strength: GB / T 529-2008
[0090] III. Elongation: GB / T 528-2009
[0091] IV. Hardness: GB / T 39693.3-2021
[0092] The results of the performance tests on the finished rubber products are shown in Table 2.
[0093] Table 2
[0094]
[0095] Note: The carbon black in Comparative Example 8 was not pulverized after drying and remained in lumps. It could not be dispersed in rubber and therefore could not be refined into rubber, thus preventing the testing of rubber properties.
[0096] Test results show that the rubber products obtained by adding the bio-based carbon black prepared in Examples 1-3 of this application have better tensile strength, tear strength, elongation, and hardness than Comparative Examples 1-10. Furthermore, the rubber products prepared using commercially available carbon black N330 also have inferior tensile strength, tear strength, elongation, and hardness compared to Examples 1-3.
[0097] The results show that, compared with existing products, the modified lignin prepared in Example 2 has a more ideal rubber reinforcing effect, and the rubber products prepared with it have better overall performance.
[0098] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for preparing high specific surface area bio-based carbon black, characterized in that, Includes the following steps: (1) Lignin was dissolved using DES solvent to obtain a homogenized colloidal solution; (2) The homogenized colloidal solution is dried to obtain lignin microspheres; (3) The lignin microspheres are pre-oxidized and then subjected to programmed temperature carbonization under an inert atmosphere with zinc chloride as a catalyst to obtain crude carbon black. (4) The crude carbon black is subjected to acid washing and pure water washing until neutral, and solid-liquid separation is performed to obtain a solid product; (5) The solid product is dried and then pulverized to obtain the high specific surface area bio-based carbon black.
2. The method for preparing high specific surface area bio-based carbon black according to claim 1, characterized in that, The lignin mentioned in step (1) includes one or more of alkali lignin, sulfate lignin, enzymatic hydrolysis lignin, and ball milled lignin. The lignin has a moisture content of 5-10%, an effective content of 80-95%, and a pH of 2.0-7.
0.
3. The method for preparing high specific surface area bio-based carbon black according to claim 1, characterized in that, The DES solvent in step (1) is a composite solvent of choline chloride, citric acid and water, with a mass ratio of choline chloride, citric acid and water of 6:2:2, and a mass ratio of lignin to the DES solvent of 1:(2-6).
4. The method for preparing high specific surface area bio-based carbon black according to claim 1, characterized in that, In step (2), the homogenized colloidal solution is dried using a pressure spray dryer. The atomization pressure of the spray dryer is 0.5-2.0 MPa, and the heat source temperature is 280-350℃.
5. The method for preparing high specific surface area bio-based carbon black according to claim 1, characterized in that, The lignin microspheres mentioned in step (2) have a particle size of 10-80 μm.
6. The method for preparing high specific surface area bio-based carbon black according to claim 1, characterized in that, The amount of zinc chloride used in step (3) is 3%-30% of the lignin quality; And / or, the pre-oxidation temperature is 150-250℃, and the holding time is 0.5-1.5 hours; And / or, the programmed heating carbonization process involves heating to 600-800℃ at a heating rate of 5-10℃ / min and carbonizing for 1-3 hours.
7. The method for preparing high specific surface area bio-based carbon black according to claim 1, characterized in that, In step (4), the crude carbon black is acid-washed with hydrochloric acid, the concentration of which is 0.1-1M and the amount used is 3-10 times the mass of the crude carbon black. And / or, the pure water is 3-10 times the amount of crude carbon black used; And / or, the washing temperature is 40-60℃, and the washing time is 0.5-1.5 hours.
8. The method for preparing high specific surface area bio-based carbon black according to claim 1, characterized in that, In step (5), an air jet mill is used for pulverization. And / or, the drying temperature is 50-80℃.
9. A high specific surface area bio-based carbon black, characterized in that, It is prepared by the method for preparing high specific surface area bio-based carbon black as described in any one of claims 1-8.
10. The application of the high specific surface area bio-based carbon black as described in claim 9 in the preparation of rubber composite materials.