CN101164876A - Method for preparing carbon black and active carbon from waste tyre pyrolytic carbon - Google Patents

Abstract

This invention relates to a method for preparing carbon-black and activated-carbon, by using waste-tyre as raw material after thermal decomposition and modification. The procedures are as follows: the carbon black from waste tyre is fed into a bag made from filter paper, extracted in flask with organic solvent; the solid is air-dried, weighing, the liquid is proceeded distillation for removing solvent, collecting the residul oil from the carbon black. The carbon black thus treated is put into a flask together with dilute acid, proceeded by agitation, vacuum filtering. The carbon black is then placed in quartz ship, and they are put in quartz tube, connected with flask with distilled water in it; heating the distilled water at 150-1000deg.C for treating the carbon black, drying, obtaining the final carbon black and activated carbon. Advantages are: reutilization of solvent and residual oil, utilization of dilute acid (less corrosion), high purity and high specific superficial area of final products.

Description

A method for preparing carbon black and activated carbon from waste tire pyrolysis carbon

technical field

The invention relates to a method for preparing carbon black and activated carbon through carbon black modification treatment, in particular to the preparation of carbon black and activated carbon through modification treatment of waste tire pyrolysis carbon.

Background technique

With the development of the automobile industry and the continuous renewal of automobiles, the disposal of waste tires has become an increasingly serious environmental problem, which not only causes a huge waste of resources, but also becomes a kind of "black pollution" that is more and more harmful. At present, pyrolysis of waste tires is one of the most ideal recycling methods. It recovers high value-added pyrolytic charcoal, oil, high calorific value gas and steel wire, etc., thereby fully recovering the precious resources of waste tires. The yield of waste tire pyrolysis charcoal is about 39%-44%. How to use this part of pyrolysis charcoal is the key factor related to the economical practicability of waste tire pyrolysis process. At present, the global demand for carbon black continues to grow. According to the forecast of Notch Consulting Group in the United States, the annual growth rate of global carbon black demand is expected to be 3.6% in the next five years. The rise in carbon black prices has not kept pace with the rapid rise in the cost of raw oil and natural gas, which has brought unprecedented shocks to the carbon black industry in history.

Commercial carbon black and waste tire pyrolytic carbon have basically the same main structure. It can be seen that using waste tire pyrolytic carbon to replace high-cost raw material oil to produce carbon black can not only solve the environmental protection problems caused by waste tires, but also alleviate the pollution caused by carbon black. Tight market conditions. However, carbonaceous coke is deposited on the surface of pyrolytic carbon, covering a certain number of surface active sites, which affects the performance of pyrolytic carbon. Therefore, through the research on the surface modification of pyrolytic carbon, carbon black with high added value can be prepared Materials can make the best use of renewable resources and maximize the value of regeneration, which is of great significance.

At present, the global demand for carbon black continues to grow, of which 70% are used in the tire industry. However, due to the limitation of the surface structure, the pyrolysis carbon black of waste tires can only be used in the production of low-grade bias tires. Most of the demand for black comes from high-performance radial tires; moreover, the development of the automobile industry has a tendency to slow down, and the growth in demand for carbon black for tire reinforcement (2.6%) has been lower than the average level of growth in carbon black demand (3.5%) ), so the carbon black with high structure and high performance prepared by pyrolysis carbon from waste tires is used in the production of high-grade tires and other rubber products, or in the production of inks, adsorbents and other industries, which has aroused great enthusiasm from domestic and foreign counterparts However, so far, no researchers have proposed an effective pyrolytic carbon modification method for industrialization.

Dension's U.S. Patent Nr.5894012 describes various methods and equipment for pyrolyzing waste rubber in automobile tires into carbon black solids, low-density hydrocarbon gas and liquid hydrocarbon oil, although its production system for refining carbon black can remove metals and Glass fiber chips produce a fairly high grade carbon black, however, it still contains difficult to remove chemical impurities (approximately 2.5 wt% metal oxide particles and sulfur particles and silica) retained from the underlying pyrolysis process . Such impurities make this kind of carbon black can not be used in places where the carbon black refining grade is high, such as electrostatic copying equipment and laser printer toner. At present, this kind of high-grade carbon black is mainly obtained from petroleum products, or can be obtained. Production from pyrolyzed hydrocarbons containing very few impurities (Chinese Patent Publication No. CN 1696210A). Therefore, if the carbon black product from pyrolysis can be directly further refined into higher grade carbon black products in a more economical way, the value of the entire pyrolysis process can thus be better marketable. The combined cycle technology company of the U.S. has designed a set of metal oxides in carbon black with acid dissolution extraction, and the method (Chinese Patent Publication No. CN 1481335A) in the carbon black after acid treatment with organic aromatic solvent extraction, but this kind The method uses concentrated hydrochloric acid and organic solvents, which requires high equipment and high operating costs, and has not yet been accepted by China's industrial production. The equipment for recovering carbon black pigments manufactured by British Rema Company includes magnetic screens, vibrating screens, reverse jet sorting mills and cyclone separators. They use physical methods to extract ink pigments from waste tire pyrolysis carbon black, avoiding acid , equipment problems and pollution problems caused by alkali reaction, but their production process requires finely pulverized carbon black, which has high requirements for raw materials and requires specific pretreatment processes and equipment (translated from carbon black in 2006 Vol. 272 p1~5).

Activated carbon is a nanomaterial widely used in the adsorption and separation of gases and liquids, and there is a great demand for environmental treatment of waste water and waste gas. At present, activated carbon is mainly prepared from wood, coal, and chaff, and the cost is extremely high; if activated carbon can be prepared from low-cost waste tires, it will not only turn waste tires into treasures, but also greatly reduce the cost of activated carbon to treat waste water and gas. cost. Helleur (Journal of Analytical and Applied Pyrolysis 2001 (58-59), 813-824), San Miguel (Carbon 2003 (41), 1009-1016) and Harris (CHEMECA 2004) et al. adopted a nitrogen atmosphere at 450-900°C After physical activation in medium, it is treated with water vapor, carbon dioxide or a mixture of the two at 850-1100 °C. This method consumes a lot of energy and requires high equipment.

It can be seen that it is of great significance to find a refined waste tire pyrolysis carbon route suitable for my country's industrial production as soon as possible for the high value of waste tire post-processing products.

Contents of the invention

The invention provides a method for preparing carbon black and activated carbon by modifying waste tire pyrolysis carbon black

The method of the present invention modifying and treating waste tire pyrolysis carbon to prepare carbon black material comprises the following steps:

(1) Put the waste tire pyrolysis carbon black powder into a paper bag sewn by filter paper, put the organic solvent into a round bottom flask, and perform Soxhlet extraction for 8 hours to separate the carbon black raw material and residual carbon black in the waste tire pyrolysis carbon of oil. Then the solid is dried and weighed, and the liquid is removed by rotary distillation to remove the organic solvent, and the residual oil in the waste tire pyrolysis carbon black is collected;

(2) Put the waste tire pyrolysis carbon black powder and dilute acid from which the oil has been removed into a round-bottomed flask, stir at 30°C for 0.5 hour, filter with suction, repeat the above steps twice, and dry the obtained carbon black solid powder for subsequent use;

(3) Put the carbon black powder that removes oil and metal oxide impurities into a quartz boat, put it into the quartz tube of a tubular electric furnace, connect a round-bottomed flask filled with distilled water at one end of the quartz tube and heat and boil the distilled water, respectively. Treat with water vapor at 150°C-1000°C for 1-10 hours, and dry to obtain carbon black or activated carbon;

The dilute acid is selected from dilute sulfuric acid, dilute hydrochloric acid or dilute nitric acid.

The organic solvent is selected from toluene, petroleum ether, dichloromethane or ethanol, and the ratio of raw materials is: 50-300ml of organic solvent is added to every 1g of carbon black powder.

The pyrolytic carbon after the oil has been extracted and the inorganic ash has been removed with acid is treated in steam at a temperature of 150°C to 1000°C, of which the carbon black powder obtained by processing at 150°C to 700°C is treated at 700°C to 1000°C to obtain Activated carbon.

During the treatment process of waste tire pyrolysis carbon, the residual oil and inorganic ash have a great influence on the treatment effect. The present invention adopts the method of organic solvent and acid pretreatment for the first time, and then conducts steam treatment to obtain high-purity , High specific surface carbon black material and activated carbon material.

The inventor carried out XRD, XPS, nitrogen adsorption-desorption and laser particle size measurement on the carbon black material and activated carbon material obtained by this method to determine the chemical composition, structural properties and surface properties of the material obtained after the waste tire pyrolysis carbon modification , see accompanying drawing 1～accompanying drawing 3 for measuring result. The results show that the obtained carbon black material does not contain Zn and basically does not contain sulfur; the particle size is uniform, the specific surface area of the carbon black material can reach 632m ² /g, and the activated carbon can reach 1240m ² /g; the surface of the modified carbon black material is further Oxidation increases the proportion of carboxyl and carbonyl functional groups. The inventor also used the obtained carbon black material for the adsorption of methylene blue, and obtained an adsorption amount (176 mmol/g) comparable to that of commercial carbon black.

Compared with prior art, the present invention has the following advantages:

The residual oil of pyrolytic carbon extracted with organic solvent can be recycled, and the solvent can also be reused.

Dilute sulfuric acid can effectively remove the residual inorganic ash in waste tire pyrolysis carbon, and avoid equipment corrosion caused by concentrated acid. The pretreated waste tire pyrolytic carbon can be treated with simple water vapor to obtain high-purity, high-specific surface area carbon black material and activated carbon. The obtained material is used for the adsorption of methylene blue, and the adsorption capacity is equivalent to that of commercial activated carbon.

Description of drawings

The XRD spectrogram (A carbon black, B activated carbon) of accompanying drawing 1 carbon black and activated carbon

The XPS spectrogram of accompanying drawing 2 materials

Detailed ways

Further describe the feature of the present invention by embodiment below, but the present invention is not limited to following example.

Embodiment 1,

Take 1g of waste tire pyrolysis carbon black powder and put it into a paper bag sewn by filter paper, put it in the reflux tube of the Soxhlet extractor, put 100ml of toluene into the round bottom flask, carry out Soxhlet extraction for 8 hours, pass the liquid through The organic solvent was removed by rotary distillation, and the oil in the waste tire pyrolysis carbon black was collected. Remove the paper bag containing the sample to dry and collect the dried solid. Take 1 g of the solid and 30 ml of dilute sulfuric acid with a concentration of 0.1 mol/L and put them into a round bottom flask, stir at 30° C. for 0.5 hour, filter with suction, repeat the above steps twice, and finally dry the solid obtained by suction filtration. Take the dried solid and put it into a quartz boat, put it into the quartz tube of the electric tube furnace, connect a round bottom flask filled with distilled water at one end of the quartz tube, heat and boil the distilled water, and treat it with water vapor at 150°C for 4 hours respectively. Dry the finally obtained solid to obtain a carbon black material with a specific surface area of 97m ² /g.

Embodiment 2,

Take 1g of waste tire pyrolysis carbon black powder and put it into a paper bag sewn by filter paper, put it in the reflux tube of the Soxhlet extractor, put 100ml of toluene into the round bottom flask, carry out Soxhlet extraction for 8 hours, pass the liquid through The organic solvent was removed by rotary distillation, and the oil in the waste tire pyrolysis carbon black was collected. Remove the paper bag containing the sample to dry and collect the dried solid. Take 1 g of the solid and 30 ml of dilute sulfuric acid with a concentration of 0.1 mol/L and put them into a round bottom flask, stir at 30° C. for 0.5 hour, filter with suction, repeat the above steps twice, and finally dry the solid obtained by suction filtration. Take the dried solid and put it into a quartz boat, put it into a quartz tube of a tube-type electric furnace, connect a round bottom flask filled with distilled water at one end of the quartz tube, heat and boil the distilled water, and treat it with water vapor at 400°C for 4 hours respectively. Dry the finally obtained solid to obtain a carbon black material with a specific surface area of 353 m ² /g.

Embodiment 3,

Take 1g of waste tire pyrolysis carbon black powder and put it into a paper bag sewn by filter paper, put it in the reflux tube of the Soxhlet extractor, put 100ml of toluene into the round bottom flask, carry out Soxhlet extraction for 8 hours, pass the liquid through The organic solvent was removed by rotary distillation, and the oil in the waste tire pyrolysis carbon black was collected. Remove the paper bag containing the sample to dry and collect the dried solid. Take 1 g of the solid and 30 ml of dilute sulfuric acid with a concentration of 0.1 mol/L and put them into a round bottom flask, stir at 30° C. for 0.5 hour, filter with suction, repeat the above steps twice, and finally dry the solid obtained by suction filtration. Take the dried solid and put it into a quartz boat, put it into the quartz tube of the tube electric furnace, connect a round bottom flask filled with distilled water at one end of the quartz tube, heat and boil the distilled water, and treat it with water vapor at 700°C for 4 hours respectively. Dry the finally obtained solid to obtain a carbon black material with a specific surface area of 632m ² /g.

Embodiment 4,

Take 1g of waste tire pyrolysis carbon black powder and put it into a paper bag sewn by filter paper, put it in the reflux tube of the Soxhlet extractor, put 100ml of toluene into the round bottom flask, carry out Soxhlet extraction for 8 hours, pass the liquid through The organic solvent was removed by rotary distillation, and the oil in the waste tire pyrolysis carbon black was collected. Remove the paper bag containing the sample to dry and collect the dried solid. Take 1 g of the solid and 30 ml of dilute sulfuric acid with a concentration of 0.1 mol/L and put them into a round bottom flask, stir at 30° C. for 0.5 hour, filter with suction, repeat the above steps twice, and finally dry the solid obtained by suction filtration. Take the dried solid and put it into a quartz boat, put it into a quartz tube of a tube-type electric furnace, connect a round-bottomed flask filled with distilled water at one end of the quartz tube, heat and boil the distilled water, and treat it with water vapor at 700°C for 8 hours respectively. Dry the finally obtained solid to obtain an activated carbon material with a specific surface area of 972m ² /g.

Embodiment 5,

Take 1g of waste tire pyrolysis carbon black powder and put it into a paper bag sewn by filter paper, put it in the reflux tube of the Soxhlet extractor, put 100ml of toluene into the round bottom flask, carry out Soxhlet extraction for 8 hours, pass the liquid through The organic solvent was removed by rotary distillation, and the oil in the waste tire pyrolysis carbon black was collected. Remove the paper bag containing the sample to dry and collect the dried solid. Take 1 g of the solid and 30 ml of dilute sulfuric acid with a concentration of 0.1 mol/L and put them into a round bottom flask, stir at 30° C. for 0.5 hour, filter with suction, repeat the above steps twice, and finally dry the solid obtained by suction filtration. Take the dried solid and put it into a quartz boat, put it into the quartz tube of the tube electric furnace, connect a round bottom flask filled with distilled water at one end of the quartz tube, heat and boil the distilled water, and treat it with water vapor at 900°C for 4 hours respectively. Dry the finally obtained solid to obtain an activated carbon material with a specific surface area of 1240m ² /g.

Claims (3)

1. A method for preparing high-quality carbon black or activated carbon by the modified treatment of waste tire pyrolysis carbon black is characterized in that it adopts the steam treatment method with pretreatment process, and the specific method may further comprise the steps: (1) Put the waste tire pyrolysis carbon black powder into a paper bag sewn by filter paper, put the organic solvent into a round bottom flask, and perform Soxhlet extraction for 8 hours to separate the carbon black raw material and residual carbon black in the waste tire pyrolysis carbon of oil. Then the solid is dried and weighed, and the liquid is removed by rotary distillation to remove the organic solvent, and the residual oil in the waste tire pyrolysis carbon black is collected; (2) Put the waste tire pyrolysis carbon black powder and dilute acid from which the oil has been removed into a round-bottomed flask, stir at 30°C for 0.5 hour, filter with suction, repeat the above steps twice, and dry the obtained carbon black solid powder for subsequent use; (3) Put the carbon black powder that removes oil and metal oxide impurities into a quartz boat, put it into the quartz tube of a tubular electric furnace, connect a round-bottomed flask filled with distilled water at one end of the quartz tube and heat and boil the distilled water, respectively. Treat with water vapor at 150°C-1000°C for 1-10 hours, and dry to obtain carbon black or activated carbon; The dilute acid is selected from dilute sulfuric acid, dilute hydrochloric acid or dilute nitric acid. 2. The method according to claim 1, wherein the organic solvent is selected from toluene, sherwood oil, methylene chloride or ethanol, and the ratio between the raw materials is: 50-300 ml of the organic solvent is added for every 1 g of carbon black powder. 3. The method according to claim 1, characterized in that the temperature of the pyrolytic charcoal after extracting the oil and removing the inorganic ash with acid in the steam is 150°C to 1000°C in the step (3), Among them, the carbon black powder obtained by processing at 150°C to 700°C is treated at 700°C to 1000°C to obtain activated carbon.

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