JP4320021B2 - Method and apparatus for analyzing particulate matter in engine exhaust gas - Google Patents

Description

  The present invention relates to a method and an apparatus for analyzing particulate matter (particulate matter, hereinafter referred to as PM) contained in gas discharged from, for example, a diesel engine.

  As a method for measuring PM contained in exhaust gas from a diesel engine, high-temperature exhaust gas discharged from a diesel engine is diluted with clean air, and the diluted exhaust gas is sucked at a constant volume and collected by a filter. A filter weight method is generally known in which a filter is weighed with a precision balance or the like and quantitatively analyzed based on a weight difference from the filter before PM collection.

Japanese Patent Publication No. 7-58264

  However, in the filter weight method, moisture adsorbed on the filter greatly affects the measurement error, so that constant temperature / humidity treatment is required to keep the moisture in the filter before and after collection constant. In addition, when measuring exhaust gas of low concentration PM, for example, it is necessary to accurately weigh 0.1 mg of PM collected on a 200 mg filter, and the measurement error of the weight of the filter itself is the measurement error of PM weight. There is a problem that it has a big influence on.

  On the other hand, as shown in the above-mentioned Patent Document 1, there is a method in which a filter in which PM is collected is heated in steps in a heating furnace to oxidize PM and measure with a gas analyzer.

  However, most of the PM is composed of inorganic carbon called dry soot (hereinafter referred to as dry soot), hydrocarbons called SOF (soluble organic fraction) (hereinafter referred to as SOF), and sulfate hydrate called sulfate. (Hereinafter referred to as sulfate), and depending on the method described in the above publication, it is difficult to separate high boiling SOF and reduce sulfate in an oxidizing atmosphere. It was difficult to measure the weight of dry soot, SOF and sulfate separately.

  The present invention has been made in consideration of the above-mentioned matters. The purpose of the present invention is to separate dry soot, SOF, and sulfate in PM contained in engine exhaust gas, even if they are in trace amounts, individually and conveniently. An object of the present invention is to provide a method and apparatus for analyzing particulate matter in engine exhaust gas that can be measured with high accuracy.

In order to achieve the above object, a method for analyzing PM in engine exhaust gas according to the present invention is provided with a filter for collecting PM contained in engine exhaust gas in a heating furnace, and first, an inert gas is allowed to flow in the heating furnace. While heating the filter at a predetermined temperature to vaporize the SOF and sulfate in the PM, the vaporized SOF is oxidized to CO ₂ , while the vaporized sulfate is reduced to SO ₂ to convert the CO ₂ and SO ₂ into was analyzed by gas analysis unit, then the while flowing oxygen into the heating furnace to heat the filter by oxidizing the remaining PM on the filter to generate CO _2, analysis of the CO ₂ gas analyzer (Claim 1).

As an apparatus for carrying out the analysis method, in the present invention, in a state in which an inert gas or oxygen is selectively supplied to the heating furnace, and the inert gas or oxygen is supplied. A heating furnace that heats a filter that collects PM contained in engine exhaust gas at a predetermined temperature, a redox treatment unit that oxidizes or reduces gas generated by the heating, and a gas from the redox treatment unit are supplied. , A gas analyzer that measures the concentration of CO ₂ and SO ₂ is used.

In the method for analyzing particulate matter in engine exhaust gas according to the present invention, a filter is installed in a flow path through which exhaust gas from the engine flows, and exhaust gas is flowed at a constant flow rate, and PM in the exhaust gas is collected by the filter. This filter is provided in a heating furnace maintained at, for example, 1000 ° C. First, the filter is heated while flowing an inert gas such as nitrogen gas in the heating furnace to vaporize SOF and sulfate in PM, thereby vaporizing SOF. while the CO ₂ by oxidizing, and SO ₂ by reducing vaporized sulfate, the CO ₂ and SO ₂ by analyzing a gas analyzer, CO ₂ concentration and SO ₂ concentration is obtained. From these CO ₂ concentration and SO ₂ concentration and the total flow rate of the inert gas, the weight of CO ₂ and SO ₂ is obtained, and based on these weights, the weight of SOF and sulfate collected in the filter is obtained. .
After that, the heating said filter while flowing oxygen into the heating furnace to oxidize the remaining PM on the filter to generate CO _2, the analysis of this CO ₂ gas analyzer, CO ₂ concentration Is obtained. The weight of CO ₂ is obtained from the CO ₂ concentration and the total flow rate of oxygen, and the weight of the dry soot collected by the filter is obtained based on this weight.

  In the method for analyzing PM in the engine exhaust gas, when heating the filter while flowing an inert gas into the heating furnace, first, low-temperature heating is performed so that low-boiling SOF is vaporized, and then high-boiling point is heated. You may make it perform high temperature heating to such an extent that SOF vaporizes (Claim 2). In such a case, it is possible to distinguish between high-boiling SOF and low-boiling SOF.

Further, in the method for analyzing PM in the engine exhaust gas, when reducing the vaporized sulfate to SO ₂ , the sulfate may be passed through heated quartz cotton. In this case, the sulfate can be heated efficiently and reliably, and the sulfate can be more reliably reduced to SO ₂ .

  According to the present invention, dry soot, SOF and sulfate in PM can be measured easily and accurately. In particular, dry soot, SOF and sulfate, which occupy most of the PM, which could not be measured by the conventional filter weight method or the method disclosed in Patent Document 1, can be separately fractionated and the concentration or weight can be measured. At the same time, low concentration PM can be measured with high accuracy.

  Embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a first embodiment of the present invention. First, FIG. 1 schematically shows one configuration example of an analyzer for particulate matter in engine exhaust gas. In this figure, 1 is a filter 2 (PM) that collects PM contained in engine exhaust gas. Is a heating furnace for heating (which will be described later), for example, an electric furnace, and provided with a heater 3 for heating. The heating heater 3 is controlled in its heat generation state by a temperature adjusting mechanism (not shown). Therefore, the temperature in the heating furnace 1 is set to an arbitrary predetermined temperature.

  Reference numeral 4 denotes a gas supply unit that selectively supplies an inert gas (for example, nitrogen gas) or oxygen to the heating furnace 1, and a flow rate control device 5, 6 such as a mass flow controller having functions of flow rate measurement and flow rate control. Are provided with a nitrogen gas supply path 7 and an oxygen supply path 8, respectively, and a three-way solenoid valve 10 to which the downstream of these supply paths 7 and 8 and a connection flow path 9 to the heating furnace 1 are respectively connected. Yes.

  Reference numeral 11 denotes a gas flow path through which the gas generated in the heating furnace 1 flows, and its downstream side branches into two mutually parallel gas flow paths 12 and 13. A redox treatment unit 14 and a gas analysis unit 15 are provided in series in this order on the downstream side of the gas flow paths 12 and 13.

More specifically, one gas flow path 12 is provided with a flow meter 16 such as a mass flow meter, for example, an oxidation catalyst such as CuO, and an oxidation treatment unit 14A to which an oxygen supply path 17 for supplying oxygen is connected. A CO ₂ analyzer 15A is provided in this order. The other gas flow path 13 is provided with a flow meter 18 similar to the flow meter 16, for example, a reduction processing unit 14B provided with a reduction catalyst such as carbon and an SO ₂ analyzer 15B in this order. The CO ₂ analyzer 15A and the SO ₂ analyzer 15B used here are, for example, non-dispersive infrared gas analyzers (NDIR gas analyzers). That is, in the oxidation-reduction processing unit 14, the oxidation processing unit 14A and the reduction processing unit 14B are arranged in parallel with each other, and in the gas analysis unit 15, the CO ₂ analyzer 15A and the SO ₂ analyzer 15B are in parallel with each other. Are arranged.

  In addition, although not shown in figure, the part (including oxidation process part 14A and reduction process part 14B) to the gas analysis part 13 of the gas flow paths 9 and 11 and the gas flow paths 12 and 13 is made into suitable temperature, for example with a heater. It can be heated and kept warm. This is to prevent changes in the components contained in the gas generated in the heating furnace 1 and to ensure that the oxidation and reduction processes are performed.

  Reference numeral 19 denotes an arithmetic control unit that performs calculations based on signals (flow rate signal Q, concentration signal C, etc.) from each part of the apparatus, and sends a control signal to each part of the apparatus based on the calculation results. It becomes more.

  By the way, the filter 2 is made of, for example, quartz having a small amount of impurities. For example, the filter 2 is configured as shown in FIG. 2 in order to collect PM contained in the engine exhaust gas. A sampling device capable of flowing a flow rate is used. That is, in FIG. 2, 20 is, for example, a diesel engine mounted on an automobile, and 21 is an exhaust pipe connected thereto. A probe 22 is inserted and connected to the exhaust pipe 21 for sampling the exhaust gas G flowing through the exhaust pipe 21, and its downstream side is connected to a dilution tunnel 23 for diluting the exhausted exhaust gas G. Reference numeral 24 denotes a dilution air supply pipe connected to the upstream side of the dilution tunnel 23.

  Reference numeral 25 denotes a gas flow path that is connected to the downstream side of the dilution tunnel 23 and through which the diluted sample gas S flows. The downstream side of the flow path 25 is branched into two flow paths 26 and 27. 27 is provided with filter devices 28 and 29 for collecting PM contained in the sample gas S, and one flow path 26 is a sample gas flow path for flowing exhaust gas during PM collection, and the other is Each of the flow paths 27 is configured as a bypass flow path for flowing exhaust gas when PM is not collected. Of the filter devices 28 and 29, one filter 28 is a measurement filter, and the other filter device 29 is a dummy filter.

  Reference numeral 30 denotes a three-way solenoid valve as a flow path switching means provided on the downstream side of the sample gas flow path 26 and the bypass flow path 27, and the downstream side is connected to the gas flow path 31. A suction pump, for example, a roots blower pump 32, whose suction capacity can be changed by numerical control, and a flow meter with high measurement accuracy, for example, a venturi meter 33, are provided in this order.

Next, a method for analyzing particulate matter using the particulate matter analyzer in engine exhaust gas having the above-described configuration will be described with reference to FIG. FIG. 3 shows the temporal change in the atmosphere in the heating furnace 1 and the heating temperature of the filter 2 and the output state in each atmosphere. Symbols a and c are CO ₂ concentration outputs, and b is an SO ₂ concentration output.

  First, prior to the analysis, the exhaust gas G from the engine 20 is sampled at a constant flow rate using the sampling device shown in FIG. 2, and PM in the exhaust gas G is collected by the filter 2.

  The filter 2 that has collected the PM is placed in a heating furnace 1 that has been heated to 1000 ° C. in advance. First, the electromagnetic valve 10 of the gas supply unit 4 is operated to connect the nitrogen gas supply path 7 to the heating furnace 1, and nitrogen gas is supplied into the heating furnace 1 through the flow rate control device 5. The flow rate of the nitrogen gas at this time is measured by the flow rate control device 5, and the result is sent to the personal computer 19 as a flow rate signal Q.

  In the heating furnace 1, the filter 2 is heated at 1000 ° C. in a nitrogen gas atmosphere, so that SOF and sulfate in the PM collected by the filter 2 are gasified, and these are gas flow paths together with nitrogen gas. 11 will flow out.

The gas flowing out of the gas flow path 11 (including gasified SOF, sulfate and other generated gases) flows through the gas flow paths 12 and 13 in a bisected state. Then, the gas flowing through one gas flow path 12 flows into the oxidation processing unit 14 </ b> A of the oxidation-reduction processing unit 14 through the flow meter 16. Oxygen is supplied to the oxidation processing unit 14A, and SOF of the gasified SOF and sulfate is oxidized by the oxidation catalyst and oxygen to become CO ₂ and H ₂ O, and the gas analysis unit together with other gases. 15 CO ₂ analyzers 15A are sent to measure the CO ₂ concentration. Further, the gas flowing through the other gas flow path 13 flows into the reduction processing unit 14B of the oxidation-reduction processing unit 14 via the flow meter 18, and the sulfated gasified SOF and sulfate is reduced by the reduction catalyst, so that the SO ₂ is sent to the SO ₂ analyzer 15B of the gas analyzer 15 together with other gases, and the SO ₂ concentration is measured.

In addition, as shown in FIG. 4, in the reduction processing unit 14B, instead of providing a reduction catalyst, quartz cotton 34 is provided, and sulfate is passed therethrough, thereby promoting reduction of sulfate to SO ₂ . You may make it do.

That is, by evaporating sulfate, SO ₃ is obtained, and by applying heat to this SO ₃ ,
SO ₃ → SO ₂ + (1/2) O ₂ −23.1 kcal
However, if the SO ₃ is simply passed through the tube 36 heated by the heater 35, the SO ₃ is not sufficiently heated and may be sent to the analyzer 15B without being reduced to SO ₂ . There is. However, by providing a quartz wool in the reduction processing unit 14B, as described above, which kept heated by the heater, if to pass SO ₃ in the quartz wool, will SO ₃ to pass through the quartz wool When the heat from the tube wall is efficiently transferred to SO ₃ by quartz cotton, SO ₃ can be heated efficiently and reliably, and the reduction to SO ₂ is more reliably performed. Sulfate can be measured with high accuracy. Of course, both the reduction catalyst and quartz cotton may be provided in the reduction processing unit 14B.

From the gas analyzer 15, for example, CO ₂ concentration and SO ₂ concentration signals having shapes as indicated by symbols a and b in FIG. 3 are output and input to the personal computer 19. Since a signal representing the flow rate of nitrogen gas is input to the personal computer 19, the SOF and sulfate in the PM collected by the filter 2 are based on the nitrogen gas flow rate and the CO ₂ concentration and SO ₂ concentration. Each weight is determined.

  Next, the solenoid valve 10 of the gas supply unit 4 is switched to connect the oxygen supply path 8 to the heating furnace 1, and oxygen is supplied into the heating furnace 1 through the flow rate control device 6. The flow rate of oxygen at this time is measured by the flow control device 6 and the result is sent to the personal computer 19 as a flow signal.

In the heating furnace 1, when the filter 2 is heated at 1000 ° C. in an oxygen atmosphere, the dry soot remaining in the filter 2 is combusted (oxidized), and CO ₂ and CO (which are almost in trace amounts) are generated. Are generated and flow into the gas flow path 11 together with oxygen.

The gas flowing out of the gas flow path 11 (including CO ₂ and CO generated by the combustion and other generated gases) branches and flows to the gas flow paths 12 and 13. Then, the gas flowing through one gas flow path 12 flows into the oxidation processing unit 14 </ b> A of the oxidation-reduction processing unit 14 through the flow meter 16. Since the oxygen is supplied to the oxidation treatment unit 14A, the CO contained in the gas is oxidized CO _2, and the mixed with CO ₂ in the gas, the gas analyzer unit 15 along with other gases The CO ₂ analyzer 15A is sent to measure the CO ₂ concentration. In addition, the gas flowing through the other gas flow path 13 flows into the reduction processing unit 14B of the redox processing unit 14 via the flow meter 18, but in this case, the SO ₂ analyzer of the gas analysis unit 15 is not processed at all. It is sent to 15B and discarded without concentration measurement.

The gas analyzer 15 outputs a signal representing the CO ₂ concentration having a shape as indicated by reference character c in FIG. Since a signal representing the oxygen flow rate is input to the personal computer 19, the weight of the dry soot in the PM collected by the filter 2 is obtained based on the oxygen flow rate and the CO ₂ concentration.

  In this embodiment, when collecting PM by the filter 2, the exhaust gas G from the engine 20 is diluted. Based on the weight of the dry soot, SOF, and sulfate, taking this dilution rate into consideration. By performing the calculation, the weight of dry soot, SOF, and sulfate in the exhaust gas G can be obtained.

As described above, in the method and apparatus for analyzing particulate matter in engine exhaust gas according to the present invention, the filter 2 that collects PM is housed in the heating furnace 1 and first, in an inert gas atmosphere such as nitrogen gas. The filter 2 is heated at a predetermined temperature to gasify SOF and sulfate, and these are further oxidized or reduced to form CO ₂ and SO ₂ , respectively, and their concentrations are measured. Based on these concentrations, portions to determine the weight of the SOF and sulfates in trapped PM that the filter 2, the filter 2 is heated in an oxygen atmosphere to generate CO ₂ in the heating furnace 1, to measure the concentration of the CO ₂ based on this concentration, since to obtain the weight of the dry soot in PM trapped in the filter 2, contained in the exhaust gas G of the engine 2 0 That dry soot in PM, the SOF and sulfates, can be measured well easily and accuracy by separating individually.

In the above-described embodiment, the gas flow path 11 provided on the downstream side of the heating furnace 1 is divided into the gas flow paths 12 and 13, and the oxidation treatment unit 14 </ _b > A and the CO ₂ analyzer 15 </ _b > A are provided in one gas flow path 12. Since the other gas flow path 13 is provided with the reduction processing unit 14B and the SO ₂ analyzer 15B, the overall configuration of the apparatus becomes complicated. A configuration for eliminating this point will be described as a second embodiment with reference to FIG.

In FIG. 5, 33 is a flow meter provided in the gas flow path 11 on the downstream side of the heating furnace 1, and is the same as the flow meters 16 and 18 in the first embodiment. The oxidation-reduction processing unit 14 provided on the downstream side of the flow meter 33 is provided with an oxidation-reduction catalyst containing platinum (Pt) as a main component, and an oxygen supply path 17 is connected. Further, in the gas analyzer 15 provided on the downstream side of the oxidation-reduction processor 14, a CO ₂ analyzer 15A and an SO ₂ analyzer 15B are arranged in series.

  The particulate matter analysis method using the particulate matter analyzer in the engine exhaust gas shown in FIG. 5 will be described. First, prior to the analysis, the sampling device shown in FIG. The exhaust gas G is sampled at a constant flow rate, and PM in the exhaust gas G is collected by the filter 2.

  The filter 2 that has collected the PM is placed in a heating furnace 1 that has been heated to 1000 ° C. in advance. First, the electromagnetic valve 10 of the gas supply unit 4 is operated to connect the nitrogen gas supply path 7 to the heating furnace 1, and nitrogen gas is supplied into the heating furnace 1 through the flow rate control device 5. The flow rate of the nitrogen gas at this time is measured by the flow rate control device 5, and the result is sent to the personal computer 19 as a flow rate signal.

  In the heating furnace 1, the filter 2 is heated at 1000 ° C. in a nitrogen gas atmosphere, so that SOF and sulfate in the PM collected by the filter 2 are gasified, and these generate other generated gases and nitrogen. It flows out to the gas flow path 11 together with the gas.

The gas flowing out of the gas flow path 11 (including gasified SOF and sulfate) flows into the oxidation-reduction processing unit 14 via the flow meter 33. Since oxygen is supplied to the oxidation-reduction processing unit 14, the SOF of the gasified SOF and sulfate is oxidized by the oxidation-reduction catalyst and oxygen to become CO ₂ and H ₂ O, while the sulfate is It is reduced by a redox catalyst to become SO ₂ . These CO ₂ , H ₂ O, and SO ₂ are sent to the gas analyzer 15 in that state.

The gas flowing into the gas analyzer 15 is first measured for CO ₂ concentration in the CO ₂ analyzer 15A, and then measured for SO ₂ concentration in the SO ₂ analyzer 15B. CO ₂ concentration and SO ₂ concentration signals are output and input to the personal computer 19. Since a signal representing the flow rate of nitrogen gas is input to the personal computer 19, the SOF and sulfate in the PM collected by the filter 2 are based on the nitrogen gas flow rate and the CO ₂ concentration and SO ₂ concentration. Each weight is determined.

  Next, the solenoid valve 10 of the gas supply unit 4 is switched to connect the oxygen supply path 8 to the heating furnace 1, and oxygen is supplied into the heating furnace 1 through the flow rate control device 6. The flow rate of oxygen at this time is measured by the flow control device 6 and the result is sent to the personal computer 19 as a flow signal.

In the heating furnace 1, when the filter 2 is heated at 1000 ° C. in an oxygen atmosphere, the dry soot remaining in the filter 2 is combusted (oxidized), and CO ₂ and CO (which are almost in trace amounts) are generated. Are generated and flow into the gas flow path 11 together with oxygen.

The gas flowing out of the gas flow path 11 (including CO ₂ and CO generated by the combustion) flows into the oxidation-reduction processing unit 14 via the flow meter 33. Since oxygen is supplied to the oxidation-reduction processing unit 14, CO contained in the gas is oxidized to CO ₂ , and together with CO _{2 in the} gas, a CO ₂ analyzer 15A of the gas analysis unit 15 is obtained. The CO ₂ concentration is measured, and this concentration signal is input to the personal computer 19. The gas exiting the CO ₂ analyzer 15A is sent to the SO ₂ analyzer 15B, but is discarded without measuring the concentration.

Since the signal representing the flow rate of oxygen is input to the personal computer 19, the weight of the dry soot in the PM collected by the filter 2 is obtained based on the oxygen gas flow rate and the CO ₂ concentration. .

  Also in the second embodiment, when collecting PM by the filter 2, the exhaust gas G from the engine 20 is diluted, so that the dilution rate is taken into consideration as in the first embodiment. And calculating the weight based on the weight of the dry soot, SOF and sulfate, the weight of the dry soot, SOF and sulfate in the exhaust gas G can be obtained.

  As described above, according to the second embodiment, dry soot, SOF, and sulfate in the PM contained in the exhaust gas G of the engine 20 can be separately separated and easily and accurately measured.

In the second embodiment described above, the gas generated in the heating furnace 1 is not divided in the middle, and the gas analyzer 15 analyzes the CO ₂ analyzer 15A and the SO ₂ analyzer arranged in series. Since the total 15B is sequentially passed, there is an advantage that the overall configuration of the apparatus is simple.

  In the first and second embodiments described above, the heating of the filter 2 in the inert gas atmosphere first performed in the heating furnace 1 is performed at a constant temperature (1000 ° C.). Heating may be performed by a combination of low temperature heating and high temperature heating. Hereinafter, this will be described as a third embodiment.

  The SOF contained in the exhaust gas G discharged from the diesel engine 20 includes those caused by light oil and those caused by engine oil. The former SOF is vaporized at a relatively low temperature (for example, about 350 ° C.), The latter SOF is vaporized at a relatively high temperature (about 700 ° C.). In the first and second embodiments, when the filter 2 is heated in an inert gas atmosphere in the heating furnace 1, the filter 2 is set to a constant temperature, so the SOF and engine caused by light oil It could not be measured separately from SOF caused by oil.

  On the other hand, in the third embodiment, when heating the filter 2 under an inert gas atmosphere, the heating temperature of the filter 2 is low-temperature heating enough to vaporize the low-boiling SOF, Thereafter, high-temperature heating is performed to such an extent that SOF having a high boiling point is vaporized. As described above, the heating of the filter 2 under the inert gas atmosphere is performed at two low and high temperatures, so that the SOF caused by the light oil and the SOF caused by the engine oil can be separately measured.

  As a heating method at the low and high two-stage temperatures, for example, the temperature in the heating furnace 1 is switched by a temperature adjusting mechanism, the filter 2 is first heated at a low temperature, and then the filter 2 is heated at a high temperature. Alternatively, there is an appropriate method such as providing a low temperature heating part and a high temperature heating part in the heating furnace 1 and moving the filter 2 to the high temperature heating part after heating by the low temperature heating part.

  The present invention is not limited to the above-described embodiment, and can be implemented with various modifications. For example, a high-frequency heating furnace or an infrared image furnace may be used as the heating furnace 1. And as inert gas supplied to the heating furnace 1, you may use appropriate things, such as argon gas, other than nitrogen gas.

Further, when the gasified SOF generated when the filter 2 is heated at a predetermined temperature in a nitrogen gas atmosphere is oxidized in the oxidation treatment unit 14A or the oxidation-reduction treatment unit 14, H ₂ O is produced together with CO ₂ . This H ₂ O may be an interference component in the measurement of CO ₂ and SO ₂ . Therefore, it can be removed before being supplied to the gas analyzer 15, or the CO ₂ analyzer 15 A and the SO ₂ analyzer 15 B provided in the gas analyzer 15 can compensate for the influence of interference components. A gas analyzer having a configuration may be used.

Further, a gas analyzer (FTIR gas analyzer) using a Fourier transform infrared spectrophotometer may be provided as a gas analyzer provided in the gas analyzer 15. This FTIR gas analyzer can measure the concentration of CO ₂ and SO ₂ at the same time, and can also measure NO _x etc., so of course dry soot, SOF and sulfate contained in PM The concentration of other components can also be measured at once. Further, a mass spectrometer (mass spectrometer) may be used as a gas analyzer provided in the gas analyzer 15. In this mass spectrometer, CO ₂ , SO ₂ , NO _{X and the} like can be simultaneously measured with this single mass spectrometer. Therefore, when these FTIR gas analyzers or mass spectrometers are provided in the gas analyzer 15, the configuration of the entire apparatus is simplified.

In the above-described three embodiments, changing the hydrocarbons and dry soot in the particulate matter into CO _2, performs analysis of the CO ₂ (concentration measurement) in the gas analyzer 15, the sulfate in particulate matter SO ₂ is varied, although to carry out analysis of sO ₂ (concentration measurement) in the gas analyzer 15 is not limited to such a configuration, for example, in the gas analyzer 15, CO ₂ alone or sO Only ₂ may be analyzed.

In the case of analyzing only CO ₂ in the gas analysis unit 15, a gas supply unit 4 that alternatively supplies an inert gas or oxygen to the heating furnace 1, and the inert gas or oxygen are supplied. The heating furnace 1 that heats the filter 2 that has collected the particulate matter contained in the engine exhaust gas at a predetermined temperature, the oxidation treatment unit 14A that oxidizes the gas generated by the heating, and the oxidation treatment unit 14A. a gas supply, using an apparatus comprising a gas analyzer 15 for measuring the concentration of CO ₂ (CO ₂ analyzer 15A), a heating furnace filter 2 that collects particulate matter contained in engine exhaust gas First, the filter 2 is heated at a predetermined temperature (for example, about 1000 ° C.) while flowing an inert gas into the heating furnace 1 to vaporize and vaporize hydrocarbons in the particulate matter. did And CO ₂ to hydrocarbons by oxidation, the CO ₂ was analyzed by a gas analyzer 15 (CO ₂ analyzer 15A), then the filter by heating the filter 2 while flowing oxygen into the heating furnace 1 2 on the residual particulate matter (dry soot) was oxidized to generate CO ₂ and, the CO ₂ may be as analyzed by gas analyzer (CO ₂ analyzer 15A).

In the case of analyzing only SO ₂ in the gas analysis unit 15, the gas analysis unit 15 includes a gas supply unit that supplies an inert gas to the heating furnace 1, and the engine exhaust gas that is supplied with the inert gas. A heating furnace 1 that heats the filter 2 that has collected particulate matter at a predetermined temperature, a reduction processing unit 14B that reduces the gas generated by the heating, and a gas from the reduction processing unit 14B are supplied, and SO ₂ A filter 2 that collects particulate matter contained in engine exhaust gas is provided (set) in the heating furnace 1 using an apparatus including a gas analyzer 15 (SO ₂ analyzer 15B) that measures the concentration. First, the filter 2 is heated at a predetermined temperature (for example, about 1000 ° C.) while flowing an inert gas in the heating furnace 1 to vaporize the sulfate in the particulate matter, and the vaporized sulfate is reduced to reduce the SO. _The SO ₂ may be analyzed by the gas analyzer 15 (SO ₂ analyzer 15B).

It is a figure which shows roughly an example of the analyzer of the particulate matter in the engine exhaust gas of this invention. It is a figure which shows roughly an example of the sampling device for making a filter collect PM. It is a figure for operation | movement description of this invention. It is a figure which shows roughly the other example of the reduction process part of this invention. It is a figure which shows roughly the other example of the analyzer of the particulate matter in the engine exhaust gas of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heating furnace 2 Filter 4 Gas supply part 14 Redox processing part 15 Gas analysis part

Claims (4)

A filter that collects particulate matter contained in the engine exhaust gas is installed in the heating furnace. First, the filter is heated at a predetermined temperature while flowing an inert gas in the heating furnace, and hydrocarbons and sulfates in the particulate matter. And the vaporized hydrocarbon is oxidized to CO ₂ , while the vaporized sulfate is reduced to SO ₂ , and the CO ₂ and SO ₂ are analyzed by a gas analysis unit, and then placed in the heating furnace. In the engine exhaust gas, the filter is heated while oxygen is flowing to oxidize particulate matter remaining on the filter to generate CO ₂ , and the CO ₂ is analyzed by a gas analyzer. Analysis method for particulate matter.   When heating the filter while flowing an inert gas in the heating furnace, first, low-temperature heating is performed so that low-boiling hydrocarbons are vaporized, and then high-temperature heating is performed so that high-boiling hydrocarbons are vaporized. The method for analyzing particulate matter in engine exhaust gas according to claim 1. The method for analyzing particulate matter in engine exhaust gas according to claim 1 or 2, wherein the sulfate is passed through heated quartz cotton when reducing the vaporized sulfate to SO ₂ . A gas supply unit that selectively supplies an inert gas or oxygen to the heating furnace, and a filter that collects particulate matter contained in the engine exhaust gas in a state where the inert gas or oxygen is supplied. A heating furnace that heats at a predetermined temperature, an oxidation-reduction treatment unit that oxidizes or reduces the gas generated by this heating, and a gas analysis that measures the concentration of CO ₂ and SO ₂ supplied with gas from this oxidation-reduction treatment unit And an analysis device for particulate matter in engine exhaust gas.

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