Efficient regeneration method for waste benzene ethylene saturated carbon in glass steel industry

Abstract

The application aims to provide a glass fiber reinforced plastic industry styrene saturated waste activated carbon efficient regeneration method, and belongs to the technical field of volatile organic compounds treatment. The catalyst of the application takes the styrene saturated industrial waste activated carbon as a carrier, and the active metal includes transition metals iron and nickel. The application loads the transition metals iron and nickel on the carrier through the impregnation method to obtain the waste activated carbon loaded bimetallic catalyst; under the catalysis of the bimetallic alloy active site, the styrene adsorbed in the activated carbon is cracked through a one-step pyrolysis method, the regeneration of the styrene saturated activated carbon is effectively realized, and under the synergistic effect of the bimetallic nickel and iron, the accumulated carbon generated by the styrene cracking is effectively eliminated and the pore blockage is prevented. Meanwhile, the adsorption capacity of the activated carbon loaded bimetallic catalyst can still be maintained at about 80% of the initial adsorption capacity after three cycles.

Description

Technical Field

[0001] This invention belongs to the field of volatile organic compound treatment technology, specifically relating to an efficient method for regenerating saturated waste carbon containing styrene from the fiberglass industry. Background Technology

[0002] Among numerous styrene removal technologies, adsorption is considered one of the most promising. Activated carbon, due to its simple preparation process, is widely used in environmental problems such as air purification, wastewater treatment, and soil remediation, especially in styrene treatment. Desorption is a crucial step in the recovery or post-treatment of styrene by adsorbents. Heating desorption is currently the most commonly used styrene desorption method. However, the narrow micropores of activated carbon can lead to difficulties and incomplete desorption of adsorbed styrene due to excessively strong adsorption forces and severely limited mass transfer. Furthermore, during the thermal desorption of styrene-saturated activated carbon, styrene undergoes cracking. During styrene cracking, a large amount of carbon is generated in the form of coke deposits. These coke deposits adhere to the surface of the activated carbon, clogging the pores and severely shortening its service life.

[0003] The presence of a catalyst can effectively promote the decomposition of styrene molecules, reduce carbon buildup, and is characterized by high efficiency, greenness, and no secondary pollution, making it an environmentally friendly technology. Therefore, catalytic cracking is the most promising method for solving the problem of styrene-saturated activated carbon regeneration. Summary of the Invention

[0004] This invention addresses the short lifespan of existing activated carbon adsorbents by providing a highly efficient regeneration method for styrene-containing saturated waste carbon in the fiberglass industry. A nickel-iron bimetallic catalyst is prepared using styrene-saturated waste carbon. Through the active sites of the metals, the cracking efficiency of styrene is improved. Simultaneously, the synergistic effect of the bimetallic nickel and iron effectively eliminates carbon deposits generated during styrene cracking and prevents pore blockage, significantly extending the lifespan of the activated carbon. This method has significant environmental and economic benefits.

[0005] The present invention adopts the following technical solution:

[0006] A method for efficient regeneration of styrene-containing saturated waste carbon from the fiberglass industry includes the following steps:

[0007] The first step is to combine the support and Ni-containing materials. 2+ After being impregnated with a salt solution, the catalyst is obtained by evaporation and drying processes. The support is saturated styrene carbon.

[0008] The second step involves combining a Ni-based catalyst with an Fe-containing catalyst. 3+ After being impregnated with a salt solution, the Ni-Fe bimetallic catalyst was obtained by evaporation and drying processes.

[0009] The third step involves pyrolyzing the Ni-Fe bimetallic catalyst to obtain a regenerated carbon-supported Ni-Fe bimetallic catalyst.

[0010] Furthermore, the Ni-containing element mentioned in the first step... 2+ The salt solution is Ni(NO3)2·6H2O with a mass concentration of 2.5%.

[0011] Furthermore, the carrier and Ni-containing material mentioned in the first step... 2+ The mass-to-volume ratio of the salt solution is 10-15g:10-20mL.

[0012] Furthermore, the soaking time in the first step is 1-2 hours, the evaporation temperature is 70-80℃, the evaporation time is 1-2 hours, the drying temperature is 100-105℃, and the drying time is 24-26 hours.

[0013] Furthermore, the Fe-containing element mentioned in the second step 3+ The salt solution is Fe(NO3)3·9H2O with a mass concentration of 2.5%.

[0014] Furthermore, the Ni-based catalyst and the Fe-containing catalyst 3+ The mass-to-volume ratio of the salt solution is 10-15g:10-20mL.

[0015] Furthermore, in the second step, the soaking time is 1-2 hours, the evaporation temperature is 70-80℃, the evaporation time is 1-2 hours, the drying temperature is 100-105℃, and the drying time is 24-26 hours.

[0016] Furthermore, in the third step, the pyrolysis treatment temperature is 900℃, the heating rate of the pyrolysis treatment is 3~5℃ / min, and the isothermal pyrolysis treatment time at 900℃ is 5~8h.

[0017] The application of the regenerated carbon-supported Ni-Fe bimetallic catalyst in styrene treatment involves placing the regenerated carbon-supported Ni-Fe bimetallic catalyst in a fixed-bed reactor to carry out the styrene adsorption reaction.

[0018] In the adsorption reaction, the mass of the regenerated carbon-supported Ni-Fe bimetallic catalyst is 0.1-0.15 g; the concentration of the styrene gas is 1000 ppm; and the flow rate of the styrene gas is 100 mL / min.

[0019] The beneficial effects of this invention are as follows:

[0020] 1. This invention employs an impregnation-pyrolysis method to load transition metals iron and nickel onto industrial waste carbon saturated with adsorbed styrene. The synthesized nickel-iron bimetallic alloy active sites promote the decomposition of styrene adsorbed in activated carbon. The transition metals iron and nickel have a strong interaction, effectively eliminating carbon deposits generated by styrene decomposition and preventing pore blockage, thus significantly extending the service life of the activated carbon adsorbent.

[0021] 2. The method for preparing the regenerated carbon-supported Ni-Fe bimetallic catalyst of the present invention is simple and easy to operate. The regenerated activated carbon adsorbent is used in the subsequent adsorption of styrene, and the adsorption effect on styrene is good, which has important environmental benefits and economic value. Attached Figure Description

[0022] Figure 1 N2- adsorption-desorption curves of 2.5Fe-2.5Ni-900 prepared in Example 1, 5Fe-900 prepared in Comparative Example 1, 5Ni-900 prepared in Comparative Example 2, and RAC-900 prepared in Comparative Example 3.

[0023] Figure 2 Pore ​​size distribution diagrams of 2.5Fe-2.5Ni-900 prepared in Example 1, 5Fe-900 prepared in Comparative Example 1, 5Ni-900 prepared in Comparative Example 2, and RAC-900 prepared in Comparative Example 3.

[0024] Figure 3 XRD patterns of 2.5Fe-2.5Ni-900 prepared in Example 1, 5Fe-900 prepared in Comparative Example 1, 5Ni-900 prepared in Comparative Example 2, and RAC-900 prepared in Comparative Example 3.

[0025] Figure 4 Raman graphs of 2.5Fe-2.5Ni-900 prepared in Example 1, 5Fe-900 prepared in Comparative Example 1, 5Ni-900 prepared in Comparative Example 2, and RAC-900 prepared in Comparative Example 3.

[0026] Figure 5 SEM images of 2.5Fe-2.5Ni-900 prepared in Example 1, 5Fe-900 prepared in Comparative Example 1, and 5Ni-900 prepared in Comparative Example 2; where a is Example 1, b is Comparative Example 1, and c is Comparative Example 2.

[0027] Figure 6 XPS images of Fe elemental composition for 2.5Fe-2.5Ni-900 prepared in Example 1 and 5Fe-900 prepared in Comparative Example 1;

[0028] Figure 7XPS images of Ni elemental composition for 2.5Fe-2.5Ni-900 prepared in Example 1 and 5Ni-900 prepared in Comparative Example 2;

[0029] Figure 8 XPS images of O element in 2.5Fe-2.5Ni-900 prepared in Example 1, 5Fe-900 prepared in Comparative Example 1, and 5Ni-900 prepared in Comparative Example 2;

[0030] Figure 9 Breakthrough curves of styrene adsorption for 2.5Fe-2.5Ni-900 prepared in Example 1, 5Fe-900 prepared in Comparative Example 1, 5Ni-900 prepared in Comparative Example 2, and RAC-900 prepared in Comparative Example 3.

[0031] Figure 10 The breakthrough curve of styrene adsorption after cyclic reaction of 2.5Fe-2.5Ni-900 prepared in Example 1. Detailed Implementation

[0032] This invention provides a method for regenerating styrene-saturated activated carbon using a nickel-iron bimetallic catalyst supported on industrial waste carbon. The invention will be further described below with reference to specific embodiments.

[0033] Example 1

[0034] 10g of styrene-saturated industrial waste carbon was immersed in 10mL of a 2.5% Ni(NO3)2·6H2O solution for 1h, evaporated to dryness in an 80℃ water bath for 1h, and then dried in an oven at 105℃ for 24h to obtain a Ni-based catalyst. The obtained Ni-based catalyst was immersed in 10mL of a 2.5% Fe(NO3)3·9H2O solution for 1h, evaporated to dryness in an 80℃ water bath for 1h, and then dried in an oven at 105℃ for 24h. Finally, it was pyrolyzed in an N2 atmosphere at a flow rate of 500mL / min and a pyrolysis temperature of 900℃ for 5h to obtain the bimetallic catalyst 2.5Fe-2.5Ni-900.

[0035] In the bimetallic catalyst 2.5Fe-2.5Ni-900 of this embodiment, the support is styrene-saturated industrial waste carbon, the loading of transition metal Ni is 2.5%, and the loading of transition metal Fe is 2.5%.

[0036] 0.1 g of bimetallic catalyst 2.5Fe-2.5Ni-900 was placed in a dynamic adsorption fixed-bed reactor, and styrene gas with a concentration of 1000 ppm was introduced at a flow rate of 100 mL / min to carry out the dynamic adsorption reaction of styrene. The concentration of styrene at the outlet was measured by gas chromatography to evaluate the amount of styrene adsorbed.

[0037] Comparative Example 1

[0038] 10g of styrene-saturated industrial waste carbon was immersed in 10mL of a 5% (w / w) Ni(NO3)2·6H2O solution for 1h, evaporated to dryness in an 80℃ water bath for 1h, and then sequentially dried in an oven at 105℃ for 24h. Finally, it was pyrolyzed for 6h in a N2 atmosphere at a flow rate of 500mL / min and a heating rate of 5℃ / min at a pyrolysis temperature of 900℃ to obtain the monometallic catalyst 5Ni-900.

[0039] In the single-metal catalyst 5Ni-900 of this comparative example, the support is styrene-saturated industrial waste carbon, and the loading of transition metal Ni is 5%.

[0040] 0.1 g of the single-metal catalyst 5Ni-900 was placed in a dynamic adsorption fixed-bed reactor, and styrene gas with a concentration of 1000 ppm was introduced at a flow rate of 100 mL / min to carry out the dynamic adsorption reaction of styrene. The concentration of styrene at the outlet was measured by gas chromatography to evaluate the amount of styrene adsorbed.

[0041] Comparative Example 2

[0042] 10g of styrene-saturated industrial waste carbon was immersed in 10mL of 5% Fe(NO3)3·9H2O solution for 1h, evaporated to dryness in a water bath at 80℃ for 1.5h, and then dried in an oven at 105℃ for 25h. Finally, it was pyrolyzed in a N2 atmosphere at a flow rate of 500mL / min and a heating rate of 3℃ / min at a pyrolysis temperature of 900℃ for 6h to obtain the monometallic catalyst 5Fe-900.

[0043] In the single-metal catalyst 5Fe-900 of this comparative example, the support is styrene-saturated industrial waste carbon, and the loading of transition metal Fe is 5%.

[0044] 0.1 g of the single-metal catalyst 5Fe-900 was placed in a dynamic adsorption fixed-bed reactor, and styrene gas with a concentration of 1000 ppm was introduced at a flow rate of 100 mL / min to carry out the dynamic adsorption reaction of styrene. The concentration of styrene at the outlet was measured by gas chromatography to evaluate the amount of styrene adsorbed.

[0045] Comparative Example 3

[0046] 10g of styrene-saturated industrial waste carbon was immersed in 10mL of deionized water for 1h, evaporated to dryness in an 80℃ water bath for 1h, and then dried sequentially in an oven at 105℃ for 24h. Finally, it was pyrolyzed in an N2 atmosphere at a flow rate of 500mL / min and a pyrolysis temperature of 900℃ for 6h to obtain unloaded metal RAC-900.

[0047] 0.1 g of unloaded metal RAC-900 was placed in a dynamic adsorption fixed-bed reactor, and styrene gas with a concentration of 1000 ppm was introduced at a flow rate of 100 mL / min to carry out the dynamic adsorption reaction of styrene. The concentration of styrene at the outlet was measured by gas chromatography to evaluate the amount of styrene adsorbed.

[0048] The N2- adsorption-desorption curves of 2.5Fe-2.5Ni-900 prepared in Example 1, 5Fe-900 prepared in Comparative Example 1, 5Ni-900 prepared in Comparative Example 2, and RAC-900 prepared in Comparative Example 3 are shown in the figure. Figure 1 As shown. The specific surface area of ​​2.5Fe-2.5Ni-900 prepared in Example 1 is 824.3 m². 2 / g, the specific surface area of ​​5Fe-900 prepared in Comparative Example 1 was 648.2m². 2 / g, the specific surface area of ​​5Ni-900 prepared in Comparative Example 2 was 593.8m². 2 / g, the specific surface area of ​​RAC-900 prepared in Comparative Example 3 was 572.4m². 2 / g. This indicates that the 2.5Fe-2.5Ni-900 prepared in Example 1 enables more thorough cracking of adsorbed styrene during the catalytic process and effectively prevents the formation of carbon deposits, which is attributed to the good synergistic effect between Ni and Fe.

[0049] The 2.5Fe-2.5Ni-900 prepared in Example 1 formed a large number of microporous structures, mainly consisting of micropores with a diameter of 0.55-0.65 nm. This indicates that the 0.55-0.65 nm micropores play a major role in the adsorption of styrene.

[0050] The XRD patterns of 2.5Fe-2.5Ni-900 prepared in Example 1, 5Fe-900 prepared in Comparative Example 1, 5Ni-900 prepared in Comparative Example 2, and RAC-900 prepared in Comparative Example 3 are shown below. Figure 3 As shown. The diffraction peak intensities of iron and nickel in the 2.5Fe-2.5Ni-900 prepared in Example 1 are lower than those in the 5Fe-900 prepared in Comparative Example 1 and the 5Ni-900 prepared in Comparative Example 2, indicating that the 2.5Fe-2.5Ni-900 prepared in Example 1 has better metal dispersion. Metal carbides were observed in both the 5Fe-900 prepared in Comparative Example 1 and the 5Ni-900 prepared in Comparative Example 2, while no metal carbides were observed in the 2.5Fe-2.5Ni-900 prepared in Example 1, indicating that the synergistic effect between the bimetals is beneficial to the elimination of carbon deposits generated by styrene cracking. The 2.5Fe-2.5Ni-900 prepared in Example 1 contains a bimetallic alloy Fe. 0.64 Ni 0.36The presence of Fe-Ni alloys indicates that bimetallic alloys are the main active sites for styrene pyrolysis.

[0051] The Raman graphs of 2.5Fe-2.5Ni-900 prepared in Example 1, 5Fe-900 prepared in Comparative Example 1, 5Ni-900 prepared in Comparative Example 2, and RAC-900 prepared in Comparative Example 3 are shown below. Figure 4 As shown, the 2.5Fe-2.5Ni-900 prepared in Example 1 exhibits the highest degree of graphitization and the most stable structure.

[0052] SEM images of 2.5Fe-2.5Ni-900 prepared in Example 1, 5Fe-900 prepared in Comparative Example 1, and 5Ni-900 prepared in Comparative Example 2 are shown below. Figure 5 As shown, the pore structures of 5Fe-900 prepared in Comparative Example 1 and 5Ni-900 prepared in Comparative Example 2 were severely blocked due to carbon deposition, which was caused by the rapid deactivation of the metal active sites. The pore structure of 2.5Fe-2.5Ni-900 prepared in Example 1 was more abundant, which can be attributed to the good synergistic catalytic effect between Ni and Fe. The synergistic catalysis between Ni and Fe prevents the catalyst from being blocked by carbon deposition during the catalytic cracking of styrene.

[0053] XPS plots of Fe elemental composition for 2.5Fe-2.5Ni-900 prepared in Example 1 and 5Fe-900 prepared in Comparative Example 1 are shown below. Figure 6 As shown in the figure. It can be seen from the figure that the Fe in the 2.5Fe-2.5Ni-900 prepared in Example 1... 2+ and Fe 0 The higher content of Ni indicates that the presence of Ni promotes the reduction of Fe, and the reduced Fe has higher catalytic activity. 0 The presence of [something] is conducive to the formation of bimetallic alloys.

[0054] XPS plots of Ni elemental composition of 2.5Fe-2.5Ni-900 prepared in Example 1 and 5Ni-900 prepared in Comparative Example 2 are shown below. Figure 7 As shown in the figure. It can be seen from the figure that Ni in the 2.5Fe-2.5Ni-900 prepared in Example 1... 0 The higher content of Fe indicates that the presence of Fe promotes the reduction of Ni, and the reduced Ni has higher catalytic activity. 0 The presence of [something] is conducive to the formation of bimetallic alloys.

[0055] XPS plots of O element in 2.5Fe-2.5Ni-900 prepared in Example 1, 5Fe-900 prepared in Comparative Example 1, and 5Ni-900 prepared in Comparative Example 2 are shown below. Figure 8As shown in the figure. It can be seen from the figure that the O in 2.5Fe-2.5Ni-900 prepared in Example 1... α The highest proportion indicates that the introduction of another component into the bimetallic catalyst leads to more surface-adsorbed oxygen. Furthermore, considering the catalyst activity during the catalytic cracking of styrene, higher O content... α The proportion is beneficial to improving the catalytic performance of the catalyst in the catalytic cracking of styrene;

[0056] The breakthrough curves of styrene adsorption by 2.5Fe-2.5Ni-900 prepared in Example 1, 5Fe-900 prepared in Comparative Example 1, and 5Ni-900 prepared in Comparative Example 2 are shown below. Figure 9 As shown. From Figure 9 As can be seen, the styrene outlet concentration of the 2.5Fe-2.5Ni-900 prepared in Example 1 was 0 in the first 70 minutes, indicating that styrene was completely adsorbed within that time. The styrene adsorption capacity of the 2.5Fe-2.5Ni-900 prepared in Example 1 was 407.5 mg / g, the styrene adsorption capacity of the 5Fe-900 prepared in Comparative Example 1 was 275.84 mg / g, the styrene adsorption capacity of the 5Ni-900 prepared in Comparative Example 2 was 255.74 mg / g, and the styrene adsorption capacity of the RAC-900 prepared in Comparative Example 3 was 252.69 mg / g. The styrene adsorption capacity of the 2.5Fe-2.5Ni-900 prepared in Example 1 was approximately 1.5 times that of the 5Fe-900 prepared in Comparative Example 1 and the 5Ni-900 prepared in Comparative Example 2, and 1.6 times that of the RAC-900 prepared in Comparative Example 3. The 2.5Fe-2.5Ni-900 prepared in Example 1 enables the styrene adsorbed in activated carbon to be cracked, effectively regenerating the styrene-saturated activated carbon. At the same time, under the synergistic effect of bimetallic nickel and iron, it effectively eliminates the carbon deposits generated by styrene cracking and prevents pore blockage.

[0057] The 2.5Fe-2.5Ni-900 saturated with styrene prepared in Example 1 was pyrolyzed and regenerated. This adsorption-pyrolysis regeneration cycle was repeated three times. The breakthrough curve of styrene adsorption after the cyclic reaction of the 2.5Fe-2.5Ni-900 prepared in Example 1 is shown in the figure. Figure 10 As shown. From Figure 10As can be seen, after one cycle, the styrene adsorption capacity of the 2.5Fe-2.5Ni-900 prepared in Example 1 was 393.57 mg / g; after two cycles, the styrene adsorption capacity was 343.99 mg / g; and after three cycles, the styrene adsorption capacity was 317.80 mg / g. Even after three cycles, the styrene adsorption capacity of the 2.5Fe-2.5Ni-900 prepared in Example 1 still reached approximately 80% of that of the 2.5Fe-2.5Ni-900 prepared in Example 1, indicating that the 2.5Fe-2.5Ni-900 prepared in Example 1 possesses high catalytic activity and cycling stability.

Claims

1. A method for efficient regeneration of styrene-containing saturated waste carbon from the fiberglass industry, characterized in that: Includes the following steps: The first step is to combine the support and Ni-containing materials. 2+ After being impregnated with a salt solution, the catalyst is obtained by evaporation and drying processes. The support is saturated styrene carbon. The second step involves combining a Ni-based catalyst with an Fe-containing catalyst. 3+ After being impregnated with a salt solution, the Ni-Fe bimetallic catalyst was obtained by evaporation and drying processes. The third step involves pyrolyzing the Ni-Fe bimetallic catalyst to obtain a regenerated carbon-supported Ni-Fe bimetallic catalyst.

2. The method for efficient regeneration of styrene-containing saturated waste carbon in the fiberglass industry according to claim 1, characterized in that: The Ni-containing component mentioned in the first step 2+ The salt solution is Ni(NO3)2·6H2O with a mass concentration of 2.5%.

3. The method for efficient regeneration of styrene-containing saturated waste carbon in the fiberglass industry according to claim 1, characterized in that: The support and Ni-containing material mentioned in the first step 2+ The mass-to-volume ratio of the salt solution is 10-15g:10-20mL.

4. The method for efficient regeneration of styrene-containing saturated waste carbon in the fiberglass industry according to claim 1, characterized in that: The soaking time in the first step is 1-2 hours, the evaporation temperature is 70-80℃, the evaporation time is 1-2 hours, the drying temperature is 100-105℃, and the drying time is 24-26 hours.

5. The method for efficient regeneration of styrene-containing saturated waste carbon in the fiberglass industry according to claim 1, characterized in that: The second step involves Fe. 3+ The salt solution is Fe(NO3)3·9H2O with a mass concentration of 2.5%.

6. The method for efficient regeneration of styrene-containing saturated waste carbon in the fiberglass industry according to claim 1, characterized in that: The Ni-based catalyst and Fe-containing 3+ The mass-to-volume ratio of the salt solution is 10-15g:10-20mL.

7. The method for efficient regeneration of styrene-containing saturated waste carbon in the fiberglass industry according to claim 1, characterized in that: The second step involves soaking for 1-2 hours, evaporating at 70-80°C for 1-2 hours, drying at 100-105°C for 24-26 hours.

8. The method for efficient regeneration of styrene-containing saturated waste carbon in the fiberglass industry according to claim 1, characterized in that: The pyrolysis treatment in the third step is carried out at a temperature of 900℃, with a heating rate of 3~5℃ / min. After reaching 900℃, the pyrolysis treatment is kept at the same temperature for 5~8 hours.

Images