Green ammonia combustion system and green ammonia combustion method

Abstract

The invention provides a green ammonia combustion system and a green ammonia combustion method, and belongs to the field of ammonia combustion, the green ammonia combustion system comprises an ammonia delivery pipe, an air delivery pipe, a mixing chamber, a combustion chamber, an ammonia decomposer, a first tail gas delivery pipe and a first tail gas processor; wherein an inner cavity of the mixing chamber is communicated with an outlet of the ammonia conveying pipe, an outlet of the air conveying pipe and an outlet of the ammonia decomposer, and an inlet of the ammonia decomposer is further communicated with an outlet of the ammonia conveying pipe; the combustion chamber communicates with the first tail gas processor through a first tail gas conveying pipe. According to the green ammonia combustion system and the green ammonia combustion method obtained through the design, ammonia gas, air and hydrogen generated through decomposition enter the mixing chamber to be evenly mixed, combustion reaction is conducted in the combustion chamber, and therefore power is provided for an engine. Tail gas generated by the combustion chamber is treated through the tail gas treater, and therefore emission of pollution gas is reduced.

Description

Technical Field

[0001] The present invention relates to the field of ammonia combustion, and in particular to a green ammonia combustion system and a green ammonia combustion method. Background Art

[0002] At present, ammonia combustion or ammonia co-combustion has wide application potential in combustion equipment such as internal combustion engines, gas turbines, gas and coal-fired boilers, and porous media combustion chambers, which can effectively promote the achievement of carbon reduction targets in related industries. But at the same time, there are problems with low ammonia combustion efficiency and excessive NOx and N2O content in tail gas. (NOx, common ones include nitrous oxide (N2O), nitric oxide (NO), nitrogen dioxide (NO2), nitrogen trioxide (N2O3), nitrogen tetroxide (N2O4) and nitrogen pentoxide (N2O5)) Among them, nitrogen oxides, mainly NO and NO2, harm the environment and human health, cause acid rain and soil acidification, and also consume ozone to indirectly enhance the greenhouse effect. N2O is a strong greenhouse gas with a warming ability about 265-300 times stronger than carbon dioxide. It has a long life in the atmosphere and can continue to affect the climate. In recent years, automotive and marine engines have undergone transformation, and it is a general trend to vigorously carry out independent research and development of ammonia fuel engines. Therefore, it is essential to have a supporting efficient ammonia combustion method and a complete exhaust gas treatment system. Summary of the invention

[0003] The object of the present invention is to provide a green ammonia combustion system, which can effectively burn and utilize ammonia and treat tail gas.

[0004] Another object of the present invention is to provide a green ammonia combustion method, which adopts the above-mentioned green ammonia combustion system.

[0005] The implementation of the present invention is as follows:

[0006] A green ammonia combustion system comprises an ammonia delivery pipe, an air delivery pipe, a mixing chamber, a combustion chamber, an ammonia decomposer, a first tail gas delivery pipe and a first tail gas processor;

[0007] The outlet of the ammonia delivery pipe is connected to the inner cavity of the mixing chamber; the outlet of the air delivery pipe is connected to the inner cavity of the mixing chamber; the outlet of the ammonia delivery pipe is also connected to the inlet of the ammonia decomposer; the outlet of the ammonia decomposer is connected to the inlet of the mixing chamber;

[0008] The combustion chamber is in communication with the first exhaust gas processor via the first exhaust gas delivery pipe.

[0009] Furthermore, it also includes a second exhaust gas delivery pipe and a second exhaust gas processor, and the first exhaust gas processor is connected to the second exhaust gas processor through the second exhaust gas delivery pipe.

[0010] Furthermore, it also includes a first exhaust gas detector and a second exhaust gas detector, the first exhaust gas detector is connected to the first exhaust gas delivery pipe, and the second exhaust gas detector is connected to the second exhaust gas delivery pipe.

[0011] Furthermore, a second catalyst is provided in the second exhaust gas processor, and the second catalyst includes a carrier, a co-catalyst on the carrier and an active component; in the second catalyst, the content of the carrier is 50-99%, the co-catalyst is 0.1%-1%, and the active component is 0.1%-1%; the sum of the total mass percentages is 100%; the second catalyst is used for removing N2O in the second exhaust gas processor B.

[0012] Furthermore, in the second catalyst, the carrier is a honeycomb filler, the active component is a combination of one or more oxides of Mo, Ni or Co, and the co-catalyst is a combination of one or more oxides of K, Sm, Ba or La; the active component and the co-catalyst are dissolved in a solution of oxalic acid, acetic acid or nitric acid, and then the carrier is impregnated for 2-4 hours, filtered and dried, and then calcined at 400-600°C for 5-12 hours, and cooled to obtain the second catalyst.

[0013] Furthermore, a first catalyst is arranged in the first exhaust gas processor, and the first catalyst includes a carrier, a co-catalyst on the carrier and an active component; the content of the carrier is 50-95%, the co-catalyst is 0.1%-1%, and the active component is 1%-10%; the sum of the total mass percentages is 100%; the first catalyst is used to remove NOx in the first exhaust gas processor.

[0014] Furthermore, the carrier of the first catalyst is a composition containing one or more oxides of aluminum, calcium, zirconium, titanium or barium, the active component is a composition containing one or more of MoO3, NiO, V2O5, Rh, Pt or Pd, and the co-catalyst is a composition containing one or more of K, Ca, Ba, La and Ce; the active component and the co-catalyst are dissolved in a solution of oxalic acid, acetic acid or ethanol, and then the powder of the carrier is added thereto and stirred thoroughly, dried at 50-110°C, calcined at 400-600°C for 1-3h, cooled and ground to obtain the first catalyst.

[0015] A green ammonia combustion method adopts the green ammonia combustion system, ammonia, air and hydrogen generated by decomposition enter a mixing chamber and are evenly mixed, a combustion reaction is carried out in the combustion chamber, and the generated gas enters two exhaust gas processors in sequence through corresponding delivery pipes; under the action of a first exhaust gas detector, the ammonia flow entering the first exhaust gas processor is regulated in real time; NOx, O2 and NH3 in the exhaust gas are converted into N2 and H2O by a first catalyst at a temperature of 200-400°C, and enter a second exhaust gas processor together with the remaining N2O-containing exhaust gas; in the second exhaust gas processor, N2O in the exhaust gas is decomposed into N2 and O2 by a second catalyst at a temperature of 200-400°C.

[0016] The beneficial effects of the present invention are:

[0017] In the green ammonia combustion system and green ammonia combustion method obtained by the above design, ammonia gas, air, and hydrogen generated by partial decomposition of ammonia enter the mixing chamber and are evenly mixed, and a combustion reaction is carried out in the combustion chamber, thereby providing power for the engine. The exhaust gas generated in the combustion chamber is processed by the exhaust gas processor, and the processing effect is monitored in real time by the exhaust gas detector, thereby reducing the emission of pollutant gases. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a schematic diagram of a green ammonia combustion system provided in an embodiment of the present invention.

[0020] Icons: 1- ammonia delivery pipe; 2- ammonia decomposer; 3- mixing chamber; 4- air delivery pipe; 5- combustion chamber; 6- first exhaust gas detector; 7- first exhaust gas processor; 8- second exhaust gas detector; 9- second exhaust gas processor; 10- first exhaust gas delivery pipe; 11- second exhaust gas delivery pipe; 12- first catalyst; 13- second catalyst. DETAILED DESCRIPTION

[0021] like Figure 1The present embodiment provides a green ammonia combustion system, comprising an ammonia delivery pipe 1, an air delivery pipe 4, a mixing chamber 3, a combustion chamber 5, an ammonia decomposer 2, a first tail gas delivery pipe 10 and a first tail gas processor 7; wherein the inner cavity of the mixing chamber 3 is connected to the outlet of the ammonia delivery pipe 1, the outlet of the air delivery pipe 4 and the outlet of the ammonia decomposer 2, and the inlet of the ammonia decomposer 2 is also connected to the outlet of the ammonia delivery pipe 1; the combustion chamber is connected to the first tail gas processor 7 through the first tail gas delivery pipe 10.

[0022] Furthermore, the green ammonia combustion system further includes a second tail gas delivery pipe 11 and a second tail gas processor 9 , and the first tail gas processor 7 is connected to the second tail gas processor 9 via the second tail gas delivery pipe 11 .

[0023] In addition, the first exhaust gas delivery pipe 10 is also connected to a first exhaust gas detector 6, and the second delivery pipe is also connected to a second exhaust gas detector 8. The first exhaust gas detector 6 can detect the content of nitrogen oxides in the gas in the first exhaust gas delivery pipe 10 in real time, and the second exhaust gas detector 8 can detect the content of nitrogen oxides in the gas in the second exhaust gas delivery pipe 11 in real time.

[0024] Furthermore, a first catalyst 12 is arranged in the first exhaust gas processor 7, and the first catalyst 12 includes a carrier, a co-catalyst on the carrier and an active component; the content of the carrier is 50-95%, the co-catalyst is 0.1%-1%, and the active component is 1%-10%; the sum of the total mass percentages is 100%; the first catalyst 12 is used to remove NOx in the first exhaust gas processor 7.

[0025] The carrier of the first catalyst 12 is a composition containing one or more oxides of aluminum, calcium, zirconium, titanium or barium, the active component is a composition containing one or more of MoO3, NiO, V2O5, Rh, Pt or Pd, and the co-catalyst is a composition containing one or more of K, Ca, Ba, La and Ce. The active component and the co-catalyst are dissolved in a solution of oxalic acid, acetic acid or ethanol, and then the powder of the carrier is added thereto and stirred thoroughly, dried at 50-110°C, calcined at 400-600°C for 1-3h, cooled and ground to obtain the first catalyst 12.

[0026] A second catalyst 13 is provided in the second exhaust gas processor 9, and the second catalyst 13 includes a carrier, a co-catalyst on the carrier and an active component; in the second catalyst 13, the content of the carrier is 50-99%, the co-catalyst is 0.1%-1%, and the active component is 0.1%-1%; the sum of the total mass percentages is 100%; the second catalyst 13 is used for removing N2O in the second exhaust gas processor 9B.

[0027] In the second catalyst 13, the carrier is a honeycomb filler, the active component is a combination of one or more oxides of Mo, Ni or Co, and the co-catalyst is a combination of one or more oxides of K, Sm, Ba or La; the active component and the co-catalyst are dissolved in a solution of oxalic acid, acetic acid or nitric acid, and then the carrier is impregnated for 2-4 hours, filtered and dried, and then calcined at 400-600°C for 5-12 hours, and cooled to obtain the second catalyst 13.

[0028] The green ammonia combustion method includes the following steps: ammonia, air, and hydrogen generated by decomposition enter the mixing chamber 3 and mix evenly, and a combustion reaction is carried out in the combustion chamber 5, and the generated gas enters the two exhaust gas processors in turn through the corresponding delivery pipes. Under the action of the first exhaust gas detector 6, the ammonia flow entering the first exhaust gas processor 7 is regulated in real time; NOx, O2, and NH3 in the exhaust gas are converted into N2 and H2O by the first catalyst 12 at a temperature of 200-400°C, and enter the second exhaust gas processor 9 together with the remaining N2O-containing exhaust gas; in the second exhaust gas processor 9, N2O in the exhaust gas is decomposed into N2 and O2 by the catalyst at 200-400°C. In the exhaust gas detection processor B, N2O in the exhaust gas is decomposed into N2 and O2 by the catalyst at 200-400°C, which greatly improves the combustion efficiency of green ammonia and reduces the exhaust gas content.

[0029] The green ammonia combustion system provided by the patent of this invention can detect the exhaust gas composition in real time and accurately replenish ammonia based on the residual ammonia amount. The catalyst is inexpensive, has a long service life and high catalytic efficiency at medium temperatures. It can convert NOx and N2O into N2, O2 and H2O, so that ammonia fuel engines can greatly improve combustion efficiency at a lower cost, reduce the content of pollutant gases in the exhaust gas, make the exhaust gas meet relevant standards, and reduce environmental pollution.

[0030] Specifically, in the first exemplary embodiment, the ammonia delivery pipe 1 provides ammonia to the ammonia decomposer 2, the first exhaust gas processor 7 and the mixing chamber 3. The hydrogen generated by the ammonia decomposer 2 and the air introduced by the air delivery pipe 4 enter the mixing chamber 3, are mixed with the ammonia and preheated to 350°C, and enter the combustion chamber 5 to burn at 350-500°C to provide power. The generated exhaust gas enters the first exhaust gas detector 6 and the first exhaust gas processor 7 in sequence through the first exhaust gas delivery pipe 10. Under the detection of the first exhaust gas detector 6, the ammonia flow rate entering the first exhaust gas processor 7 is accurately controlled. The exhaust gas is catalyzed by the first catalyst 12 at 300-460°C (or 260-460°C, or 200-400°C) to react and convert NOx into N2 and H2O. The remaining exhaust gas continues to enter the exhaust gas detector 8 and the exhaust gas processor 9 in sequence along the exhaust gas pipeline 11. Under the detection of the second exhaust gas detector 8, the exhaust gas is catalyzed by the second catalyst 13 at 260-400°C (or 200-450°C, or 300-400°C) in the second exhaust gas processor 9 to react, converting N2O into N2 and O2, and is discharged after passing the detection.

[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A green ammonia combustion system, characterized in that: It includes an ammonia delivery pipe, an air delivery pipe, a mixing chamber, a combustion chamber, an ammonia decomposer, a first tail gas delivery pipe and a first tail gas processor; The outlet of the ammonia delivery pipe is connected to the inner cavity of the mixing chamber; the outlet of the air delivery pipe is connected to the inner cavity of the mixing chamber; the outlet of the ammonia delivery pipe is also connected to the inlet of the ammonia decomposer; the outlet of the ammonia decomposer is connected to the inlet of the mixing chamber; The combustion chamber is in communication with the first exhaust gas processor via the first exhaust gas delivery pipe.

2. The green ammonia combustion system according to claim 1, characterized in that: It also includes a second exhaust gas delivery pipe and a second exhaust gas processor, and the first exhaust gas processor is connected to the second exhaust gas processor through the second exhaust gas delivery pipe.

3. The green ammonia combustion system according to claim 2, characterized in that: It also includes a first exhaust gas detector and a second exhaust gas detector, the first exhaust gas detector is connected to the first exhaust gas delivery pipe, and the second exhaust gas detector is connected to the second exhaust gas delivery pipe.

4. The green ammonia combustion system according to claim 2, characterized in that: The second exhaust gas processor is provided with a second catalyst, which includes a carrier, a co-catalyst on the carrier and an active component; in the second catalyst, the content of the carrier is 50-99%, the co-catalyst is 0.1%-1%, and the active component is 0.1%-1%; the sum of the total mass percentages is 100%; the second catalyst is used for removing N2O in the second exhaust gas processor B.

5. The green ammonia combustion system according to claim 4, characterized in that: In the second catalyst, the carrier is a honeycomb filler, the active component is a combination of one or more oxides of Mo, Ni or Co, and the co-catalyst is a combination of one or more oxides of K, Sm, Ba or La; the active component and the co-catalyst are dissolved in a solution of oxalic acid, acetic acid or nitric acid, and then the carrier is impregnated for 2-4 hours, filtered and dried, and then calcined at 400-600°C for 5-12 hours, and cooled to obtain the second catalyst.

6. The green ammonia combustion system according to any one of claims 1 to 5, characterized in that: A first catalyst is arranged in the first exhaust gas processor, and the first catalyst includes a carrier, a co-catalyst on the carrier and an active component; the content of the carrier is 50-95%, the co-catalyst is 0.1%-1%, and the active component is 1%-10%; the sum of the total mass percentages is 100%; the first catalyst is used to remove NOx in the first exhaust gas processor.

7. The green ammonia combustion system according to claim 6, characterized in that: The carrier of the first catalyst is a composition containing one or more oxides of aluminum, calcium, zirconium, titanium or barium, the active component is a composition containing one or more of MoO3, NiO, V2O5, Rh, Pt or Pd, and the promoter is a composition containing one or more of K, Ca, Ba, La and Ce; The active component and the promoter are dissolved in a solution of oxalic acid, acetic acid or ethanol, and then the powder of the carrier is added thereto and stirred thoroughly. After drying at 50-110° C., the mixture is calcined at 400-600° C. for 1-3 hours, cooled and ground to obtain the first catalyst.

8. A green ammonia combustion method, the green ammonia combustion method adopting the green ammonia combustion system according to any one of claims 1 to 7, characterized in that: Ammonia, air and hydrogen generated by partial decomposition of ammonia enter the mixing chamber for uniform mixing, and combustion reaction is carried out in the combustion chamber. The generated gas enters the two exhaust gas processors in turn through the corresponding delivery pipes; Under the action of the first tail gas detector, the flow rate of ammonia entering the first tail gas processor is regulated in real time; NOx, O2 and NH3 in the exhaust gas are converted into N2 and H2O by the first catalyst at a temperature of 200-400°C, and enter the second exhaust gas processor together with the remaining N2O-containing exhaust gas; in the second exhaust gas processor, N2O in the exhaust gas is decomposed into N2 and O2 by the catalyst at a temperature of 200-400°C.

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