CN115634684A - High-specific-surface-area biomass charcoal low-temperature SCR catalyst, and preparation method and application thereof - Google Patents
High-specific-surface-area biomass charcoal low-temperature SCR catalyst, and preparation method and application thereof Download PDFInfo
- Publication number
- CN115634684A CN115634684A CN202211089346.4A CN202211089346A CN115634684A CN 115634684 A CN115634684 A CN 115634684A CN 202211089346 A CN202211089346 A CN 202211089346A CN 115634684 A CN115634684 A CN 115634684A
- Authority
- CN
- China
- Prior art keywords
- biomass charcoal
- surface area
- specific surface
- biomass
- high specific
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Abstract
The invention discloses a preparation method and application of a biomass charcoal low-temperature SCR catalyst with a high specific surface area. According to the invention, biomass is used as a raw material, a novel high-temperature pyrolysis carbonization ventilation mode is adopted, and carbon dioxide and water vapor are left in the tubular furnace in the high-temperature carbonization process, so that the pore-forming of biomass charcoal is facilitated, the specific surface area of the biomass charcoal is greatly increased, and active components are stably loaded on the biomass charcoal; meanwhile, the biomass carbon with high specific surface area is used as a carrier to load active components, so that the low-temperature SCR catalyst with high load capacity is prepared, and the catalyst has good sulfur resistance and water resistance.
Description
Technical Field
The invention relates to the technical field of low-temperature SCR denitration, in particular to a biomass charcoal low-temperature SCR catalyst with a high specific surface area, and a preparation method and application thereof.
Background
Sulfur dioxide, nitrogen oxides, particulate matter and volatile organic compounds all belong to atmospheric pollutants, wherein nitrogen oxides can cause environmental problems such as photochemical smog, acid rain and the like, and simultaneously cause respiratory diseases, thereby endangering human health. Small-sized kilns such as cement kilns and the like are one of main emission sources of nitrogen oxides, and effective measures are urgently needed to reduce the emission of the nitrogen oxides. At present, the emission reduction technology of nitrogen oxides includes a selective catalytic reduction method, an adsorption method, an absorption method, and the like, wherein the Selective Catalytic Reduction (SCR) technology is an effective and most widely-used method for removing NOx.
Currently, in industry, commercial SCR catalysts are mainly V 2 O 5 -WO 3 (MoO 3 )/TiO 2 The catalyst, which has an activity temperature of 300-400 ℃, is usually placed before the dust collector in order to keep the catalyst working in the optimum activity temperature window, but this can lead to catalyst attrition and deactivation. After the catalyst is placed in a dust removal and desulfurization environment, a low-temperature SCR denitration technology is developed, so that the service life of the catalyst is prolonged, and the denitration cost is reduced, so that the low-temperature SCR catalyst becomes a research hotspot.
Biomass charcoal requires that the biomass feedstock be subjected to thermochemical conversion in an anoxic or anaerobic environment to produce a char-rich solid. The biomass carbon has the advantages of rich pore structure, large specific surface area, wide source, low cost and the like, and can be used as a low-temperature SCR catalyst carrier. The specific surface area is a key factor influencing the activity of the biomass charcoal as the SCR catalyst, and the specific surface area of the biomass charcoal is improved, so that the improvement of the low-temperature activity of the biomass charcoal-based low-temperature SCR catalyst is facilitated.
The invention prepares the biomass charcoal with high specific surface area by adjusting the carbonization flow, the carbonization atmosphere and the like, and takes the biomass charcoal as a carrier to load active components (cerium oxide, manganese oxide and the like) to prepare the low-temperature SCR catalyst with good water resistance and sulfur resistance.
Disclosure of Invention
The invention aims to provide a biomass charcoal low-temperature SCR catalyst with a high specific surface area, and a preparation method and application thereof.
A calcination method which is different from the traditional high-temperature pyrolysis aeration mode and is used for increasing the specific surface area of the biomass charcoal.
The invention also aims to provide a preparation method and application of the biomass charcoal low-temperature SCR catalyst with high specific surface area.
The invention is implemented according to the following technical scheme:
a preparation method of a biomass charcoal low-temperature SCR catalyst with a high specific surface area comprises the following steps:
(1) Preparing biomass charcoal with high specific surface area;
s1, crushing and loading a biomass raw material, and feeding the biomass raw material into a tubular furnace;
s2, preparing the biomass charcoal by using a tubular furnace, and introducing N before heating and carbonizing 2 Stopping introducing N when temperature rising is started 2 And closing the air inlet valve to pyrolyze the biomass at high temperature in an anoxic environment, closing the air outlet valve before carbonization is finished, sealing the furnace body, and cooling to room temperature to obtain the biomass charcoal with high specific surface area.
(2) Loading of active ingredients
S1, taking 10g of biomass charcoal with high specific surface area in the step (1), soaking the biomass charcoal in 200mL of nitric acid with the concentration of 2mol/L for 12h, washing the biomass charcoal to be neutral, and drying the biomass charcoal to obtain acid-washed biomass charcoal;
s2, weighing an active component precursor, and ultrasonically dissolving;
s3, mixing the biomass charcoal subjected to acid washing with an active component solution, heating the mixture in a water bath kettle, and drying the mixture;
and S4, placing the mixture obtained in the step S3 in a tubular furnace, and roasting to obtain the biomass charcoal low-temperature SCR catalyst with the high specific surface area.
Further, the biomass raw material in the step (1) S1 is one of biomass raw materials such as rape straw, soybean straw and the like.
Further, in step (1) S2, N 2 The gas flow rate is 50-500 ml/min, and N is introduced 2 The time is 5-20 min, the heating rate is 1-10 ℃/min, the pyrolysis temperature is 600-800 ℃, the calcination time is 2-4 h, and the time for closing the air outlet valve is 1-5 min before the carbonization is finished.
In step (2) S1, the concentration of the nitric acid is 1 to 3mol/L (more preferably 2 mol/L), and the biomass charcoal with high specific surface area is soaked in the nitric acid for 8 to 14 hours, and more preferably, 10g of the biomass charcoal with high specific surface area in step (1) is soaked in 200mL of nitric acid with concentration of 2mol/L for 12 hours.
Further, in the step (2) S2, the active component precursor is cerium nitrate, manganese nitrate or other active component precursors.
Further, in the step (2) S3, the mixture is heated in a water bath kettle at the temperature of 70-80 ℃ for 2-4 h, and the mixture is dried.
Further, in the step (2) S4, the heating rate is 1-10 ℃/min, the pyrolysis temperature is 300-600 ℃, and the roasting time is 2-4 h.
The invention also discloses application of the biomass charcoal low-temperature SCR catalyst with high specific surface area in the technical field of a charcoal-based low-temperature SCR denitration system, wherein the loading capacity (active component mass/(active component mass + carrier mass)) of cerium oxide is 40-60%, the cerium oxide is coated on the surface of the biomass charcoal, and the reaction temperature is 100-300 ℃.
Compared with the existing biomass charcoal low-temperature SCR catalyst, the invention has the beneficial effects that:
(1) The invention firstly adopts a novel high-temperature pyrolysis ventilation mode to fire the biomass charcoal, and N is introduced before the carbonization 2 The air in the tube furnace is discharged, and the introduction of N is stopped in the carbonization process 2 The inlet valve of the tubular furnace is closed, the outlet valve is kept normally open, carbon dioxide and water vapor generated in the high-temperature pyrolysis process are filled in the tubular furnace, the pore-forming of the biomass carbon is facilitated, the specific surface area of the biomass carbon is greatly increased compared with the traditional high-temperature pyrolysis ventilation mode, the biomass carbon is not required to be further subjected to activated pore-forming treatment by an active carbon preparation method, and energy is saved.
(2) The biomass charcoal with high specific surface area is used as a carrier, active components are loaded, the low-temperature SCR catalyst with high metal oxide loading capacity can be prepared, the metal loading capacity is improved, the sulfur resistance and the water resistance of the catalyst can be obviously improved, and the cerium oxide is wrapped on the surface of the biomass charcoal, so that a local oxygen-limited area can be formed on the surface of the biomass charcoal-based catalyst, and the oxidation loss of the biomass charcoal is prevented.
Drawings
FIG. 1 is a graph comparing the specific surface areas of biomass char (BC-2) prepared by pyrolysis and aeration of example 1 with biomass char (BC-1) prepared by conventional pyrolysis and aeration;
FIG. 2 is a graph showing the effect of the Ce activity assay on Biomass charcoal (BC-2) and BC-60% of example 1;
FIG. 3 is a graph comparing the sulfur-resistance and water-resistance performances of BC-5% Ce and BC-60% Ce of Biomass charcoal of example 1.
The specific implementation mode is as follows:
the invention is further illustrated by the following specific examples. The specific embodiments described herein are merely illustrative of the invention and are not intended to be limiting.
(1) Rape straws are crushed, sieved to 60-80 meshes and respectively sent into two tubular furnaces.
(2) Heating the No. 1 tube furnace to 800 ℃ at the heating rate of 5 ℃/min, calcining for 2h, and introducing N in the whole process at the flow rate of 100mL/min 2 Cooling to room temperature after high-temperature pyrolysis to prepare biomass charcoal BC-1; no. 2 tube furnace is introduced for 5min N at the flow rate of 100mL/min 2 Then closing the gas cylinder and the gas inlet, pyrolyzing at high temperature, heating to 800 deg.C at a rate of 5 deg.C/min, calciningAnd (4) burning for 2h, closing the gas outlet within 5min before cooling, and cooling to room temperature to obtain the biomass charcoal BC-2. The biomass carbon prepared by the two methods is characterized, and the specific surface area is compared.
(3) 10g of the biomass charcoal with the optimized high specific surface area is soaked in 200mL of nitric acid with the concentration of 2mol/L for 12h, washed to be neutral, and dried to obtain the biomass charcoal after acid washing.
(4) 0.0816g, 0.1722g, 0.3874g, 0.5166g, 1.1623g and 3.0994g of cerium nitrate are respectively weighed into a centrifuge tube, 0.5mL of distilled water is added, and the mixture is evenly dissolved by ultrasonic. Weighing 0.5g of the biomass charcoal after acid washing in a centrifuge tube, placing the centrifuge tube in a water bath kettle at 80 ℃ for heating for 3h, then respectively pouring into a ark and drying at 75 ℃, sending into a tube furnace, heating to 400 ℃ at a heating rate of 10 ℃/min, and roasting for 2h to obtain the biomass charcoal low-temperature SCR catalyst with the high specific surface area of 5%, 10%, 20%, 40%, 60% and 80% respectively.
Specific surface areas of two biomass charcoals prepared in example 1 are detected and compared, and a high specific surface area biomass charcoal low-temperature SCR catalyst prepared in example 1 is subjected to further denitration performance test and sulfur resistance and water resistance test.
1. Biomass charcoal specific surface area test contrast
BC-1 and BC-2 were characterized using a surface texture analyzer, and the results are shown in Table 1.
TABLE 1
As can be seen from Table 1 and FIG. 1, the biomass charcoal (BC-2) prepared by the novel high-temperature pyrolysis ventilation method adopted by the invention has the advantages that the specific surface area is increased by 5 times, the total pore volume is increased by 5 times, the average pore diameter is reduced, and the micro-nano pore diameter is increased.
2. Further denitration performance test of biomass charcoal low-temperature SCR catalyst with high specific surface area
Sieving the prepared catalyst to 100-200 meshes, loading the catalyst into a fixed bed reactor with the inner diameter of 4mm, wherein the loading height is 1.2cm, and the simulated reaction gas contains 500ppm NH 3 ，500ppm NO，5％O 2 Introduction of N 2 And (4) balancing. The total flow rate of the gas is 250mL/min, the activity test is carried out in the temperature range of 100-300 ℃, and the test result is shown in figure 2.
As can be seen from FIG. 2, the biomass charcoal low temperature SCR catalyst (BC-60% Ce) with high specific surface area prepared by the present invention has the highest overall NOx conversion at 40-60% and the best denitration performance at 250 ℃.
3. Sulfur and Water resistance test
Sieving the prepared catalyst to 100-200 meshes, loading the catalyst into a fixed bed reactor with the inner diameter of 4mm, wherein the loading height is 1.2cm, and the simulated reaction gas contains 500ppm of NH 3 ，500ppm NO，5％O 2 ，10％H 2 O (when used), 100ppm SO 2 (when in use), N is introduced 2 The balance is carried out, the total flow of gas is 250mL/min, the temperature is maintained at 250 ℃, and continuous sampling is carried out, and the test result is shown in figure 3.
As can be seen from FIG. 3, a high specific surface area Biomass charcoal low temperature SCR catalyst (BC-60% Ce) prepared by the present invention can support high loading of active component, which in turn improves the sulfur and water resistance of the catalyst.
4. Comparison of the Activity of conventional activated carbon catalysts
The results of comparing the biomass charcoal low-temperature SCR catalyst (BC-60% Ce) prepared by the invention with the traditional activated carbon catalyst are shown in Table 2.
TABLE 2
As can be seen from Table 2, the denitration performance of a high specific surface area biochar low temperature SCR catalyst prepared by the present invention (BC-60% Ce) is more than 40% higher than that of the conventional activated carbon catalyst.
The experimental result of the biomass charcoal low-temperature SCR catalyst with the high specific surface area prepared by the invention is integrated to discover that:
(1) Compared with the traditional high-temperature pyrolysis ventilation mode, the biomass charcoal prepared by the novel high-temperature pyrolysis ventilation mode has the advantages that N is introduced before carbonization 2 Discharging the air in the tube furnace, stopping introducing N in the carbonization process 2 And closing the inlet valve of the tubular furnace, keeping the outlet valve normally open, and filling the tubular furnace with carbon dioxide and water vapor generated in the high-temperature pyrolysis process, so that the pore-forming of the biomass carbon is facilitated, the specific surface area of the biomass carbon is greatly increased, and the active components are stably loaded on the biomass carbon.
(2) The biomass charcoal low-temperature SCR catalyst with the high specific surface area prepared by the invention can bear cerium oxide active components with high loading capacity, and has the advantages of good water resistance and sulfur resistance.
The above embodiments are only for illustrating the present invention, the technical solution of the present invention is not limited by the above embodiments, and any other modifications, substitutions, improvements, etc. without departing from the spirit and principle of the present invention are included in the protection scope of the present invention.
Claims (10)
1. A preparation method of a biomass charcoal low-temperature SCR catalyst with a high specific surface area is characterized by comprising the following steps;
(1) Preparing the biomass charcoal with high specific surface area:
s1, crushing and loading a biomass raw material, and feeding the biomass raw material into a tubular furnace;
s2, preparing the biomass charcoal by using a tubular furnace, and introducing N before heating and carbonizing 2 Stopping introducing N when the temperature starts to rise 2 Closing the air inlet valve to pyrolyze the biomass at high temperature in an anoxic environment, closing the air outlet valve before carbonization is finished, sealing the furnace body, and cooling to form a negative pressure environment to obtain biomass charcoal with high specific surface area;
(2) Loading of active components:
s1, soaking the biomass charcoal with high specific surface area in the step (1) with nitric acid, washing to be neutral, and drying to obtain the biomass charcoal after acid washing;
s2, weighing an active component precursor, and ultrasonically dissolving to obtain an active component solution;
s3, mixing the biomass charcoal subjected to acid washing with an active component solution, heating the mixture in a water bath kettle, and drying the mixture;
and S4, placing the dried mixture obtained in the step S3 in a tubular furnace, and roasting to obtain the biomass charcoal low-temperature SCR catalyst with high specific surface area and prepared by wrapping biomass charcoal with metal oxides.
2. The preparation method of the high specific surface area biomass charcoal low-temperature SCR catalyst according to claim 1, wherein in step (1) S1, the biomass raw material is one or two of rape straw and soybean straw biomass raw materials.
3. The preparation method of the high specific surface area biomass charcoal low-temperature SCR catalyst according to claim 1, wherein in step (1) S2, N is 2 The gas flow rate is 50-500 ml/min, and N is introduced 2 The time is 5-20 min, the heating rate is 1-10 ℃/min, the pyrolysis temperature is 600-800 ℃, the calcination time is 2-4 h, and the time for closing the air outlet valve is 1-5 min before the carbonization is finished.
4. The preparation method of the high specific surface area biomass charcoal low-temperature SCR catalyst according to claim 1, wherein in the step (2) S1, the concentration of the nitric acid is 1-3 mol/L, and the nitric acid is soaked for 8-14 h.
5. The preparation method of the high specific surface area biomass charcoal low-temperature SCR catalyst according to claim 1, wherein in step (2) S2, the active component precursor is cerium nitrate or manganese nitrate.
6. The preparation method of the biomass charcoal low-temperature SCR catalyst with the high specific surface area as claimed in claim 1, wherein in the step (2) S3, the mixture is heated in a water bath kettle at 70-80 ℃ for 2-4 h, and the mixture is dried.
7. The preparation method of the biomass charcoal low-temperature SCR catalyst with the high specific surface area as claimed in claim 1, wherein in the step (2) S4, the temperature rise rate is 1-10 ℃/min, the pyrolysis temperature is 300-600 ℃, and the roasting time is 2-4 h.
8. The biomass charcoal low-temperature SCR catalyst with high specific surface area prepared by the preparation method according to any one of claims 1 to 7.
9. The application of the biomass charcoal low-temperature SCR catalyst with the high specific surface area prepared by the preparation method according to claim 8 in preparing low-temperature SCR denitration.
10. The application of claim 9, wherein the loading amount of cerium oxide of the high specific surface area biomass charcoal low-temperature SCR catalyst is 40-60%, the cerium oxide is coated on the surface of the biomass charcoal, and the reaction temperature is 100-300 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211089346.4A CN115634684A (en) | 2022-09-07 | 2022-09-07 | High-specific-surface-area biomass charcoal low-temperature SCR catalyst, and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211089346.4A CN115634684A (en) | 2022-09-07 | 2022-09-07 | High-specific-surface-area biomass charcoal low-temperature SCR catalyst, and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115634684A true CN115634684A (en) | 2023-01-24 |
Family
ID=84940670
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211089346.4A Pending CN115634684A (en) | 2022-09-07 | 2022-09-07 | High-specific-surface-area biomass charcoal low-temperature SCR catalyst, and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115634684A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107126955A (en) * | 2017-06-01 | 2017-09-05 | 重庆大学 | A kind of base low-temperature sintered catalyst for denitrating flue gas of charcoal and preparation method |
| WO2017181570A1 (en) * | 2016-04-20 | 2017-10-26 | 复旦大学 | Alkali (alkaline earth) metal-resistant, sulfur-resistant, and water-resistant denitrification catalyst, and manufacturing method and application thereof |
| CN107353169A (en) * | 2017-07-05 | 2017-11-17 | 安徽华联肥业有限公司 | A kind of preparation method of straw biomass charcoal bundled slow-releasing fertilizer |
| CN109019595A (en) * | 2018-09-29 | 2018-12-18 | 中国林业科学研究院林产化学工业研究所 | The method that the one step pyrolysis of biomass low pressure prepares high performance active carbon in tube furnace |
| CN111790375A (en) * | 2020-07-27 | 2020-10-20 | 佛山科学技术学院 | Biochar loaded manganese cerium low-temperature NH3-SCR catalyst, method for the production thereof and use thereof |
-
2022
- 2022-09-07 CN CN202211089346.4A patent/CN115634684A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017181570A1 (en) * | 2016-04-20 | 2017-10-26 | 复旦大学 | Alkali (alkaline earth) metal-resistant, sulfur-resistant, and water-resistant denitrification catalyst, and manufacturing method and application thereof |
| CN107126955A (en) * | 2017-06-01 | 2017-09-05 | 重庆大学 | A kind of base low-temperature sintered catalyst for denitrating flue gas of charcoal and preparation method |
| CN107353169A (en) * | 2017-07-05 | 2017-11-17 | 安徽华联肥业有限公司 | A kind of preparation method of straw biomass charcoal bundled slow-releasing fertilizer |
| CN109019595A (en) * | 2018-09-29 | 2018-12-18 | 中国林业科学研究院林产化学工业研究所 | The method that the one step pyrolysis of biomass low pressure prepares high performance active carbon in tube furnace |
| CN111790375A (en) * | 2020-07-27 | 2020-10-20 | 佛山科学技术学院 | Biochar loaded manganese cerium low-temperature NH3-SCR catalyst, method for the production thereof and use thereof |
Non-Patent Citations (1)
| Title |
|---|
| 刘雪梅等: ""椰壳热解活化制备活性炭及其机理研究"", 《安徽农业科学》, vol. 45, pages 140 - 143 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102553574B (en) | Method for preparing flue gas SCR (Selective Catalytic Reduction) denitration catalyst | |
| CN106925294B (en) | Foam metal nickel-loaded manganese-based low-temperature SCR catalyst and preparation method thereof | |
| WO2012162864A1 (en) | Surface deposition-type honeycomb catalyst for flue gas denitrification and preparation method thereof | |
| CN110508274A (en) | Modification biological charcoal low-temperature denitration catalyst and its application | |
| CN102716753A (en) | Catalyst for low-temperature selective catalytic reduction of nitric oxide and preparation method of catalyst | |
| CN103464194A (en) | SCR (Selective catalytic reduction) monolithic honeycombed catalyst for low-temperature flue gas de-nitrification and preparation method thereof | |
| CN101804289B (en) | Preparation of flue gas desulfurizer and use and regeneration method thereof | |
| CN111229209B (en) | Lotus leaf source charcoal-loaded manganese oxide low-temperature SCR (selective catalytic reduction) flue gas denitration catalyst and preparation method and application thereof | |
| CN109046441B (en) | Titanium dioxide/carbon nitride/Cu-ZSM-5 photocatalyst and preparation method thereof | |
| CN107138132A (en) | Prepare the method that semicoke loads polynary nanometer metal oxide desulphurization denitration adsorbent | |
| CN110624380A (en) | Synergistic desulfurization and denitrification agent and preparation and application thereof | |
| CN101804344A (en) | Manganese/carbon nanotube denitrification catalytic reduction catalyst and preparation method thereof | |
| CN102247834A (en) | Preparation method of flue gas denitration catalyst | |
| CN105879879A (en) | High-sulfur-resistant ultralow-temperature SCR (Selective Catalytic Reduction) denitration catalyst and preparation method thereof | |
| CN109569229B (en) | Method for combined desulfurization and denitrification of iron ore sintering flue gas | |
| CN105797715A (en) | Preparation method of loaded manganese-cerium complex oxide nanowire catalyst | |
| CN102728347B (en) | MnO2-TiO2 graphite-porous inorganic ceramic membrane low temperature catalyst denitration self-cleaning material and its preparation method | |
| CN115634684A (en) | High-specific-surface-area biomass charcoal low-temperature SCR catalyst, and preparation method and application thereof | |
| CN108262049B (en) | Modified low-temperature SCO denitration catalyst and preparation method thereof | |
| KR101109483B1 (en) | Supported catalyst for removing nitrogen oxides, method for preparing the same and method for removing nitrogen oxides using the same | |
| CN111408379B (en) | Purification treatment method for tail gas of diesel engine | |
| CN109248688B (en) | Method for in-situ preparation of carbon-based NOx adsorption reduction catalyst from coal-biomass | |
| CN113578333A (en) | Low-temperature denitration catalyst and preparation method and application thereof | |
| CN115193434B (en) | Method and system for cooperatively removing carbon-based catalyst, VOCs and nitrogen oxides | |
| CN111375304A (en) | Method for treating organic waste gas containing low-carbon hydrocarbon |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |