JP3997349B2 - Odor gas combustion deodorizing method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and apparatus for combustion deodorization of odor gas mainly composed of ammonia generated from an animal manure fermentation apparatus or the like.
[0002]
[Prior art]
In small-scale poultry farms, poultry manure discharged in a large amount per day is put into a closed-type fermenter and fermented over about 3 days to produce fertilizer. At this time, up to about 2000 ppm of ammonia and The odor consisting of several ppm of methyl mercaptan, methyl sulfide, and methyl disulfide will be released, but the odor concentration is not constant, and the generation of malodorous peaks after 15-20 hours after pouring chicken manure into the fermentation apparatus. In particular, it has caused troubles with the surrounding residents to release a high concentration of ammonia odor to the atmosphere as it is.
[0003]
In order to avoid such trouble, a deodorizing apparatus as shown in FIG. 5 has been proposed in order to release odorous gas into the deodorizing apparatus and deodorizing it before releasing it into the atmosphere. This deodorizing apparatus ferments livestock droppings 1 such as chicken droppings into fertilizer 2 and in the closed fermentation apparatus 3 in which the odorous gas 8 is taken out by the odorous gas line 6, the odorous gas line 6 is treated with a water treatment device. 7, an odor gas 8 mainly composed of ammonia (NH ₃ ) generated in the closed fermentation apparatus 3 is introduced into the water treatment apparatus 7 to perform ammonia removal treatment by water treatment, and An incinerator 10 is connected to the water treatment device 7 through a gas line 9, and the odor gas 8 a after removing ammonia from the odor gas 8 by the water treatment device 7 is introduced into the incinerator 10, and the kerosene It is configured such that it is deodorized by being burned together with such fuel 11 and discharged from the exhaust line 12 as exhaust gas having no odor from the incinerator 10. In addition, the said closed-type fermentation apparatus 3 is, for example, the fermenter 4 which accommodates the livestock droppings 1, the stirrer 5 which stirs the livestock droppings 1 in this fermenter 4, fermentation, in order to ferment the livestock droppings 1 continuously aerobically A heater (not shown) for heating the inside of the tank 4, a blower blower (not shown) for taking air into the fermenter 4, and the like are forced into the fermenter 4 by the operation of the blower blower. Is introduced to promote the fermentation of livestock droppings 1.
[0004]
[Problems to be solved by the invention]
However, in the case of the above-mentioned conventional deodorizing apparatus, a large space is required for installing the water treatment device 7 and further treatment of the treated water (chemical solution) is necessary, so that it is not suitable for use by general farmers. Also, there is a problem that the fuel cost in the incinerator 10 is high and the economic burden is large.
[0005]
Therefore, the present invention is intended to make it possible to easily deodorize odor gas containing ammonia, and to make it possible to clean the exhaust gas after deodorization.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present invention deodorizes odor gas by introducing an odor gas containing high-concentration ammonia into a combustion engine and combusting it with fuel, and at the same time, in the exhaust gas discharged from the combustion engine. oxygen concentration by adjusting the amount of odor gases to be introduced into the combustion engine to be retained within the required range, so as to reduce the nitrogen oxides concentration in the exhaust gas, also the oxygen concentration in the exhaust gas 11 It is set as the combustion deodorizing method and apparatus of the odor gas made to be in the range of -15%.
[0007]
When odor gas containing high-concentration ammonia is burned together with fuel in a combustion engine, odor components such as ammonia can be thermally decomposed. At this time, power generation by the combustion engine can reduce costs. it can. Further, if the oxygen concentration in the exhaust gas is maintained within a predetermined range, both ammonia and nitrogen oxides in the exhaust gas can be reduced.
[0008]
Further, exhaust gas discharged from the combustion engine passes through the catalyst and then released into the atmosphere so that nitrogen oxides in the exhaust gas are reduced and unburned ammonia is oxidized, thereby remaining in the exhaust gas. Nitrogen oxides can be denitrated and unburned ammonia odor can be deodorized and discharged as clean gas.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0010]
FIG. 1 shows an embodiment of an odor gas combustion deodorization apparatus according to the present invention, in which animal manure 1 is fermented to become fertilizer 2 and odor gas 8 is taken out from odor gas line 6. In the closed-type fermentation apparatus 3 having the same configuration as that shown in FIG. 5, a combustion engine that burns odor gas together with fuel, for example, a small diesel engine 14, is used as the deodorization apparatus. The line 6 is connected so that the odor gas 8 mainly composed of ammonia generated in the closed fermentation apparatus 3 is introduced into the diesel engine 14 through the odor gas line 6, and the diesel engine 14 is supplied with the diesel engine 14. A generator 15 that is driven by the engine 14 to generate power is connected to the fuel 11 such as kerosene with the diesel engine 14. The odorous gas 8 by burning the odorous gas 8 at the same time to be able to deodorization by thermal decomposition, the generator 15 so that power is generated is driven.
[0011]
Further, the ammonia odor that is most abundant in the odor gas 8 generated by the fermentation of livestock manure 1 is deodorized when burned by the diesel engine 14 as the combustion engine, but high-concentration nitrogen oxides (NOx) are present in the exhaust gas. The present inventors have conducted experiments and confirmed the occurrence. The result was as shown in FIG.
[0012]
FIG. 2 shows the relationship between ammonia and nitrogen oxide (O ₂ = 13% conversion) and oxygen concentration in the exhaust gas when ammonia is burned. When the oxygen concentration of the exhaust gas is 16 to 17%, FIG. The results show that the ammonia concentration is low but the nitrogen oxide concentration is high, while the exhaust gas oxygen concentration is 8 to 9%, the ammonia concentration is high but the nitrogen oxide concentration is low. Therefore, in the present invention, the oxygen concentration of the exhaust gas is set to an optimal value of 11 to 15%, the deodorization is performed by burning the odor gas 8 including the ammonia odor, and at the same time, the supply amount of the fuel 11 and the combustion temperature Is adjusted appropriately so that low NOx combustion occurs.
[0013]
Therefore, in the present invention, an oxygen concentration meter 18 is installed in the exhaust gas line 17 of the diesel engine 14, a flow rate adjusting valve 19 is provided in the odor gas line 6, and the engine exhaust gas 13 detected by the oxygen concentration meter 18 is detected. A controller 16 for sending an opening / closing command to the flow rate adjustment valve 19 based on the oxygen (O ₂ ) concentration value therein, and the oxygen concentration of the exhaust gas 13 discharged from the diesel engine 14 is within the range of about 11 to 15%. The combustion temperature and equivalent ratio of the odor gas 8 by the diesel engine 14 are appropriately adjusted so as to be maintained, and low nitrogen oxide (low NOx) combustion is performed so that high efficiency deodorization and low NOx can be achieved. To do.
[0014]
When the odor gas 8 mainly composed of ammonia generated in the closed fermentation apparatus 3 is deodorized using the odor gas combustion deodorization apparatus according to the present invention having the above-described configuration, the odor gas 8 is sealed in the closed fermentation. It is introduced into the diesel engine 14 from the device 3 through the odor gas line 6 and is burned together with the fuel 11 here. By this combustion, the odor component of the odor gas 8 is thermally decomposed and deodorized, and at the same time, the generator 15 can be driven using the diesel engine 14 as a drive source to generate electric power. Thereby, the economic cost for the electric power obtained by this power generation can be reduced.
[0015]
When the odor gas 8 is deodorized by combustion in the diesel engine 14, the oxygen concentration of the exhaust gas 13 is detected by the oxygen concentration meter 18 provided in the exhaust gas line 17 of the diesel engine 14, and the value thereof is 11 to 15. %, The amount of the odor gas 8 introduced into the diesel engine 14 is controlled by adjusting the opening degree of the flow rate adjustment valve 19 of the odor gas line 6 according to a command from the controller 16. Thus, the exhaust gas 13 discharged from the diesel engine 14 can have a low concentration of nitrogen oxides.
[0016]
In addition, since the generation | occurrence | production density | concentration of ammonia in the fermentation process using the closed-type fermentation apparatus 3 changes to 0-2000 ppm, in order to maintain low nitrogen oxide combustion even if the generation | occurrence | production density | concentration of ammonia changes, in order to maintain low nitrogen oxide combustion It is necessary to adjust the introduction amount to the diesel engine 14 while observing the generated concentration or to perform gas treatment with a denitration catalyst, but according to the results of experiments by the present inventors, the load (the output of the generator 15 is 3), as shown in an example in FIG. 3, it has been confirmed that even if the ammonia concentration in the odor changes, the nitrogen oxide emission concentration does not change significantly. Therefore, at the same load, the operation can be performed with the nitrogen oxide concentration almost constant only by controlling the oxygen concentration in the exhaust gas, regardless of the change in the ammonia concentration in the odor.
[0017]
In FIG. 3, ◇ indicates the nitrogen oxide value at the diesel engine outlet when the load at the load of 10 kW is 0 ppm, 230 ppm, and 370 ppm at the diesel engine inlet, and the □ indicates the load 13 This shows the value of nitrogen oxides at the diesel engine outlet when the ammonia at the diesel engine inlet is 400 ppm and 770 ppm in the case of .75 kW.
[0018]
Next, FIG. 4 shows another embodiment of the present invention. In the same configuration as that shown in FIG. 1, the exhaust gas line 17 of the diesel engine 14 is connected to the catalyst reaction vessel 20 containing the catalyst. In this connection, the exhaust gas 13 of the diesel engine 14 is released to the atmosphere after passing through the catalyst in the catalytic reaction vessel 20. 4, the same parts as those in FIG. 1 are denoted by the same reference numerals.
[0019]
The embodiment shown in FIG. 4 is employed when the unburned ammonia content and the nitrogen oxide residual concentration contained in the exhaust gas 13 of the diesel engine 14 are high, so that ammonia is oxidized by a catalyst to deodorize and nitrogen oxidation. The product can be reduced to denitrate, and the exhaust gas 13 can be converted into clean gas.
[0020]
In the above-described embodiment, the case where the odor gas generated from the apparatus for fermenting livestock feces is shown, but for example, the odor gas generated in a terminal treatment plant for treating sewage can be similarly adopted, Further, the engine for burning the odor gas is not limited to the diesel engine, but may be a gas turbine or the like, and it is needless to say that various changes can be made without departing from the gist of the present invention.
[0021]
【The invention's effect】
As described above, according to the odor gas combustion deodorization method and apparatus of the present invention, the following excellent effects are exhibited.
(1) Deodorizing odor gas by introducing odor gas containing high-concentration ammonia into the combustion engine and burning it with fuel, and at the same time, the oxygen concentration in the exhaust gas discharged from the combustion engine is maintained within the required range. by adjusting the amount of odor gases to be introduced into the combustion engine so that, so as to reduce the nitrogen oxides concentration in the exhaust gas, also to be in the range of oxygen concentration in the exhaust gas of 11 to 15% Therefore, deodorization can be performed with high efficiency, and at the same time, low nitrogen oxides of exhaust gas can be achieved, and water treatment is not required, so that it can be easily carried out for general farmers.
(2) The exhaust gas discharged from the combustion engine is exhausted from the combustion engine by reducing the nitrogen oxides in the exhaust gas and oxidizing unburned ammonia by passing it through the catalyst and releasing it to the atmosphere. The exhaust gas to be produced can be made into a clean gas, which is extremely advantageous.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an embodiment of an odor gas combustion deodorization apparatus of the present invention.
FIG. 2 is a graph showing the relationship between ammonia, nitrogen oxide concentration and oxygen concentration contained in exhaust gas in odor gas combustion deodorization using a diesel engine.
FIG. 3 is an example of an experimental result showing a relationship between the concentration of ammonia introduced into a diesel engine at the same load and the concentration of nitrogen oxides in exhaust gas.
FIG. 4 is a schematic view showing another embodiment of the present invention.
FIG. 5 is a schematic view showing an example of a conventional deodorizing apparatus.
[Explanation of symbols]
6 Odor gas line 8 Odor gas
11 Fuel 13 Exhaust gas 14 Diesel engine (combustion engine)
15 Generator 16 Controller 17 Exhaust gas line 18 Oxygen concentration meter 20 Catalytic reaction vessel

Claims (5)

Deodorizing odor gas by introducing odor gas containing high-concentration ammonia into the combustion engine and burning it with fuel so that the oxygen concentration in the exhaust gas discharged from the combustion engine is kept within the required range by adjusting the amount of odor gases to be introduced into the combustion engine, the combustion deodorizing method of odorous gases, characterized in that so as to reduce the nitrogen oxides concentration in the exhaust gas. At the same time by introducing odorous gas containing a high concentration of ammonia in the combustion engine deodorizing odorous gases by combusting together with the fuel, the oxygen concentration in an exhaust gas discharged from the combustion engine is within a range of 11 to 15% Thus, the amount of odorous gas introduced into the combustion engine is adjusted to reduce the concentration of nitrogen oxides in the exhaust gas. After the odor gas deodorized by burning with fuel in the combustion engine, exhaust gases and unburned ammonia through the catalyst so as to release into the atmosphere by reducing nitrogen oxides in an exhaust gas discharged from the combustion engine The odor gas combustion deodorization method according to claim 1 or 2, wherein the odor gas is oxidized. An oxygen concentration meter that detects the oxygen concentration in the exhaust gas is installed in the exhaust gas line of the combustion engine that deodorizes by burning the odor gas containing high-concentration ammonia together with the fuel. Odor is characterized by having a controller for adjusting the amount of odorous gas introduced into the combustion engine so as to reduce the nitrogen oxide concentration in the exhaust gas so as to be maintained within a predetermined range. Gas combustion deodorization device. The combustion of odor gas according to claim 4 , wherein the exhaust gas line of the combustion engine is connected to a catalyst reaction vessel containing a catalyst, and the exhaust gas discharged from the combustion engine is discharged after passing through the catalyst in the catalyst reaction vessel. Deodorizing device.

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