JP2002243720A - Method and detector for detecting poison in platinum catalyst - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a component bringing a poison in a platinum catalyst, which affects infavorably an after-burner provided with the platinum catalyst. SOLUTION: This method of detecting the poison of the platinum catalyst has a process for vaporizing a sample by the first heating, a process for heating the vaporized sample by the second heating, a process for bringing the heated vaporized sample into contact with the platinum catalyst, and a process for anlayzing a surface of the platinum after the contact, and the processes are carried out in order.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting poisons when platinum is used as a catalyst.

[0002]

2. Description of the Related Art Since the gas generated from a baking furnace in an automobile coating line contains an organic compound having a volatile property or a property harmful to the human body, it is not preferable to directly release these to the atmosphere. Therefore, a so-called afterburner method is used in which the generated gas is heated at a high temperature, burned, and the organic compound is decomposed by the catalytic action of platinum to remove volatile organic compounds in the gas. However, if the generated gas contains compounds such as organic lead compounds, phosphorus compounds, sulfur compounds, and halogenated substances, these compounds act on the platinum provided in the afterburner and adhere to the surface. And platinum may not be able to function as a catalyst.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method and a device for detecting a platinum catalyst poison used for detecting a component which is a platinum catalyst poison that has a bad effect on an afterburner having a platinum catalyst. To provide.

[0004]

According to the method for detecting a platinum catalyst poison of the present invention, a step of vaporizing a sample by a first heating, a step of further performing a second heating on the vaporized sample,
The step of contacting the vaporized sample after the second heating with a platinum catalyst and the step of performing a surface analysis of the platinum catalyst after the contact are sequentially performed, and the sample vaporized by heating contains a platinum catalyst poison. This is for determining whether or not to do so. Here, the second heating temperature may be higher than the first heating temperature, and the vaporized sample may be transported by blowing a carrier gas. Further, the surface analysis may be performed by using an elemental analysis method.

The platinum catalyst poison detection device of the present invention includes an inlet for a vaporized sample, a unit for heating the vaporized sample, a unit for installing a platinum catalyst, and an exhaust port. Further, a unit for vaporizing the sample or a unit for blowing the carrier gas may be provided.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The method for detecting a platinum catalyst poison according to the present invention comprises a step of vaporizing a sample by a first heating, a step of further performing a second heating on the vaporized sample, and a second step of:
Contacting the vaporized sample after heating with a platinum catalyst,
The step of sequentially performing the surface analysis of the platinum catalyst after the contact is performed to determine whether or not the sample generates platinum catalyst poison by heating.

[0007] In the first step of the method for detecting a platinum catalyst poison of the present invention, first, a sample is vaporized by heating. Elements that can be poisonous catalysts for platinum include silicon,
Examples include sulfur, phosphorus, tin, lead, and halogens. Samples often contain components containing these elements, but the type of sample is not limited as long as it is desired to test whether heating causes platinum catalyst poisoning. It may be a composition comprising a plurality of components or a single component constituting the composition such as an additive or a catalyst.

The heating here is performed at a temperature at which at least a part of the sample is vaporized, for example, at 100 to 300 ° C. Heating can be performed by a unit for heating. As the heating unit, a device that can be heated to a predetermined temperature such as a glass tube oven or a mini jet oven may be used as a small unit, or a baking furnace for a coating line may be used.

Next, in the method for detecting platinum catalyst poison of the present invention,
The sample thus vaporized undergoes a second heating step. This second heating temperature is usually set to be higher than the heating temperature in the previous sample vaporization step.
It can be set to 00 to 500 ° C. If there is no large difference between the first heating temperature in the previous step and the second heating temperature in this step, the previous sample vaporizing step and the vaporized sample heating step can be combined into one. It is.

The next step in the method for detecting a platinum catalyst poison of the present invention is to contact the vaporized sample after the second heating with a platinum catalyst. The platinum catalyst used here is not particularly limited, and a platinum catalyst whose poison is desired to be detected may be used. In this step, the platinum catalyst is supported by a porous organic or inorganic substance, and preferably has a form such as a honeycomb structure that enhances the contact efficiency with the vaporized sample.

The method for contacting is not particularly limited. For example, the platinum catalyst may be provided in the middle of the path through which the vaporized sample after the second heating passes. In addition to this contact, the transport of the vaporized sample is
This is preferably performed by blowing a carrier gas. In this case, the above three steps need to be connected in order to carry out transportation efficiently. As the carrier gas,
What does not participate in the reaction between the vaporized sample and platinum is used, and it is usually preferable to feed air or nitrogen gas from a pump or a cylinder.

The final step in the method for detecting a platinum catalyst poison of the present invention is to analyze the surface of the platinum catalyst after the contact. If the vaporized sample becomes a platinum catalyst poison, the presence of the compound can be confirmed by analyzing the surface of the platinum catalyst because the compound based on the vaporized sample adheres to the platinum catalyst. Various methods can be used for the surface analysis. If a substance that becomes a catalyst poison is specified from the beginning, a method capable of detecting the substance may be adopted. Furthermore, if a substance containing a specific element such as silicon, sulfur, or phosphorus is a target, it is preferable to confirm the presence or absence, abundance, and the like by elemental analysis. There are a variety of elemental analysis methods, but by detecting characteristic X-rays and examining the intensity ratio, X-ray microscopy can identify the elements contained in the sample and quantify the proportions of the constituent elements. Analyzer (EPMA: Elect)
ron Probe Micro-Analysis
By using, surface analysis can be performed efficiently. The elemental analysis by EPMA itself is not special and can be performed by a generally well-known method.

The platinum catalyst poison detecting device of the present invention includes an inlet for a vaporized sample, a unit for heating the vaporized sample, and a unit for installing a platinum catalyst. Hereinafter, this will be described in detail with reference to the drawings.

FIG. 1 is a configuration diagram showing an example of the detection device of the present invention. The detection device 1 is provided with a unit 9 for heating the vaporized sample and a unit 4 for installing a platinum catalyst in a case 9 having an exhaust port 5 above and an inlet 2 for a vaporized sample below. Have been. A platinum catalyst 7 is provided on the unit 4 for installing the platinum catalyst.
Is provided, and the space between the platinum catalyst 7 and the case 9 is filled with glass wool 10. A temperature sensor 8 is provided above the platinum catalyst 7. Further, the inlet 2 for the vaporized sample is connected to a unit 20 for vaporizing the sample by a pipe, and the pipe is provided with a heater 6. The unit 20 for vaporizing a sample is provided with a temperature sensor 21 and a pipe 22 for blowing air, and a stage 27 for setting a sample 23 is provided at a tip of the temperature sensor 21. A pipe 22 for blowing air is connected to a buffer tank 25 and a pump 24 which constitute a unit 26 for blowing a carrier gas. Here, in the case where the unit for vaporizing the sample is a large one such as a baking furnace, the unit for blowing the carrier gas may be, for example, a suction type one or the like. be able to.

Hereinafter, a method of using the detection device of the present invention will be described. First, the sample 23 to be measured is set on the stage 27 provided at the tip of the temperature sensor 21. The sample 23 is preferably placed in a container having a large surface area having heat resistance, such as an aluminum pan, for example. After installing the sample 23, heating for vaporization (first heating) is started. For example, the unit 20 for vaporizing this sample is a glass tube oven,
A mini jet oven can also be used. When a mini-jet oven is used, it is preferable to use one that can introduce nitrogen gas in terms of the configuration of the apparatus. Here, the temperature sensor 21 is for directly measuring the temperature in the glass tube, and based on the value indicated by the temperature sensor 21,
It is preferable to set the heating temperature of the glass tube oven.

It is preferable that the supply of air in the direction of the arrow by operating the pump 24 is performed simultaneously with the heating for vaporization. Various pumps can be used, and a diaphragm pump is used here. The buffer tank 25 is provided between the pump 24 and the unit 20 for vaporizing the sample. Although this buffer tank 25 is not always necessary, it may be provided as one constituent unit of the unit 26 for blowing the carrier gas in order to alleviate the pulsating flow by the pump 24 and to perform stable carrier gas blowing. preferable. The amount of air to be sent is preferably set using a flow meter (not shown) installed in the unit 26 for blowing the carrier gas. The specific value of the amount of air sent is, for example, 1 to 20 L / min. If the sample 23 is sensitive to moisture, a moisture removing means such as a calcium chloride tube may be provided in the unit 26.

The sample vaporized by the heating is transported in the direction of the arrow through a pipe leading to the inlet 2 for the vaporized sample. The pipe is provided with a heater 6 in order to prevent the vaporized sample from being liquefied when transported through this pipe. Since this heater 6 is installed in the pipe,
For example, it is preferable to use a flexible material such as a ribbon heater. Further, a temperature sensor (not shown) is provided near the heater, and the temperature of the heater 6 can be set so that the temperature indicated by the sensor is close to the temperature indicated by the temperature sensor 21. preferable.

The sample vaporized by heating in this way reaches the unit 3 for heating the vaporized sample through the inlet 2. The unit 3 is a heater whose surface is coated with a material to which a vaporized sample does not adhere. The vaporized sample is further heated (second heating) when passing through the unit 3 by blowing air from the unit 26 that blows the carrier gas, and comes into contact with the platinum catalyst 7 installed above. The platinum catalyst 7 used here has a structure having air permeability, and it is preferable to use a platinum catalyst having a large surface area so that the chance of contact with the vaporized sample after the second heating is increased. Here, the space between the platinum catalyst 7 and the case 9 is filled with glass wool 10. The glass wool fixes the platinum catalyst 7 and efficiently removes the vaporized sample after the second heating.
Play a role in leading to The contact temperature between the vaporized sample after the second heating and the platinum catalyst 7 can be confirmed by the temperature sensor 8. This temperature is determined by the flow rate of the unit 26 for blowing the carrier gas and the heating of the unit 3 for heating the vaporized sample, and the preferable temperature varies depending on the type of the sample or the catalyst. Usually, the temperature is preferably from 300 to 450 ° C. After contact,
The vaporized sample after the second heating is discharged from the exhaust port 5. When it is not desired to discharge the discharged gas to the atmosphere as it is, a pipe can be provided from the exhaust port 5 to cool and liquefy, or to guide the trap to a chemical trap. It is desirable that the case 9 provided with the unit 3 for heating the vaporized sample is covered with a heat insulating material so that the case 9 is not affected by the outside air temperature as much as possible.

Second vaporized sample after heating and platinum catalyst 7
Can be set for a predetermined time, but can be continued until the sample 23 in the unit 20 for vaporizing the sample is exhausted. Further, by adding the sample 23 and heating again under the same conditions, the contact between the vaporized sample after the second heating and the platinum catalyst can be performed for a long time.

In this way, the platinum catalyst 7 in contact with the vaporized sample after the second heating is removed from the unit 4 for installing the platinum catalyst, and is used for surface analysis.

Using the above apparatus, experiments were carried out on those containing 2% of a phosphorus compound in 0.42 g of a coating additive and those not containing the same, and elemental analysis was performed on each of the obtained platinum catalysts by EPMA. Was. As a result, the phosphorus / platinum weight ratio was 0.35 for those containing a phosphorus compound.
In contrast, those containing no phosphorus compound were below the detection limit. At this time, the first heating condition was 160 ° C., the second heating condition was 450 ° C., and the flow rate of the pump was 10 L / min.

[0022]

By using the method for detecting a platinum catalyst poison of the present invention, it can be determined whether or not a sample vaporized by heating contains a platinum catalyst poison. That is, it is possible to determine whether the sample generates platinum catalyst poison by heating. As a result, it is possible to prevent components that adversely affect the afterburner provided with the platinum catalyst from being mixed. Furthermore, since the sample may be a composition or a single component, it can be applied to various types. Further, since the platinum catalyst poison detection device of the present invention can change the size of each unit, it can be freely designed from a laboratory level to a factory line level.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an example of a detection device according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Detection apparatus, 2 ... Inlet of vaporized sample, 3 ... Unit for heating vaporized sample, 4 ... Unit for installing platinum catalyst, 5 ... Exhaust port, 6 ... Heater, 7 ...
Platinum catalyst, 8, 21 ... temperature sensor, 9 ... case, 10
... Glass wool, 20 ... Sample vaporizing unit, 2
2 ... Piping, 23 ... Sample, 24 ... Pump, 25 ... Buffer tank, 26 ... Unit for blowing carrier gas, 27 ...
stage

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G001 AA03 BA05 CA01 GA01 JA12 KA01 MA01 NA04 NA07 NA08 NA13 RA03 2G042 AA01 BE10 CA08 CA10 CB03 CB06 FA11 FB04 GA01 HA03 HA05 HA07 4D048 AA17 AB01 BA30X DA02 DA20 4G069 AA02 BC CA07 CA11 CA15 DA06

Claims (7)

[Claims] A first heating step of vaporizing the sample;
A step of further performing a second heating for the vaporized sample, a step of contacting the vaporized sample after the second heating with a platinum catalyst, and a step of performing a surface analysis of the platinum catalyst after the contact. A method for detecting a platinum catalyst poison for determining whether a sample vaporized by heating contains a platinum catalyst poison. 2. The method for detecting platinum catalyst poison according to claim 1, wherein the second heating temperature is higher than the first heating temperature. 3. The method for detecting a platinum catalyst poison according to claim 1, wherein the vaporized sample is transported by blowing a carrier gas. 4. The method for detecting a platinum catalyst poison according to claim 1, wherein said surface analysis is performed by using an elemental analysis method. 5. An apparatus for detecting a platinum catalyst poison comprising an inlet for a vaporized sample, a unit for heating the vaporized sample, a unit for installing a platinum catalyst, and an exhaust port. 6. The platinum catalyst poison detecting device according to claim 5, further comprising a unit for vaporizing the sample. 7. The platinum catalyst poison detecting device according to claim 5, further comprising a unit for blowing a carrier gas.