JPH10299999A - City gas supply quantity regulating method and city gas tank therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To store a large quantity of city gas and supply it if necessary by arranging a city gas tank stored with city gas occluded by porous material under the coexistence of a compound to be a host, in a city gas manufacturing plant or a city gas supply base. SOLUTION: In a city gas tank for regulating the supply quantity of city gas, porous material 2 is stored in a tank container 1, and an in-out conduit 3 for city gas and a compound to be a host is provided with a switching valve 4. An opening, opened to the inside of the container 1, of the conduit pipe 3 is made to face the upper space 5 of the tank container 1. The city gas and the compound to be the host led in from the opening, opened to the inside of the container 1, of the conduit 3 are adsorbed and occluded by the porous material 2, and the occluded city gas is supplied to a city gas supply pipe from the conduit 3 at the time of being discharged by heating or the like. Such a city gas tank 24 is provided at a city gas manufacturing plant or a city gas supply base 21, and the city gas is supplied to various factories, facilities and each home via city gas supply main line piping 22 and branch lines 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adjusting a city gas supply amount and a city gas tank therefor, and more particularly, to a method for adjusting a city gas supply amount by storing a large amount of city gas in a porous material. And a city gas tank for adjusting the supply of city gas therefor.

[0002]

2. Description of the Related Art A gas has a very large volume and a low specific gravity in a gaseous state. For this reason, when storing or transporting a gas, there is a demand for a method of reducing the volume of the gas and increasing the density in order to increase the storage efficiency and the transport efficiency. As this method, (1) a method of compressing to a high pressure in a gas state as seen in a high-pressure gas cylinder or the like,
(2) In addition to the method of cooling and liquefying a gas such as liquid nitrogen, liquid oxygen, or liquefied natural gas, the following (3) to
Various methods such as (6) have also been proposed.

(3) A method of adsorbing on the surface of a solid adsorbent such as silica gel or activated carbon (JP-A-49-104213)
(4) a method using a storage alloy such as hydrogen, or a method using a combination of a hydrogen storage alloy and an adsorbent (Japanese Patent Application Laid-Open No. 4-131598), and (5) decomposition of methane. (6) Contacting hydrocarbon gas containing methane or ethane as a main component with water in the presence of an aliphatic amine, A method using a Japanese product (JP-A-54-135708).

However, among these methods, the method (1) requires a storage container to have a sufficient pressure resistance.
There is a disadvantage that the weight of the container becomes very large as compared with the weight of the gas to be stored.
If the pressure exceeds the atmospheric pressure (gauge pressure: 10 kg / cm ² ), materials, equipment, piping, etc., that meet the specifications stipulated by the High Pressure Gas Control Law are required, which increases the cost. In the liquefaction method according to (2), it is necessary to compress and cool the gas to liquefy it, which is not only very costly but also requires special equipment for keeping the obtained liquefied gas cool. Required. And in this case,
It is subject to legal regulations as in the case of (1) above. For this reason, even if this liquefaction method is applied, it is still economically feasible only in the case of high-value gas such as helium or liquefied natural gas (LNG) having large scale merits.

In the case of the method (3), the gas is occluded by physical adsorption on the solid surface. However, since this method utilizes the equilibrium phenomenon with the pressure, the adsorption speed is low, and the method is not sufficient. To obtain a sufficient amount of occlusion, considerable pressurization is required. According to this method, gas can be stored at a low pressure as compared with the above-described method using a high-pressure cylinder.
A pressure of 0.68 atm (10 kg / cm ^{2 in} gauge pressure) or more is required.

In the method (4), for example, when the target gas is hydrogen, the storage target gas and the necessary material have a substantially one-to-one specific relationship, such as palladium or an alloy thereof. And it is expensive because the occlusion material itself is special. Furthermore, there is a problem of material embrittlement that occurs during repeated use, and handling is extremely difficult. Further, the method (5) also has a problem that the target gas is limited as in the case of (4), and the necessary materials are special and expensive. In the case of (6), since it is a gas-liquid contact type, the efficiency is greatly influenced by the gas-liquid contact efficiency, and the actual gas storage amount is larger than the theoretically expected storage amount. Is also quite low.

[0007] Among various gases, city gas is produced in a city gas production plant and supplied to each customer through a gas supply conduit. The supply of city gas to each customer varies seasonally and daily. There are fluctuations. For this reason, care is taken to make the capacity of the manufacturing plant and the supply conduit correspond to the fluctuation of the supply amount, and to be able to correspond to the maximum demand amount. However, for example, when the main raw material of city gas is LNG,
LNG storage facilities and the like in a manufacturing plant will need to have stockpiling facilities to meet peak demand in the winter season, and the cost for that will be enormous. In addition, there is a problem in that the cost is increased in the city gas supply pipe, for example, in order to meet the maximum demand, a high-pressure resistant pipe is required.

By the way, the inventors of the present invention have proposed that a porous material such as activated carbon and ceramics be used to cool a compound serving as a host and a gas to be stored in the pores at a low temperature, a normal temperature or a temperature close to these temperatures. By contacting under a mild condition of low pressure, normal pressure or a pressure close to these pressures, a large amount corresponding to a volume of at least 180 times (converted to a standard state) per unit volume of the porous material is obtained in a very short time. A gas storage method and a transportation method capable of storing and transporting the same gas have been developed (Japanese Patent Application No. 8-37526).

FIG. 1 shows an example supporting the characteristics of the porous material. Here, the specific surface area is 1765 m ²
/ G, average pore diameter 1.13 nm (nanometer), pore volume 0.971 cc / g, true specific gravity 2.13 g / cc,
First, 0.0083 g of water was adsorbed on 0.0320 g (0.0461 cc) of pitch-based activated carbon having an apparent specific gravity of 0.694 g / cc, and methane gas at 0.2 atm was introduced at a temperature of 30 ° C. For comparison,
Except that water was not adsorbed, the same procedure was followed when methane gas was introduced. FIG. 1 shows the change over time in the weight of methane adsorbed per 1 g of activated carbon at this time. In FIG. 1, the change in weight when methane is adsorbed after water is previously adsorbed on activated carbon is plotted with a circle (open circle), and the case where methane is directly adsorbed on activated carbon is plotted with a black circle (black circle). ing.

As shown in FIG. 1, when water is first adsorbed on activated carbon and then methane gas is introduced, the activated carbon starts to absorb methane rapidly after the introduction of methane, and the methane gas is introduced into the activated carbon.
After the lapse of time (h), the amount of methane adsorbed was 15 g / g of activated carbon.
The amount exceeds 500 mmol and reaches about 17 mmol when 0.5 hour has elapsed, and this storage amount is maintained thereafter. The pressure of the introduced methane gas at this point is 0.2 atm (temperature 30 ° C)
In view of the above, it can be said that the adsorption rate and the adsorption amount of methane are superior to the conventional adsorbent.

On the other hand, when methane gas is introduced without adsorbing water on activated carbon as in the prior art, only slight adsorption of methane is caused, and time elapses in the same atmosphere as described above. No change was observed in the amount of adsorption. In this regard, for example, according to the method disclosed in Japanese Patent Application Laid-Open No. 49-104213, silicate gel, molecular sieve, activated carbon, and the like are accommodated in a pressure tank and about 68 atm.
psia) stores methane under pressure.
In this technique, even if the same adsorbent is used, such a high pressure operation is indispensable.

[0012]

[Table 1]

Table 1 compares the amounts of adsorbed methane per gram of activated carbon shown in FIG. As shown in Table 1, for example, at the point of time after 0.2 hours, when methane was directly adsorbed on the same activated carbon, the amount of methane adsorbed was only 0.18 mmol, but water was previously allowed to coexist. In this case, it was 12.08 mmol, and the ratio was 67 times. At the time when 0.9 hour has elapsed, the direct adsorption on activated carbon is also 0.18 mmol, whereas
When water coexists, the methane adsorption amount is 16.46 mmol, and the ratio is 91 times.

Further, based on the apparent volume of activated carbon of 1 cc, the amount of methane adsorbed in the presence of water is 183 cc when converted to the standard condition of 0 ° C. and 1 atm. According to this result, at a pressure of only 0.2 atm, just 18
This indicates that three times as much volume of methane was adsorbed. After that (after 0.9 hours), the amount of adsorption slightly decreases, but finally reaches an equilibrium at 11.77 mmol, and there is no change thereafter.

[0015]

SUMMARY OF THE INVENTION In the present invention, in view of the above-mentioned problems in a city gas production plant, a city gas supply base, or a city gas supply system to each customer, the present invention relates to a method for manufacturing a porous material. Regarding characteristics, conventional technology,
Focusing on the fact as shown in FIG. 1 and Table 1 which cannot be expected at all from recognition, this fact is applied so that it can be applied for adjusting the city gas supply.

That is, the present invention provides a method of adjusting a supply amount of city gas by storing a large amount of city gas by using a porous material together with a host compound, and supplying the gas as needed. It aims to provide a city gas tank.

[0017]

According to the present invention, a city gas tank storing a city gas in a porous material in the coexistence of a host compound is disposed in a city gas production plant or a city gas supply base. The present invention provides a method for adjusting a city gas supply amount.

According to the present invention, there is provided a city gas supply amount characterized by disposing a city gas tank for storing city gas in a coexistence of a host compound with a porous material in the middle of a city gas supply conduit. The adjustment method of is provided.

According to the present invention, there is provided a city gas tank for adjusting a city gas supply amount, wherein a city gas is absorbed into a porous material housed in a container in the presence of a host compound. provide.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The porous material in the present invention is not particularly limited as long as it is a porous material having pores. Preferably, the porous material has a specific surface area of 100 m ² / g or more. Can be used. In addition, as long as it does not react with or dissolve in water, alcohols, or a host compound having an equivalent function (ie, as long as it does not substantially adversely affect the dissolution or reaction). It can be used irrespective of its material, manufacturing method and shape, and further, uniformity is not required for the shape of the pores and the distribution of the diameters of the pores.

The porous material in the present invention includes:
Any porous material having such properties can be used. Among them, activated carbon (including porous carbon) and ceramics are particularly preferably used. For example, since the activated carbon and ceramics are inexpensive and easily available, the present invention is extremely advantageous in this respect. Examples of the compound serving as a host in the present invention include water, alcohols such as methyl alcohol and ethyl alcohol, organic acids such as formic acid and acetic acid, and quinones such as benzoquinone. Among them, water or alcohols are particularly preferably used.

According to the present invention, for a porous material such as activated carbon or ceramics, the compound serving as a host and the city gas to be occluded inside the pores are at room temperature, normal pressure or close to these temperatures and pressures. Contact under mild conditions. As a result, it is possible to occlude a large amount of city gas in a very short time, for example, 180 times (converted to a standard state) or more per unit volume of the porous material.

The pressure at the time of storing the city gas in the tank is not limited to a low pressure of normal pressure to 10.68 atm (10 kg / cm ^{2 in} gauge pressure) or less, for example, 0.2 atm. It can be stored under such reduced pressure, and can be stored at 10.68 atm (10 kg
/ Cm ² ), even at high pressures, more gas can be stored in the tank corresponding to the pressure. As described above, the city gas tank for adjusting the supply amount of city gas according to the present invention does not require any special cooling device or the like and does not require any special pressure equipment, so that it is extremely effective in practical use.

FIGS. 2 and 3 show the characteristics of the porous material used in the present invention depending on the pressure. The same activated carbon as that obtained the results of FIG.
0461 cc), firstly, 0.0083 g of water was adsorbed, and then, at a temperature of 30 ° C., from 0 atm.
Methane gas up to 0 atm was introduced, and the amount of adsorption after reaching equilibrium at each of these pressures was measured. FIG. 2 shows a transition from 0 atm to 20 atm in FIG. 3 from 0 atm to 1.5 atm, enlarged in the horizontal axis direction. In both figures, the change in weight when methane was adsorbed after water was previously adsorbed on activated carbon was plotted with a circle (white circle), and the change in weight when methane was directly adsorbed on activated carbon was plotted with a black circle (black circle). It is plotted.

As shown in FIG. 2, when methane gas is introduced after water is adsorbed on activated carbon, methane is rapidly absorbed after the introduction even if the pressure is extremely low. When the pressure is 1 atm, the amount of adsorption is about 12 mmol. When methane is directly adsorbed on activated carbon, the amount is about 1 mmol per 1 g of activated carbon at 1.5 atm. On the other hand, when methane gas is introduced after water is adsorbed on activated carbon. It stores 13 mmol of methane at 5 atm.

Table 2 compares the amounts of adsorbed methane per gram of activated carbon shown in FIG. As shown in Table 2, for example, when the amount of methane reaching the adsorption equilibrium at 0.2 atm is compared, when water coexists, the amount of adsorption is 11.77.
It was only 0.18 mmol when directly adsorbed on activated carbon, whereas the ratio was 65 times. Also, when comparing the amount of methane that reached the adsorption equilibrium at 1.5 atm, it was 13.08 mmol when water coexisted, whereas it was 0.88 mmol when directly adsorbed on activated carbon. The ratio was 15 times.

[0027]

[Table 2]

FIG. 3 shows the measurement results when activated carbon was contacted with methane under a higher pressure than the pressure condition shown in FIG. 2, and the data up to 1.5 atm shown in FIG. 2 are also shown. Are plotted. As is clear from FIG.
When water coexists, the amount of occlusion gradually increases with a pressure increase after the methane pressure of 1.5 atm. At a methane pressure of 20 atm, 21 mmol of methane is stored per 1 g of activated carbon.

On the other hand, when methane is directly adsorbed on activated carbon, the amount of methane adsorbed increases only slightly with increasing pressure, and even at 20 atm.
It is only on the order of millimoles. Also, when water is allowed to coexist with activated carbon, activated carbon 1
As much as 12 mmol of methane is adsorbed per gram, which is more than twice the amount of adsorption at 20 atm (about 5 mmol) when methane is directly adhered to activated carbon without water. ing.

Further, based on FIG. 3, a case where water was adsorbed on activated carbon and then methane was adsorbed on activated carbon 1c
When the amount of methane adsorbed under each pressure was converted into the volume in the standard state based on the pressure c, 191 cc at 0.7 atm, 203 cc at 1.5 atm, and 2 at 5.0 atm, respectively.
71cc, 10atm 290cc, 20atm 326c
c. As described above, according to the present invention, in addition to excellent adsorption and occlusion effects under reduced pressure or low pressure such as normal pressure to 5 atm, it is more effective even under pressurized pressure such as 10 atm, 20 atm or more. It shows that a great occlusion effect can be obtained.

For example, in the case of activated carbon, powders, granules, fibers, and various other shapes having various pore diameters and large specific surface areas are easily available, and the pore diameter distribution and specific surface area are as follows. Can be easily confirmed by measuring the nitrogen adsorption amount and the adsorption isotherm at the liquid nitrogen temperature. This activated carbon material has a very large specific surface area, so that a very large number of molecules can be adsorbed on its surface. By controlling the amount of the molecules adsorbed thereon, most of the molecules can be exposed to the surface inside the pores.

Since these materials have a sufficiently small pore size, for example, several nanometers to several tens of nanometers, the molecules adsorbed on the surface of the pores behave as if they were under high pressure conditions. This behavior itself is a phenomenon known as a phenomenon called a pseudo high pressure effect. As described above, a phase change or a reaction that normally occurs only at a high pressure may occur under mild conditions of a lower pressure and a lower temperature by using a porous material having pores. Although the reason for the effect is not known in detail, it is presumed that such a phenomenon is possibly involved.

On the other hand, the compound serving as the host in the present invention is not particularly limited as long as it is a compound capable of forming a certain structure via hydrogen bonding when several molecules are gathered. Examples thereof include water, alcohols, other organic acids and quinones, and among them, water and alcohols are particularly preferably used. As a host compound, for example, hydrogen sulfide, urea, or the like may be used. However, these compounds generate harmful gases during combustion because they generate sulfurous acid gas or nitrogen oxide (NOx) during combustion as a fuel. Is used after the problem is solved.

According to the technical knowledge known so far, these host compounds form clathrates when co-existing with gas molecules having a certain range of sizes (called guest molecules). As a result, the gas molecules crystallize and stabilize at very close positions. This phenomenon occurs when a compound serving as a host and a gas molecule serving as a guest coexist at a certain pressure and temperature conditions, the compound serving as a host and a gas molecule serving as a guest via a hydrogen bond have a certain three-dimensional structure, for example, the host has a certain three-dimensional structure. This is a phenomenon that forms a cage-like structure that surrounds the guest. This clathrate compound is usually generated under low-temperature and high-pressure conditions.

On the other hand, in the present invention, the combination of the high adsorptivity of the porous material having pores, the pseudo high pressure effect in the pores, and the property of forming an inclusion compound of gas is used. Accordingly, a large amount of fuel gas can be quickly stored under mild conditions without requiring such a high pressure. The gas storage capacity obtained by the method of the present invention greatly exceeds the ratio of the number of guest to host molecules in the clathrates known so far, and is based only on the principle of such known clathrate formation. This phenomenon cannot be explained. In the present invention, it is considered that some kind of synergistic effect due to the combination of the pore material and the clathrate compound, that is, an effective and excellent gas occlusion effect is produced by some new and useful principle.

In the city gas tank for adjusting the supply amount of city gas according to the present invention, the mode of storing the city gas in the tank is as follows: (1) After the porous material is contained in the tank container, the compound serving as the host is supplied. (2) A porous material having a host compound absorbed therein is accommodated in a tank container, and then a city gas is introduced. (3) A porous material is introduced into the tank container. And then simultaneously introducing a compound serving as a host and city gas, using two or more of the embodiments (4) and (1) to (3), and various other methods.

In this case, in any of these embodiments, since it is possible to adsorb and occlude even at a low pressure, a high-pressure container is not required as the container. At this time, of course, a high-pressure container may be used, and according to the city gas tank for adjusting the supply amount of city gas of the present invention, the gas can be similarly stored at a pressure exceeding 10.68 atm (10 kg / cm ² at a gauge pressure). However, in this case, a high-pressure container that can withstand this is used.

Next, the external shape of the city gas tank for adjusting the supply amount of city gas according to the present invention may be cylindrical, spherical, cubic, rectangular, or the like, as in the case of tanks conventionally used for city gas and other various gases. Any shape can be used. The constituent material of the tank container is not particularly limited, and any material that can be used for a hydrocarbon fuel, such as stainless steel, is used.

The inside of the tank is filled with a porous material. As a mode of filling, the porous material may be filled as it is, or may be formed in an appropriate manner such as one layer or two or more layers. The tank is provided with an inlet pipe for the compound serving as a host and an inlet pipe for the fuel gas. In addition to providing both pipes separately, a single pipe that serves both may be used. In this case, it can also be used as a discharge pipe when using gas. In the present invention, the porous material once filled in the tank and the gas storage tank can be used repeatedly.

The city gas tank of the present invention is disposed in the middle of a city gas supply conduit, and is used for adjusting a city gas supply amount according to a change in demand amount such as a seasonal variation or a daily variation. The method of arrangement may be such that (1) after storing and filling the tank with city gas, transporting and shipping the tank, and installing the tank at the place where the tank is arranged; May be installed at the location where the gas is stored and filled with city gas. In particular, in the case of a large-capacity tank such as a case in which the tank is arranged in the middle of a main line pipe for supplying city gas, the mode (2) is preferably adopted.

The city gas tank is not limited to the one for adjusting the supply amount, but is also used as a tank for supplying city gas to the city gas supply main line. That is, by arranging the city gas tank in a city gas production plant or a supply base, city gas production in the city gas production facility can be flattened. For example, even if the city gas production capacity of the city gas production facility is not increased in accordance with the peak of the demand, it is stored in the city gas tank when the demand is low, and released when the demand is high.
City gas production can be flattened. Further, the city gas tank for adjusting the supply amount according to the present invention can be used for supplying a city gas tank until the end of the work by arranging the city gas tank in the extension work area for laying the city gas supply pipe.

[0042]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but it goes without saying that the present invention is not limited to these Examples.

FIG. 4 is a sectional view showing an example of an embodiment of the city gas tank for adjusting the city gas supply amount according to the present invention. FIG.
(A) shows an embodiment in which the porous material is directly charged into the tank, and FIG. 4 (b) shows an embodiment in which the porous material is filled in the tank in a layered manner. FIG. 4B shows the case of two layers, but three or more layers may be used. In this regard, the same applies to the case of the multilayer mode described below.

In FIG. 4, reference numeral 1 denotes a tank container, 2 denotes a porous material, 3 denotes an inlet / outlet tube for a compound serving as a host and city gas, and an opening of the conduit 3 in the container is an upper space 5 of the tank container. It is facing. 4 is an on-off valve, and FIG.
(B) 6 is an intermediate space between the upper and lower layers 2. FIG.
Members such as a porous plate and a mesh body are arranged on the upper surface of the porous material in FIG. 4A and on the upper and lower surfaces of the porous material in FIG. 4B. The same applies to the embodiments below this point.

FIG. 5 is a sectional view showing another embodiment of the supply gas adjusting city gas tank. FIG. 5A shows an example in which an opening is provided by vertically penetrating a layer of a porous material arranged in layers. In FIG. 5A, reference numeral 7 denotes the through hole, and reference numeral 8 denotes a lower space. The through-hole 7 is formed of, for example, a mesh body or a cylindrical body having a large number of holes. Although one through hole 7 is provided in the illustrated embodiment, two or more through holes 7 may be provided at intervals if necessary. The host compound and city gas introduced from the opening inside the container of the conduit 3 facing the upper space of the tank container enter from the wall of the through hole 7 in addition to the upper and lower surfaces of the porous material layer, It is more evenly adsorbed and stored on the porous material.

When the stored city gas is released by heating or the like, it is adsorbed and directed in the opposite direction to that during the storage, and is supplied from the conduit 3 to the city gas supply pipe. This point is the same in the following embodiments. FIG. 5B is a modification of FIG.
This is a mode in which an opening in the container of the conduit 3 faces the lower space of the tank container. Also in this case, the host compound and the city gas introduced from the opening in the vessel of the conduit 3 penetrate not only from the upper and lower surfaces of the porous material layer, but also from the wall of the through-hole 5, and the porous material is more evenly distributed. It is adsorbed and occluded.

FIG. 5 (c) shows two layers of porous material provided with an opening penetrating in the vertical direction. In the figure, 9 is a through hole, and 10 is an intermediate space between both layers. is there. FIG.
In (c), two layers are provided, but three or more layers can be provided. The through-hole 9 is formed of, for example, a tubular mesh body or a tubular body having a large number of holes. In the illustrated embodiment, one through hole 9 is provided in each of the upper layer and the lower layer. However, two or more through holes 9 may be provided at intervals if necessary. In this case, the number of through holes provided in the upper layer and the lower layer may be changed. The host compound and city gas introduced from the opening inside the container of the conduit 3 facing the upper space of the tank container enter from the wall of the through hole 5 in addition to the upper and lower surfaces of each porous material layer. Is more evenly adsorbed and occluded by the porous material.

FIG. 5D is a modification of FIG. 5C, in which the opening of the conduit 3 in the container faces the lower space of the tank container. Also in this case, the host compound and the city gas introduced from the opening in the vessel of the conduit 3 penetrate not only from the upper and lower surfaces of each porous material layer, but also from the wall of the through-hole 5, so that the porous material is more uniformly formed. Adsorbed to the material and stored. The opening in the container of the conduit 3 may be provided with a branch pipe from the conduit 3 in addition to the lower space so that the opening faces the upper space 6 and / or the intermediate space 10.

FIG. 5E is a sectional view of still another embodiment. In this case, through holes 11 are provided in the vertical direction in the filling layer of the porous material, and a plurality of branch pipes 12 are radially formed from the through holes 11.
Is provided. The compound serving as a host and the fuel gas introduced from the opening in the vessel of the conduit 3 penetrate not only from the upper surface of the porous material layer but also from the wall of the through-hole 11 and the wall of the radial branch pipe 12 so that the porous material is more evenly distributed. It is adsorbed and occluded.

FIG. 6 shows a modification of FIG. 5 (e). FIG. 6A shows a mode in which the conduit 3 is extended from the through-hole 11 to a plurality of branch pipes 12 provided radially, and the end openings thereof face each branch pipe 12. Also in this case, the host compound and the city gas introduced from the opening in the vessel of the conduit 3 enter the porous material layer from the upper and lower surfaces thereof and also from the walls of the branch pipes 12 so as to be more evenly porous. Adsorbed and occluded in the material. FIG. 6B shows a mode in which a space 8 is also provided below the filling layer. At this time, a branch pipe may be provided in the conduit 3 corresponding to the radial branch pipe 12 as in the case of FIG. 6A, and each opening thereof may face the radial branch pipe 12. The branch pipe 12 may have a structure like a human lung communicating with the bronchi.

Next, FIG. 7 shows an example of the mode of adsorption and filling of city gas into the city gas tank for supply amount adjustment.
Reference numeral 13 in FIG. 7 denotes a city gas conduit, which is connected to a city gas production plant, a city gas storage tank, and the like. Reference numeral 14 denotes a mechanism for generating water vapor, and reference numeral 15 denotes a city gas tank for adjusting a city gas supply amount. The tank 15 is filled with a porous material such as activated carbon. During the adsorption filling operation, the valve 16 is closed and the valve 17 is closed.
Then, the valve 18 is opened, steam is generated by the steam generating mechanism 14, and introduced into the tank 15 through the conduits 19 and 20. Next, the valve 16 is opened and city gas is introduced into the tank 15.

By the above operation, the city gas is rapidly adsorbed on the porous material by the host action of water vapor or condensed water, and is adsorbed and stored in a large amount such as 180 times or more the volume of the porous material. In the above operation example, the city gas is introduced after the steam is generated in advance and introduced into the porous material. However, it goes without saying that the city gas may be introduced simultaneously with the steam. In this case, it is necessary to take care not to cause inconvenience due to condensation or solidification of steam by adjusting the diameter of the conduit (20 in FIG. 7), the flow rate of the city gas, the temperature, and the like. It is.

In the present invention, the above-described city gas tank is installed or provided in a city gas production plant or a satellite base (supply base), and is disposed in the middle of a city gas supply main line or a branch pipe. FIG. 8 is a diagram schematically showing an example of these aspects. In FIG. 8, reference numeral 21 denotes a city gas production plant or a supply base using LNG or the like as a raw material, which is supplied to various factories, facilities, and homes via a supply main pipe 22 and branch lines 23. Reference numeral 24 denotes an example of the attached city gas tank, and reference numeral 25 denotes an example of the city gas tank arranged in the branch pipe.

FIG. 9 shows an example of the mode of the juxtaposition or arrangement.
A supply gas regulating city gas tank is connected to the city gas supply main line 22 or the branch pipe 23 by a conduit 27 via a regulating valve 26. For example, when the demand becomes relatively large due to, for example, seasonal fluctuations, or when the amount of supply from a city gas production plant or a supply base (= satellite base: a city gas storage base connected to a city gas supply trunk) is temporarily increased. In the case of a shortage, for example, the shortage is supplied from a supply gas adjusting city gas tank via a regulating valve (open / close valve) 26 to a required amount from a conduit 27 by heating or the like, and supplied and replenished.

[0055]

According to the present invention, a large amount of city gas can be stored in a small volume by a porous material and a host compound under mild temperature and pressure conditions without the need for a high-pressure tank as in the prior art. It can be released and its handling is easy and safe. For this reason, city gas production in the city gas production facility can be easily flattened,
Further, the city gas supply amount can be easily adjusted according to the fluctuation of the demand amount such as seasonal fluctuation or daily fluctuation. At that time, the storage tank itself can be made compact, so that the equipment cost can be significantly reduced.

Further, not only low pressure to normal pressure but also 10.68 atm (10 kg / c gauge pressure)
Since a large amount of city gas can be stored even under a pressurization of m ² ) or more, the degree of freedom in designing and arranging the city gas tank is high, which is extremely advantageous in practical use.
In addition, the porous material used in the present invention is inexpensive and easily available, and water and alcohols are used as the host compound.

[Brief description of the drawings]

FIG. 1 is a graph showing the change over time of the amount of methane adsorbed per 1 g of activated carbon, when water is coexisted and when it is directly contacted with methane (temperature 30 ° C., pressure 0.2 atm).

FIG. 2 is a graph comparing the change in the amount of methane adsorbed per gram of activated carbon with pressure between the case where water is coexisted and the case where it is directly contacted with methane (temperature 30 ° C.).

FIG. 3 is a graph comparing the change in the amount of methane adsorbed per gram of activated carbon with pressure in the case of coexisting water and in the case of direct contact with methane (temperature of 30 ° C.).

FIG. 4 is a diagram (cross-sectional view) showing an example of an embodiment of a city gas tank for adjusting a city gas supply amount according to the present invention.

FIG. 5 is a view (cross-sectional view) showing another example of the city gas tank for adjusting the city gas supply amount according to the present invention.

FIG. 6 is a view (cross-sectional view) showing a modification example of FIG. 5 (e).

FIG. 7 is a diagram showing an example of a mode of adsorption and filling of city gas into a supply amount adjusting city gas tank.

FIG. 8 schematically shows an example in which a supply gas regulating city gas tank is provided alongside a city gas production plant or a satellite base (supply base) in the present invention, or is disposed in the middle of a city gas supply main line or a branch pipe. FIG.

FIG. 9 is a view showing an example of a mode of juxtaposition or arrangement in FIG. 8;

[Explanation of symbols]

REFERENCE SIGNS LIST 1 tank container 2 porous material 3 inlet / outlet pipe for host compound and city gas 4 on-off valve 5 upper space of tank container 6 intermediate space between upper and lower layers 2 through hole 8 lower space 9 through hole 10 vehicles Intermediate space between layers 11 Through hole 12 Radial branch pipe 13 City gas conduit 14 Mechanism for generating water vapor 15 City gas tank for regulating supply of city gas 16-18 Valve 19, 20 conduit 21 City gas production plant using LNG as raw material or Transmission base 22 City gas supply main line piping 23 Branch line 24 Example of city gas tank attached 25 Example of city gas tank arranged in branch pipe 26 Regulator (open / close valve) 27 Pipe

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[Procedure amendment]

[Submission date] May 8, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

[Fig. 1]

FIG. 2

[Fig. 3]

[Fig. 4]

[Fig. 5]

[Fig. 6]

[Fig. 7]

[Fig. 8]

[Fig. 9]

Claims (9)

[Claims] 1. A city gas supply characterized by disposing a city gas tank storing a city gas in a coexistence of a host compound with a porous material in a city gas production plant or a city gas supply base. How to adjust the amount. 2. A method for adjusting a supply amount of a city gas, wherein a city gas tank for storing a city gas in the coexistence of a compound serving as a host with respect to a porous material is disposed in the middle of a city gas supply pipe. Method. 3. The porous material is activated carbon or ceramics, and the host compound is water, alcohols,
The method for adjusting the supply amount of city gas according to claim 1, which is an organic acid or a quinone. 4. A city gas tank for adjusting a city gas supply amount, wherein a city gas is occluded in a porous material housed in a container in the presence of a compound serving as a host. 5. A city gas tank according to claim 4, wherein said porous material is activated carbon or ceramics, and said host compound is water, alcohols, organic acids or quinones. City gas tank for gas supply adjustment. 6. The city gas tank according to claim 4, wherein said porous material is contained in said container in one or more layers. City gas tank for volume adjustment. 7. A city gas tank for adjusting a supply of city gas according to claim 6, wherein a layer for a host material and a city gas is provided in a layer of a porous material accommodated in the container. A city gas tank for adjusting city gas supply. 8. The city gas tank for adjusting the supply of city gas according to claim 7, wherein said passage is provided radially. 9. The city gas tank according to claim 7, wherein a compound serving as a host and a city gas conduit are arranged and opened in said passage. A city gas tank for adjusting city gas supply.