JPS62225590A - Production of high-caloric gas - Google Patents

Abstract

PURPOSE:To efficiently obtain a high-caloric gas, by passing a low-caloric raw material gas through two specific kinds of pressure adsorption columns one after another to adsorb and remove low-caloric and noncombustible components, etc. CONSTITUTION:A low-caloric raw material gas consisting of low-caloric components, e.g. H2, CO, CO2, N2, etc., and/or noncombustible components and hydrocarbons is passed through the first pressure swing adsorbent column filled with an adsorbent for selectively separating CO and clinoptilolite based adsorbent to give an intermediate product gas, which is then introduced into the second pressure swing adsorbent column filled with a porous adsorbent having adsorptivity for organic gases or a material obtained by treating the surface thereof to carry out pressure swing operation and/or the above-mentioned column is washed with CH4 or the product gas to afford the aimed high-caloric gas.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides low-calorie raw material gas consisting of low-calorie components such as H2, CO1Co, N2, etc. and/or non-combustible components and hydrocarbons. - ingredients and/or
Alternatively, the present invention relates to a method for obtaining a high-calorie product gas by separating and removing non-combustible components.

Conventional technology Low calorie ingredients such as Hz, Co, Coz, N, etc.
Alternatively, in order to obtain a high-calorie product gas from a low-calorie raw material gas consisting of non-combustible components and hydrocarbons, it is necessary to efficiently separate and remove these low-calorie components and/or non-combustible components from the raw material gas. be.

Conventionally H2, CO, CO2, or N2. The following methods have been put into practical use to remove these components from gases containing them.

1) Hz removal PSA method (pressure fluctuation adsorption separation method), membrane separation method, cryogenic separation method 1i) Co removal cryogenic separation method, copper ammonia method, cosorb (cO3ORB)
) method, methanation of CO 1ii) Removal of COλ Hot alkali carbonate method, two-stage treatment method of hot alkali carbonate and monoethanolamine, PSA method 1) Removal of Nz PSA method, cryogenic separation method The invention will solve the problem. However, the above-mentioned separation technology for each gas alone has
With the exception of the PSA method, equipment costs are generally large, and electricity,
Steam and other thermal energy consumption is large, and the combination of these technologies requires more complex equipment, so although it is suitable for processing large volumes of gas, it is not advantageous for processing small and medium volumes of gas. do not have.

In addition, although the PSA method, which is suitable for processing small volumes of gas, is capable of removing each gas individually, H,
, Co, Co2. , N, and other low-calorie components and/or non-combustible components at the same time from the raw material gas.

In view of the above situation, the present inventors decided to use N2, CO, Co
2. A low-calorie raw material gas consisting of low-calorie components and/or non-combustible components such as N2 and hydrocarbons is first passed through a pressure swing adsorption tower (A) filled with a clinobutyrolite-based adsorbent. A method of converting the intermediate product gas into a high-calorie product gas by introducing the intermediate product gas into a pressure swing tower (B) filled with a porous adsorbent having organic gas adsorption properties and performing a pressure swing operation. , and has already filed a patent application in 1986-9925.
A patent application has been filed as No. 9. The present invention aims to provide a more industrially advantageous method by improving the invention related to the earlier patent application.

Means for Solving the Problems The method for producing high calorie gas of the present invention is based on N2. ,co,
A low-calorie raw material gas (a
) is first made into an intermediate product gas (b) by passing it through the first pressure swing adsorption tower (A) filled with an adsorbent for CO selective separation and a clinobutyrolite adsorbent, and then this intermediate product gas is (b) is introduced into a second pressure swing adsorption tower (B) filled with a porous adsorbent having organic gas adsorption properties or a surface-treated product thereof, and a pressure swing operation is performed, and/or the second pressure swing adsorption tower (B) is This method is characterized by converting B) into a high-calorie product gas (c) by washing it with CH4 or product gas (c), and by finding such a method, the above problems can be solved. According to the present invention, a large amount of raw material gas can be treated in the pressure swing column (A) compared to when a clinobutyrolite adsorbent is used alone. For example, when using 240cc of adsorbent, the raw material gas that can be processed is 800cc.
Increase from cc/win to 1600cc/win.

In the method of the present invention, first, in a first pressure swing adsorption tower (A) filled with an adsorbent for CO selective separation and a clinobutyrolite adsorbent, a raw material gas is extracted from Co, CO-2, N
The z component is removed, and then hydrocarbon components are separated from N2 and N2 in a second pressure swing adsorption tower (B) filled with a porous adsorbent having organic gas adsorption properties or a surface-treated product thereof. .

The present invention will be explained in detail below.

[Red 11] The raw material gas (a) that can be applied to the present invention includes HL, Co,
It refers to a low-calorie raw material gas consisting of low-calorie components and/or non-combustible components such as COz and Nz, and hydrocarbons. For example, coke oven gas generated from a coke oven, methanation reaction gas, etc. are used. However, low calorie components and/or non-combustible components include HL, Co, Co
2, N2. It does not have to contain all the ingredients.

In addition, when the raw material gas (a) contains H2O, it is necessary to remove this to below the permissible limit. The presence of N20 interferes with the adsorption of polar components such as Co and CO2 in the first pressure swing adsorption tower (A) packed with an adsorbent for CO selective separation and a clinobutyrolite adsorbent. Because it does.

11-1 in 10;7'''A In the present invention, the first adsorption tower (A) is filled with an adsorbent for separating CO plate and a clinobutyrolite-based adsorbent. The adsorption tower (A) is usually filled with adsorbents such that the upper layer is a clinobutyrolite adsorbent, and the lower layer is an adsorbent for selective separation of CO.

The ratio of the adsorbent for CO selective separation and the clinobutyrolite adsorbent packed in the first adsorption tower (A) is from 1=1 to 1 in terms of volume ratio.
It is desirable to select from the range of 1:9, and by setting this ratio, the most efficient adsorption operation can be achieved.

(Adsorbent for Selective Separation of CO) As an adsorbent for selective separation of CO, an adsorbent in which a copper compound is supported on a porous carrier is used.

Examples of porous carriers include: - activated carbon, graphite, - polystyrene, - silica or/and alumina, - composite support with silica or/and alumina as a core and a layer of active organic material carbide formed on its surface, and - titania. , magnesia, etc. are all used.

Among these, the silica and/or alumina carriers (1) and (2) are preferred in terms of adsorption effect and lifespan, and the composite carrier (2) is particularly preferred, so the composite carrier (4) will be further described.

After the organic material is adsorbed onto silica or/and alumina, the composite carrier (2) is heat-treated for 30 minutes to 4 hours at a temperature of 300 to 800°C in an inert gas atmosphere such as N, argon, or helium. or,
It is produced by heat treatment at 500-1000'C for 30 minutes to 2 hours in an inert atmosphere of N2, argon, helium, etc. containing water vapor or CO2.

Yes J! A wide variety of monolithic materials can be used as long as they are carbonizable and soluble in solvents, such as water-soluble organic materials (polyacrylamide, polyvinylpyrrolidone, polyacrylates, polyvinyl methyl ether,
Polyethylene oxide, carboxyvinyl polymer ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose, alginate, gelatin, casein, dextrin, dextran, xanthine gum, guar gum, carrageenan, mannan, gum tragacanth, gum arabic, water-soluble acrylic copolymer, Water-soluble polyethyl, phenolic resin initial reactants, waste liquid-containing substances or intermediate products from wood, pulp and paper mills, waste liquid-containing substances or intermediate or final products from sucrose and starch factories, adhesive and textile dyeing factories organic solvent-soluble organic materials (polyamide, polystyrene, polyvinyl chloride, polyunidensyl chloride, polyester, polyutethane, polyacrylonitrile, polyolefin, acrylic resin, acetyl cellulose, petroleum or coal derivatives (e.g. Examples include polycyclic aromatic compounds and heterocyclic compounds with relatively large molecular weights. Particularly preferred are water-soluble organic materials, and a suitable one is selected from among these, taking into consideration ease of availability and economical aspects. Note that the polymers listed above include those with a low degree of polymerization and oligomers.

The quantitative ratio of the carbide layer formed on the surface of silica and/or alumina is 100 parts of the former to 0.0 parts of the latter.
The content is preferably 1 to 30 parts by weight, particularly 0.5 to 10 parts by weight, but is not necessarily limited to this range.

Next, the copper compounds to be supported on the porous carrier include copper halides (1) including copper chloride (I), copper oxide (I), and copper oxide (I).
), other copper(I) compounds, copper(II) halides including copper(II) chloride, copper(II) oxide,
Other copper (II) compounds may be mentioned. Copper (II
) When a compound is supported on a carrier, a reduced product of the compound may also be used. When copper (I) halide is used, aluminum halide can also be used together with it.

The amount of copper compound supported on the porous carrier is usually 0,5-
10 m-mol/g, preferably 1-6 m
It is often selected from the range of -mol/g.

(Clinobutyrolite adsorbent) The clinobutyrolite adsorbent is made from naturally occurring clinobutyrolite.

In other words, commercially available naturally occurring clinobutyrolite can be used as it is, or after being subjected to chemical treatment such as ion exchange and then crushed if necessary, or crushed and molded, sintered, or sintered with the addition of a suitable binder, or simply the above-mentioned. Heat-treated clinobutyrolite is used, and clinobutyrolite obtained by one synthesis method is also used as a raw material.

Ordinary zeolite adsorbents cannot convert low-calorie gas into high-calorie gas that does not contain CO, and are not suitable for the purpose of the present invention.

In the present invention using the second adsorption tower (B), the second adsorption tower (B) is filled with a porous adsorbent having organic gas adsorption properties or a surface-treated material thereof.

The porous adsorbent in the porous adsorbent packed tower (B) is preferably activated carbon, zeolite other than the above-mentioned clinobutyrolite (for example, mordenite), or molecular sieving carbon, but porous adsorbents having organic gas adsorption properties are preferred. Other adsorbents can also be used as long as they are adsorbents.

In addition, as a surface treatment material for a porous adsorbent having organic gas adsorption properties, the above-mentioned activated carbon, zeolite other than clinobutyrolite, or molecular sieving carbon may be used, and various water-soluble and/or organic solvent-soluble materials may be used. The surface is treated with a substance that has the following properties. Particularly suitable are those surface-treated with water-soluble polymers, water-soluble salts, or acids.

Here, examples of water-soluble polymers include those belonging to the water-soluble polymer materials among the organic materials described above in the description of the adsorbent for CO selective separation. Water-soluble salts include halides, nitrates, sulfates, sulfites, and acid sulfates of metal elements such as alkali metals, alkaline earth metals, zinc group metals, aluminum, chromium group metals, manganese group metals, and iron group metals. , phosphates, carbonates, heavy acid salts, acetic acid and other organic acid salts, cyanides, various complex salts, etc., which are water-soluble. As acids, hydrochloric acid,
Examples include nitric acid, sulfuric acid, sulfite, phosphoric acid, acetic acid, oxalic acid, citric acid, tartaric acid, malic acid, maleic acid, fumaric acid, and itaconic acid.

The adsorption operation in the adsorption towers (A) and (B) can be carried out at room temperature or under heating.

More specifically, the method of the present invention is carried out by the following process operations.

(1) Prior to introducing the raw material gas (a) and/or the exhaust gas (d) described below into the first adsorption tower (A), the same bath (
Intermediate product gas (b) derived from A), raw material gas (a)
) and exhaust gas (d); (2) source gas (a) and/or exhaust gas (d);
The raw material gas (a) is introduced into the first adsorption tower (A).
) and/or CO1C contained in exhaust gas (d)
A step in which O2, N2 components are adsorbed and an intermediate product gas (b) from which these components have been removed is led out from the same bath (A).

(3) C01C adsorbed in the first adsorption tower (A)
oz and Nz components are desorbed by decompression operation and exhaust gas (
Step d) of removing.

(4) Before introducing the intermediate product gas (b) derived from the first adsorption tower (A) into the second adsorption tower (B), the intermediate product gas (b) containing N2 derived from the second adsorption tower (B) is rich gas (
e), intermediate product gas (b), CH now or product gas (
Exhaust gas (f) during cleaning with c) and product gas (c)
The second adsorption tower (
(5) intermediate product gas (b) derived from the first adsorption tower (A) and/or CH or product gas (c);
By introducing the exhaust gas (f) during cleaning into the second adsorption tower (B), or by subsequently introducing the CH or product gas (
By cleaning with c), the intermediate product gas (b) and/or CH or product gas (c) adsorbs hydrocarbon components contained in the exhaust gas (f) during cleaning, and also removes H2 containing N2. (6) The hydrocarbon components adsorbed in the second adsorption tower (B) are depressurized to a certain pressure by a pressure reduction operation, and then CH4 or product gas is extracted. After washing in (c), the pressure is reduced to a predetermined pressure to desorb and recover as product gas (c).

FIG. 1 is a flow sheet showing the flow of the above steps.

Each of the above steps will be explained in detail below.

In the step (1), before introducing the raw material gas (a) and/or the exhaust gas (d) described below into the first adsorption tower (A),
It consists of a step of pressurizing the column (A) with at least one gas selected from intermediate product gas (b), raw material gas (a), and exhaust gas (d) derived from the column (A).

This pressure increase is necessary for the adsorption of C01Co2, N, L and for the effective separation of these components from the hydrocarbon components.

The pressure in this pressure increasing step (1) is 1 to 50 kg/c
It is possible to select from the range of m2G, but considering problems such as the increase in energy cost for gas compression,
It is preferable to set it to 5 to 1 Okg/cm"G.

In step (2), the raw material gas (a) and/or exhaust gas (d) is introduced into the first adsorption tower (A). c contained in
It consists of a step of adsorbing o, coλ, and N2 components, and deriving an intermediate product gas (b) from which these components have been removed from the same column (A).

This step is carried out in a first step.

The raw material gas (a) and/or exhaust gas (d) are introduced into the first adsorption tower (A) pressurized in the previous step (1) to
o, co, NZ acid components are adsorbed onto an adsorbent consisting of an adsorbent for CO selective separation and a clinobutyrolite adsorbent, and at the same time, hydrocarbon components are concentrated.

For example, the hydrocarbon component with the highest boiling point in the intermediate product gas (b) derived from the column (A) is the raw material gas (a).
) When the moisture content in the raw material gas (a) and/or
Or introduce exhaust gas (d) to the market. For example, when the CO concentration in the intermediate product gas (b) reaches a certain value or more, the raw material gas (a) and/or the exhaust gas (d)
1L of introduction.

In addition, CO1CO, N2. derived from the column (A). A part of the intermediate product gas (b) from which the components have been removed is used for pressurizing the column (A) in the above-mentioned step (1), and the remainder is introduced into the second adsorption column (B) described below.

In the upper step (3), the C adsorbed in the first adsorption tower (A) is
O, C02, N2. It consists of a step of desorbing the components by a reduced pressure operation and removing them as exhaust gas (d).

In this case, the pressure in the column CA) is reduced from a predetermined pressure to atmospheric pressure, and then further reduced in vacuum. At that time, a part of the exhaust gas (d) may be used as a recycled gas and used to boost the pressure of the column (A) in the above step (1), or introduced into the column (A) in the above step (2). I can do it.

The degree of vacuum in this step (3) is 0 to 760 torr.
From the range of co, C0-L, N2. adsorption amount, deflI
n or the rate of desorption.

In the Tokyo Tech process (4), before introducing the intermediate product gas (b) derived from the first adsorption tower (A) into the second adsorption tower (B),
Exhaust gas (f) during cleaning with N2-rich H2-rich gas (e), intermediate product gas (b), CH+ or product gas (c) derived from the second adsorption tower (B), and product gas ( It consists of a step of pressurizing the second adsorption tower (B) with at least one kind of gas selected from c).

Increasing the pressure in this manner is necessary to effectively adsorb and concentrate hydrocarbon components onto the porous adsorbent or its surface-treated material.

The pressure in this pressure increasing step (4) is 1 to 50 kg/
Although it can be selected from the range of CIIZG, it is preferable to set it to 5 to 10 kg/cm''G in consideration of problems such as increase in energy cost for gas compression.

In step (5), the intermediate product gas (b) derived from the first adsorption tower (A) and/or the exhaust gas (f ) into a second adsorption column (B) or by subsequent washing with CH4 or product gas (c).
and/or a step of adsorbing hydrocarbon components contained in the exhaust gas (f) during cleaning with CH+ or product gas (c), and deriving a gas (e) containing NZ and rich in H2.

This process is carried out in the following steps.

Intermediate product gas (b) derived from the first adsorption tower (A) to the second adsorption tower (B) pressurized in the previous step (4), and/or discharged during cleaning with CH4 or product gas (c) By introducing gas (f) or subsequently CH
By washing with water or product gas (c), hydrocarbon components are adsorbed onto the porous adsorbent or its surface-treated material, and at the same time, H2 and N2 components are separated.

Then, the introduction of the intermediate product gas (b) is stopped when, for example, CH4 is found in the Nz-rich H2-rich gas (e) derived from the column (B).

Note that a part of the gas (e) containing N and rich in H2 derived from the column 7 (B) is transferred to the column (B) in the above-mentioned step (4).
) and purge the remainder. Further, the exhaust gas (f) during cleaning with CH or product gas (c) can be introduced into the same bath (B) as a recycled gas.

In the first step (6), the hydrocarbon components adsorbed in the second adsorption tower (B) are reduced to a certain pressure by a pressure reduction operation and/or to CH4 or product gas (c). It consists of a step of desorbing and recovering product gas (c) by washing with water and then reducing the pressure to a predetermined pressure.

In this case, the pressure in the column (B) is reduced from a predetermined pressure to atmospheric pressure, and then further reduced in vacuum. At this time, a part of the product gas (e) desorbed during the pressure reduction is used as a recycle gas to increase the pressure of the column (B) in the above-mentioned step (4), and the remainder is recovered as a product gas.

Also, when cleaning with CH now or product gas (c),
The pressure in the column (B) is reduced from a predetermined pressure to an arbitrary pressure, and then washed with a predetermined amount of CH4 or product gas (c). Then, the pressure is reduced from an arbitrary pressure to atmospheric pressure. At that time, the product gas desorbed during depressurization (c) and the exhaust gas during cleaning (f
) is introduced as a recycle gas into the column (B) for pressurizing the column (B) in the above-mentioned step (4) or the column (B) in the above-mentioned step (5), and the remainder is recovered as a product gas (c).

The degree of vacuum in this step (6) is O to 760 torr.
It is set as appropriate from the range according to the amount of adsorption, amount of desorption, or rate of desorption of hydrocarbon components.

As mentioned in 1 above, the gas desorbed and recovered from the second adsorption tower (B) in step (6) by pressure reduction operation is the product gas (c).
It can be used directly as a fuel or as an additive for producing alternative natural gas.

Further, in step (3), the co, co, Nz concentrated gas desorbed from the first adsorption tower (A) by pressure reduction operation becomes exhaust gas (d) and is used as a chemical raw material or the like.

Similarly, the Nz-containing H2-rich gas (e) derived from the second column (B) in step (5) is used as a chemical raw material or the like.

Function In the present invention, Co, C is removed from the raw material gas (a) by pressure swing operation in the first adsorption tower (A) filled with an adsorbent for co selective separation and a clinobutyrolite adsorbent.
oλ component and intermediate product gas (b) are separated, and a second adsorption tower (B) filled with a porous adsorbent or its surface-treated product
Hydrocarbon components are separated and recovered by a pressure swing operation at.

Example Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Example 1 shows a case where the first half of the method of the present invention was carried out.

80 cc of commercially available activated alumina with an average particle size of 2 mm was added to 80 cc of a liquid obtained by diluting sulfite pulp waste liquid with a solid content of 47.5% by weight 10 times with water, and after soaking at room temperature for 30 minutes, filtered. It was dried at a temperature of 110° C. for 4 hours. After drying, the temperature was raised at 5 l/min under an NZ gas atmosphere using a heating furnace, and then heat treatment was performed at 550° C. for 1 hour to perform carbonization. As a result, a composite carrier having an alumina carrier as a core and an organic material carbide layer formed on the surface thereof was obtained. The quantitative ratio of the carbide layer to ioo parts by weight of the alumina support is 2
．． It was 3 parts by weight.

Copper (I) chloride 18 to 48 cc of hydrochloric acid warmed to about 60°C
g was dissolved. 80 cc of the composite carrier heated to 100°C was added to this solution, and while heating to 200 cc with a mantle heater, the solvent was distilled off in a Nz stream, cooled to room temperature, and an adsorbent for COJ distillation separation was added. Obtained.

The adsorbent for CO selective separation obtained above and a commercially available clinobutyrolite adsorbent were mixed at a volume ratio of 1.3 to 3. l: A first adsorption tower (A) filled with a clinobutyrolite adsorbent in the layer and an adsorbent for CO selective separation in the lower layer,
The raw material gas having the composition shown in the raw material gas column of Table 1 (
a) was introduced and the PSA cycle was repeated under the following operating conditions.

Operating conditions 1) Gas flow rate 11300 cc/win 2) Filling rate 240 cc (21mmφx 700mmH) 3) Pressure 7 kg/cmZG 4) Inner column temperature Room temperature 5) PSA cycle pressure increase 80 torr + 2 kg/ami
G (uses exhaust gas (d) that is desorbed when depressurizing from 7 kg/am"ZG to 4 kg/c+a2G) 2 kg/cm"G → 7 kg/cm2-G
(Using intermediate product gas (b)) - Adsorption 10 win 9 win: Adsorption time of raw material gas (a) Ill1in: 4 kg/am G to 200
Adsorption time of exhaust gas (d) desorbed when the pressure is reduced to torr/Atmospheric pressure reduction 7 kg/cm”G −+ Okg/c
m”GΦvacuum pressure reduction Okg/c+*”G+80
torr (exhaust gas (d) desorbed when reducing the pressure from 200 torr to 80 torr is removed as purge gas) The composition is shown in the column of intermediate product gas in Table 1.

Comparative Example 1 For comparison, the same raw material gas (a) as above was charged into the first adsorption tower (A) using only a commercially available clinobutyrolite adsorbent as an adsorbent, and the same raw material gas (a) as in Example 1 was charged. PS with conditions
Table 1 also shows the results when Cycle A was repeated 5 times.

Note to Table 1: The unit of gas composition is maol % The unit of gas calorie is kca I/N As can be seen from Table 1, in Example 1, CO2 is 100%,
Toxic CO was also significantly removed, resulting in an increase in the calorie content of the intermediate product gas (b). On the other hand, in Comparative Example 1 using only a clinobutyrolite adsorbent as an adsorbent, 100% of CO□ was removed, but toxic CO
Almost no O was removed, and more hydrocarbons to be recovered as intermediate product gas (b) were adsorbed than in Example 1. As a result, the calorie content of intermediate product gas (b) was lower than in Example 1. And it's getting lower.

Example 2 Example 2 shows the implementation of all steps of the method of the present invention.

The first adsorption tower (A) filled with the same CO selective separation adsorbent and clinobutyrolite adsorbent as in Example 1 was charged with a raw material gas (a) having the composition shown in the raw material gas column of Table 2. ), a PSA cycle was carried out under the following operating conditions, and a second adsorption tower (
B) is an intermediate product gas (
b) was introduced, and a PSA cycle was performed under the following operating conditions. In addition, in the second adsorption tower (B), the total of the gases desorbed from 3 kg/cm''G to Okg/cm2G at atmospheric pressure reduction and during vacuum reduction was defined as product gas (c).

Operating conditions of column (A) 1) Gas flow rate 1800 cc/win2) Filling amount
240 cc (21mmφX 700mmH) 3) Pressure 7 kg/cm"G 4) Inner tower temperature Room temperature 5) PSA cycle/pressure increase 80 torr + 2 kg/cm2
G (using the exhaust gas (d) that is desorbed when reducing the pressure from 7 kg/c+s2G to 4 kg/cmlG) 2 kg/cm2-G + 7 kg/c+5zG (using the intermediate product gas (b)) e-adsorption 10 rnin 9 win: Adsorption time of raw material gas (a) I l1in: 4 kg/am”G to 200to
Adsorption time of exhaust gas (d) desorbed during pressure reduction to rr Atmospheric pressure reduction 7 kg/cm"G + Okg/cm
”G・Vacuum reduced pressure Okg/cmLG + 80 to
rr (Exhaust gas (d) desorbed during pressure reduction from 200 torr to 80 torr is removed as purge gas) Operating conditions of tower (B) l) Gas flow rate 880 cc/main2) Filling @
240cc (21ausΦX 700mmH) 3) Pressure 8 kg/cmZG 4) Inner tower temperature 30°C 5) PSA cycle/pressure increase 200 torr-+ 2 kg/ca
+2G (from 6kg/cm1G to 3kg/ca+zG
2 kg/cm2-G + 8 g/cm2G (Nz
・Adsorption 5m1n30sec ・Atmospheric pressure reduction 8 kg/c+++”G→Okg/cm
'LG・Vacuum reduced pressure Okg/cm'LG + 200
The first adsorption tower (A
) and the composition of the product gas (c) recovered from the second adsorption tower (B) at the fifth indentation of the cycle are shown in Table 2.

Note to Table 2: The unit of gas composition is maol %. The unit of gas calorie is kcal/8m." As can be seen from Table 2, the product gas (c) has a COL of 100 % removed, CO, N, L, H2,
has also been largely removed. In addition, the recovery rate of product gas (c) (
The recovery rate of hydrocarbon components was 95%, and the gas calories improved significantly from 7640 to 080 kcal/Nm''.

Example 3 Example 3 shows the entire process of the present invention.

Dissolve commercially available polyvinyl alcohol in distilled water and add 10
00 ppm aqueous solution was made once, and then this polyvinyl alcohol aqueous solution 19. 250 cc of commercially available activated carbon was added to the solution and soaked for 1 hour. After that, separate the same activated carbon into 11
It was dried at 0° C. for 24 hours to obtain polyvinyl alcohol-treated activated carbon.

This polyvinyl alcohol-treated activated carbon is transferred to the second adsorption tower (B
) The PSA cycle was carried out under the same operating conditions as in Example 2, except that the intermediate product gas (b ) and the composition of the product gas (e) recovered from the second adsorption tower (B) at the fifth concavity of the cycle are shown in Table 3.

Note to Table 3: The unit of gas composition is Ma of %. The unit of gas calorie is kcal/Nm3. As can be seen from Table 3 and Example 2, polyvinyl alcohol-treated activated carbon was used in the second adsorption column (B). In this case, although the recovery rate of product gas (e) (recovery rate of hydrocarbon components) is the same as when commercially available activated carbon is used as is,
Gas calories are 7640 to 10380 kcal/N
m”. In this way, the second adsorption tower (
It can be seen that as the adsorbent to be filled in B), activated carbon treated with polyvinyl alcohol is superior to commercially available activated carbon.

Example 4 Example 4 shows the entire process of the present invention.

A 10% aqueous solution was prepared by dissolving commercially available MgC1z2 in distilled water, and then 250 cc of commercially available activated carbon was added to this MgC1z aqueous solution and immersed for 48 hours. After that, the activated carbon was separated and dried at 110°C for 48 hours, and the activated carbon was dried with N.
, MgC was heat treated at 300°C for 2 hours in an atmosphere.
1-4 treated activated carbon was obtained.

A PSA cycle was carried out under the same operating conditions as in Example 2, except that this MgCl2-treated activated carbon was used as an adsorbent to fill the second adsorption tower (B).

The composition of the intermediate product gas (b) derived from the first adsorption tower (A) at the fifth depression of the cycle, and the product gas (B) recovered from the second adsorption tower (B) at the fifth depression of the cycle execution. The composition of c) is shown in Table 4.

Note to Table 4: The unit of gas composition is malo 1z.The unit of gas calorie is kca 1/N. When used as an adsorbent to be filled in (B), the adsorption time is slightly shorter than when polyvinyl alcohol-treated activated carbon is used because the adsorption capacity is smaller, and the N2. Although there is a tendency for the removal rate of H2 to be slightly lower, the N2. , H2 removal rate is good, gas calories are 7640 to 10200
It can be seen that using MgCl and treated activated carbon is superior to using commercially available activated carbon.

Example 5 Example 5 shows the entire process of the present invention.

Add 300 cc of commercially available activated carbon to 1M of 1N-HCl, and add 1i! ! Soaked for a while. After that, separate the same activated carbon into 11
It was dried at 0°C for 48 hours.

PSA was carried out under the same operating conditions as in Example 2, except that this acid-washed activated carbon was used as an adsorbent to fill the second adsorption tower (B).
I went through a cycle.

The composition of the intermediate product gas (b) derived from the first adsorption tower (A) at the fifth depression of the cycle, and the product gas (B) recovered from the second adsorption tower (B) at the fifth depression of the cycle execution. The composition of c) is shown in Table 5.

Note to Table 5: The unit of gas composition is vol %. The unit of gas calorie is kca I/Ntn'. ), polyvinyl alcohol-treated activated carbon or MgCl
Compared to the case of using 2-treated activated carbon, N2. Although there is a tendency for the removal rate of , H2, to be slightly low, the removal rate of N, , and H2 is better than when commercially available activated carbon is directly filled, and the gas calories are 7,640 to 10,150 kca.
l/Nm'', indicating that the use of acid-washed activated carbon is superior to the use of commercially available activated carbon.

Example 6 Example 6 shows a case in which all the steps of the present invention were carried out, and in particular, a case in which a CH4 washing step was included in the second adsorption tower (B).

The raw material gas (a) shown in Table 6 was introduced into the first adsorption tower (A) filled with the same CO selective separation adsorbent and clinobutyrolite adsorbent as in Example 1, and the following operating conditions were applied. tePSA
While performing the cycle, the intermediate product gas (b) derived from the first adsorption tower (A) was introduced into the second adsorption tower (B) filled with commercially available activated carbon as an adsorbent, and P was heated under the following operating conditions.
An SA cycle was performed.

In addition, in the second adsorption tower (B), 3
The gas desorbed from kg/cm'G to Okg/c layer'LG was defined as product gas (c).

Operating conditions of column (A) 1) Gas flow rate 1800 cc/win2) Filling amount
240 cc (21 mmφ
(Using exhaust gas (d) that is desorbed when reducing the pressure from 7 kg/cm'LG to 4 kg/cmzG) 2 kg/cm"G → 7 kg/cm"G (using intermediate product gas (b))・Adsorption 10 win 9 win: Adsorption time of raw material gas (a) 1 sin: 4 kg/am”G to 200 tor
Adsorption time of exhaust gas (d) desorbed when the pressure is reduced to r 6 Atmospheric pressure reduction 7 kg/am2G −+ Okg/c
m2G/vacuum pressure reduction Okg/cm2G + 80 t
orr (Exhaust gas (d) desorbed when reducing the pressure from 200 torr to 80 tarr is removed as purge gas) Operating conditions of tower (B) l) Gas flow 7jH880cc c/min2) Filling amount 240 cc (21a+mφX 700mmH) 3) Pressure 6 kg/ca+2-G4) Tower internal temperature 30°C 3) PSA cycle/pressure increase Okg/am"G + 3 kg/cm
”G (using product gas (c) that is desorbed when depressurizing from 8 kg/cmzG to 3 kg/cm2-G) 3 kg/cm”G + 8 g/cya”G (Nz
0 adsorption 3 m 1n30sec -CH, cleaning 1000 cc ・Atmospheric pressure reduction 6 kg/c + w2G + Okg/c
Composition of the intermediate product gas (b) derived from the first adsorption tower (A) at the 5th concavity of the m''G cycle, and the composition of the intermediate product gas (b) recovered from the second adsorption tower (B) at the 5th time of the cycle implementation. The composition of the product gas (c) is shown in Table 6. Note to Table 6: The unit of gas composition is Ma of %. The unit of gas calorie is kcal/Nm. According to Table 6 and Examples 2 to 6, In the adsorption tower (B), CH
+ When washing and cleaning steps are included, the gas calorie of product gas (c) is 7640 to 10510 kcal/Nrn
” shows the greatest improvement compared to other examples.

As mentioned above, in order to increase product gas calories, CH
It can be seen that this process, which incorporates four cleaning steps, is very superior.

Effects of the Invention Since the present invention consists of the above-described process sequence, each process operation can be carried out smoothly and efficiently, and the target high-calorie product gas can be recovered with a high yield. Especially the second adsorption tower (
If a cleaning process is incorporated in B), the product gas calorie will be further improved.

Therefore, by implementing the method of the present invention, N2, C
Since high-calorie gas can be produced at low cost from hydrocarbon gas containing 01C02, NZ, etc. through a process that is simpler than before, it has great industrial significance.

In addition, during the production of high-calorie product gases, CO, CO2, and NZ W1i! are separated from the first adsorption tower (A). N2, including gas and N derived from the second adsorption tower (B)
Any gas rich in carbon dioxide can be used as a chemical raw material, etc., so it is advantageous in this respect as well.

[Brief explanation of drawings]

FIG. 1 is a flow sheet showing the process flow of the present invention. (1), (2), (3), (4), (5), (6)...
・Process, (a)... Raw material gas, (b)... Intermediate product gas, (c)... Product gas, (d)... Exhaust gas,
(e)...N2. N2-rich gas containing (f)...
・Exhaust gas during cleaning Figure 1 CH4 Procedure Ne City official document (voluntary) January 18, 1988

Claims (1)

[Claims] 1. A low-calorie raw material gas (a) consisting of low-calorie components and/or non-combustible components such as H_2, CO, CO_2, N_2 and hydrocarbons is first treated with an adsorbent for CO selective separation. An intermediate product gas (b) is produced by passing through a first pressure swing adsorption tower (A) filled with a clinobutyrolite-based adsorbent, and then this intermediate product gas (b) has organic gas adsorption properties. By introducing it into a second -pressure swing adsorbator (B) filled with porous adsorbent or its surface treatment, and / or the tower (b) by CH_4 or product gas (C). A method for producing a high-calorie gas, characterized in that a high-calorie product gas (c) is produced by washing. 2. The manufacturing method according to claim 1, wherein the adsorbent for CO selective separation is an adsorbent in which a copper compound is supported on a porous carrier. 3. The manufacturing method according to claim 2, wherein the porous carrier is a silica-based or/and alumina-based carrier. 4. Claim 1, wherein the clinobutyrolite adsorbent is made from naturally occurring clinobutyrolite or from synthetically obtained clinobutyrolite. manufacturing method. 5. The porous adsorbent having organic gas adsorption properties is activated carbon,
The manufacturing method according to claim 1, which is a zeolite other than clinobutyrolite or molecular sieving carbon. 6. The surface-treated porous adsorbent having organic gas adsorption properties is activated carbon, zeolite other than clinobutyrolite, or molecular sieving carbon that has been surface-treated with a water-soluble polymer, water-soluble salts, or acids. A manufacturing method according to claim 1. 7. A low-calorie raw material gas (a) consisting of low-calorie components such as H_2, CO, CO_2, N_2 and/or non-combustible components and hydrocarbons is first treated with an adsorbent for CO selective separation and clinobutyrolite-based adsorption. An intermediate product gas (b) is produced by passing through the first pressure swing adsorption tower (A) filled with an organic gas adsorbent, and then this intermediate product gas (b) is passed through a porous adsorbent having organic gas adsorption properties or its By introducing the surface-treated material into the second pressure swing adsorption tower (B) and performing a pressure swing operation, and/or by washing the same tower (B) with CH_4 or product gas (c), high In producing the calorie product gas (c), (1) the raw material gas (a) and/or the exhaust gas (described below)
d) into the first adsorption tower (A).
), intermediate product gas (b) and raw material gas (a) derived from
and a step of pressurizing the column (A) with at least one type of exhaust gas (d); (2) introducing the raw material gas (a) and/or the exhaust gas (d) into the first adsorption column (A); Possibly the raw material gas (a)
and/or CO contained in exhaust gas (d), CO
_2, a step of adsorbing N_2 components and deriving the intermediate product gas (b) from which these components have been removed from the same column (A), (3) CO adsorbed in the first adsorption column (A), CO_2 , a step of desorbing the N_2 component by decompression operation and removing it as exhaust gas (d), (4) intermediate product gas derived from the first adsorption tower (A) (
b) is introduced into the second adsorption tower (B), the N_2-containing H_2-rich gas (e), intermediate product gas (b), CH_4 or product gas ( Exhaust gas (f) during cleaning with c), and product gas (
c) pressurizing the second adsorption tower (B) with at least one type of gas selected from (5) intermediate product gas derived from the first adsorption tower (A) (
b), and/or CH_4 or product gas (c)
By introducing the exhaust gas (f) during washing into the second adsorption tower (B) or by subsequently washing with CH_4 or product gas (c), intermediate product gas (b) and/or CH_4 or product a step of adsorbing hydrocarbon components contained in the exhaust gas (f) during cleaning with the gas (c) and deriving a gas (e) containing N_2 and rich in H_2; (6) a second adsorption tower (B); The hydrocarbon components adsorbed in the step are desorbed by a pressure reduction operation and/or by reducing the pressure to a certain pressure, washing it with CH_4 or product gas (c), and then reducing the pressure to a predetermined pressure. 2. The manufacturing method according to claim 1, characterized in that the step of recovering as ) is performed.