JP4156275B2 - Digestion gas adsorption storage device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a digestion gas adsorption storage device.
[0002]
[Prior art]
Biological treatment of organic waste produced in sewage treatment plants, food factories, beer factories, livestock breeding plants, etc. generates digestive gases consisting of methane, carbon dioxide, water vapor, hydrogen sulfide, and the like. In recent years, in order to effectively use such digestion gas as an energy source, for example, a technique such as a digestion gas storage method in which digestion gas is adsorbed and stored in a storage tank containing an adsorbent such as activated carbon has been studied.
[0003]
[Problems to be solved by the invention]
In the digestion gas adsorption storage tank that has been proposed in the past, water vapor is likely to condense while the digestion gas is supplied to the tank for adsorption storage. There is a problem that there is a case where it is desired to release a large amount.
[0004]
It is an object of the present invention to prevent condensation of water vapor while supplying digestion gas to the tank and storing it in an adsorption manner, and to release a larger amount when digestion gas is released from the digestion gas adsorption storage tank. It is another object of the present invention to provide a digestion gas adsorption storage device which can be further economically improved.
[0005]
[Means for Solving the Problems]
The present invention is a digestion gas adsorption storage device having a cylindrical saddle type pressure vessel for accommodating a digestion gas adsorbent, wherein the cylindrical saddle type pressure vessel has a gas permeability in the lower part, but the digestion gas adsorbent is A sheet or plate that does not pass through and supports the digestion gas adsorbent, an inlet for feeding compressed digestion gas below the sheet or plate, and a gas outlet below and above the digestion gas adsorbent layer, Digestion gas adsorbent is disposed on the sheet or plate, and gas outlet pipes are connected to the gas outlets, and automatic valves are provided in the gas outlet pipes. This is a digestion gas adsorption storage device.
[0006]
The inlet for sending the compressed digestion gas may be provided in the lower outlet pipe instead of the lower side of the cylindrical saddle type pressure vessel.
The automatic valve may be provided in each pipe after the outlet pipes join instead of being provided in each outlet pipe.
When the automatic valve is provided in a pipe after the outlet pipe merges, a pipe for expelling a gas having a high water vapor concentration is provided at the upper part of the cylindrical saddle type pressure vessel separately from the gas outlet pipe. It is good to have been.
The cylindrical saddle type pressure vessel preferably has a heat retaining or heating means.
It is preferable that the digestion gas adsorption storage device functions alone or in parallel.
The cylindrical saddle-shaped pressure vessel preferably has an end plate at the top, and has a digestion gas adsorbent inlet near the center of the end plate.
The automatic valve is preferably electric.
The automatic valve is preferably air-driven.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, the digestion gas is a biological treatment of waste generated at a sewage treatment plant, a food factory, a beer manufacturing factory, a livestock breeding plant, etc. There is no particular limitation on the method. The composition of digestion gas is generally composed of methane as a main component, and is composed of carbon dioxide, water vapor, hydrogen, nitrogen, hydrogen sulfide and the like. A gas in which these components are reduced by treating the gas with desulfurization, carbon dioxide removal or the like is preferable.
[0008]
The digestion gas adsorption storage device of the present invention preferably further has a digestion gas cooling unit on the upstream side of the cylindrical vertical pressure vessel. The digestion gas cooling unit cools the digestion gas to preferably 10 ° C. or less, particularly preferably 5 ° C. or less. As the digestion gas is cooled, adsorption to the adsorbent is enhanced. The digestion gas cooling unit is preferably capable of removing moisture from the digestion gas. If moisture is removed from the digestion gas, the adsorption efficiency of the digestion gas is further improved. By removing moisture, the water vapor pressure in the digestion gas is preferably 9.2 mmHg corresponding to a dew point of 10 ° C. or lower, particularly 4.6 mmHg corresponding to 0 ° C. or lower at the pressure to be adsorbed. By setting the dew point to 0 ° C. or lower, the digestion gas adsorption efficiency is further improved.
[0009]
FIG. 1 illustrates one embodiment of the present invention. In this figure, 1 is a digestion gas adsorption storage device, 2 is a digestion gas adsorbent, 3 is a cylindrical saddle type pressure vessel that accommodates the digestion gas adsorbent 2, and 4 has air permeability, but the digestion gas adsorbent is used. A sheet or plate that supports the digestion gas adsorbent (hereinafter referred to as “adsorbent support plate”) and 5 is below the adsorbent support plate 4 and sends compressed digestion gas to the cylindrical vertical pressure vessel 3. 6 is a gas outlet located above the digestion gas adsorbent layer, 7 is a gas outlet below the digestion gas adsorbent layer, and 8 is a gas outlet pipe connected to the gas outlet 6. , 9 are gas outlet pipes connected to the gas outlet 7, 10 and 11 are automatic valves provided in the gas outlet pipes 8 and 9, respectively, and 12 is a confluence of the gas outlet pipes 8 and 9. Reference numeral 13 denotes a delivery pipe for delivering further gas from the junction 12.
[0010]
The cylindrical vertical pressure vessel 3 is filled with the digestion gas adsorbent 2. The cylindrical saddle type pressure vessel 3 preferably has a structure capable of exchanging heat between the heat medium and the adsorbent via a heat exchange mechanism installed on the wall surface or inside thereof. Examples of the adsorbent include activated carbon, artificial zeolite, natural zeolite, silica gel, organometallic complex (copper fumarate, copper terephthalate, etc.), and one or more of these can be used.
[0011]
When the digestion gas is adsorbed to the cylindrical vertical pressure vessel 3, the compressed digestion gas is fed from the digestion gas feed inlet 5, passes through the adsorbent support plate 4, and is adsorbed on the adsorbent 2 thereabove. During this adsorption, water vapor-rich gas is expelled from the upper gas outlet. Next, when the adsorbed digestion gas is released from the storage device 1, the adsorbent 2 is heated to desorb the digestion gas from the adsorbent 2, and the gas outlet pipes 8 and 9 and the automatic valve are discharged from the gas outlets 6 and 7. The gas is discharged through 10 and 11 and the junction 12.
[0012]
In the case where the cylindrical bowl-shaped container 3 is a fixed type, it can be easily transported after being manufactured in a factory, so that there is little on-site work and cost can be reduced. This shape is easy to mount on the vehicle.
[0013]
As the digestion gas rises in the adsorbent 2, methane is absorbed and becomes a gas rich in moisture, and the moisture may condense on the surface of the adsorbent 2. When the adsorbent 2 gets wet with water, the ability to store methane decreases. Further, in order to quickly remove the condensation in the inlet pipe, a space for draining water and drainage are required at the bottom of the cylindrical bowl-shaped container 3. In order to prevent the condensed water from touching the adsorbent, an adsorbent support plate 4 is provided in the lower part of the cylindrical saddle-shaped container 3 and the adsorbent 2 is placed thereon. The adsorbent support plate 4 is preferably a perforated plate or a wire mesh. The upper space of the cylindrical bowl-shaped container 3 is not particularly required, but as a practical matter, it is difficult to completely pack the adsorbent 2 up to the upper portion.
[0014]
It is convenient to provide an inlet 5 for sending compressed digestion gas into the lower space. If the inlet is provided at the upper part, the adsorbent 2 may get wet by condensation of water vapor generated before reaching the inlet.
Gas outlets 6 and 7 are provided above and below the adsorbent in the cylindrical bowl-shaped container 3. Since condensation of water vapor easily occurs in the cylindrical bowl-shaped container 3, in order to prevent condensation as much as possible, it is desirable to expel a gas having a high water vapor concentration from the top during the digestion gas filling. Therefore, an upper gas outlet 6 is provided. Further, when the adsorbed digestion gas is released, there is a possibility that sufficient gas release may not occur due to the pressure loss of the adsorbent 2. Therefore, by providing two gas outlets at the top and bottom, the discharge flow rate can be doubled compared to a tank with one outlet.
[0015]
The automatic valves 10 and 11 provided in the gas outlet pipes 8 and 9 are closed during digestion gas filling to maintain the internal pressure of the container 3. During digestion gas filling, the upper valve 10 is slightly opened continuously or intermittently to expel water vapor. Since digestion gas is presupposed to be injected, there is always a check valve somewhere upstream of the digestion gas inlet. This check valve may be attached to the digester gas supply compressor.
[0016]
The digestion gas discharged from the cylindrical saddle type pressure vessel 3 joins at the junction 12. This is to suppress the drift in the container 3 by making the back pressure applied to the upper and lower outlets constant. If drift is suppressed, entrainment of the adsorbent and an increase in pressure loss can be prevented. The lower gas outlet 7 is provided below the adsorbent support plate 4.
[0017]
As shown in FIG. 2, the digestion gas supply inlet 5 may be provided upstream of the automatic valve of the lower gas outlet pipe 9. This facilitates the production of the cylindrical saddle-shaped container 3 and facilitates the maintenance and repair of the digestion gas supply inlet 5. Thereby, the number of nozzles can be reduced and the amount of piping can be reduced. In FIG. 2, 21 is a digestion gas adsorption | suction storage apparatus, The meaning of each other number is the same as FIG.
[0018]
Instead of providing the automatic valves 10 and 11 at the outlet pipes 8 and 9, an automatic valve 15 may be provided at the delivery pipe downstream of the junction 12 as shown in FIG. 3. In this case, only one automatic valve can be used. However, in this case, it is desirable to provide the water vapor expelling pipe 16 in order to expel the water vapor accumulated in the upper part of the container 3. In FIG. 3, 31 is a digestion gas adsorption | suction storage apparatus, and each other number represents the same meaning as FIG.
[0019]
The cylindrical saddle-shaped pressure vessel 3 preferably has a means for keeping warm or heating. This is to prevent moisture from condensing on the adsorbent and to secure the heat of desorption of the digestion gas. As the digestion gas is desorbed, the temperature of the adsorbent decreases due to the heat of desorption. Since desorption is hindered when the thermal energy is insufficient, the released heat needs to be supplemented by heating.
In order to keep the adsorbent 2 warm or heated, the container 3 may be capable of heat exchange with the heat medium via a heat exchange mechanism installed on the wall surface or inside. The adsorbent is preferably heated to 5 ° C. or higher, particularly preferably 15 ° C. or higher.
[0020]
The digestion gas adsorption storage device 1 is preferably used alone or in a plurality installed in parallel. There is a limit to the size of the cylindrical vertical pressure vessel 3 that can be manufactured in the factory and brought into the field. When a large capacity is required, it is preferable to install and use several digestion gas adsorption storage devices having a cylindrical vertical pressure vessel of a prescribed size in parallel. It is not preferable to install digestion gas adsorption storage devices in series because pressure loss in the adsorbent layer increases.
[0021]
The cylindrical bowl-shaped container 3 preferably has an end plate at the top, and a digestion gas adsorbent inlet is preferably provided at the center of the end plate. This facilitates filling of the adsorbent. In addition, the upper space of the tank can be minimized.
[0022]
The automatic valves 10, 11, 16 are preferably electrically operated. This is because utility equipment such as compressed air is unnecessary and the apparatus is simple.
On the other hand, it is also preferable that the automatic valves 10, 11, 16 are air driven. It is safe because it does not use electricity.
[0023]
【The invention's effect】
According to the present invention, it is difficult for water vapor to condense while feeding and storing the digestion gas to the tank, and when the digestion gas is released from the digestion gas adsorption storage tank, a larger amount is released. The digestion gas adsorption | suction storage apparatus which was made can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic view showing one embodiment of the device of the present invention.
FIG. 2 is a schematic view showing another embodiment of the device of the present invention.
FIG. 3 is a schematic view showing another embodiment of the device of the present invention.
[Explanation of symbols]
1, 21, 31 ... Digestion gas adsorption storage device 2 ... Digestion gas adsorbent 3 ... Cylindrical vertical pressure vessel 4 ... Adsorbent support plate 5 ... Digestion gas feed port 6, 7 ... Gas outlet 8, 9 ... Gas outlet Pipes 10, 11, 15 ... automatic valve 12 ... confluence 13 ... delivery pipe 16 ... steam expelling pipe

Claims (9)

A digestion gas adsorption storage device having a cylindrical vertical pressure vessel for containing a digestion gas adsorbent, wherein the cylindrical vertical pressure vessel has a gas permeability in the lower part but does not pass through the digestion gas adsorbent. A sheet or plate that supports the adsorbent; an inlet for feeding compressed digestion gas below the sheet or plate; and a gas outlet below and above the layer of the digestion gas adsorbent, the digestion gas adsorbent Are arranged on the sheet or plate, each gas outlet is connected to a gas outlet pipe, each gas outlet pipe is provided with an automatic valve, and each gas outlet pipe is joined Digestion gas adsorption storage device characterized by. 2. The digestion gas adsorption storage device according to claim 1, wherein an inlet for feeding the compressed digestion gas is provided in the lower outlet pipe in place of the lower side of the cylindrical vertical pressure vessel. The digestion gas adsorption storage device according to claim 1, wherein the automatic valve is provided in a pipe after the outlet pipes are joined instead of being provided in each outlet pipe. The digestion gas adsorption storage device according to claim 3, wherein a pipe for expelling a gas having a high water vapor concentration is provided at an upper part of the cylindrical vertical pressure vessel separately from the gas outlet pipe. The digestive gas adsorption storage device according to any one of claims 1 to 4, wherein the cylindrical vertical pressure vessel has a heat retaining or heating means. The digestion gas adsorption | suction storage apparatus in which the digestion gas adsorption | suction storage apparatus in any one of Claims 1-5 is installed individually or in parallel. The digestive gas adsorption storage device according to any one of claims 1 to 6, wherein the cylindrical saddle type pressure vessel has an end plate at an upper portion thereof and has a digestion gas adsorbent inlet near the center of the end plate. The digestion gas adsorption storage device according to any one of claims 1 to 7, wherein the automatic valve is electrically operated. The digestion gas adsorption storage device according to any one of claims 1 to 7, wherein the automatic valve is an air drive type.

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