Method for preparing regenerated rubber from biomass oil

Abstract

The invention provides a method for preparing regenerated rubber from biomass oil, and belongs to the field of rubber production and manufacturing. Industrial lignin and waste rubber are dried and uniformly mixed, a co-pyrolysis reaction is performed in a thermal cracking reactor, the obtained biomass oil and waste rubber powder are stirred and mixed and then enter a desulfurization device, decrosslinking of a rubber network is realized, and the finally prepared reclaimed rubber is high in oil content, low in Mooney viscosity and good in mechanical property, and has a good application prospect. Multiple purposes can be met, the additional value of resource utilization of the waste rubber and the industrial lignin is greatly improved, and the production cost is reduced.

Description

Technical Field

[0001] The invention relates to a regenerated rubber manufacturing technology, in particular to a method for preparing regenerated rubber from biomass oil, and belongs to the technical field of regenerated rubber production and manufacturing. Background Art

[0002] With the development of social economy, a large amount of waste rubber has been produced, which has brought great pressure to resources and the environment. How to efficiently and greenly recycle waste rubber is one of the great challenges currently faced by polymer science and the rubber industry. At present, the effective ways to recycle waste rubber mainly include thermal cracking, production of rubber powder and recycled rubber.

[0003] When preparing reclaimed rubber, in order to achieve a better desulfurization effect, it is usually necessary to add a certain amount of rubber regenerating agent and swelling agent, which can not only improve the dispersion of desulfurization aids and increase the degree of desulfurization, but also give the reclaimed rubber good processing properties and mechanical properties. During the regeneration process, the swelling agent first penetrates into the cross-linked network of the vulcanized rubber, weakening the interaction between the rubber macromolecular chains and between the rubber macromolecular chains and the filler, expanding the volume, and increasing the distance between the rubber macromolecular chains, which is conducive to the diffusion of additives such as regeneration activators into the cross-linked network. The rubber regenerating agent and softener used in industrial production are used in large quantities and require high temperatures when used. In the rubber regeneration process, toxic gases such as hydrogen sulfide are easily produced, energy consumption is high, and secondary pollution to the environment is easily caused. Therefore, the development of efficient and environmentally friendly rubber regeneration aids is of great significance to the green and sustainable development of the rubber industry.

[0004] Lignin, one of the three main components of woody biomass, is composed of randomly bonded phenylpropane structural units. It has the outstanding characteristics of wide sources, huge reserves, and recyclable renewable, and has great application potential. However, in actual production, lignin is mainly discharged as waste or directly burned as fuel, resulting in serious waste of resources.

[0005] Pyrolysis technology is a process that rapidly pyrolyzes biomass into liquid bio-oil, solid carbon residue and non-condensable gas under moderate temperature, short residence time and oxygen-free conditions. The bio-oil obtained by pyrolysis of lignin can be used as a swelling agent in the rubber regeneration process. Therefore, it is of great significance to find the utilization value of lignin in the rubber production process. Summary of the invention

[0006] The invention provides a novel method for preparing regenerated rubber by using biomass oil. The biomass oil is added to waste rubber powder, thereby enhancing the performance of the regenerated rubber, so as to solve the technical problem of low application value of lignin in the regenerated rubber in the prior art.

[0007] The method for preparing regenerated rubber from biomass oil according to an embodiment of the present invention comprises the following steps:

[0008] The first step is to prepare biomass oil; industrial lignin, waste rubber powder A, and catalyst are put into a stirring device according to a mass ratio of 10:4-6:0.5-2, stirred and mixed, and heated to 90-100°C; sent to a thermal cracking reaction device to complete a co-pyrolysis reaction, and the biomass pyrolysis gas with solid carbon residue is sent to a cyclone separator, and the biomass pyrolysis gas is separated from the carbon residue and then enters a cooling device, and biomass oil is obtained after cooling;

[0009] The second step is to prepare the reclaimed rubber; the waste rubber powder B and the biomass oil prepared in the first step are put into an internal mixer at a mass ratio of 100:15-30, the internal mixer is heated to 130-150°C and then discharged into a desulfurization device, the temperature of the device is controlled at 200-260°C, the reaction is carried out for 2-5 minutes, and the decrosslinking of the waste rubber powder B is completed; then the material is sent to a double-roll refiner for roller refining, the refining time is 3-5 minutes, and a thin sheet is passed to obtain reclaimed rubber with a Mooney viscosity of 40-65.

[0010] In the method for preparing reclaimed rubber from biomass oil as described above, in the first step, the mesh size of the waste rubber powder A is 5-15 meshes, the water content is less than 1%, and the waste rubber powder A is any one or more combinations of waste tire tread rubber and full tire rubber.

[0011] In the method for preparing regenerated rubber from biomass oil as described above, the thermal cracking reaction device in the first step is any one of a fluidized bed reactor, a moving bed reactor, and a fixed bed reactor, and the residence time of the thermal cracking gas is 0.5s-1s.

[0012] In the method for preparing regenerated rubber from biomass oil as described above, the cooling medium of the cooling device in the first step is oily substance, and the temperature is 110-140°C.

[0013] The method for preparing regenerated rubber from biomass oil as described above, wherein the mesh size of the waste rubber powder B in the second step is 20-40 meshes, and the waste rubber powder B is any one or more of waste tires or tread rubber, waste rubber shoes, waste EPDM rubber, and waste butyl rubber; and the desulfurization device is one of a twin-screw extruder, a spiral plasticizer, and a high-speed mixer.

[0014] The method for preparing regenerated rubber from biomass oil as described above, wherein in the second step, the roller spacing of the double-roll refiner is 0.3-0.5 mm, the roller speed is 25-35 r / min, the speed ratio is 1:1.25, and the roller temperature is 40-60°C.

[0015] The method for preparing reclaimed rubber from biomass oil as described above, wherein the water content of the industrial lignin is less than 5%, and the industrial lignin is a combination of any one or more of alkali lignin, sulfate lignin, and lignin sulfonate; and the catalyst is one of the molecular sieve catalysts ZSM-5, HZSM-5 or MCM-41.

[0016] The invention dries and uniformly mixes industrial lignin and waste rubber, performs co-pyrolysis reaction in a thermal cracking reactor, and the obtained biomass oil and waste rubber powder are stirred and mixed before entering a desulfurization device to achieve de-crosslinking of the rubber network. The finally prepared reclaimed rubber has high oil content, low Mooney viscosity, good mechanical properties, can meet multiple uses, and greatly increases the added value of the resource utilization of waste rubber and industrial lignin, while reducing production costs. DETAILED DESCRIPTION

[0017] The method for preparing regenerated rubber from biomass oil of the present invention can be made of the following materials and components, but is not limited to the following materials and components, for example: waste rubber powder, lignin, etc.

[0018] The method for preparing regenerated rubber from biomass oil according to an embodiment of the present invention comprises the following steps:

[0019] The first step is to prepare biomass oil; industrial lignin, waste rubber powder A, and catalyst are put into a stirring device according to a mass ratio of 10:4-6:0.5-2, stirred and mixed, and heated to 90-100°C; sent to a thermal cracking reaction device to complete a co-pyrolysis reaction, and the biomass pyrolysis gas with solid carbon residue is sent to a cyclone separator, and the biomass pyrolysis gas is separated from the carbon residue and then enters a cooling device, and biomass oil is obtained after cooling;

[0020] The moisture content of the industrial lignin is lower than 5%, and the industrial lignin is any one or more combinations of alkali lignin, sulfate lignin, and lignin sulfonate; the catalyst is one of the molecular sieve catalysts ZSM-5, HZSM-5 or MCM-41.

[0021] In the first step, the mesh size of the waste rubber powder A is 5-15 meshes, the water content is less than 1%, and the waste rubber powder A is any one or more combinations of waste tire tread rubber and full tire rubber;

[0022] Among them, the thermal cracking reaction device in the first step is any one of a fluidized bed reactor, a moving bed reactor, and a fixed bed reactor, and the residence time of the thermal cracking gas is 0.5s-1s.

[0023] Among them, the cooling medium of the cooling device in the first step is oil substance, and the temperature is 110-140℃.

[0024] The second step is to prepare the reclaimed rubber; the waste rubber powder B and the biomass oil prepared in the first step are put into an internal mixer at a mass ratio of 100:15-30, the internal mixer is heated to 130-150°C and then discharged into a desulfurization device, the temperature of the device is controlled at 200-260°C, the reaction is carried out for 2-5 minutes, and the decrosslinking of the waste rubber powder B is completed; then the material is sent to a double-roll refiner for roller refining, the refining time is 3-5 minutes, and a thin sheet is passed to obtain reclaimed rubber with a Mooney viscosity of 40-65.

[0025] In the second step, the mesh size of the waste rubber powder B is 20-40 meshes, and the waste rubber powder B is any one or more combinations of waste tires or tread rubber, waste rubber shoes, waste EPDM rubber, and waste butyl rubber; the desulfurization device is one of a twin-screw extruder, a spiral plasticizer, and a high-speed mixer.

[0026] Among them, in the second step, the roller spacing of the double-roll refiner is 0.3-0.5mm, the roller speed is 25-35r / min, the speed ratio is 1:1.25, and the roller temperature is 40-60℃.

[0027] The present invention co-pyrolyzes the uniformly mixed waste rubber powder and industrial wood in a pyrolysis reactor. This step uses 5-15 mesh waste rubber powder, which can ensure the co-pyrolysis reaction on the one hand, and reduce the energy consumption of crushing the waste rubber into particles on the other hand. Lignin is first pyrolyzed to produce active free radicals, and existing studies have shown that the thermal degradation of high molecular polymers is mainly a free radical-dominated mechanism. Therefore, the active free radicals released by the pyrolysis of lignin will effectively promote the de-crosslinking reaction of the waste rubber powder. The effective hydrogen-carbon ratio of the waste rubber powder is relatively high, and the hydrogen free radicals are released into the "free radical pool". The bio-oil produced by the pyrolysis of lignin is promoted to be converted from oxygen-containing compounds to hydrocarbons through hydrogen transfer reaction. The presence of the catalyst can not only improve the pyrolysis efficiency of lignin, but also effectively reduce the generation of coke during the pyrolysis process, promote the formation of aromatic compounds, and thus improve the quality of pyrolysis biomass oil.

[0028] The biomass oil obtained by cooling after cracking has a high temperature and has a composition similar to that of aromatic hydrocarbon oil. It can be used as a swelling agent to participate in the desulfurization and regeneration process of waste rubber powder. In the desulfurization device, waste rubber powder of 20-40 mesh is used. Based on the principle of similar compatibility, the waste rubber powder of this mesh can be stirred and mixed with the added biomass oil in a relatively short time to a uniformly dispersed state. At the same time, the heat of the biomass oil itself can be effectively transferred to the waste rubber powder, and the de-crosslinking of the rubber powder can be achieved at a lower regeneration temperature. The prepared reclaimed rubber has a high oil content and low viscosity, and the original additives in the waste rubber are less damaged. When added to the rubber composition, it can replace more raw rubber, carbon black, operating oil, etc. The energy consumption in the production process is low, which greatly increases the added value of the resource utilization of waste rubber and industrial lignin.

[0029] Example 1

[0030] Kraft lignin, 10-mesh waste tire tread rubber powder and catalyst ZSM-5 are put into a stirring device in a mass ratio of 10:5:1, stirred and mixed, and then heated to 95°C and sent to a fluidized bed reactor. The residence time of the pyrolysis gas is 0.5s. After the co-pyrolysis reaction is completed, the biomass pyrolysis gas with solid carbon residue is sent to a cyclone separator, and after the carbon residue is separated, it enters a cooling device. The temperature of the cooling oil is 134°C, and biomass oil is obtained after cooling. The 30-mesh waste tire rubber powder and the prepared biomass oil were put into an internal mixer at a mass ratio of 100:17. After the internal mixing was heated to 136°C, they were discharged into a twin-screw extruder with a screw length-to-diameter ratio of 40:1. The reaction lasted for 3 minutes to complete the de-crosslinking of the waste rubber powder. The material was then sent to a twin-roll refiner with a roller pitch of 0.35 mm, a roller speed of 27 r / min, a speed ratio of 1:1.25, a roller temperature of 40°C, and refined for 3 minutes. The recycled rubber was thinly sliced ​​to obtain a Mooney viscosity of 58.

[0031] Example 2

[0032] Alkali lignin, 15-mesh waste tire tread rubber powder and catalyst HZSM-5 were put into a stirring device in a mass ratio of 10:6:1.5, stirred and mixed, and then heated to 93°C and sent to a moving bed reactor. The residence time of the pyrolysis gas was 0.6s. After the co-pyrolysis reaction was completed, the biomass pyrolysis gas with solid carbon residue was sent to a cyclone separator, and after the carbon residue was separated, it entered a cooling device. The temperature of the cooling oil was 140°C, and biomass oil was obtained after cooling. The 40-mesh waste tire tread rubber powder and the prepared biomass oil were put into an internal mixer at a mass ratio of 100:23. After the internal mixing was heated to 140°C, they were discharged into a high-speed mixer at a speed of 450-560rpm and reacted for 4 minutes to complete the de-crosslinking of the waste rubber powder. The material was then sent to a double-roll refiner with a roller spacing of 0.32mm, a roller speed of 29r / min, a speed ratio of 1:1.25, a roller temperature of 45°C, and refined for 3 minutes. The recycled rubber was thinly sliced ​​to obtain a Mooney viscosity of 47.

[0033] Example 3

[0034] Alkali lignin, 12-mesh waste tire rubber powder, and catalyst MCM-41 were put into a stirring device at a mass ratio of 10:4:4, stirred and mixed, heated to 96°C, and then sent to a moving bed reactor. The pyrolysis gas residence time was 0.6s. After the co-pyrolysis reaction was completed, the biomass pyrolysis gas with solid carbon residue was sent to a cyclone separator, separated from the carbon residue, and then entered a cooling device to obtain biomass oil after cooling. 30-mesh waste butyl rubber powder and the prepared biomass oil were put into a mixer at a mass ratio of 100:21, mixed and heated to 144°C, and then discharged into a twin-screw extruder with a screw length-diameter ratio of 42:1. The reaction lasted for 3 minutes to complete the de-crosslinking of the waste rubber powder, and then the material was sent to a double-roll refiner with a roller pitch of 0.36mm, a roller speed of 30r / min, a speed ratio of 1:1.25, a roller temperature of 50°C, and refined for 4 minutes. Thin sheets were obtained to obtain recycled rubber with a Mooney viscosity of 43. The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages and disadvantages of the embodiments. Through the description of the above implementation methods, those skilled in the art can clearly understand that the above embodiment methods can be implemented by means of some deformations plus the necessary general technology superposition; of course, they can also be implemented by simplifying some important technical features. Based on this understanding, the technical solution of the present invention is essentially or contributes to the prior art in the following aspects: the overall structure and connection method, and the structure described in each embodiment of the present invention.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing regenerated rubber from biomass oil, characterized in that: The following steps are involved: The first step is to prepare biomass oil; industrial lignin, waste rubber powder A, and catalyst are put into a stirring device according to a mass ratio of 10:4-6:0.5-2, stirred and mixed, and heated to 90-100°C; sent to a thermal cracking reaction device to complete a co-pyrolysis reaction, and the biomass pyrolysis gas with solid carbon residue is sent to a cyclone separator, and the biomass pyrolysis gas is separated from the carbon residue and then enters a cooling device, and biomass oil is obtained after cooling; The second step is to prepare the reclaimed rubber; the waste rubber powder B and the biomass oil prepared in the first step are put into an internal mixer at a mass ratio of 100:15-30, the internal mixer is heated to 130-150°C and then discharged into a desulfurization device, the temperature of the device is controlled at 200-260°C, the reaction is carried out for 2-5 minutes, and the decrosslinking of the waste rubber powder B is completed; then the material is sent to a double-roll refiner for roller refining, the refining time is 3-5 minutes, and a thin sheet is passed to obtain reclaimed rubber with a Mooney viscosity of 40-65.

2. The method for preparing regenerated rubber from biomass oil according to claim 1, characterized in that: In the first step, the mesh number of the waste rubber powder A is 5-15 meshes, the water content is less than 1%, and the waste rubber powder A is any one or more combinations of waste tire tread rubber and full tire rubber.

3. The method for preparing regenerated rubber from biomass oil according to claim 1, characterized in that: In the first step, the thermal cracking reaction device is any one of a fluidized bed reactor, a moving bed reactor, and a fixed bed reactor, and the residence time of the thermal cracking gas is 0.5s-1s.

4. The method for preparing regenerated rubber from biomass oil according to claim 1, characterized in that: In the first step, the cooling medium of the cooling device is oily substance, and the temperature is 110-140°C.

5. The method for preparing regenerated rubber from biomass oil according to claim 1, characterized in that: In the second step, the mesh number of the waste rubber powder B is 20-40 meshes, and the waste rubber powder B is any one or more combinations of waste tires or tread rubber, waste rubber shoes, waste EPDM rubber, and waste butyl rubber; the desulfurization device is one of a twin-screw extruder, a spiral plasticizer, and a high-speed mixer.

6. The method for preparing reclaimed rubber from biomass oil according to claim 1, characterized in that: In the second step, the roller gap of the double-roll refiner is 0.3-0.5 mm, the roller speed is 25-35 r / min, the speed ratio is 1:1.25, and the roller temperature is 40-60°C.

7. The method for preparing regenerated rubber from biomass oil according to claim 2, characterized in that: The moisture content of the industrial lignin is lower than 5%, and the industrial lignin is any one or more combinations of alkali lignin, sulfate lignin, and lignin sulfonate; the catalyst is one of the molecular sieve catalysts ZSM-5, HZSM-5 or MCM-41.