CN110987696A - Evaluation method for firmness of wall-flow catalyst coating - Google Patents
Evaluation method for firmness of wall-flow catalyst coating Download PDFInfo
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- CN110987696A CN110987696A CN201911087968.1A CN201911087968A CN110987696A CN 110987696 A CN110987696 A CN 110987696A CN 201911087968 A CN201911087968 A CN 201911087968A CN 110987696 A CN110987696 A CN 110987696A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/56—Investigating resistance to wear or abrasion
- G01N3/567—Investigating resistance to wear or abrasion by submitting the specimen to the action of a fluid or of a fluidised material, e.g. cavitation, jet abrasion
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
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- G01N19/04—Measuring adhesive force between materials, e.g. of sealing tape, of coating
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N31/00—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods
- G01N31/12—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods using combustion
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N5/00—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid
- G01N5/04—Analysing materials by weighing, e.g. weighing small particles separated from a gas or liquid by removing a component, e.g. by evaporation, and weighing the remainder
Abstract
The invention discloses a wall flow catalyst coating firmness evaluation method, which can better simulate the influence of thermal shock experienced by a wall flow catalyst in the actual use process and the physical impact effect of graphite particles on the coating firmness, has a more objective process, does not need to damage the catalyst, and is suitable for popularization and application. The method has important significance for evaluating the durability of the wall flow catalyst.
Description
Technical Field
The invention relates to the technical field of automobile exhaust treatment, in particular to an evaluation method for firmness of a wall-flow catalyst coating.
Background
In recent years, with the rapid development of the automobile industry, the life of people is facilitated, and meanwhile, the ecological environment is seriously damaged. For example, the pollutants discharged from the automobile exhaust mainly include carbon monoxide, hydrocarbons, nitrogen oxides, particulate matters, etc., and in order to limit the pollution of the automobile exhaust to the ecological environment, a series of regulations are set by the state to regulate the emission. In order to achieve the emission standards set by the regulations, the automobile industry generally adopts a gasoline engine particulate filter (GPF), a diesel engine particulate filter (DPF) or a Selective Catalytic Reduction Filter (SCRF) to treat the exhaust generated by an engine, the particulate filter can be also called as a wall-flow catalyst, the particulate filter mainly comprises a carrier with a certain shape and a catalyst coating coated on the carrier, the shape is different from a straight-through catalyst, the straight-through catalyst is of an end surface semi-sealed hole structure, an air inlet or an air outlet in one pore channel is in a sealed state, after the exhaust airflow enters the carrier from the pore channel with an opening on the air inlet end surface, because the air outlet of the pore channel is in a sealed state, the gas can flow from a micropore gap of the carrier pore channel wall to flow out of an adjacent pore channel, so that particulate matters (mainly soot particles) wrapped in the gas can be intercepted by the pore channel wall and the, meanwhile, the catalytic function of the coating can purify the tail gas, and finally the effects of capturing particles and purifying the tail gas are achieved.
The endurance course of light gasoline and diesel vehicles in VI stage of China is generally improved to 200000km, so that higher requirements are put on the endurance performance of the wall-flow catalyst coating on the carrier. The coating firmness is an important index for representing the durability of the catalyst, the higher the coating firmness is, the firmer the coating is combined with the carrier member, the high coating firmness can greatly reduce the loss of the catalyst in the using process and ensure various performances of the durable catalyst, particularly the particle capture performance and the catalytic performance. In the prior art, the common catalyst coating firmness test generally adopts an air gun direct blowing method or an ultrasonic method, wherein, the air gun blowing method is that high-pressure air flow with room temperature is blown in from one end surface and flows through a pore channel to be blown out from the other end, calculating the coating shedding rate and evaluating the firmness of the catalyst coating by the weight difference of the catalyst before and after purging, however, because the wall-flow catalyst channel is not straight, the airflow can flow out only through the wall of the channel, the resistance of the airflow of the straight-through catalyst is increased, the air gun is directly used for blowing the most airflow which rebounds to the inlet and can not penetrate through the wall of the channel, so the blowing method is not suitable for evaluating the coating firmness of the wall-flow catalyst, the ultrasonic method needs to destroy and cut the catalyst into small pieces, which can cause the rise of the testing cost and can not be applied in large scale, therefore, no objective, comprehensive and non-destructive evaluation method for the firmness of the catalyst coating has been established for the wall-flow catalyst.
Disclosure of Invention
In order to solve the technical problem, the invention provides a method for evaluating the firmness of a wall-flow catalyst coating, which comprises the following steps: the robustness of the coating under thermal shock was evaluated by setting a series of flow rates and temperatures at which the gas stream impinges the wall flow catalyst coating.
Further, the firmness of the coating under the impact of the exhaust carbon particles was evaluated by increasing the airflow impact of graphite particles of a set series of concentrations.
Specifically, the method comprises the following steps:
(1) the wall flow catalyst to be evaluated was loaded and recorded as M1;
(2) fixedly communicating the gas inlet end of the wall-flow catalyst with a gas pipeline; then introducing air flow, and sequentially adjusting the air flow temperature to 200-300 ℃, 400-500 ℃, 600-700 ℃ and 200-300 ℃, wherein the air flow rate of each temperature interval is 60-70g/s, 70-80g/s, 80-100g/s and 70-80g/s, the air flow blowing duration of each temperature interval is 5-10min, and the adjustment time interval of different temperature intervals is less than 1 min;
(3) controlling the gas flow temperature at 200-300 ℃ and the gas flow at 70-80 g/s; dispersing graphite particles into the intake gas stream, the graphite particles being capable of being deposited from the gas stream onto the wall-flow catalyst and being captured by the wall-flow catalyst; controlling the concentration of graphite particles in the airflow to be 5-20mg/m3, and controlling the blowing time of the graphite particles to be 1-10 min;
(4) after the graphite particles are blown in, the temperature of the air flow is raised to 600-700 ℃, the gas flow is controlled to be 80-100g/s, the duration is controlled to be 5-20min, and the graphite particles trapped on the wall-flow catalyst are combusted;
(5) the combusted wall-flow catalyst was cooled and weighed and recorded as M2;
(6) calculating the coating falling rate: (M1-M2)/M1 × 100%.
Further, the particle size of the graphite particles in the step (3) is 1-10 um.
Further, in the step (2), before introducing the high-temperature airflow, introducing an air airflow with the temperature of 20-30 ℃ and the flow rate of 40-60g/s for 1-5 min.
Further, before weighing in the step (1), roasting the wall-flow catalyst to be evaluated at 600 ℃ in a muffle furnace for 1-2h, and after the roasting is finished, taking out the wall-flow catalyst when the temperature of the muffle furnace is reduced to 300 ℃ at 200-.
Further, the cooling process of step (5) is as follows: placing the wall-flow catalyst in a muffle furnace at the temperature of 500-.
Further, in the step (2), the gas outlet end of the wall-flow catalyst is fixedly communicated with a gas outlet pipe.
Preferably, the wall-flow catalyst is a gasoline engine particulate trap, a diesel engine particulate trap, or a selective catalytic reduction particulate trap.
Compared with the prior art, the technical scheme of the invention has the following advantages:
(1) the method for evaluating the firmness of the wall-flow catalyst coating can better simulate the thermal shock of the wall-flow catalyst in the actual use process and the influence of the physical impact effect of graphite particles on the firmness of the coating, the process is more objective, the catalyst does not need to be damaged, and the method is suitable for popularization and application; meanwhile, in the evaluation method, the inlet end of the wall-flow catalyst is connected with the air inlet pipe, so that the phenomenon of rebound cannot be caused when air flow with certain flow velocity is continuously introduced, the air flow introduced into the pore channel of the wall-flow catalyst is in a stable state, the service environment of the wall-flow catalyst can be simulated to the greatest extent, and the result obtained by the evaluation method is stable and has the highest reliability. The method has important significance for evaluating the durability of the wall flow catalyst.
Detailed Description
The present invention will now be described more fully hereinafter with reference to the accompanying examples, in which some, but not all embodiments of the invention are shown. The embodiments in the present invention, other embodiments obtained by persons skilled in the art without any inventive work, belong to the protection scope of the present invention.
Example 1
The wall-flow catalyst to be evaluated is a gasoline engine particulate trap (GPF) with the parameters: the coating is prepared from alumina and cerium-zirconium composite oxide which are loaded with palladium and rhodium, phi 132.1mm 127mm, 300 meshes, 203.2 mu m of pore wall thickness, 65% of porosity, 20 mu m of median pore diameter, 1.741L of volume and 100g/L of coating.
The method for evaluating the coating firmness of the wall-flow catalyst comprises the following steps:
(1) roasting GPF to be evaluated at 600 ℃ in a muffle furnace for 2h, taking the GPF out after roasting is completed and the temperature of the muffle furnace is reduced to 300 ℃, placing the GPF in a dryer, and naturally cooling to 30 ℃;
(2) and weighing the cooled GPF on an electronic scale, wherein the precision of the electronic scale is at least 0.1 g. Record weight as M1; m1 ═ 670.6 g;
(3) respectively fixing the gas inlet end and the gas outlet end of the GPF in a gas pipeline; introducing air flow with temperature of 30 deg.C and flow rate of 60g/s into the pipeline for 5 min;
(4) the temperature of the airflow is adjusted to 300 ℃, 500 ℃, 700 ℃ and 300 ℃ in sequence, the gas flow of each temperature interval is 70g/s, 80g/s, 100g/s and 80g/s in sequence, the duration of the airflow purging of each temperature interval is controlled to be 10min, and the adjustment time interval of different temperature intervals is controlled to be less than or equal to 1 min;
(5) the temperature of the gas flow is controlled at 300 ℃, and the gas flow is controlled at 80 g/s. Average particle diameterGraphite particles at 1 um are dispersed into the GPF inlet gas stream and can be deposited onto the GPF by the gas stream to be captured by it. The concentration of graphite particles in the gas flow is controlled at 5mg/m3The graphite particle purging time is controlled to be 1 min;
(6) after the graphite particles are swept, the temperature of the gas flow is raised to 700 ℃, the gas flow is controlled at 100g/s, the duration is controlled at 5min, and the graphite particles trapped on GPF are combusted;
(7) after the step (6) is finished, placing the GPF in a muffle furnace for roasting at 600 ℃ for 2h, taking out the GPF after the roasting is finished and when the temperature of the muffle furnace is reduced to 300 ℃, placing the GPF in a dryer for natural cooling to 30 ℃;
(8) and (3) weighing the cooled GPF on an electronic scale, wherein the electronic scale is the same as that used in the step (2). Record weight as M2; m2 ═ 669.9 g;
(9) calculating the coating falling rate: (M1-M2)/M1 ═ 100% ((670.6-669.7)/670.6 ≈ 0.1%).
Example 2
The wall-flow catalyst to be evaluated is a diesel particulate trap (DPF) with the parameters: phi is 190.5mm, 203.2mm, the mesh number is 300 meshes, the wall thickness of a pore channel is 228.6 mu m, the porosity is 48%, the median pore diameter is 15 mu m, the volume is 5.792L, and the coating amount is 30g/L, wherein the coating is platinum-loaded alumina.
The method for evaluating the coating firmness of the wall-flow catalyst comprises the following steps:
(1) roasting the DPF to be evaluated at 500 ℃ in a muffle furnace for 1.5h, taking out the DPF after the roasting is finished and the temperature of the muffle furnace is reduced to 200 ℃, placing the DPF in a dryer, and naturally cooling to 25 ℃;
(2) and weighing the cooled DPF on an electronic scale, wherein the precision of the electronic scale is at least 0.1 g. Record weight as M1; m1 ═ 2901.2 g;
(3) respectively fixing the air inlet end and the air outlet end of the DPF in a gas pipeline; introducing air flow with temperature of 20 deg.C and flow rate of 50g/s into the pipeline for 1 min;
(4) the temperature of the gas flow is adjusted to 200 ℃, 450 ℃, 650 ℃ and 200 ℃ in sequence, the gas flow of each temperature interval is 60g/s, 75g/s, 90g/s and 70g/s in sequence, the gas flow purging duration of each temperature interval is controlled to be 5min, and the adjusting time interval of different temperature intervals is controlled to be less than or equal to 1 min;
(5) the temperature of the gas flow is controlled at 200 ℃, and the gas flow is controlled at 75 g/s. Graphite particles having an average particle size of 10um are dispersed into the DPF intake air stream and can be deposited onto the DPF from the air stream and trapped therein. The concentration of graphite particles in the gas flow is controlled to be 20mg/m3The graphite particle purging time is controlled to be 10 min;
(6) after the graphite particle purging is finished, the temperature of the gas flow is raised to 600 ℃, the gas flow is controlled at 90g/s, the duration is controlled at 20min, and the graphite particles trapped on the DPF are combusted;
(7) after the step (6) is finished, placing the DPF in a muffle furnace for roasting at 500 ℃ for 1.5h, and after the roasting is finished, taking out the DPF when the temperature of the muffle furnace is reduced to 200 ℃, placing the DPF in a drier for natural cooling to 20 ℃;
(8) and (3) weighing the cooled DPF on an electronic scale, wherein the electronic scale is the same as that used in the step (2). Record weight as M2; m2 ═ 2900.5 g;
(9) calculating the coating falling rate: (M1-M2)/M1 ═ 100% ((2901.2-2900.5)/2901.2 ≈ 0.02%).
Example 3
The wall-flow catalyst to be evaluated was a selective catalytic reduction particulate trap (SCRF) with the parameters: phi 190.5mm, 203.2mm, mesh number of 300 meshes, pore wall thickness of 304.8 μm, porosity of 63%, median pore diameter of 20 μm, volume of 5.792L, coating amount of 120g/L, wherein the coating is a copper molecular sieve.
The method for evaluating the coating firmness of the wall-flow catalyst comprises the following steps:
(1) roasting the SCRF to be evaluated at 500 ℃ in a muffle furnace for 1h, taking out the SCRF after the roasting is finished and the temperature of the muffle furnace is reduced to 200 ℃, placing the SCRF in a dryer and naturally cooling to 20 ℃;
(2) the cooled SCRF is weighed on an electronic scale with an accuracy of at least 0.1 g. Record weight as M1; m1 ═ 2411.6 g;
(3) respectively fixing the air inlet end and the air outlet end of the SCRF in a gas pipeline; introducing air flow with temperature of 20 deg.C and flow rate of 40g/s into the pipeline for 1 min;
(4) the temperature of the gas flow is adjusted to 200 ℃, 400 ℃, 600 ℃ and 200 ℃ in sequence, the gas flow of each temperature interval is 60g/s, 70g/s, 80g/s and 70g/s in sequence, the gas flow purging duration of each temperature interval is controlled to be 5min, and the adjusting time interval of different temperature intervals is controlled to be less than or equal to 1 min;
(5) the temperature of the gas flow is controlled at 200 ℃, and the gas flow is controlled at 70 g/s. Graphite particles having an average particle size of 10um are dispersed into the SCRF inlet gas stream and can be deposited onto the SCRF by the gas stream and captured by it. The concentration of graphite particles in the gas flow is controlled at 10mg/m3The graphite particle purging time is controlled to be 10 min;
(6) after the graphite particle purging is finished, the temperature of the gas flow is increased to 600 ℃, the gas flow is controlled at 80g/s, the duration is controlled at 20min, and the graphite particles trapped on the SCRF are combusted;
(7) after the step (6) is finished, placing the SCRF in a muffle furnace for roasting at 500 ℃ for 1h, and after the roasting is finished, taking out the SCRF when the temperature of the muffle furnace is reduced to 200 ℃ and placing the SCRF in a dryer for natural cooling to 20 ℃;
(8) and (3) weighing the cooled SCRF on an electronic scale, wherein the electronic scale is the same as the electronic scale used in the step (2). Record weight as M2; m2 ═ 2360.1 g;
(9) calculating the coating falling rate: (M1-M2)/M1 ═ 100% ((2411.6-2360.1)/2411.6 ≈ 2.13%).
Example 4
The wall-flow catalyst to be evaluated is a gasoline engine particulate trap (GPF) with the parameters: the coating is prepared from alumina and cerium-zirconium composite oxide which are loaded with platinum and rhodium, phi 132.1mm 127mm, 300 meshes, 203.2 mu m of pore canal wall thickness, 60% of porosity, 18 mu m of median pore diameter, 1.741L of volume and 120g/L of coating amount.
The method for evaluating the coating firmness of the wall-flow catalyst comprises the following steps:
(1) roasting GPF to be evaluated at 550 ℃ in a muffle furnace for 2 hours, taking the GPF out after roasting is completed and the temperature of the muffle furnace is reduced to 250 ℃, placing the GPF in a dryer, and naturally cooling to 25 ℃;
(2) and weighing the cooled GPF on an electronic scale, wherein the precision of the electronic scale is at least 0.1 g. Record weight as M1; m1 ═ 710.1 g;
(3) respectively fixing the gas inlet end and the gas outlet end of the GPF in a gas pipeline; introducing air flow with temperature of 25 deg.C and flow rate of 50g/s into the pipeline for 1 min;
(4) the temperature of the airflow is adjusted to 250 ℃, 500 ℃, 700 ℃ and 250 ℃ in sequence, the gas flow of each temperature interval is 65g/s, 80g/s, 100g/s and 75g/s in sequence, the duration of the airflow purging of each temperature interval is controlled to be 8min, and the adjustment time intervals of different temperature intervals are controlled to be less than or equal to 1 min;
(5) the temperature of the gas flow is controlled at 250 ℃ and the gas flow is controlled at 80 g/s. Graphite particles having an average particle size of 5um are dispersed into the GPF inlet gas stream and can be deposited onto the GPF by the gas stream and captured by it. The concentration of graphite particles in the gas flow is controlled at 10mg/m3The graphite particle purging time is controlled to be 5 min;
(6) after the graphite particle purging is finished, raising the temperature of the gas flow to 650 ℃, controlling the gas flow at 100g/s and controlling the duration at 10min, so that the graphite particles trapped on the GPF are combusted;
(7) after the step (6) is finished, placing the GPF in a muffle furnace for roasting at 550 ℃ for 2h, and after the roasting is finished, taking the DPF out when the temperature of the muffle furnace is reduced to 250 ℃, placing the DPF in a drier for natural cooling to 25 ℃;
(8) and (3) weighing the cooled DPF on an electronic scale, wherein the electronic scale is the same as that used in the step (2). Record weight as M2; m2 ═ 697.5 g;
(9) calculating the coating falling rate: (M1-M2)/M1 × 100% ((710.1-697.5)/710.1 × 100% ≈ 1.8%).
Comparative example 1
The parameters of the wall-flow catalyst support to be evaluated, the coating and the coating amount were the same as in example 1. The comparative example adopts an air gun purging method to evaluate the coating firmness, and comprises the following steps:
(1) roasting GPF to be evaluated at 600 ℃ in a muffle furnace for 2h, taking the GPF out after roasting is completed and the temperature of the muffle furnace is reduced to 300 ℃, placing the GPF in a dryer, and naturally cooling to 30 ℃;
(2) and weighing the cooled GPF on an electronic scale, wherein the precision of the electronic scale is at least 0.1 g. Record weight as M1; m1 ═ 670.2 g;
(3) controlling the pressure of the high-pressure air gun to be (0.5 +/-0.05) MPa;
(4) GPF is horizontally placed on a horizontal table top (the outer wall is in contact with the table top, and the end face is vertical to the table top) and fixed. The sweeping posture standard is as follows: the nozzle of the air gun is aligned with the end face of the catalyst, and the distance between the nozzle opening of the air gun and the end face of the carrier is (1 +/-0.5) cm;
(5) purging the catalytic end face by using a high-pressure air gun, wherein the purging range is the whole end face, the gas temperature is room temperature, and the purging time is 51min, which is the same as the total purging time of the embodiment 1;
(6) after the step (5) is finished, placing the GPF in a muffle furnace for roasting at 600 ℃ for 2h, taking out the GPF after the roasting is finished and when the temperature of the muffle furnace is reduced to 300 ℃, placing the GPF in a dryer for natural cooling to 30 ℃;
(8) and (3) weighing the cooled GPF on an electronic scale, wherein the electronic scale is the same as that used in the step (2). Record weight as M2; m2 ═ 670.0 g;
(9) calculating the coating falling rate: (M1-M2)/M1 × 100% ((670.2-670.0)/670.2 × 100% ≈ 0.03%).
Comparative example 2
The parameters of the wall-flow catalyst support to be evaluated, the coating and the coating amount were the same as in example 2. The comparative example adopts an air gun purging method to evaluate the coating firmness, and comprises the following steps:
(1) roasting the DPF to be evaluated at 500 ℃ in a muffle furnace for 1.5h, taking out the DPF after the roasting is finished and the temperature of the muffle furnace is reduced to 200 ℃, placing the DPF in a dryer, and naturally cooling to 25 ℃;
(2) and weighing the cooled DPF on an electronic scale, wherein the precision of the electronic scale is at least 0.1 g. Record weight as M1; m1 ═ 2905.5 g;
(3) controlling the pressure of the high-pressure air gun to be (0.5 +/-0.05) MPa;
(4) the DPF is horizontally placed on a horizontal table top (the outer wall of the DPF is in contact with the table top, and the end face of the DPF is vertical to the table top) and fixed. The sweeping posture standard is as follows: the nozzle of the air gun is aligned with the end face of the catalyst, and the distance between the nozzle opening of the air gun and the end face of the carrier is (1 +/-0.5) cm;
(5) purging the catalytic end face by using a high-pressure air gun, wherein the purging range is the whole end face, the gas temperature is room temperature, and the purging time is 51min, which is the same as the total purging time of the embodiment 2;
(6) after the step (5) is finished, placing the DPF in a muffle furnace for roasting at 500 ℃ for 1.5h, and after the roasting is finished, taking out the DPF when the temperature of the muffle furnace is reduced to 200 ℃, placing the DPF in a drier for natural cooling to 20 ℃;
(8) and (3) weighing the cooled DPF on an electronic scale, wherein the electronic scale is the same as that used in the step (2). Record weight as M2; m2 ═ 2905.4 g;
(9) calculating the coating falling rate: (M1-M2)/M1 ═ 100%, (2905.5-2905.4)/2905.5 ≈ 0.003%.
Comparative example 3
The parameters of the wall-flow catalyst support to be evaluated, the coating and the coating amount were the same as in example 3. The comparative example adopts an air gun purging method to evaluate the coating firmness, and comprises the following steps:
(1) roasting the SCRF to be evaluated at 500 ℃ in a muffle furnace for 1h, taking out the SCRF after the roasting is finished and the temperature of the muffle furnace is reduced to 200 ℃, placing the SCRF in a dryer and naturally cooling to 20 ℃;
(2) the cooled SCRF is weighed on an electronic scale with an accuracy of at least 0.1 g. Record weight as M1; m1 ═ 2410.5 g;
(3) controlling the pressure of the high-pressure air gun to be (0.5 +/-0.05) MPa;
(4) the SCRF is placed horizontally on a horizontal table top (the outer wall contacts the table top, and the end face is vertical to the table top) and fixed. The sweeping posture standard is as follows: the nozzle of the air gun is aligned with the end face of the catalyst, and the distance between the nozzle opening of the air gun and the end face of the carrier is (1 +/-0.5) cm;
(5) purging the catalytic end face by using a high-pressure air gun, wherein the purging range is the whole end face, the gas temperature is room temperature, and the purging time is 51min, which is the same as the total purging time of the embodiment 3;
(6) after the step (5) is finished, placing the SCRF in a muffle furnace for roasting at 500 ℃ for 1h, and after the roasting is finished, taking out the SCRF when the temperature of the muffle furnace is reduced to 200 ℃ and placing the SCRF in a dryer for natural cooling to 20 ℃;
(8) and (3) weighing the cooled SCRF on an electronic scale, wherein the electronic scale is the same as the electronic scale used in the step (2). Record weight as M2; m2 ═ 2409.3 g;
(9) calculating the coating falling rate: (M1-M2)/M1 × 100% (2410.5-2409.3)/2410.5 × 100% ≈ 0.05%.
Comparative example 4
The parameters of the wall-flow catalyst support to be evaluated, the coating and the coating amount were the same as in example 4. The comparative example adopts an air gun purging method to evaluate the coating firmness, and comprises the following steps:
(1) roasting GPF to be evaluated at 550 ℃ in a muffle furnace for 2 hours, taking the GPF out after roasting is completed and the temperature of the muffle furnace is reduced to 250 ℃, placing the GPF in a dryer, and naturally cooling to 25 ℃;
(2) and weighing the cooled GPF on an electronic scale, wherein the precision of the electronic scale is at least 0.1 g. Record weight as M1; m1 ═ 711.6 g;
(3) controlling the pressure of the high-pressure air gun to be (0.5 +/-0.05) MPa;
(4) GPF is horizontally placed on a horizontal table top (the outer wall is in contact with the table top, and the end face is vertical to the table top) and fixed. The sweeping posture standard is as follows: the nozzle of the air gun is aligned with the end face of the catalyst, and the distance between the nozzle opening of the air gun and the end face of the carrier is (1 +/-0.5) cm;
(5) purging the catalytic end face by using a high-pressure air gun, wherein the purging range is the whole end face, the gas temperature is room temperature, and the purging time is 48min, which is the same as the total purging time of the embodiment 4;
(6) after the step (5) is finished, placing the GPF in a muffle furnace for roasting at 550 ℃ for 2h, taking out the GPF after the roasting is finished and when the temperature of the muffle furnace is reduced to 250 ℃, placing the GPF in a dryer for natural cooling to 25 ℃;
(8) and (3) weighing the cooled GPF on an electronic scale, wherein the electronic scale is the same as that used in the step (2). Record weight as M2; m2 ═ 711.0 g;
(9) calculating the coating falling rate: (M1-M2)/M1 ═ 100% ((711.6-711.0)/711.6 ≈ 0.08%).
The wall-flow catalysts of examples 1 to 4 and comparative examples 1 to 4, which were treated by the corresponding evaluation methods, were subjected to the following endurance tests and emission performance tests, specifically as follows:
and (3) durability test:
each example wall flow catalyst was encapsulated and example 1, comparative example 1, example 4 and comparative example 4 were aged for 50 hours as required by GB 18352.6-2016. Example 2, comparative example 2, example 3 and comparative example 3 were subjected to 50h aging durability as required by the GB17691-2018 standard.
Emission performance test:
after the durability test was completed, example 1, comparative example 1, example 4 and comparative example 4 were each mounted on a Hoverh 6 national sixth vehicle equipped with a 1.5TGDI gasoline engine, subjected to a WLTC test in accordance with the requirements of the GB18352.6-2016 standard, and tested for PN and NOxDischarging and comparing; example 2, comparative example 2, example 3 and comparative example 3 were respectively installed on a 4.5L capacity diesel engine of Yuchai, and subjected to WHTC test according to the standard requirements of GB17691-2018 to test PN and NOxAnd (5) discharging and comparing. Coating peeling off rates, PN and NO for the examplesxThe emission results are shown in table 1.
TABLE 1 coating stripping Rate, PN and NO for the examplesxEmission results
| Coating peeling rate | PN discharging | NOxDischarging | |
| Example 1 | 0.1％ | 1.6E +11 pieces/km | 11mg/km |
| Comparative example 1 | 0.03％ | 1.7E +11 pieces/km | 13mg/km |
| Example 2 | 0.02％ | 9.7E + 10/kWh | 227mg/kWh |
| Comparative example 2 | 0.003％ | 9.5E + 10/kWh | 213mg/kWh |
| Example 3 | 2.13％ | 5.8E + 11/kWh | 470mg/kWh |
| Comparative example 3 | 0.05％ | 5.7E + 11/kWh | 486mg/kWh |
| Example 4 | 1.8％ | 5.6E +11 pieces/km | 38mg/km |
| Comparative example 4 | 0.08％ | 5.9E +11 pieces/km | 42mg/km |
TABLE 2 PN and NOx emissions limits
| PN | NOx | |
| GB18352.6-2016(WLTC cycle) | 6.0E +11 pieces/km | 35mg/km |
| GB17691-2018(WHTC working condition) | 6.0E + 11/kWh | 460mg/kWh |
As can be seen from the peeling rates in table 1, the coating peeling rates of the wall-flow catalysts of examples 1 and 2 evaluated by the method of the present invention were below 1%, and the PN emissions and NOx emissions of the above-mentioned wall-flow catalysts in the emission performance test completely met the requirements of the national standards (see table 2); the wall-flow dropping rate of the coatings of the embodiment 3 and the embodiment 4 is 2.13 percent and 1.8 percent respectively, and the PN emission and the NOx emission of the wall-flow catalyst in the emission performance test slightly exceed the requirements of the national standard. In contrast, in comparative examples 1 to 4, although the coating peeling rates were all 1% or less, the differences in PN emission and NOx emission in the emission test were significant (see table 1), and thus the coating firmness and durability were not judged to be practical. It can be seen from the test results of the examples that the wall-flow catalyst with the coating peeling rate of less than 1% evaluated by the evaluation method meets the regulatory requirements and does not affect the subsequent use.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.
Claims (9)
1. A method for evaluating the coating firmness of a wall-flow catalyst is characterized by comprising the following steps: the robustness of the coating under thermal shock was simulated by setting a series of flow rates and temperatures of the gas stream impinging on the wall-flow catalyst coating.
2. The method of evaluating wall-flow catalyst coating firmness according to claim 1, wherein the firmness of the coating under the impact of exhaust carbon particulate matter is simulated by increasing the set series of concentrations of graphite particle gas flow impingement.
3. The method for evaluating the firmness of a wall-flow catalyst coating according to claim 2, comprising the steps of:
(1) the wall flow catalyst to be evaluated was loaded and recorded as M1;
(2) fixedly communicating the gas inlet end of the wall-flow catalyst with a gas pipeline; then introducing air flow, and sequentially adjusting the air flow temperature to 200-300 ℃, 400-500 ℃, 600-700 ℃ and 200-300 ℃, wherein the air flow rate of each temperature interval is 60-70g/s, 70-80g/s, 80-100g/s and 70-80g/s, the air flow blowing duration of each temperature interval is 5-10min, and the adjustment time interval of different temperature intervals is less than 1 min;
(3) controlling the gas flow temperature at 200-300 ℃ and the gas flow at 70-80 g/s; dispersing graphite particles into the intake gas stream, the graphite particles being capable of being deposited from the gas stream onto the wall-flow catalyst and being captured by the wall-flow catalyst; controlling the concentration of graphite particles in the airflow to be 5-20mg/m3, and controlling the blowing time of the graphite particles to be 1-10 min;
(4) after the graphite particles are blown in, the temperature of the air flow is raised to 600-700 ℃, the gas flow is controlled to be 80-100g/s, the duration is controlled to be 5-20min, and the graphite particles trapped on the wall-flow catalyst are combusted;
(5) the combusted wall-flow catalyst was cooled and weighed and recorded as M2;
(6) calculating the coating falling rate: (M1-M2)/M1 × 100%.
4. The method for evaluating the firmness of the wall-flow catalyst coating according to claim 3, wherein the particle size of the graphite particles in the step (3) is 1-10 um.
5. The method for evaluating the coating firmness of the wall-flow catalyst according to claim 4, wherein in the step (2), before the high-temperature air flow is introduced, an air flow with the temperature of 20-30 ℃ and the flow rate of 40-60g/s is introduced, and the duration is 1-5 min.
6. The method for evaluating the coating firmness of the wall-flow catalyst as claimed in claim 5, wherein before weighing in step (1), the wall-flow catalyst to be evaluated is calcined in a muffle furnace at 600 ℃ for 1-2h, and after the calcination is completed, the wall-flow catalyst is taken out and placed in a dryer for natural cooling to 20-30 ℃ when the temperature of the muffle furnace is reduced to 200 ℃ and 300 ℃.
7. The method for evaluating the firmness of a wall-flow catalyst coating according to claim 6, wherein the cooling process in step (5) is as follows: placing the wall-flow catalyst in a muffle furnace at the temperature of 500-.
8. The method for evaluating the firmness of the wall-flow catalyst coating according to claim 7, wherein in the step (2), the gas outlet end of the wall-flow catalyst is fixedly communicated with the gas outlet pipe.
9. The method of evaluating wall-flow catalyst coating firmness according to claim 8, wherein the wall-flow catalyst is a gasoline engine particulate trap, a diesel engine particulate trap, or a selective catalytic reduction particulate trap.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111097630A (en) * | 2020-01-14 | 2020-05-05 | 重庆实创钢结构有限公司 | Steel structure painting process |
| CN113702239A (en) * | 2021-09-14 | 2021-11-26 | 中自环保科技股份有限公司 | Falling rate detection method for motor vehicle exhaust treatment catalytic converter |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5100632A (en) * | 1984-04-23 | 1992-03-31 | Engelhard Corporation | Catalyzed diesel exhaust particulate filter |
| WO2003011437A1 (en) * | 2001-08-01 | 2003-02-13 | Johnson Matthey Public Limited Company | Gasoline engine with an exhaust system for combusting particulate matter |
| CN101644655A (en) * | 2008-08-06 | 2010-02-10 | 比亚迪股份有限公司 | Method and equipment for measuring bonding strength of active component coating in catalyst |
| CN103063563A (en) * | 2013-01-10 | 2013-04-24 | 湘潭大学 | Testing device for simulation and real-time detection of high-temperature deposition corrosion of thermal barrier coatings |
| CN103091239A (en) * | 2013-01-10 | 2013-05-08 | 湘潭大学 | Tester for simulation and real-time test of gaseous corrosion failure of thermal barrier coating |
| CN107560957A (en) * | 2016-06-30 | 2018-01-09 | 中国石油化工股份有限公司 | A kind of evaluation method of catalyst abrasion index |
| CN208636195U (en) * | 2018-08-14 | 2019-03-22 | 常州新日催化剂有限公司 | A kind of maleic anhydride catalyst coating shedding rate measurement device |
| CN109900577A (en) * | 2019-03-21 | 2019-06-18 | 湘潭大学 | A kind of detection method of thermal barrier coating high temperature erosion |
-
2019
- 2019-11-08 CN CN201911087968.1A patent/CN110987696B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5100632A (en) * | 1984-04-23 | 1992-03-31 | Engelhard Corporation | Catalyzed diesel exhaust particulate filter |
| WO2003011437A1 (en) * | 2001-08-01 | 2003-02-13 | Johnson Matthey Public Limited Company | Gasoline engine with an exhaust system for combusting particulate matter |
| CN101644655A (en) * | 2008-08-06 | 2010-02-10 | 比亚迪股份有限公司 | Method and equipment for measuring bonding strength of active component coating in catalyst |
| CN103063563A (en) * | 2013-01-10 | 2013-04-24 | 湘潭大学 | Testing device for simulation and real-time detection of high-temperature deposition corrosion of thermal barrier coatings |
| CN103091239A (en) * | 2013-01-10 | 2013-05-08 | 湘潭大学 | Tester for simulation and real-time test of gaseous corrosion failure of thermal barrier coating |
| CN107560957A (en) * | 2016-06-30 | 2018-01-09 | 中国石油化工股份有限公司 | A kind of evaluation method of catalyst abrasion index |
| CN208636195U (en) * | 2018-08-14 | 2019-03-22 | 常州新日催化剂有限公司 | A kind of maleic anhydride catalyst coating shedding rate measurement device |
| CN109900577A (en) * | 2019-03-21 | 2019-06-18 | 湘潭大学 | A kind of detection method of thermal barrier coating high temperature erosion |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111097630A (en) * | 2020-01-14 | 2020-05-05 | 重庆实创钢结构有限公司 | Steel structure painting process |
| CN113702239A (en) * | 2021-09-14 | 2021-11-26 | 中自环保科技股份有限公司 | Falling rate detection method for motor vehicle exhaust treatment catalytic converter |
| CN113702239B (en) * | 2021-09-14 | 2023-09-26 | 中自环保科技股份有限公司 | Method for detecting falling rate of catalytic converter for treating tail gas of motor vehicle |
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