KR20060134688A - Two-step catalytic combustion apparatus, combined generation system and method thereof - Google Patents

Abstract

A two-stage catalyst combustion apparatus, a combined generating system and a method thereof are provided to prevent environmental pollution by efficiently burning biomass mixed fuel containing ammonia with two-stage catalytic combustion, and to cut down management expenses by simplifying a biomass gas treatment system. A two-stage catalyst combustion apparatus(10) includes a first catalyst combustion unit(20) performing catalytic reduction combustion in reduction by mixing low calorific value fuel containing ammonia with mixed air at a rich phase of fuel, a second catalyst combustion unit(30) performing high temperature catalytic combustion by mixing a rich reaction product with air at a lean phase of fuel, and a CST(Catalytically Stabilized Thermal) combustion chamber(40) burning unreacted products from the second catalyst combustion unit at high temperature with the catalyst. The first catalyst combustion unit has a first mixing chamber(21) spraying fuel through a fuel spray nozzle(22) and flowing mixed air with a first mixed air control damper(26), a first turning mixer(23) mixing fuel with air at the excess air ratio of 0.85 5 to 1.0, and a reduction combustion catalyzing unit(25) formed of a honeycomb coated by catalyst oxidized with ammonia among fuel to burn mixed gas.

Description

Two-step catalytic combustion apparatus, combined generation system and method

1 is a block diagram of a two-stage catalytic combustion device according to the present invention.

Figure 2 is a schematic diagram of the overall configuration of the combined cycle power system according to the present invention.

3A and 3B are conceptual views illustrating a fuel supply control method for cold start and normal operation of the combined cycle power generation system according to the present invention.

Explanation of symbols on the main parts of the drawings

10: two stage catalytic combustion device 20: primary catalytic combustion unit

21: primary mixing chamber 22: fuel spray nozzle

23: primary swing mixer 25: catalyst for reducing combustion

26: primary mixed air control damping 30: secondary catalytic combustion unit

31: 2nd mixing chamber 32: air injection slot

33: 2nd swing mixer 35: high temperature combustion catalyst

36: secondary mixed air control dam 40: CST combustion chamber

50 gas turbine 51 exhaust gas outlet

52: exhaust gas regulator 60: air compressor

The present invention relates to a two-stage catalytic combustion device, a hybrid power generation system using the same, and a method thereof. In particular, a post-treatment facility is required for a low calorific gas fuel containing nitrogen components such as a mixed fuel gas generated during a biomass gasification process. The present invention relates to a two-stage catalytic combustion device, a combined cycle power generation system, and a method for obtaining clean energy with little pollution of nitrogen oxides or soot gas.

The gas composition of the gaseous fuel obtained during the gasification of biomass varies depending on the raw materials, but the representative gas compositions obtained by the biomass gasification are as follows.

Composition CO (%) CO ₂ (%) H ₂ (%) H ₂ O (%) N ₂ (%) CH ₄ (%) C ₂ H ₄ (%) NH ₃ (ppm) H ₂ S (ppm) content 15 14 12.6 11 44 5 One Less than 3,000 Less than 100

The calorific value of the biomass pyrolysis gas fuel (2,500kcal / m is less than ³⁾ is lower than the heating value (≒ 10,000kcal / m ³⁾ for natural gas, the ammonia in the fuel as the combustion causes the generation of Fuel-NOx as follows: .

2NH ₃ + 7 / 2O ₂ → 2NO ₂ + 3H ₂ O

2NH ₃ + 5 / 2O ₂ → 2NO + 3H ₂ O

2NH ₃ + 2O ₂ → N ₂ O + 3H ₂ O

At this time, NH ₃ can be converted to N ₂ in the presence of excess hydrogen and carbon monoxide through conversion to NO if the reaction time is maintained at about 1000 ° C. for 1 to 4 seconds (Oyvind Skreiberg, Pia Kilpinen, and Peter Glarborg J). Combustion and Flame v136 pp 501-518 2004).

EP 0706816A1 discloses that ammonia in waste gas is suitably oxygen on a mixture of copper (Cu), cobalt (Co), iron (Fe), chromium (Cr), nickel (Ni), manganese (Mn), or an oxide or sulfate catalyst. It was interposed that it can be converted into nitrogen molecules immediately by treating in the range of 200 degreeC-500 degreeC on conditions.

2NH ₃ + 3 / 2O ₂ → N ₂ + 3H ₂ O

In addition, European Patent Publication EP 1000900A1 discloses that NH ₃ in biomass pyrolysis gas is rhodium (Rh), platinum (Pt), palladium (Pd), iridium (Ir), osmium (Os) and rucedium (in the presence of CO and H ₂ ). Ru), silver (Ag), catalysts or mixtures thereof were first disclosed to form NOx and convert back to N ₂ .

2NO + 2CO → 2CO ₂ + N ₂

2NO + 2H ₂ → 2H ₂ O + N ₂

These noble metal catalysts have a higher conversion of CO, H ₂ gas and low molecular hydrocarbons in biomass cracking gas with lower calorific value in excess air and NH ₃ conversion to NO (Henrik MJ Kusar, Anders G. Ersson, Sven G. Jaras J. Applied Catalysis B v45 pp 1-11 2003).

On the other hand, in order to reduce thermal-NOx generation in gas turbine combustion of ammonia-free low calorific fuels, a nitrogen-based combustion method is used to recycle nitrogen or remove nitrogen sources (T. Hasegawa et al.). J. of Eng. For Gas Turbine and Power v125 pp 1-10 2003).

In addition, US Pat. No. 5,199,255 discloses thermal-NOx and Fuel-NOx generated during the gas turbine combustion process by injecting urea into the gas turbine combustor to reduce NOx to N ₂ at high temperatures. Started.

In addition, for the complete combustion of a hydrocarbon fuel having a high reaction start temperature in a gas turbine combustor, US Pat. No. 6,109,018, in order to maintain the start temperature of the catalytic reaction at the first cold start, generates electricity by applying electricity to a metal honeycomb support. We have proposed the use of an EHC (Electrically-Heated Catalytic Converter).

This is applied when the temperature of the air compressor outlet can be maintained above 300 ℃, but it takes a relatively long time to reach normal operation from cold start, and continuous heat supply is needed when the heat loss of the catalyst system is large. .

The present invention has been studied in the background as described above, such as ammonia-containing low-calorie biomass pyrolysis gas, such as ammonia in the fuel, while minimizing the generation of fuel-NOx of low-calorie mixed gas fuel containing fuel, even a small amount of hydrocarbons are completely burned and polluted It is an object of the present invention to provide a catalytic combustion device, a combined cycle power generation system and a method for minimizing material generation.

The present invention for achieving the above object is a first catalytic combustion unit for mixing the low calorific value fuel containing ammonia component and the mixed air to the fuel and a concentrated atmosphere to reduce the catalytic combustion in a reducing atmosphere; A second catalytic combustion unit which mixes the superconcentration product discharged from the first catalytic combustion unit with the mixed air to form a fuel lean atmosphere and reacts with the high temperature combustion catalyst; And a high temperature thermal combustion unit for thermally burning the catalyst support thermal combustion of the unreacted material discharged from the second catalytic combustion unit by the high temperature.

Preferably, the first catalytic combustion unit comprises: a first mixing chamber in which the fuel is sprayed through a fuel spray nozzle and the mixed air flows through a first mixed air control dama; A first mixer having a swirling structure and uniformly mixing the fuel and the mixed air with a fuel and a concentration in an excess air ratio of 0.85-1.0; It may have a honeycomb shape coated with a catalyst capable of oxidation reaction with ammonia contained in the fuel, and may include a catalyst for reducing combustion for surface combustion of the mixed gas.

Preferably, the catalyst for reducing combustion is gold (Au), silver (Ag), copper (Cu), nickel (Ni), iron (Fe), cobalt (Co), titanium (Ti), chromium (Cr) , A manganese (Mn), palladium (Pd), platinum (Pt), rhodium (Rh), ruthedium (Ru) may be sintered at 500 ° C or more by supporting the combined multi-component catalyst on a support.

Preferably, the second catalytic combustion unit comprises: a second mixing chamber through which the super-reaction product flows from the first catalytic combustion unit, and wherein the mixed air is sprayed through an air injection slot via a second mixed air control dama; A second mixer having a swirling structure and uniformly mixing the excess reaction product and the mixed air with an excess of oxygen in an excess air ratio of 1.1-2.0; The lanthanum-hexaaluminate (La-Hexxaaluminate) support may be formed of a Pd single catalyst or a platinum-based binary catalyst, and may include a high-temperature combustion catalyst body for catalytically burning the mixed gas.

In a combined power generation system using two-stage catalytic combustion according to another aspect of the present invention, a first catalytic combustion unit that reacts with a low calorific value fuel containing ammonia and mixed air to form a concentrated atmosphere with fuel is reduced combustion catalytic reaction in a reducing atmosphere. Wow; A second catalytic combustion unit which mixes the superconcentration product discharged from the first catalytic combustion unit with the mixed air to form a fuel lean atmosphere and reacts with the high temperature combustion catalyst; A high temperature thermal combustion unit for thermally burning the catalyst support thermally burning the unreacted material discharged from the second catalytic combustion unit by a high temperature; A gas turbine connected to the thermal combustion unit; An air compressor for mixing a portion of the hot exhaust gas discharged from the gas turbine with air introduced from the outside and providing the mixed air to the first catalytic combustion unit; A pipe connecting the exhaust gas outlet of the gas turbine and the air compressor; It is characterized in that it comprises a exhaust gas regulator installed in the pipe to adjust the amount of exhaust gas flowing into the air compressor.

Preferably, the air compressor adjusts the ratio of the exhaust gas to the incoming air to 1-3 to increase the temperature of the mixed air discharged to the first catalytic combustion unit, and adjusts the excess air ratio of the first catalytic combustion unit. Can be.

Preferably, the first catalytic combustion unit may selectively supply fuel when the temperature of the mixed air introduced from the air compressor is less than 350 ° C.

Preferably, when the total concentration of carbon monoxide and hydrogen is less than 30% in the injected fuel, the first catalytic combustion unit may increase the temperature therein by introducing hydrogen fuel.

According to another aspect of the present invention, there is provided a two-stage catalytic combustion method comprising: a first catalytic combustion step of mixing a low calorific value fuel containing ammonia and mixed air in a concentrated atmosphere with a fuel, thereby reducing and catalytically reacting in a reducing atmosphere; A second catalytic combustion step of mixing the super-reactant produced in the first catalytic combustion step with the mixed air so as to be a fuel lean atmosphere for high temperature combustion catalytic reaction; It characterized in that it comprises a high temperature thermal combustion step of the catalyst support thermal combustion of the unreacted material in the second catalytic combustion step by the high temperature.

Preferably, the first catalytic combustion step may include a first fuel mixing step of uniformly mixing the fuel and the mixed air with a fuel and a concentration in the excess air ratio of 0.85-1.0 range.

Preferably, the second catalytic combustion step may include a second fuel mixing step of uniformly mixing the excess reaction product and the mixed air in an excess of oxygen in an excess air ratio of 1.1-2.0.

In a combined power generation method using two-stage catalytic combustion according to another aspect of the present invention, a first catalytic combustion in which a low calorific value fuel containing ammonia and mixed air are mixed with a fuel in a concentrated atmosphere to reduce catalytic combustion in a reducing atmosphere. Steps; A second catalytic combustion step of mixing the super-reactant produced in the first catalytic combustion step with the mixed air so as to be a fuel lean atmosphere for high temperature combustion catalytic reaction; A high temperature thermal combustion step of catalytically supporting thermal combustion of the unreacted material in the second catalytic combustion step by a high temperature; And a recirculation step of mixing a portion of the high temperature exhaust gas generated in the high temperature thermal combustion step and air introduced from the outside to provide the mixed air of the first catalytic combustion step.

Preferably, the recirculation step adjusts the ratio of the exhaust gas to the incoming air to 1 to 3 to increase the temperature of the mixed air of the first catalytic combustion step, and to increase the excess air ratio of the first catalytic combustion step. I can regulate it.

Preferably, the first catalytic combustion step may selectively supply fuel when the temperature of the mixed air mixed and introduced in the recycle step is less than 350 ° C.

Preferably, the first catalytic combustion step may increase the temperature by introducing hydrogen fuel when the total concentration of carbon monoxide and hydrogen in the injected fuel is less than 30%.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation of the present invention.

1 is a block diagram of a two-stage catalytic combustion device according to the present invention.

The two-stage catalytic combustion device 10 includes a primary catalytic combustion unit 20 and a primary catalyst for reducing combustion catalytic reaction in a reducing atmosphere by mixing a low calorific value fuel containing ammonia and a mixture of air in a concentrated atmosphere. The secondary catalyst combustion unit 30 and the unreacted substance discharged from the secondary catalyst combustion unit 30 which mix the superconcentration reaction product discharged from the combustion unit 20 and the mixed air so as to be a fuel lean atmosphere and react with high temperature combustion. It consists of a Catalytically Stabilized Thermal combustion (CST) combustion chamber 40 that thermally supports the catalyst by high temperature.

The primary catalytic combustion unit 20 has a primary mixing chamber 21 in which fuel is sprayed through the fuel spray nozzle 22 and the mixed air flows through the primary mixed air control dama 26, and a swing structure. And a primary swirl mixer 23 which uniformly mixes fuel and mixed air with fuel and a concentration in the excess air ratio of 0.85-1.0, and a honeycomb shape coated with a catalyst capable of oxidizing with ammonia contained in the fuel. It is composed of a catalyst body for reducing combustion (25) for catalytically burning the mixed gas.

Here, the catalyst for reducing combustion (25) is composed of a ceramic or metal support, more preferably, iron-chromium alloy (FeCr-alloy) metal support, such a support with a high temperature resistant alumina washcoat ( After washcoat, gold (Au), silver (Ag), copper (Cu), nickel (Ni), iron (Fe), cobalt (Co), titanium (Ti), chromium (Cr), manganese (Mn), etc. Non-platinum series, platinum cracking metals such as palladium (Pd), platinum (Pt), rhodium (Rh) and rucedium (Ru) are supported on a binary catalyst carrying at least 1% and sintered at 500 ° C or higher and then reduced again. It is prepared by treatment.

The secondary catalytic combustion unit 30 is a secondary in which the super-reaction product is introduced from the primary catalytic combustion unit 20 and the mixed air is sprayed through the air injection blot 32 via the secondary mixed air control dam 36 A primary mixing chamber (31), a secondary swirl mixer (33) which has a swirling structure and uniformly mixes the supercondensation product and the mixed air with an excess of oxygen in an excess air ratio of 1.1 to 2.0, and lanthanum-hexaaluminate It is composed of a high-temperature combustion catalyst body 35 formed of a Pd single catalyst or a platinum-based binary catalyst on the support and catalytically burning the mixed gas.

The two-stage catalytic combustion device 10 having such a configuration can completely burn even a small amount of hydrocarbons while minimizing Fuel-NOx generation of a low calorific value mixed gas fuel containing ammonia in the fuel, such as biomass pyrolysis gas.

The operation and effects of the two-stage catalytic combustion device 10 will be described in detail. First, in the primary catalytic combustion unit 20, ammonia or hydrogen cyanide is nitrogen molecules or nitrogen oxides in an atmosphere of 500 ° C. or more of fuel and concentration. Is converted into carbon monoxide, and the hydrocarbon is mainly decomposed into carbon monoxide and hydrogen.

More specifically, the low calorific value biomass gasification fuel flowing into the two-stage catalytic combustion device 10 is sprayed through the fuel spray nozzle 22 in the primary mixing chamber 21, and the primary mixed air control damping 26 It is mixed with the hot mixed air introduced through the) is uniformly mixed by the primary rotary mixer (23).

The mixture of fuel and air uniformly mixed in the fuel and concentrated state completes the conversion reaction of ammonia and the decomposition reaction of hydrocarbon in the catalyst body for reduction combustion 25. Here, the fuel and the concentrated atmosphere is adjusted to the excess air ratio (SR) to adjust the excess air ratio to the range 0.85-1.0.

At this time, the inlet temperature in the primary mixing chamber 21 is maintained at 500 ℃ or more, the outlet temperature of the catalyst body for reducing combustion 25 should be maintained at 650 ℃ or more.

In the above-mentioned ammonia conversion reaction, ammonia is first converted into nitrogen oxides and then into nitrogen molecules, and the reaction is sequentially performed. A short time of less than 0.05 seconds in residence time under conditions in which a large amount of carbon monoxide and hydrogen, which are reducing substances, are present The conversion reaction is carried out by the catalyst body 25 for reduction combustion.

In addition, in the hydrocarbon decomposition reaction, partial combustion of carbon monoxide and hydrogen occurs, and a complete combustion reaction occurs simultaneously.

Here, the reducing atmosphere is maintained by carbon monoxide or hydrogen gas, and the hydrocarbon is also decomposed into reducing gas by the catalytic combustion catalyst 25 of 500 ° C or higher.

In the reduction combustion catalytic reaction as described above, the residence time may be maintained at 0.05 seconds or more in a reducing atmosphere of 550 ° C. or higher, but at this time, the linear velocity should be maintained at 20 m / s or more to overheat the reduced combustion catalyst body 25. Or deterioration can be prevented.

Next, in the secondary catalytic combustion unit 30, nitrogen oxides, carbon monoxide, hydrogen, and hydrocarbons remaining on the high temperature combustion catalyst of 500 ° C. or higher of fuel lean are burned.

More specifically, the fuel and the concentrated reaction product after the reduction atmosphere catalytic combustion reaction of the primary catalytic combustion unit 20 include carbon monoxide, hydrogen, hydrocarbons, carbon dioxide, water vapor, and some nitrogen oxides, which are mixed at a high temperature in a secondary mixing chamber. Flows into (31).

Combustion mixed air is sprayed through the air injection blot 32 after the inflow rate is controlled through the secondary mixed air control dam 36, and mixed with the fuel and the concentrated reaction product, uniformly in the secondary swing mixer 33 After mixing, the carbon monoxide, hydrogen, and hydrocarbon are oxidized by the high-temperature combustion catalyst body 35.

In addition, some nitrogen oxides in which the reaction is not completed in the reduced combustion catalyst body 25 are converted into nitrogen molecules on the high temperature combustion catalyst body 35 in the excess oxygen state. At this time, the inlet temperature in the secondary mixing chamber 31 must be maintained at 600 ° C. or higher so that the residual hydrocarbon, carbon monoxide and hydrogen can be reacted with each other.

On the other hand, when the temperature in the high temperature combustion catalyst body 35 is overheated, the remaining unreacted substances are completed in the CST combustion chamber 40.

Here, the fuel lean atmosphere of the secondary mixing chamber 31 can be achieved by promoting the excess air ratio SR in the range of 1.1 to 2.0.

The high temperature combustion catalyst body 35 maintains a residence time of 0.05 seconds or more at 600 ° C or higher when a Pd single catalyst or a platinum-based binary catalyst is used for the lanthanum-hexaaluminate support calcined at 1200 ° C. Should be kept above 20m / s.

In addition, the temperature in the CST combustion chamber 40 should be maintained at 800 ° C. or more, and when the outlet temperature of the high temperature combustion catalyst body 35 is 1000 ° C. or more, the residence time of the high temperature combustion catalyst body 35 is reduced and the CST combustion chamber 40 is used. The high temperature heat in allows the combustion reaction of the remaining unreacted materials to be completed.

On the other hand, in the existing catalytic combustion gas turbine, it is difficult to simultaneously maintain the high temperature of 550 ° C. or higher at the inlet of the catalyst body 25 for reducing combustion of excess fuel, and the excess air ratio of the proper flow rate.

In view of this point, the present invention recycles low-heat biomass gasification fuel in a gas turbine combustor and recycles and mixes it with temperature to recycle hot exhaust gas in order to achieve a reduced combustion catalytic reaction of fuel and enrichment and a high temperature combustion catalytic reaction of fuel lean. A method for simultaneously adjusting the air inflow rate and the excess air ratio has been proposed, and an overview of the system configuration thereof is shown in FIG. 2.

Figure 2 is a schematic diagram of the overall configuration of the combined cycle power system according to the present invention.

The hybrid power generation system comprises a primary catalytic combustion unit 20 and a primary catalytic combustion unit 20 for reducing and catalytically reacting in a reducing atmosphere by mixing a low calorific value fuel containing ammonia and a mixture of air in a concentrated atmosphere. The secondary catalyst combustion unit 30 and the unreacted substance discharged from the secondary catalyst combustion unit 30 are mixed at high temperature to react the high-temperature combustion catalyst reaction by mixing the super-reaction product and the mixed air discharged from the fuel mixture into a fuel lean atmosphere. The primary catalyst is a mixture of the CST combustion chamber 40 to support thermal combustion, the gas turbine 50 connected to the CST combustion chamber 40, a part of the high temperature exhaust gas discharged from the gas turbine 50 and the air introduced from the outside. An air compressor (60) provided to the combustion unit (20) as mixed air, a pipe connecting the exhaust gas outlet (51) of the gas turbine (50) and the air compressor (60), and an air compressor (60) installed in the pipe. To control the amount of flue gas It is composed of flue-gas regulator (52).

Here, the suction side of the air compressor 60 has a structure in which the atmospheric air and the circulating exhaust gas can be introduced at the same time, the ratio of the circulating exhaust gas amount to the atmospheric air amount is adjusted to about 1-3, the temperature of the outlet of the air compressor 60 By maintaining at least 500 ℃, it is possible to achieve a stable catalytic reaction without a separate heat supply.

In general, the temperature from the cogeneration system to the chimney after the waste heat boiler or the regenerative heat exchanger is 120 to 250 ° C. At this time, a branch pipe is installed at the exhaust gas outlet 51 immediately before the exhaust gas is discharged to the chimney for the recycling of the flue gas. The flow rate into the observation is controlled by the exhaust gas regulator 52.

Such exhaust gas regulator 52 should be available below 500 ° C, and serves to supply circulating exhaust gas to the air compressor (60).

On the other hand, the temperature of the compressed air discharged without cooling at the outlet of the air compressor 60 is less than 350 ℃. Oxidation reactions of carbon monoxide and hydrogen, which are the main components of the biomass gasification fuel, are started at less than 200 ° C, ammonia is about 250 ° C or more, and methane is 450 ° C or more, even when the linear velocity of the noble metal catalyst layer is about 10 m / s.

However, when the excess air ratio is about 0.9, as in the primary catalytic combustion unit 20, the reaction start temperature of the reaction is increased by about 100 ° C. or more, and thus the reduced combustion catalytic reaction cannot be smoothly achieved.

In addition, when the temperature of the exhaust gas to be recycled is low or in winter, it takes a long time to reach a steady state for maintaining the temperature of 550 ℃ or more in the catalyst body for reducing combustion (25).

The present invention proposes a method for reaching the steady state as soon as possible when the initial state is difficult to start or late in the start state, such as fuel and fuel having a low calorific value, high catalyst initiation reaction temperature, the system configuration for this The outline of is as shown in Figures 3a to 3b.

3A and 3B are conceptual views illustrating a fuel supply control method for cold start and normal operation of the hybrid power generation system according to the present invention.

When starting the operation of the two-stage catalytic combustion device 10, or in a state where the atmospheric air temperature flowing into the air compressor 60 is low due to the low outside temperature, hydrogen fuel is first injected before fuel inflow, as shown in FIG. In this case, when sprayed in the state of slightly excess air of theoretical air ratio, the temperature is easily increased by exothermic reaction with oxygen.

After that, when the inlet temperature of the reduced combustion catalyst body 25 is increased to 550 ° C. or more, the quasi-steady state can be reached so that the hydrogen fuel is converted into the used fuel as shown in FIG. 3B and gradually adjusted to the excess fuel atmosphere. .

On the other hand, if the sum of carbon monoxide and hydrogen in the used fuel is 30% or more, the carbon monoxide and hydrogen contained in the fuel easily generate exothermic oxidation reactions at low temperatures by the precious metal contained in the catalyst for reducing combustion 25. There is no need to replace it with fuel.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1

In the two-stage catalytic combustion apparatus, the fuel surplus atmosphere was set to 1.0 and the fuel lean atmosphere was set to 2.0 to measure the combustion efficiency and catalytic concentration of Fuel-NOx.

Here, as a comparative example, the same experiment was conducted for flame combustion and single stage catalytic combustion. In particular, compared with flame combustion, the thermal combustion chamber at the lower end was the same, but the burner side at the upper end was measured in a combustion device designed for combustion characteristics.

Table 2 shows the results of the measurement under the heat load conditions in which both the fuel and the excess air ratio supply are similar in the state of considering the heat resistance temperature of the catalyst layer in the catalytic combustion and in the combustion prevention in the flame combustion.

In flame combustion, the air ratio for combustion was supplied at one time by the burner, but in catalytic combustion, the fuel was supplied in two stages: the fuel and the concentration of the first stage, and the two stages of the fuel thinning. The combustion efficiency and the NOx measurement were all measured at the outlet of the combustion apparatus. .

In flame combustion, as the excess air ratio approached the equivalence ratio, combustion efficiency increased and NOx generation increased.

On the other hand, in the catalytic combustion, the combustion efficiency is similar to that of the first stage catalytic combustion, which is supplied in the same ratio in the first stage and the same amount in the second stage, but the combustion efficiency is similar, but the NOx generation is significantly reduced. .

In addition, even when supplying excessive excess air ratio, the catalytic combustion method is more efficient to control fuel-nox than flame combustion.

division Combustion method LNG / air NH ₃ / LNG Excess air cost Combustion efficiency (%) NO _X (ppm) Comparative Example 1 Flame combustion 0.035 0.000 2.72 98.9 4.45 Comparative Example 2 0.035 0.035 1.47 99.4 153.3 Comparative Example 3 1st stage catalyst combustion 0.030 0.038 2.0 99.4 38.7 Experimental Example 1 2-stage catalytic combustion 0.030 0.038 1st stage-1.0, 2nd stage 2.0 99.2 2.89

Example 2

In the two stage catalytic combustion apparatus, combustion efficiency, ammonia conversion rate, and NO generation amount were measured while changing the main active materials of the first stage catalyst and the two stage catalyst.

Ammonia-containing hydrocarbon fuels are decomposed into carbon monoxide and hydrogen in a relatively low state of hydrocarbons in the presence of fuel and concentrated catalysts.

In addition, carbon monoxide, hydrogen, and some methane gas generated during biomass pyrolysis do not have a large conversion reaction of carbon monoxide and hydrogen during catalytic combustion of fuel and concentrates, and some of methane causes pyrolysis reaction, resulting in low overall combustion efficiency. > Can be seen.

In the case of fuel and enriched conditions, the 1% Pd-10% Ni catalyst has low combustion efficiency for the conversion of methane to complete combustion or partial oxidation, but the conversion reaction of ammonia is large. In particular, the conversion reaction from ammonia to NO through N ₂ was better when the space velocity (SV) was not large.

However, most of the NO generated in the first stage is converted to N ₂ in the two-stage catalyst layer of fuel lean, that is, the high-temperature combustion catalyst body 35, but some of the unreacted residual ammonia in the primary catalytic combustion unit 20 Subsequently, NO was generated in the fuel thinning two-stage catalyst layer, that is, the high-temperature combustion catalyst body 35.

Increasing the temperature of the catalyst beds of the first and second stages or increasing the catalyst residence time increases the reaction speed and the reaction time, thereby improving the catalytic combustion efficiency.

Next, in the case of the 1% Pd-1% Rh catalyst, even though the oxygen is slightly lower than the theoretical air, the complete combustion reaction of methane occurs better than the 1% Pd-10% Ni catalyst, and the combustion reaction of carbon monoxide or hydrogen is also good. It was good.

In comparison, ammonia conversion was poor and converted ammonia also contributed to NO production.

Afterwards, the combustion efficiency and the ammonia conversion were greatly improved in the two-stage catalyst layer, that is, the high temperature combustion catalyst body 35, but the unreacted ammonia was oxidized in the first-stage catalyst layer to generate a large amount of NO.

On the other hand, the 2% Rh catalyst in the primary catalytic combustion section 20 of the fuel and enrichment showed the characteristics between 1% Pd-10% Ni catalyst and 1% Pd-1% Rh catalyst.

  division Single stage catalyst outlet (excess air ratio (SR) ≒ 0.95) 2-stage catalyst outlet (excess air ratio (SR) ≒ 2.0)  Catalyst name SV (h ^-1 ) NH ₃ conversion (%)  NO (ppm) Combustion efficiency (%)  Catalyst name SV (h ^-1 ) NH ₃ conversion (%)  NO (ppm) Combustion efficiency (%) Experimental Example 2 1% Pd-10% Ni 86,000 95.6 9.4 34.3   2% Pd 126,000 99.5 11.3 98.1 Experimental Example 3 172,000 89.2 24.4 28.5 212,000 99.3 12.9 98.6 Experimental Example 4 1% Pd-10% Rh 86,000 54.2 49.1 84.4 126,000 99.3 63.5 99.5 Experimental Example 5 172,000 48.6 65.5 78.3 212,000 99.2 89.9 99.4 Experimental Example 6 2% Rh 86,000 76.8 38.3 77.8 126,000 99.6 24.7 99.5 Experimental Example 7 172,000 67.6 40.2 71.6 212,000 99.4 24.5 98.7

* Ammonia concentration in total inlet gas: 800ppm

* First stage catalyst inlet temperature: 610 ° C; 2 stage catalyst inlet temperature: 580 ℃

Example 3

In the two-stage catalytic combustion device, in order to maintain a constant volume velocity for the same catalyst, the nitrogen-air and air ratios are changed so that only the excess air ratio of the first stage catalyst layer is changed, and the excess air ratio of the two-stage catalyst layer is kept constant at 2.0. It measured similarly to 2.

In addition, it is shown in Table 4 when the case of changing the temperature of the first stage catalyst inlet under constant SV and SR conditions.

First, for all experimental catalysts, the ammonia conversion, combustion efficiency and NO production concentration in the primary catalyst bed were very low at SR <0.85, but at SR 반응 0.9, the catalytic reaction started to be activated and the combustion reaction was completed in the two stage catalyst bed. Showed a tendency.

When 1% Pd-1% Rh catalyst was used in the first stage catalyst, NO production was increased in the first stage catalyst layer as the excess air ratio was increased, but the concentration of NO was converted to N ₂ in the second stage catalyst layer. Seemed.

However, in the case of 1% Pd-10% Ni catalyst or 2% Rh catalyst, the conversion reaction of ammonia was higher than that of 1% Pd-1% Rh catalyst at the excess air ratio 0.9-0.95, and the NO production was also 1% Pd in the two-stage catalyst layer. Much lower than the -1% Rh catalyst, the former showed good results with the single stage catalyst.

In the case of 1% Pd-1% Rh catalyst, the reaction was not smooth when the inlet temperature of the first stage catalyst was less than 600 ° C. in SR ≒ 0.95, and the reaction was smoothed above 650 ° C. In particular, as the NO production was greatly increased in the first stage catalyst bed, the conversion reaction and combustion efficiency of ammonia were greatly increased, the complete combustion reaction occurred at the outlet of the second stage catalyst, and NO production was also greatly decreased.

However, above 650 ° C., some flame combustion occurs in the first stage catalyst layer, and the linear velocity needs to be increased. In order to increase the linear velocity and space velocity, increase the inlet temperature, and increase the excess air ratio, it can be seen that the exhaust gas recirculation method is the most ideal.

  division 1st stage catalyst side 2 stage catalyst side  Change condition SV (h ^-1 ) NH ₃ conversion (%)  NO (ppm) Combustion efficiency (%)  Change condition SV (h ^-1 ) NH ₃ conversion (%)  NO (ppm) Combustion efficiency (%) Experimental Example 8 SR ≒ 0.9 147,000 (entrance 610 ℃) 38.4 7.0 34.3 SR ≒ 2.0 126,000 Entrance572 ~ 614 ℃ 98.8 81.3 99.1 Experimental Example 9 SR ≒ 1.0 56.6 54.7 80.9 99.7 56.7 99.4 Experimental Example 10 SR ≒ 1.1 83.8 59.2 85.4 99.6 28.9 99.4 Experimental Example 11 560 ℃ 186,000 (SR ≒ 0.95) 19.2 2.7 3.4 SR ≒ 2.0 226,000 Inlet 612 ~ 686 ℃ 97.4 75.7 97.4 Experimental Example 12 610 ℃ 44.4 41.2 74.0 98.2 52.5 98.6 Experimental Example 13 650 ℃ 68.9 107.3 89.5 99.6 9.1 99.8

* Ammonia concentration in total inlet gas: 800ppm

* 1st stage catalyst 1% Pd-1% Rh (catalyst) / 4% La-Al ₂ O ₃ (wash coating agent)

2 stage catalyst 2% Pd (catalyst) / 4% La-Al ₂ O ₃ (wash coating agent)

As described above, the two-stage catalytic combustion device, the combined cycle system, and the method according to the present invention efficiently burn biomass mixed fuel containing ammonia through two-stage catalytic combustion, so that there is no pollution without post-treatment. It is possible to obtain clean energy, and to further simplify and efficiency of biomass gas-fueled treatment facilities, and to significantly reduce facility and operating costs.

In addition, the present invention partially recycles the exhaust gas discharged to the atmosphere by a low-calorie biomass or coal pyrolysis gas containing ammonia and reuses it as combustion air, thereby starting high catalytic reaction of low-calorie fuel gas without additional heat source supply. Temperature can be provided.

In addition, the present invention uses a catalyst at a relatively low temperature and converts ammonia component to nitrogen-molecule through a fuel-NOx formation reaction at a high temperature without a catalyst, and completely combusts while minimizing the generation of NO by controlling the oxidizing and reducing atmospheres well. Clean combustion technology can be achieved.

In addition, the present invention, in the biomass or waste incineration process, does not require a post-treatment facility for pollutants before the release of the atmosphere, it is possible to achieve the simplicity and miniaturization than conventional combustion systems.

Claims (15)

A first catalytic combustion unit for mixing the low calorific value fuel containing the ammonia component and the mixed air so as to form a fuel and a concentrated atmosphere, and reacting the reduction combustion catalyst in a reducing atmosphere; A second catalytic combustion unit which mixes the superconcentration product discharged from the first catalytic combustion unit with the mixed air to form a fuel lean atmosphere and reacts with the high temperature combustion catalyst; And a high temperature thermal combustion unit configured to thermally burn the catalyst support thermal combustion of the unreacted material discharged from the second catalytic combustion unit by a high temperature. The method of claim 1, The first catalytic combustion unit, A first mixing chamber in which the fuel is sprayed through a fuel spray nozzle and the mixed air flows through a first mixed air control dama; A first mixer having a swirling structure and uniformly mixing the fuel and the mixed air with a fuel and a concentration in an excess air ratio of 0.85-1.0; A two-stage catalytic combustion device having a honeycomb shape coated with a catalyst capable of oxidizing reaction with ammonia contained in the fuel, and including a catalyst for reducing combustion of the mixed gas on the surface of the catalyst. . The method of claim 2, The catalyst for reducing combustion is gold (Au), silver (Ag), copper (Cu), nickel (Ni), iron (Fe), cobalt (Co), titanium (Ti), chromium (Cr), manganese ( Two-stage catalytic combustion device characterized in that the plural catalysts selected from Mn), palladium (Pd), platinum (Pt), rhodium (Rh) and rucedium (Ru) are supported on a support and sintered at 500 ° C. or more. . The method of claim 1, The second catalytic combustion unit, A second mixing chamber into which the concentrated reaction product flows from the first catalytic combustion unit, and the mixed air is sprayed through an air injection slot via a second mixed air control dama; A second mixer having a swirling structure and uniformly mixing the excess reaction product and the mixed air with an excess of oxygen in an excess air ratio of 1.1-2.0; Two-stage catalytic combustion, characterized in that the lanthanum-hexaaluminate (La-Hexxaaluminate) support is formed of a Pd single catalyst or a platinum-based binary catalyst and comprises a high-temperature combustion catalyst body for catalytically burning the mixed gas Device. A first catalytic combustion unit for mixing the low calorific value fuel containing the ammonia component and the mixed air so as to form a fuel and a concentrated atmosphere, and reacting the reduction combustion catalyst in a reducing atmosphere; A second catalytic combustion unit which mixes the superconcentration product discharged from the first catalytic combustion unit with the mixed air to form a fuel lean atmosphere and reacts with the high temperature combustion catalyst; A high temperature thermal combustion unit for thermally burning the catalyst support thermally burning the unreacted material discharged from the second catalytic combustion unit by a high temperature; A gas turbine connected to the thermal combustion unit; An air compressor for mixing a portion of the hot exhaust gas discharged from the gas turbine with air introduced from the outside and providing the mixed air to the first catalytic combustion unit; A pipe connecting the exhaust gas outlet of the gas turbine and the air compressor; It is installed in the pipe complex power generation system using a two-stage catalytic combustion comprising an exhaust gas regulator for controlling the amount of exhaust gas flowing into the air compressor. The method of claim 5, The air compressor adjusts the ratio of the exhaust gas to the introduced air to 1-3 to increase the temperature of the mixed air discharged to the first catalytic combustion unit, and adjusts the excess air ratio of the first catalytic combustion unit. Combined power generation system using two-stage catalytic combustion. The method of claim 5, And the first catalytic combustion unit selectively supplies fuel when the temperature of the mixed air introduced from the air compressor is less than 350 ° C. 2. The method of claim 7, wherein The first catalytic combustion unit is a combined power generation system using a two-stage catalytic combustion, characterized in that when the total concentration of carbon monoxide and hydrogen in the injected fuel is less than 30% to increase the temperature inside the hydrogen fuel. A first catalytic combustion step of mixing the low calorific value fuel containing ammonia and the mixed air in a concentrated atmosphere with the fuel, thereby reducing and catalytically reacting in a reducing atmosphere; A second catalytic combustion step of mixing the super-reactant produced in the first catalytic combustion step with the mixed air so as to be a fuel lean atmosphere for high temperature combustion catalytic reaction; And a high temperature thermal combustion step of catalytically supporting the thermal combustion of the unreacted material in the second catalytic combustion step by the high temperature. The method of claim 9, The first catalytic combustion step, And a first fuel mixing step of uniformly mixing the fuel and the mixed air with a fuel and a concentration in an excess air ratio of 0.85-1.0. The method of claim 9, The second catalytic combustion step, And a second fuel mixing step of uniformly mixing the excess reaction product and the mixed air in an excess of oxygen in an excess air ratio of 1.1 to 2.0. A first catalytic combustion step of mixing the low calorific value fuel containing ammonia and the mixed air in a concentrated atmosphere with the fuel, thereby reducing and catalytically reacting in a reducing atmosphere; A second catalytic combustion step of mixing the super-reactant produced in the first catalytic combustion step with the mixed air so as to be a fuel lean atmosphere for high temperature combustion catalytic reaction; A high temperature thermal combustion step of catalytically supporting thermal combustion of the unreacted material in the second catalytic combustion step by a high temperature; And a recirculation step of mixing a portion of the high temperature flue gas generated in the high temperature thermal combustion step and air introduced from the outside to provide the mixed air of the first catalytic combustion step. Combined power generation method used. The method of claim 12, The recycling step is to adjust the ratio of the exhaust gas to the incoming air to 1-3 to increase the temperature of the mixed air of the first catalytic combustion step, to adjust the excess air ratio of the first catalytic combustion step Combined power generation method using two-stage catalytic combustion characterized in that. The method of claim 12, The first catalytic combustion step is a two-stage catalytic combustion method characterized in that for selectively supplying fuel when the temperature of the mixed air mixed and introduced in the recirculation step is less than 350 ℃. The method of claim 14, The first catalytic combustion step is a combined power generation method using a two-stage catalytic combustion, characterized in that the temperature is increased by adding hydrogen fuel when the total concentration of carbon monoxide and hydrogen in the injected fuel is less than 30%.

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