JPH11285616A - Heavy oil lightening/flue gas treating device and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a device and method by which the lightening of heavy oil and the flue gas treatment such as deNOx and deCOx, and decomposing removal of VOC can be performed by the same constitution in which plasma and an inorganic ion exchange body are combined and only a catalyst deposited on the inorganic ion exchange body is changed. SOLUTION: Relating to a heavy oil lightening/flue gas treating device constituted so that a reaction tank is arranged in a line in which gas to be treated flows and in the reaction tank, a zeolite honeycomb 1 consisting of an inorganic ion exchange body is installed to contact the gas to be treated with the zeolite honeycomb 1, line electrodes 3a and 3b covered with dielectric covering tubes 4 are inserted and arranged in circular openings 1a in such position relation that they become a pair of positive and negative poles, and between the line electrodes 3a, 3b, plasma is generated by applying high alternating voltage, allowing a catalyst 2 to be deposited on the zeolite honeycomb 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to lightening of heavy oils (higher hydrocarbons composed of C12 + such as heavy oil and pyrolysis wax of waste plastics) (C1-4: gas components, C5-5).
11: lower hydrocarbons such as gasoline components) and deN
The present invention relates to flue gas treatment such as decomposition and removal of Ox, deCOx, and VOC.

[0002]

BACKGROUND OF THE INVENTION (weight lightening of fuel oil) containing 1-5 about gaseous hydrocarbon carbon _{(CH 4, C 2 H 6} , C 3 H 8, C 4 H 10, C
Such as ₅ H ₁₂₎ is a good reducing agent, these are ammonia, be possible replacement of a reducing agent such as urea are known, such as in the denitration reaction. Specifically, in the flue gas denitrification of diesel motor equipment using heavy oil as fuel, a part of fuel heavy oil is gasified, and if it can be efficiently lightened to gaseous hydrocarbons having about 1 to 5 carbon atoms, it is reduced. Utilization as an agent makes it possible to construct an inexpensive denitration system that does not require a reducing agent such as ammonia or urea.

Conventionally, as a method for lightening a hydrocarbon having 6 to 10 carbon atoms such as naphtha (heavy gasoline) to a lower gaseous hydrocarbon such as CH ₄ or C ₂ H ₆ , FIGS.
There is a “steam reforming method” shown in FIG. This is because of the high temperature (500-900
℃), high-pressure (30-50atm), direct lightening cracking of heavy oil by steam, which has been established as a method suitable for mass production.

[0004] Lightening of heavy oil with a catalyst-supporting zeolite is currently performed at 300 to 400 ° C and 10 to 20 atm.
It is widely performed under such conditions.

[0005] (deNOx and deCOx) When burning fossil fuels such as petroleum, coal and LNG, NOx, SO
Since harmful gases such as x and COx are generated, it is necessary to make these harmless. In recent years, from the viewpoint of protection of the global environment, it has been required to decompose greenhouse gases such as CO ₂ , for which regulations on large amounts of harmless emissions are being studied.

Conventionally, deNOx is mainly used in all fields of industry, such as iron and steel, non-ferrous metals, paper and pulp, ceramics and cement, electric power, petroleum and chemicals, waste incineration plants, and prime movers involving fossil fuel combustion. The ammonia catalytic reduction method (SCR method to 350 ° C.) has been applied as an established method.

The SCR method is a direct catalytic reduction method using ammonia, urea or the like as a reducing agent at a high temperature (up to 350 ° C.).

In the same high temperature region, metal Cu
-5 zeolite carrying Si (Si / Al = 31)
Has been established as a technology for treating flue gas in automobiles and diesel internal combustion engines.

[0009] Further, various researches have been conducted on the denitration technology using plasma. For example, JP-A-6-269
No. 635 describes an exhaust gas treatment device using plasma.

[0010] Regarding deCOx, in particular, the conversion of CO ₂ into methanol has been proposed, and various methods have been studied. As for the refueling technology to methanol, CO ₂ is converted into CO and CO + 2H ₂ → CH ₃ O
It is important to achieve the H reaction, especially CO + 2H ₂ → C
Regarding the H ₃ OH reaction, (CO +
2H ₂ ) in a ZnO catalyst at a high temperature (300
~ 400 ° C) and high pressure (150 ~ 200atm).

In addition, methanol is produced as a hydrogenation reaction using a zeolite supporting a transition metal catalyst.

CO + 2H ₂ → CH ₃ OH (exothermic reaction) From thermodynamic and stoichiometric equilibrium conditions, the reaction is accelerated by cooling and pressurizing.

Regarding the conversion of CO ₂ to CO, reduction by plasma treatment is promising, and various studies have been made.

(Decomposition of VOC (Volatile Organic Compound)) Benzene, trichloroethylene, tetrachloroethylene,
The four dioxins are designated by the Air Pollution Control Law / Amendment from April 1997 as "designated emission or scattering must be suppressed immediately", and special measures are required.

The generation of VOCs is mainly caused by boilers and electric precipitators in a temperature range around 350 ° C., when NOx, SOx, COx, hydrocarbons, halogen gas and the like contained in flue gas when fossil fuels are combusted. It is synthesized using a metal such as an electrode as a catalyst.

Therefore, it is urgently necessary to take measures especially for smoke emission from a waste incineration plant, and in addition, benzene and the like are contained in gasoline combustion smoke, and measures for an engine (motor) are also regarded as important.

The conventional VOC decomposition and removal methods mainly include a combustion catalyst method (> 450 ° C.) and an activated carbon adsorption method.

Regarding the VOC decomposition technology using plasma, various substances (benzene, trichloroethylene,
Research on tetrachloroethylene, acetone, chlorofluorocarbons, toluene, etc.) has been attempted, and each result has been obtained. FIG. 13 shows a device for decomposing dilute benzene (200 ppm) by the bed reactor method.
15 shows the results. In this method, electrodes are formed of coaxial cylinders, and dielectric particles (ceramic pellets) are filled between the electrodes to apply a high alternating voltage. The dielectric particles in contact with both electrodes are charged, and the adjacent dielectric particles are successively charged by the contact between the dielectric particles, so that the entire dielectric particles are charged and polarized. The flue gas is passed through the dielectric particles and is ionized and turned into plasma by the polarization electric field of each polarized dielectric particle. The kinetic energy of the excited electrons collides with the VOC molecules, and , And dissociation of halogen bonds due to hydrogen radicals, decyclization, lower hydrocarbon conversion, and the like.

[0019]

The above-mentioned prior art has the following problems.

(Lightening of Heavy Oil) The conventional technology is to use gaseous lower hydrocarbons as a reducing agent to lighten heavy oil fuel for exhaust gas treatment in engines such as motors using heavy oil as fuel. the is intended to be obtained directly, for example, thereby obtaining a mixture hydrocarbons corresponding to NOx1000ppm 1000 ppm of _{CH 4 + C 2 H 6 +} C 3 H 8 + C 4 H 10 + C 5 H 12 in the denitration. In that sense, there is no need to mass-produce light oil, but rather a relatively compact and inexpensive method that does not require large-scale equipment (high temperature, high pressure, a catalyst that can withstand it, etc.).

For the lightening of heavy oil by using a catalyst-supporting zeolite, further lowering the temperature and pressure is desired for the above-mentioned purpose of use.

(DeNOx and deCOx) Techniques such as the SCR method and the Cu-ZSM-5 method are effective in a high temperature region. However, with regard to high-temperature technology, benzene synthesized in high-temperature flue gas (> 300 ° C),
In order to control harmful VOCs (volatile organic compounds) such as dioxins, it is necessary to consider lowering the temperature in the future.

On the other hand, the plasma method is an effective method in a low temperature region, but generates harmful substances such as NO ₂ by itself and requires a secondary treatment. In that sense, the plasma method is significant for lowering the temperature, but is not effective alone.

That is, Japanese Patent Application Laid-Open No. Hei 6-269
A process in an exhaust gas treatment apparatus using plasma as disclosed in Japanese Patent Application Laid-Open No. 635 is described below with respect to NOx.

[0025] By _{2NO + e → N 2 + O} 2 + e 2e + 2NO 2 → N 2 + 2O 2 + 2e the plasma excitation reactions, NOx is reduced to N2, the O2 or O ₃ generated at the same time N ₂ is reoxidized, and under general conditions, NO is oxidized to NO ₂ and the reaction is terminated.

NO ₂ generated by this reaction is a harmful substance having higher toxicity than NO. Therefore, since it is impossible to end the treatment as it is, generally, the prior art requires post-treatment of NO ₂ as in an adsorbent device. Therefore, deNO by the plasma alone treatment of NOx
The problem of x lies in the removal of O ₂ and O _{3 that} occur simultaneously.

With regard to the conversion of CO ₂ into CO in deCOx, reduction by plasma treatment is promising, but CO ₂ is reduced to CO in 2e + 2CO ₂ → 2CO + O ₂ + 2e, but it is generated simultaneously. Since O ₂ or O ₃ re-oxidizes CO to generate CO ₂ , the problem of deCOx is removal of O ₂ and O _{3 which} are generated at the same time as deNOx.

(Decomposition of VOC (Volatile Organic Compound))
Although the generation mechanism and source of OC have been described in the related art, the removal method is mainly the combustion catalyst method (>
450 ° C), by the activated carbon adsorption method. However, in either method, VOC resynthesis in the 350 ° C. region,
There is a problem such as desorption and reprocessing of the adsorbate, which is not necessary and sufficient.

Further, in the degradation of benzene with bed reactor system, other C ₂ H ₂ (acetylene) as shown in FIGS. 17 and 18, are generated NOx, by-products such as O _3. Both NOx and O ₃ are harmful substances and require detoxification treatment. In the generation of by-products in this method, a large amount of air excluding 200 ppm of benzene is simultaneously decomposed by plasma, and N ₂ is oxidized by O ₂ or O ₃ to generate NOx. Therefore, deNOx, d
As with eCOx, it is necessary to take measures for removing O ₂ and O ₃ .

In the case of halogenated VOCs, selective removal of separated halogens with a metal catalyst or the like, for example, fixation by adsorption to active sites of zeolite, etc., means that O ₂ and O ₃ can be removed. Required as well.

According to the present invention, the above-mentioned three treatments, that is, heavy oil lightening deNOx and deCOxVOC
The present invention provides an apparatus and a method thereof, wherein a flue gas treatment such as decomposition and removal of a gas is constituted by a combination of a plasma and an inorganic ion exchanger, and all the treatment can be carried out by the same constitution only by changing a catalyst carried on the inorganic ion exchanger. Aim.

[0032]

SUMMARY OF THE INVENTION (Lightening of Heavy Oil) The present invention is an apparatus and method for obtaining a small amount of gaseous lower hydrocarbons relatively inexpensively without using a large-scale apparatus. Lightening of heavy oil with a catalyst-supported zeolite is a widely practiced method usually at 300 to 400 ° C. and 10 to 20 atm. The present invention employs a combination with plasma decomposition as a means for executing the reaction at a lower temperature (up to 150 ° C.) and a lower pressure (normal pressure) based on this method.

According to the present invention, first, gasified heavy oil is introduced into a processing apparatus (reaction tank). The inside of the reaction tank is composed of a zeolite / catalyst carrying a catalyst, a dielectric coating tube and a positive / negative electrode pair arranged approximately symmetrically vertically and horizontally in the honeycomb, and a high-voltage alternating voltage is applied between the electrodes. Is applied.

The dielectric cladding is charged and polarized by the high alternating voltage, and is polarized in opposite phases corresponding to the positive / negative poles, and an alternating high electric field is always generated in both dielectric claddings.

The alternating high electric field applies (charges) the sample gas (heavy oil gas), the electrons in the sample gas molecules are accelerated and excited by the electric field, and their kinetic energy is reduced by the surrounding light molecules ( _{H 2 O, H 2, O} 2, etc. N ₂₎ accelerated, excited, eventually partially ionized sample gas molecules, radicalization ^{(H +, 0H -, N} 3+, 0 2- , etc.) to Performs oxidation and reduction reactions with other molecules.

The sample gas (heavy oil gas) is lightened into low-molecular hydrocarbons by the chemical action of the radical species accompanying the plasma generation constituted by the above mechanism, but at the same time, the oxidation reaction by O ₂ radicals is performed. Other side reactions such as (ketonization, alcoholization, etc.) are also performed.

Therefore, in order to execute and control a more efficient lightening reaction, it is important to suppress the oxidation reaction mainly by O ₂ radicals among the secondary reactions which proceed simultaneously. O ₂ adsorption on active sites, such as zeolite is promising.

Furthermore, the isomerization function of the zeolite active site and the hydrogenation function of the supported catalyst promote lightening, and by utilizing them together, lightening of low molecular weight can be more selectively performed.

In addition, some higher hydrocarbons, ketones, alcohols, carbon, etc. generated in other lightening processes are trapped inside or near the surface of the zeolite by a molecular sieve effect, a selective adsorption effect, and the like. , Emission is suppressed.

However, the increase of these trapped O ₂ , some higher hydrocarbons, ketones, alcohols, carbon, etc., gradually occupies the active sites on the inside and on the surface, selective adsorption sites, etc. It reduces the selective adsorption and molecular sieving functions, and also lowers the original isomerization and hydrogenation functions, which hinders lightening.

Accordingly, hydrogen is introduced into the reaction tank for the purpose of periodically decomposing, reducing, or hydrocarbon-converting the by-products trapped inside and on the surface thereof, and the hydrogen plasma in a hydrogen atmosphere is introduced. Hydrodecomposition of trapped by-products is performed to clean and reactivate the zeolite honeycomb and the supported catalyst.

(DeNOx and deCOx) deNOx
In the present invention, gasified flue gas is introduced into a treatment device (reaction tank) in the same manner as lightening of heavy oil.

The configuration of the reaction tank and the like are the same as those for the lightening of the heavy oil described above.

That is, the reaction vessel is a catalyst-supported zeolite.
It is composed of a honeycomb, a dielectric coating tube and a positive / negative wire electrode pair which are arranged substantially symmetrically in the honeycomb vertically and horizontally, and a high alternating voltage is applied between the electrodes.

The dielectric cladding is charged and polarized by the high alternating voltage, and is polarized in opposite phases corresponding to the positive / negative poles, and an alternating high electric field is always generated in both dielectric claddings.

The alternating high electric field impresses the sample gas (flue gas), the electrons in the sample gas molecules are accelerated and excited by the electric field, and their kinetic energy is reduced by the surrounding light molecules (H ₂ O,
H ₂ , O ₂ , N _2, etc.) are accelerated and excited, and then some of the sample gas molecules are ionized and radicalized (H ⁺ , 0H ⁻ ,
N ³⁺ , O ^2−, etc.) to perform oxidation and reduction reactions with other molecules.

This process is described below for NOx.

2NO + e → N ₂ + O ₂ + e 2e + 2NO ₂ → N ₂ + 2O ₂ + 2e By the above plasma excitation reaction, NOx is reduced to N ₂ , but simultaneously generated O ₂ or O _{2 3} re-oxidizes N ₂ , and under general conditions NO is oxidized to NO ₂ and the reaction is terminated.

As described above, NO ₂ generated by this reaction is a toxic substance that is more toxic than NO, and therefore, it is impossible to end the treatment as it is. Post treatment of NO ₂ is required.

In the present invention, the generated O ₂ , O _3, etc. are selectively and appropriately adsorbed to and removed from the active sites of the zeolite honeycomb by the function of the catalyst supported on the zeolite honeycomb, thereby preventing the re-oxidation of N ₂ .

NOx is reduced to N ₂ and detoxified and released. On the other hand, O ₂ , O _{3 and the} like are reduced in the zeolite due to the reducing property of the supported catalyst and the selective ion adsorption of inorganic ion exchangers such as zeolite. Alternatively, they are fixed to active points near the surface.

However, as the amount of O ₂ adsorbed increases, the active sites are occupied by O ₂ , and the new O ₂ adsorbing ability decreases, and thus the oxidation reaction of N ₂ to NO ₂ occurs. Hydrogen is introduced into the reactor for the purpose of preventing them and periodically decomposing and reducing (converting to H ₂ O) O ₂ , O _3, etc. trapped inside and on the surface, and using hydrogen plasma in a hydrogen atmosphere. Hydrocracking is performed to clean and reactivate the zeolite honeycomb and the supported catalyst.

The same applies to the mechanism of deCOx. First, CO ₂ in COx is reduced to CO, and then methanolization is performed by hydrogenation of CO.

Regarding the conversion of CO ₂ into CO, reduction by plasma treatment is performed, and 2e + 2CO ₂ → 2CO + O ₂ + 2e In the above reaction, CO ₂ is reduced to CO, but O ₂ or O ₃ generated simultaneously Reoxidizes CO to generate CO ₂ .

Therefore, in this case, as in the case of deNOx, the generated O ₂ , O _3, etc. are selectively adsorbed and removed to the active sites of the zeolite honeycomb by the function of the catalyst supported on the zeolite honeycomb supporting the catalyst, and the CO is regenerated. Prevent oxidation.

CO ₂ is reduced to CO and is converted to methanol by a hydrogenation reaction. On the other hand, O ₂ , O _{3 and the} like are reduced in the zeolite due to the reducing property of the supported catalyst and the selective ion adsorption of an inorganic ion exchanger such as zeolite. Alternatively, they are fixed to active points near the surface.

Next, methanol is produced as a hydrogenation reaction of CO with H ₂ .

CO + 2H ₂ → CH ₃ OH (exothermic reaction) From thermodynamic and stoichiometric equilibrium conditions, the reaction is accelerated by cooling and pressurizing.

In the plasma process, hydrogen is easily ionized by applying a high voltage in the above-mentioned mixed gas, thereby promoting a hydrogenation reaction by generation of hydrogen ion radicals. on the other hand,
The O ₂ and O ₃ selective adsorption catalyst, zeolite active site function and the like are also effective for selectively adsorbing these CO and H _2, etc., and promoting the hydrogenation reaction.

Then, when appropriate, hydrogen is introduced into the reaction tank, and hydrogenolysis is performed by hydrogen plasma in a hydrogen atmosphere.
Cleaning and reactivation of zeolite honeycomb and supported catalyst.

(Decomposition of VOC (volatile organic compound))
The function of the plasma in the process of decomposing OC is that electrons in gas molecules are accelerated and excited by an electric field, and the kinetic energy accelerates and excites surrounding light molecules (H ₂ O, H ₂ , O ₂ , N _2, etc.). Eventually, some of the gas molecules are ionized or radicalized (H ⁺ , 0H ⁻ , N ³⁺ , O ^2−, etc.) and decomposed by performing oxidation and reduction reactions with other molecules, especially dehalogenation. Cyclization and decyclization are the objectives.

However, in the case of the plasma alone treatment, it is necessary to consider the generation of halogen gas, NOx, O _{3 and} other intermediate harmful compounds contained in the decomposition product, and the detoxification treatment thereof. The resulting catalyst-supported zeolite honeycomb is for that purpose.

Halogen adsorption to zeolite active sites by transition metal catalysts, prevention of NOx generation by selective adsorption of O ₂ and O ₃ , further conversion of intermediate harmful compounds by functions such as zeolite active site isomerization, hydrogenation and molecular sieve It is assumed that the molecular weight is reduced, the hydrocarbon is converted, and the internal retention is promoted, and selection and combination of a supported catalyst type, a zeolite type, and the like according to the molecular structure of the cracked VOC are effective.

Further, an increase in the amount of adsorbed halogen gas, O ₂ , O ₃ intermediate harmful compounds and the like at active sites inhibits new adsorption and makes the detoxification process incomplete. Therefore, hydrogen is periodically introduced into the reaction tank for the purpose of decomposing, reducing, and further converting hydrocarbons to the by-products trapped inside and on the surface thereof. Hydrocracking of by-products collected by plasma is performed,
Cleaning and reactivation of zeolite honeycomb and supported catalyst.

(Lightening Experiment by Plasma of Heavy Oil) As shown in FIG. 7, a dielectric spherical pellet (BaTiO ₃ : barium titanate, dielectric constant = 4500) was impregnated with heavy oil A to form a cylindrical glass tube (diameter). 30φ), and the upper and lower ends are sealed with a disk-shaped metal (SUS). The dielectric sphere pellets are pressurized and compressed by a disk and come into contact with each other,
The upper and lower pellets are in contact with the disk.

The disk also serves as an electrode, and a high-frequency alternating voltage of 15 kV with a commercial frequency (50 Hz) is applied to both ends.
Also, argon gas is flowed into the reaction tank as a carrier gas, O ₂ and N _{2 are} purged, and the heat generated by plasma generation is also cooled.

The dielectric sphere pellet is charged by the high alternating voltage, polarizes and generates an alternating electric field. In addition, the electric field charges the gas inside the cell, and the cell is filled with argon gas and A heavy oil gas vaporized from the dielectric pellets. These gases are charged by the electric field and accelerated excited electrons, etc. Surrounding light molecules (H ₂ O, H ₂ , O ₂ , N _2, etc.) that have received the kinetic energy of are accelerated and excited, and then some of the gas molecules are ionized and radicalized (H ⁺ , 0H ⁻ ,
N ³⁺ , O ^2−, etc.) to perform oxidation and reduction reactions with other molecules.

FIG. 8 shows the results of collecting and analyzing the generated gas components when an alternating high voltage is applied.

According to the result, the decomposition gas component was C ₂
Examples include H ₄ (ethylene), CH ₄ (methane), C ₃ H ₈ (propane), C ₂ H ₆ (ethane), and others, of which ethylene accounts for about 60 vol% of the generated gas amount.

The increase time of the amount of generated gas was about 2 minutes in the present apparatus, and no generation of decomposition gas was observed when the voltage was applied after that. Therefore, it was impregnated into the dielectric sphere pellet. It is considered that heavy fuel oil A was decomposed in about 2 minutes, and a certain portion was decomposed, and the subsequent decomposition did not proceed any more.

Regarding the rate-determining factors of the reaction, not all the dielectric sphere pellets are in a dielectrically polarized state, but a decomposition gas is generated only from the pellet near the disk electrode, and the other pellets contribute to the reaction. Absent.

With respect to the pellets involved in the decomposition reaction, liquid hydrocarbons (gasoline) having about 6 to 12 carbon atoms adhered to the surfaces thereof, and the dielectric activity was reduced.

[0073] There is a possibility of such a problem, and it is necessary to improve these as a reaction tank.

FIG. 9 shows a detailed analysis result of the generated gas component by GC-MS. According to this result, carbon number 1-5
Production of hydrocarbons, alcohols and ketones to some extent is observed, and production of C ₃ H ₈ (propane) is particularly remarkable.

It is assumed that information on the generation conditions and the control method for each of these generated substances is separately grasped, and that the heavy oil is lightened by plasma to reduce the carbon number of 1 to 1 as a reducing agent in place of ammonia and urea in denitration and the like. It was again confirmed that about 5 hydrocarbons (mixtures) were available.

(Denitration experiment using plasma together with an inorganic ion exchanger not carrying a catalyst) In this experiment, ZSM-5 and NaY zeolite were used as the inorganic ion exchanger. However, a catalyst such as oxidation and reduction into zeolite which is not supported was used. The wire electrodes are bare wires (not covered with a dielectric material) and the ground electrode (●) and high-voltage electrode (○) are almost symmetrical in the left-right and up-down directions (in a staggered pattern) in a honeycomb (5 mm mesh). The sample gas (exhaust gas of diesel engine: NOx concentration = 150) was arranged in the honeycomb.
２００200 ppm) and apply a high voltage pulse to both electrode tubes.

Electrons in the sample gas are excited by the high voltage pulse, giving kinetic energy to nearby molecules, and light-weight molecules (H ₂ O, H ₂ , O ₂ , N _2, etc.) are accelerated and excited. Eventually, some of the gas molecules are ionized and radicalized (H
⁺ , 0H ⁻ , N ³⁺ , 0 ^2−, etc.) to perform oxidation and reduction reactions with other molecules.

Zeolite is an inorganic ion exchanger,
NaY = 1.0, ZSM-5 = 31 in i / Al ratio
Since the number of active points is NaY >> ZSM-5, the insulation resistance is NaY << ZSM
−5, when applying a high voltage without a dielectric coating, dielectric breakdown often occurs with NaY when the voltage rises (up to 15 kV), and sufficient boosting is not performed. Therefore, plasma generation becomes insufficient, and data Acquisition became impossible. Therefore, characteristic evaluation was performed only on ZSM-5 having a small number of active points.

From the above, in order to evaluate the characteristics using NaY, mordenite, ZK-5, etc. having a large number of active points, it is necessary to cover the wire electrodes with a dielectric coating tube and adopt a plasma generation method by applying a high alternating voltage. It turned out to be favorable.

Insertion of bare wire electrode in ZSM-5 without catalyst
FIG. 6 shows the result of decomposition of NOx in the high-pressure pulse voltage applied plasma generation system. According to the experimental results, the removal rate of NOx with respect to the input power (watt) has a monotonically increasing relationship, but the removal rate decreases with the power of 1 / m (m = positive number). Usually, the decomposition reaction at this time mainly involves an oxidation reaction from NO to NO ₂ , but in this experiment, a reduction reaction was performed in a form in which about 30% of NO was changed from NO to N ₂ O.

The cause of the reduction reaction is considered to be the adsorption of O ₂ to the active site of zeolite, and the reduction effect of zeolite is assumed.

Therefore, as a measure to remarkably increase the reduction effect, it is preferable to carry an O ₂ adsorption promoting catalyst on NaY, mordenite, or ZK-5 zeolite having more active sites, and from the viewpoint of plasma generation. It has been found that it is preferable to employ a method of generating a high voltage alternating voltage on the dielectric.

According to FIG. 6, the oxidation and reduction reactions are 1
Achieved at a temperature level of 20 to 150 ° C., and by implementing the above-described measures for increasing the reduction effect, a low-temperature region (120 to 150
C) is realized.

(Heavy oil lightening and flue gas treatment apparatus) A reaction tank is disposed in a pipe through which a gas to be treated flows, and a honeycomb made of an inorganic ion exchanger is installed in the reaction tank. In the heavy oil lightening and flue gas treatment apparatus configured to contact the honeycomb with the honeycomb, a position in which each of the pores of the honeycomb is covered with a dielectric coating tube to form a pair of a positive electrode and a negative electrode. Plasma is generated by applying a high alternating voltage between the line electrodes, and a catalyst is carried on the honeycomb.

(Method of Lightening Heavy Oil) The direct lightening decomposition of heavy oil by plasma and the lightening reaction by the isomerization function at the active site of the inorganic ion exchanger and the hydrogenation function of the supported catalyst are complemented. It is characterized by being combined.

(DeNOx method) NOx by plasma
Direct NO ₂ reduction and O ₂ generated during the N ₂ reduction are adsorbed and removed at the active sites of the inorganic ion exchanger by a supported catalyst, and deNOx is performed while preventing re-oxidation of N _2. And

(DeCOx Method) COx by Plasma
Direct methanol generation with + H ₂ gas and O ₂ generated at the re-generation of methanol are adsorbed and removed at the active sites of the inorganic ion exchanger by the supported catalyst, and deCOx is performed while preventing re-oxidation of CO. Features.

(Method of Decomposing VOC) VO by Plasma
It is characterized in that the direct reaction of C is decomposed by combining the isomerization function at the active site of the inorganic ion exchanger, the dehydrogenation function using a supported catalyst, and the halogen adsorption function.

[0089]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an inorganic ion exchanger and a plasma generator of a heavy oil lightening and flue gas treatment apparatus according to an embodiment of the present invention, and FIG. 2 is a side view thereof. Reference numeral 1 denotes a zeolite honeycomb, which is an inorganic ion exchanger, on which a catalyst 2 for promoting the reaction is selectively supported. Mesh-shaped voids 1 of zeolite honeycomb 1
a includes line electrodes 3a covered with a dielectric coating tube 4;
A pair of positive and negative electrodes 3 b are inserted and arranged symmetrically in a left-right and up-down direction (in a zigzag pattern) and fixed by a dielectric support member 5. Reference numeral 6 denotes an AC power supply,
a, 3b. By applying a high alternating voltage from the power supply 6 between the line electrodes 3a and 3b,
It is configured to generate plasma.

It is desirable that the line electrodes 3a and 3b are arranged in a pair of positive and negative electrodes symmetrically in the left-right and up-down directions (in a staggered pattern). What is necessary is just to arrange symmetrically (houndstooth check). Also,
The dielectric support member 4 needs to be formed into small pieces in consideration of its shape so as not to hinder the introduction of the gas to be treated introduced into the pores 1 a of the zeolite honeycomb 1.

Regarding the zeolite type of the zeolite honeycomb 1, the density of active sites (Si / Al ratio)
A, LiA, sodalite (1.0), ZK-5 (2.
2), Y (2.6), mordenite (5.0), ZSM
-5 (31), ZSM-11 (40) and the like, and various catalysts 2 based on them for replacing with Al ions include catalytically active metal ions, metal oxides and metal sulfides. The desired reaction is achieved by their combination.

Specific examples of the zeolite type of the zeolite honeycomb 1 and the catalyst 2 to be supported are shown below.

Lightening of heavy oil, conversion of aromatic aliphatic hydrocarbon (hydrogenation reaction) a. Y zeolite containing Fe (Group 8-10 transition metal) ion b. (Pt, Ni, Co, Mo, W) sulfide Y zeolite c. Rare earth metal ion-containing Y zeolite (REY zeolite) d. Cu / ZnO, CrO Y zeolite denitration (deNOx), deCOx, methanolization a. Cu ion exchange ZSM-5 (deNOx) b. Ce ion exchange ZSM-5 (deNOx) c. (Fe, Co, Ni, Ru) silicate ZSM-5
(DeCOx) d. (Pt, Pd, Ir) ion exchange ZSM-5 (methanol) dehalogenation a. Cu ion exchange ZSM-5 b. Ni ion exchange ZSM-5 The gas to be treated is the pore 1a of the honeycomb zeolite 1.
And subjected to treatments such as lightening decomposition, reduction, dehalogenation, non-cyclization (aliphatic hydrocarbon conversion), and methanolization by plasma radicals.

In general, a plasma generation method using a direct current or a pulsed high voltage often achieves uniform plasma generation over the entire electrode surface due to a slight difference in physical conditions such as a relative distance between electrodes and a microscopic surface shape. Not done. Therefore, as in the present embodiment, the dielectric coating tube 4
The high voltage alternating voltage is applied to the
It is more desirable to employ a method of generating an alternating high electric field by polarizing the electrode in order to generate a uniform plasma over the entire electrode surface.

In the present invention, which mainly focuses on the combination of the effect of complementarily promoting the reaction with the zeolite honeycomb 1, the zeolite is an inorganic ion exchanger and has ionic conductivity, so that a high voltage cannot be directly applied. From
It is desirable to adopt a dielectric charging method as in this embodiment.

Further, the physical properties of the dielectric coating tube 4 are defined by the relative permittivity, and ε = 40 at the commercial frequency.
It is desirable to be about 00 to 5000, and the power efficiency is reduced when the relative dielectric constant is smaller than about 5000. In addition, in the case of high frequency power, the alternation frequency dependency increases the reactive power, so that the power efficiency also decreases in this case. The material is BaTi
O ₃ , CaTiO ₃ , SrTiO ₃ , quartz glass and the like are desirable.

The arrangement of the line electrodes 3a and 3b is shown in FIG.
As shown in the figure, both of the alternating electrodes are arranged as indicated by (●, ○). Therefore, the line electrodes 3a and 3b are always applied with a voltage of 100% between the two electrodes due to a phase shift of 180 °, and an electric field is generated accordingly.
In addition, by being located on the opposite sides in the left, right, up and down directions, the generation of plasma extends over the entire area of the honeycomb zeolite 1 and a favorable reaction field is formed.

Based on the above configuration, the gas flow rate (N
m3 / hr), taking into account various conditions such as required processing speed, pressure loss, power efficiency, treatment device shape, etc., the honeycomb mesh shape / dimension, honeycomb length / width / length dimension, applied voltage, current, frequency, power supply Design capacity etc.

FIG. 3 shows the catalyst 2 installed in the reaction tank 10.
1 shows an example of the configuration of a zeolite honeycomb 1 that carries. The zeolite honeycomb 1 supporting the catalyst 2 is supplied to the reaction vessel 10
It is fixed and installed inside. The gas to be treated is the reactor 10
The reaction tank 1 is guided by the induction duct 11 attached to the
It is sent into 0. The guide duct 11 is used for cleaning the inside of the reaction tank 10 and reactivating the zeolite honeycomb at the same time as guiding the gas to be treated.
It also functions as a duct for introducing hydrogen gas for generating hydrogen plasma.

The entrance 11a and the exit 1 of the guide duct 11
1b adjusts the flow rate of the inflow and outflow gas amounts by the electromagnetic valves 13 and 14, etc., and also adjusts the switching of the inflow and outflow gas types.

FIG. 4 shows line electrodes 3a and 3b for plasma generation.
And a dielectric coating tube 4, electromagnetic valves 13 and 14, a high-voltage alternating voltage / current generating power supply 6, a gas flow control unit 7, a control unit 8, etc. Generation superposition method-heavy oil lightening / smoke flue speculation system ". This system is
Optimal control is executed by monitoring the gas flow rate, pressure, temperature, voltage, current, inflow gas property, outflow gas property, added gas property, and the like.

[0102]

As described above, according to the present invention,
The flue gas treatment such as the lightening of heavy oil deNOx and deCOxVOC is carried out by plasma + inorganic ion exchanger, and all are treated by the same equipment just by changing the catalyst carried on the inorganic ion exchanger to an appropriate one. it can.

[Brief description of the drawings]

FIG. 1 is a front view of a schematic configuration of a catalyst-carrying zeolite honeycomb and a plasma generating unit according to an embodiment of the present invention.

FIG. 2 is a side view showing a schematic configuration of a catalyst-carrying zeolite honeycomb and a plasma generating unit according to the embodiment of the present invention.

FIG. 3 is a configuration diagram of a reaction tank showing an embodiment of the present invention.

FIG. 4 is a system configuration diagram showing an embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a denitration experiment using a plasma in combination with an inorganic ion exchanger not carrying a catalyst.

FIG. 6 is a diagram showing experimental results of a denitration experiment in which a plasma is used in combination with an inorganic ion exchanger not carrying a catalyst.

FIG. 7 is a schematic configuration diagram of a lightening experiment using heavy oil plasma.

FIG. 8 is a characteristic diagram of generated gas in a lightening experiment using heavy oil plasma.

FIG. 9 is an analysis diagram of a gas generated in a lightening experiment using heavy oil plasma.

FIG. 10 is a diagram for describing a steam reforming method.

FIG. 11 is a characteristic diagram for describing a steam reforming method.

FIG. 12 is a characteristic diagram for describing a steam reforming method.

FIG. 13 is a schematic configuration diagram of a decomposition apparatus using a bed reactor system.

FIG. 14 shows decomposition characteristics of dilute benzene by a bed reactor system.

FIG. 15 shows decomposition characteristics of dilute benzene by a bed reactor system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Zeolite honeycomb 1a ... Void part 2 ... Catalyst 3 ... Distribution line 3a, 3b ... Wire electrode 4 ... Dielectric coating tube 5 ... Dielectric support member 6 ... AC power supply 7 ... Flow control part 8 ... Control part 10 ... Reaction tank 11 ... Induction duct 11a ... Inlet 11b ... Outlet 12,13 ... Electromagnetic valve

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C10G 49/04 B01D 53/36 101Z

Claims (5)

[Claims] 1. A reaction vessel is arranged in a pipe through which a gas to be treated flows, a honeycomb made of an inorganic ion exchanger is installed in the reaction vessel, and the honeycomb is made to contact the gas to be treated with the honeycomb. In the heavy oil lightening and flue gas treatment apparatus, wire electrodes covered with a dielectric coating tube are inserted and arranged in each of the holes of the honeycomb in a positional relationship of a positive electrode and a negative electrode, and A plasma is generated by applying a high alternating voltage to the honeycomb, and a catalyst is supported on the honeycomb. 2. A heavy-duty fuel characterized in that the direct light-weight cracking of heavy oil by plasma and the lightening reaction by the isomerization function at the active site of the inorganic ion exchanger and the hydrogenation function of the supported catalyst are complementarily combined. Lightening method of high quality oil. 3. A direct N ₂ reduction of NOx by the plasma, the N ₂ adsorption of O ₂ generated during the reduction in active sites of inorganic ion exchangers according to the supported catalyst, is removed, to prevent re-oxidation of N2 And performing deNOx by using a smoke exhaust treatment method. Prevention 4. A direct methanol production in COx + H ₂ gas plasma, adsorption of O ₂ occurring again in the methanol generated active sites of the inorganic ion exchanger by supported catalyst, removed, re-oxidation of the CO And performing deCOx. 5. A method for treating flue gas, comprising decomposing a direct reaction of VOC by plasma by a combination of an isomerization function at an active site of an inorganic ion exchanger, a dehydrogenation function using a supported catalyst, and a halogen adsorption function.