KR100700702B1 - Catalysis device for combustion of hydrocarbon - Google Patents

Abstract

A catalyst reactor for combustion of hydrocarbon is provided to minimize slip of unburned hydrocarbon and minimize a consumption amount of power required to start the catalyst reactor for combustion of hydrocarbon. A catalyst reactor for combustion of hydrocarbon has a lighter(500) by electric heating and a catalyst for burning and reforming a reactant. An igniting part is formed to start combustion by introducing a reactant. A main reacting part(300) reforms the reactant passing through the igniting part. A cross section of the igniting part is smaller than a cross section of the main reacting part. The lighter is installed at the igniting part.

Description

Catalytic device for combustion of hydrocarbons

1 is a schematic diagram of a catalytic reactor for heating using a conventional rod-type heater

2 is a schematic diagram of a catalytic reactor for heating a catalyst layer using EHC.

3 is a schematic diagram of a catalytic reactor according to the present invention Example 1

Figure 4 is a schematic view of the catalytic reactor according to the present invention Example 2

5 is an experimental result according to Example 1 of the present invention.

<Description of the symbols for the main parts of the drawings>

11: electric heater 12: combustion / reforming catalyst

13: Catalytic Reactor 21: EHC

22: combustion / reforming catalyst 23: catalytic reactor

100,110: oxidation catalyst 200: reforming catalyst

300: main reaction unit 400: secondary reactant supply line

500: igniter 510: igniter connector

520: igniter connector 530: power supply line

600: mixer 700: reactant inlet

710: reactant supply line 900: expansion tube

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalytic combustion reactor for hydrocarbon combustion, and more particularly, in a catalytic combustor driven by raw materials of DME and alcohols, which are LPG, LNG, gasoline, diesel, or oxygenated hydrocarbons, using less electric energy. A catalytic reactor for hydrocarbon combustion that can be started.

Although the hydrocarbon combustion apparatus using the catalyst is slightly different from the initial starting temperature depending on the type of hydrocarbon, since the combustion of the catalyst may proceed when heated above a predetermined temperature by an external heat source, the combustion is performed using a heater.

FIG. 1 is a configuration diagram of a catalytic reactor 13 for heating using a conventional rod type electric heater 11, and FIG. 2 is a diagram for configuration of a catalytic reactor 23 for heating using an EHC (electric heating catalyst) 21. to be.

Then, the mixed air of hydrocarbon and air passing through the electric heater 11 or the EHC 21 is burned and reformed by the combustion reforming catalysts 12 and 22 installed thereafter.

In addition to the heating mechanisms shown in FIGS. 1 and 2, depending on the type of the catalytic reactor, various types of ignition burners or exothermic heaters may be used for initial heating.

However, in the case of hydrocarbons, especially liquid phases, the presence or absence of a stable combustion reaction is determined according to the degree of mixing of fuel and air. The combustion is carried out by contacting the gas, or converted into the gas phase using a vaporization apparatus, followed by mixing with air and combustion through contact with the combustion catalyst.

Recently, many studies are underway to utilize a catalytic reactor as a combustion / reformation system for exhaust gas emitted from an internal combustion engine.

Although a number of concept patents have been filed for supplying hydrocarbons in the exhaust gas to heat the exhaust gas or simultaneously to form a reducing gas through reforming, it does not present a specific system configuration necessary for its combustion / reformation.

In particular, since the evaporation of diesel oil is not rapid at an exhaust gas temperature of 300 ° C. or less, it is a difficulty in heating the exhaust gas itself through catalytic combustion.

The temperature of the exhaust gas varies greatly depending on the driving condition of the vehicle, and in particular, the need for a separate heater is raised because the conditions under which the high temperature at which the diesel gas is evaporated and ignited are maintained are very small.

In addition, the nature of the vehicle is required to minimize the amount of electrical energy used when starting the catalytic combustion.

An object of the present invention devised to solve the above problems, in the catalytic combustor driven by LPG, LNG, gasoline, DME and alcohols which are diesel or oxygen-containing hydrocarbons as a raw material, using less electrical energy quickly It is to provide a catalytic reactor for startable hydrocarbon combustion.

In order to achieve the above object, the present invention provides a catalytic reactor for a hydrocarbon combustion comprising an igniter and a catalyst for burning / reforming a reactant by electric heating. It is a catalytic reactor for hydrocarbon combustion, characterized in that the reactant is modified to include a main reaction portion, the cross-sectional area of the complex portion is smaller than the cross-sectional area of the main reaction portion.

The ratio of the cross-sectional area of the complexing unit to the cross-sectional area of the main reaction unit is 0.01 to 0.9.

The igniter may be installed in the ignition unit.

In addition, a particle catalyst in the form of a sphere or a cylinder is charged at the lower end of the ignition unit.

In addition, a particulate catalyst or a monolith catalyst is charged to the main reaction portion.

In addition, the catalyst is characterized by consisting of a combustion catalyst composed of one or more of platinum and ruthenium and a reforming catalyst comprising rhodium.

In addition, the hydrocarbon is one or more selected from methane, natural gas, propane, butane, LPG, gasoline, diesel, dimethyl ether (DME), alcohol.

In addition, the reactants include a hydrocarbon and air for combustion reforming, and the ratio of combustion reforming air to hydrocarbon (O / CH) is 0.3 to 20.0.

In addition, the igniter is characterized by heating the catalyst for 2 to 600 seconds.

An exhaust gas heating apparatus for heating exhaust gas using the hydrocarbon combustion catalyst reactor, a reducing gas supply apparatus for removing nitrogen oxides from the exhaust gas, or a DPF heat source supply for supplying a heat source for regenerating a modified hydrocarbon to DPF. It can be utilized.

Hereinafter, the present invention will be described in more detail.

In order to proceed with the complexation of hydrocarbons, heating the catalyst to the activation temperature is essential and requires heating in some way at the beginning of the startup.

In the present invention, the configuration of the reactor is divided into a complex consisting of a ignition unit and a main combustion unit or a reforming unit configured to have a low thermal mass, thereby minimizing the use of electric energy during ignition and suppressing the slip of hydrocarbon. Follow.

 The fuel required for combustion utilizes some of the fuel mounted on the vehicle or a separate hydrocarbon, and air is supplied through an external compressor. The upper complex part of the catalytic reactor has a small diameter so that the thermal mass is small, and the lower main reaction part has an enlarged diameter. The exothermic heater is mounted at a small diameter at the top thereof, and air and fuel supply lines are installed around the exothermic heater.

Therefore, the apparatus for ignition of the catalytic reactor according to the present invention minimizes the power used at the start and does not require a separate effort for evaporation or injection of the liquid phase.

It also minimizes the slip of hydrocarbons at the start of the run to reduce pollutant emissions. In the upper catalyst layer having a small reactor diameter, some hydrocarbons are burned and fuel is evaporated by the heat of combustion, and then mixed with air to be moved to the catalyst bed of the expanded main reaction part, where most of the combustion or reforming reaction proceeds.

Figure 3 shows a catalytic reactor according to an embodiment of the present invention, the ignition portion is configured to be small in volume to heat a small amount of catalyst, the lower portion is composed of the main combustion portion of the gradually expanded form.

The ignition unit is configured in the order of the reactant introduction unit 700, the igniter 500, and the oxidation catalyst 100 composed of a particulate ceramic support with respect to the advancing direction of the reactant.

The reactant introduction part 700 is connected to the reactant supply line 710 to receive a hydrocarbon and combustion air from the outside.

The igniter 500 requires an output density of 10 W / cm ² or more in order to heat the surrounding catalyst to a high temperature.

The igniter 500 is installed in connection with the igniter connector 520 in the igniter connector 510 formed on the side of the ignition unit.

In addition, a power supply line 530 is installed to supply power to the igniter 500 into the igniter connecting pipe 520.

After the igniter 500, a part of the ignition unit and the main combustion unit 300 are filled with oxidation catalysts 100 and 110.

Chemical changes made by the catalytic reactor of FIG. 3 are shown in Scheme 1 below.

Scheme 1

C ₁₅ H ₃₂ + 23 O ₂ → CO ₂ + H ₂ O, heat of combustion = 11,000 kcal / kg

As the heating cross-sectional area of the reactant introduction portion is reduced by the installation of the igniter 500 in the small diameter portion as described above, most hydrocarbons supplied can be contacted with the heated oxidation catalyst 100. It is possible to minimize the electrical energy.

When some hydrocarbons are complexed, their heat causes the surrounding and bottom catalysts to heat up.

The composition of the oxidation catalysts 100 and 110 is not particularly limited, and any material based on precious metal or transition metal may be used.

However, sufficient heat resistance should be ensured even at least 1000 ℃.

In terms of morphology, the oxidation catalyst 100 of the reactor ignition unit is required to have a spherical or cylindrical particle form to facilitate the mixing of reactants and air, and the oxidation catalyst 110 of the main combustion unit 300 has a particulate form, a gate gate, Any form, such as monolith (channel or foam) may be used.

The oxidation catalyst 100 of the ignition unit is suitable for a catalyst prepared by supporting an active metal on ceramic particles, and the oxidation catalyst 110 of the expanded portion of the main combustion unit may be coated with a ceramic monolith or metal monolith in the form of a slurry. It's okay. At this time, the oxidation catalyst 100 of the ignition part requires a ceramic granular support in order to smoothly proceed the ignition.

In addition, it is necessary to mount a coupler for measuring the temperature T1 of the rear end of the ignition portion of the catalytic reactor and the temperature T2 of the outlet.

Power is supplied for a certain time to heat the catalyst 100 at the inlet side and supply air and hydrocarbons.

When the temperature of T1 reaches 300 ° C. or more, the amount of heat generated is increased by increasing the supply of hydrocarbons and air.

At this time, the supply amount of oxygen increases the supply amount in a range in which the temperatures of T1 and T2 are maintained at 1000 ° C. or lower to suppress deterioration of the catalyst.

That is, the catalytic reactor supplies power to the igniter 500 for a predetermined time to heat the catalyst around the igniter 500, and then supplies air and hydrocarbons to perform ignition. The heat generated thereby heats the expanded lower catalyst and determines its heating state by T1.

Figure 4 shows a catalytic reactor according to the second embodiment of the present invention, if necessary to increase the supply of fuel and hydrocarbon to increase the amount of heat generated or to increase the supply of fuel to produce a synthesis gas (Scheme 2) Can be used for the purpose of).

Scheme 2

C ₁₅ H ₃₂ + 7.5O ₂ --------> 15CO + 16H ₂ , generated heat = 3,587 kcal / kg

The catalytic reactor of Example 2 may supply secondary air and hydrocarbons to the rear end of the ignition unit to perform combustion and / or reforming by the reforming catalyst 200.

This configuration also provides the simplicity of the system configuration by facilitating catalytic combustion by partial heating and by evaporation of the liquid fuel by the heat of combustion.

In this case, however, the mixer 600 is preferably mounted.

Example 2 is the same as that of Example 1, but the complexing part is different in the structure of the main reaction part.

First, the secondary reactant supply line 400 is installed in the expansion tube 900 having a space in which the tapered space passes through the oxidation catalyst 100.

In addition, the expansion tube 900 is connected to the main reaction unit 300, the mixer in order to help the mixing of the air and fuel charged into the secondary reactant supply line 400 to the front end of the main reaction unit 300 600 is installed.

In addition, the secondary oxidation catalyst 200 is installed at a predetermined interval from the mixer 600.

The shape of the cross section of the catalytic reactor of Example 2 is circular or rectangular in shape without any limitation. However, the most important requirement is to reduce the thermal mass by reducing the ignition portion and the cross-sectional area.

The oxidation catalyst 100, it is preferable to use platinum or / at the same time ruthenium composition as an active ingredient, the support requires a product manufactured to have high temperature heat resistance. Active noble metals may be used in addition to incipient wetness, solution impregnation, and reduction deposition, which are widely used in the catalyst manufacturing process. Most importantly, the combustion catalyst is exposed to high heat and therefore requires durability at least 1000 ° C.

The method and characteristics of the reforming catalyst 200 are also the same as the oxidation catalyst 100. However, rhodium is used as the active metal. In this case, the content of rhodium includes 0.05-1.00% based on the total weight of the catalyst. In consideration of economics and activity, the preferred content of rhodium is 0.1-0.3% by weight.

The oxidation catalyst 100 prepared by the above method is used in the ignition unit and the reforming catalyst 200 is filled in the main reaction unit 300. At this time, each catalyst may be mixed and packed or a single catalyst may be used.

However, in order to obtain an optimum effect, it is preferable to fill the ignition unit with a noble metal catalyst with emphasis on oxidizing power and to install a reforming catalyst in the main reaction unit 300.

FIG. 5 illustrates the temperature change T1 of the catalytic reactor with time by applying the combustion catalyst and the reforming catalyst as follows in Example 1. FIG.

As the combustion catalyst, platinum alone was used as an active ingredient, and a support was made of 3-5 mm particulate activated alumina (gamma-Al ₂ O ₃ , manufactured by Canto). Prior to supporting the active metal, 5% by weight of cerium (Ce (NO ₃ ) ₂ .xH ₂ O, manufactured by Aldrich) was loaded on the alumina, and dried at 105 ° C. for 24 hours and then calcined at 1300 ° C. for 12 hours to give heat resistance. Platinum chloride (H ₂ PtCl ₆ .xH ₂ O, manufactured by HanGold Gold Co., Ltd.) was dissolved in distilled water on the finished support to carry platinum.

The input amount of the platinum precursor (H ₂ PtCl ₆ .xH ₂ O) was added to include 0.2% by weight based on the total weight of the catalyst. After supporting, drying (105 DEG C, 24 hours) and firing (1300 DEG C, 12 hours) were completed.

The reforming catalyst was prepared in the same order as the combustion catalyst. However, cerium was replaced by magnesium with a precursor (Mg (NO 3) 2.xH ₂ O, manufactured by Aldrich), and platinum by rhodium precursor (RhCl ₃ .xH ₂ O, manufactured by Kojima).

Ignition was made using a 3/8 inch Tee.

Fuel and air were introduced at the top and a 120W electric heater was mounted as an igniter 500 at the side. The main reaction part 300 bonded the tube to the ignition part.

The oxidizing catalyst was filled in the ignition unit and the main reaction unit 300.

The oxidation catalyst was mixed so that the combustion catalyst and the reforming catalyst were 50% by weight, respectively, and the same composition was filled in the ignition unit and the main reaction unit. At this time, the volume of the filled catalyst is 29 ml.

The reactor was mounted in an automobile exhaust pipe (160 ° C.), and after the temperature reached a steady state, power was applied using a 12V battery, and after 1 minute, air (6liter / min) and diesel oil (0.3 ml / min) were supplied.

The power supply was stopped 1 minute after the start of fuel supply. In this process, changes in the catalytic reactor temperature (T1) were recorded at intervals of 10 seconds, as shown in FIG.

As can be seen in Figure 5, 50 seconds after the fuel supply and the rapid heating proceeds and after 3 minutes you can see the name at 800 ℃. In particular, combustion can be performed stably even when diesel fuel, which is a liquid fuel, is not provided with a separate evaporation device.

The use of the present invention is as follows.

First, diesel engines emit soot particles (PM) or very small droplets of condensate or aggregates (SOF), in addition to unburned hydrocarbons, nitrogen oxides and carbon monoxide, which are internal combustion engine exhaust pollutants, due to their fuel and operating characteristics. These particles (hereinafter simply referred to as "diesel soot" or "soot") contain particularly high amounts of condensable polycyclic hydrocarbons (some of which are known to be carcinogenic).

In order to reduce the emission of particles, an exhaust gas aftertreatment device is required, and a method for regenerating the filter by collecting diesel soot into the filter and periodically burning the accumulated particles has been proposed.

Under normal operating conditions, the temperature of the diesel exhaust is not sufficient to burn off the accumulated soot, and as a function of the soot composition depending on the engine or load conditions, a temperature of 500 to 600 ° C. is required for this purpose.

To this end, it is possible to install a burner for heating the filter to a temperature necessary to ignite the exhaust gas system to burn off soot prior to the filter, and as such a burner, the catalytic reactor of the present invention can be used.

In addition, olefins (ethene, propylene, butenes), lower hydrocarbons (methane, ethane, propane, butane), hydrogen, and carbon monoxide produced during the partial oxidation of hydrocarbons are used as reducing agents for nitrogen oxides. The reactor can be used for the production of the reducing agent because the incomplete combustion can proceed according to the ratio of fuel and air (O / CH).

At this time, the hydrocarbon is preferably gasoline, petroleum, diesel, or a combination of at least two or more thereof, and the hydrocarbon to be introduced may be a paraffinic hydrocarbon, an olefinic hydrocarbon or an aromatic hydrocarbon.

Therefore, the catalytic reactor of the present invention can be utilized as a reducing gas supply device for removing nitrogen oxides.

In addition, the catalytic reactor of the present invention can be utilized as a DPF heat source supply for supplying a heat source for regenerating the DPF.

In general, diesel engines have high fuel efficiency, high power and high load operation, and demand thereof continues to increase.

However, air pollution by diesel vehicles is caused by nitrogen oxides (NOx) and particulate matter (PM) that are contained in the exhaust gas, and it is recognized as a major cause of air pollution, accounting for about 40% of total air pollution. In response, countries are tightening emission regulations for diesel engines.

In order to cope with the regulation of exhaust gas for diesel engines, Diesel Oxidize Catalyst (DOC) was initially applied. However, as the regulations are gradually tightened, recently, a Diesel Particulate Matter Filter (DPF) is additionally applied. To respond.

The diesel oxidation catalyst is mainly aimed at improving the cold initial purification performance of CO (light off: the lower the temperature, the better the performance is required until the catalyst exhibits qualitative performance), and a soluble organic fraction (PM) in PM; SOF) functions to purify the components.

The DPF has a configuration arranged in series at the rear end of the diesel oxidation catalyst, and serves to reduce the particulate matter of the exhaust gas discharged by accumulating particulate matter from the diesel engine in the filter, and when the amount of PM is accumulated a certain amount of oxidation catalyst And it is used by regenerating with the after-fuel injection device.

In order to regenerate the DPF, a small amount of fuel may be burned or partially oxidized using the catalytic reactor of the present invention to supply a heat source for regenerating the DPF.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

By developing the catalytic combustion device according to the present invention, it is possible to minimize the power consumption required for start-up and minimize slip of unburned hydrocarbons.

In particular, it is possible to provide a catalytic combustion system in which the restriction on the properties of the fuel is eliminated.

Claims (12)

A catalytic reactor for a hydrocarbon combustion comprising an igniter and a catalyst for burning / reforming a reactant by electric heating, the catalyst reactor comprising: a ignition unit in which a reactant is introduced and combusting is started; The cross-sectional area of the complex part is formed smaller than the cross-sectional area of the main reaction part, The igniter is a catalytic reactor for hydrocarbon combustion, characterized in that installed in the ignition. The catalytic reactor for hydrocarbon combustion according to claim 1, wherein the ratio of the cross-sectional area of the complex to the cross-sectional area of the main reaction part is 0.01 to 0.9. delete The catalyst reactor for hydrocarbon combustion according to claim 1, wherein a particle catalyst in the form of a sphere or a cylinder is charged at a lower end of the ignition unit. The catalyst reactor for hydrocarbon combustion according to claim 1, wherein a particulate catalyst or a monolith catalyst is charged into the main reaction portion. The catalyst reactor for hydrocarbon combustion according to claim 1, wherein the catalyst is composed of a combustion catalyst composed of one or more of platinum and ruthenium and a reforming catalyst including rhodium. The catalytic reactor of claim 1, wherein the hydrocarbon is at least one selected from methane, natural gas, propane, butane, LPG, gasoline, diesel, dimethyl ether (DME), and alcohol. The catalytic reactor of claim 1, wherein the reactant comprises a hydrocarbon and air for combustion reforming, and the ratio of combustion reforming air to hydrocarbons (O / CH) is 0.3 to 20.0. The catalyst reactor for hydrocarbon combustion according to claim 1, wherein the catalyst is heated for 2-600 seconds with the power to the igniter. An exhaust gas heating apparatus for heating exhaust gas by using the catalytic reaction reactor of any one of claims 1, 2, and 4 to 9. A reducing gas supply apparatus for removing nitrogen oxides using the catalytic reaction reactor of any one of claims 1, 2, and 4 to 9. 10. A DPF heat source supplyer for supplying a heat source for regenerating a DPF to a hydrocarbon modified by using the catalytic reaction reactor of any one of claims 1, 2, and 4-9.

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