JPS61255994A - Production of high-calorie gas - Google Patents

Abstract

PURPOSE:To efficiently separate and remove a low-calorie gas component etc. and to recover a high-calorie product gas at low cost, by using a PSA method for removing a low-calorie component etc., from a low-calorie raw material gas comprising low-calorie components such as H2, CO, CO2 and N2 and/or a non-combustible component and hydrocarbon. CONSTITUTION:A low-calorie raw material gas comprising low-calorie components such as H2, CO, CO2 and N2 and/or a non-combustible component and a hydrocarbon is passed through a pressure swing adsorption tower packed with a clinoptilite adsorbent where a low-calorie component etc., are adsorbed to obtain an intermediate product gas. The intermediate product gas is fed to a pressure swing adsorption tower packed with a porous adsorbent having organic gas adsorbing properties where a hydrocarbon component is adsorbed while H2 is discharged. The adsorbed hydrocarbon component is desorbed in vacuo to obtain a high-calorie product gas.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to the production of the above-mentioned raw material gas from a low-calorie raw material gas consisting of a low-calorie component and/or a non-combustible component such as H, Co, CO2, NZ, and a hydrocarbon. Low calorie ingredients and/
Alternatively, the present invention relates to a method for obtaining a high-calorie product gas by separating and removing non-combustible components.

BACKGROUND ART In order to obtain a high-calorie product gas from a low-calorie raw material gas consisting of low-calorie components and/or non-combustible components such as Hz, CO, COx, N, etc. and hydrocarbons, it is necessary to extract these from the raw material gas. It is necessary to efficiently separate and remove low calorie components and/or non-combustible components. .

Conventionally, the following methods have been put to practical use as methods for removing these components from gases containing H2, CO, CO, or N2.

i) Removal of 'Hz PSA method (pressure fluctuation adsorption separation method), membrane separation method, cryogenic separation method 1i) Removal of Go cryogenic separation method, copper ammonia method, Cosorb (cO5ORB)
) method, methanesic electrification of CO1ii) Removal of CO2, thermal alkali carbonate method, two-stage treatment method of hot alkali carbonate and monoethanolamine, PSA methodi) Removal of Nz PSA method, cryogenic separation method Invention Problems to be solvedHowever, the above-mentioned separation technology for each gas alone is
With the exception of the PSA method, equipment costs are generally high, and the thermal energy of electricity, steam, etc. is large, and the combination of these technologies requires even more complex equipment, so it is not suitable for processing large volumes of gas. However, it cannot be said that it is advantageous for processing medium to small volumes of gas.

In addition, with regard to the PSA method, which is suitable for processing small volume gases, although it is possible to remove each gas individually, H,
, Co, Co, , N, etc., from a raw material gas containing various low-calorie components and/or non-combustible components, there is no method to simultaneously remove these components.

In view of the above situation, the present invention adopts the PSA method to
2. , C01CO1, N2. An industrial method for obtaining a high-calorie product gas by separating and removing the low-calorie components and/or non-combustible components from a low-calorie raw material gas consisting of low-calorie components and/or non-combustible components such as hydrocarbons, etc. This was done to find an advantageous method.

Means to solve problems The method for producing high calorie gas of the present invention includes H.

A low-calorie raw material gas (a) consisting of hydrocarbons and low-calorie components and/or non-combustible components such as CO, CO2, N, etc. is first passed through a pressure swing adsorption tower ( A) is passed through to form intermediate product gas (b), and then this intermediate product gas (b
) is introduced into a pressure swing adsorption tower (B) filled with a porous adsorbent having organic gas adsorption properties and subjected to a pressure swing operation to produce a high-calorie product gas (e). By discovering such a method, the above problems have been solved.

In the method of the present invention, first, in a pressure swing adsorption tower filled with a clinobutyrolite adsorbent, that is, a tower packed with a clinobutyrolite adsorbent (A), a raw material gas is
C02,, N2. a pressure swing adsorption tower that removes components and is then filled with a porous adsorbent that has organic gas adsorption properties;
That is, in the porous adsorbent packed column (B), hydrocarbon components and "N2" are separated.

The raw material gas (5L) applicable to the present invention includes H,
Co, CO, L, N2. It refers to a low-calorie raw material gas consisting of low-calorie components and/or non-combustible components such as hydrocarbons, and includes, for example, coke oven gas generated from a coke oven, methanation reaction gas, etc. however,
The low calorie component and/or non-combustible component is H,,C
Note that the raw material gas (a) does not need to contain all the components of N2. If O is included, it must be removed to below the permissible limit.

The presence of HzO indicates that the clinobutyrolite-based adsorbent packed column (
This is because, in A), it interferes with the adsorption of polar components such as CO and COλ.

The clinobutyrolite adsorbent in the clinobutyrolite packed tower (A) is one made from naturally occurring clinobutyrolite, that is, commercially available naturally occurring clinobutyrolite as it is or After chemical treatment such as ion exchange, it is crushed as necessary, or it is crushed and molded and sintered with the addition of an appropriate binder.
Alternatively, a material obtained by simply heat-treating the above-mentioned clinobutyrolite may be used, or a material made from clinobutyrolite obtained by a synthetic method may also be used.

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

The adsorption operation in the columns (A) and (B) can be performed at room temperature or under heating.

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

(1) *Before introducing the raw material gas (a) into the clinobutyrolite-based adsorbent packed column (A), the intermediate product gas (b) or the raw material gas C&') itself derived from the column (A) (2) introducing the raw material gas (a) into the clinobutyrolite-based adsorbent packed tower (A) to reduce the Co, COz, and CO contained in the raw material gas (a); a step of adsorbing the Nz component and deriving the intermediate product gas (b) from which these components have been removed from the tower (A); (3) adsorbing in the clinobutyrolite-based adsorbent packed tower (A); TaCO, COs, N2. (4) transferring the intermediate product gas (b) derived from the clinobutyrolite-based adsorbent-packed tower (A) to the porous adsorbent-packed tower; (
B) pressurizing the porous adsorbent packed column CB) with the N2-rich gas (e) or intermediate product gas (b) itself derived from the porous adsorbent packed column (B); (5) Clinobutyrolite-based adsorbent packed column (A
) by introducing the intermediate product gas (b) derived from the porous adsorbent packed tower (B), the intermediate product gas (b)
In addition to adsorbing the hydrocarbon components contained in the N2.
(6) Desorbing the hydrocarbon components adsorbed in the porous adsorbent packed tower (B) by depressurizing operation to produce a 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 step (1), before introducing the raw material gas (a) into the clinobutyrolite-based adsorbent packed column (A), the intermediate product gas (b) derived from the column (A), The pressure of the column (A) is increased by the following steps. In addition, the above intermediate product gas (b)
Instead of or together with this gas (b), raw material gas (a
) itself may be used for boosting the pressure.

This pressure increase is necessary for the adsorption of CO1CO1, N, 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 mG, but considering problems such as increase in energy cost for gas compression,
It is preferable to set it to 5 to 10 kg/c 2G.

In the process (2), the raw material gas (a) is introduced into the clinobutyrolite-based adsorbent packed column (A).
), the intermediate product gas (b) from which these components have been removed is led out from the same column (A).

This process is carried out in the following steps.

The raw material gas (a) is introduced into the clinobutyrolite-based adsorbent packed tower (A) pressurized in the previous step (1) to produce CO1C.
O$ and N2 components are adsorbed onto a clinobutyrolite adsorbent, and at the same time, hydrocarbon components are concentrated.

Then, the introduction of the raw material gas (a) is stopped when the concentration of the hydrocarbon component with the highest boiling point in the intermediate product gas (b) derived from the column (A) reaches a concentration equal to or higher than that in the raw material gas (a).

Note that a part of the intermediate product gas (b) from which CO1CO, N, and components have been removed derived from the column (A) is used for pressurizing the column (A) in the above-mentioned step (1), and the remainder is used as described below. into a porous adsorbent packed column (B).

The first step (3) in "L" is a clinobutyrolite-based adsorbent packed column (A
), the adsorbed CO1CO1, N, and components are desorbed by a reduced pressure operation and removed as a purge gas (d).

That is, first, the pressure in the column (A) is reduced from a predetermined pressure to atmospheric pressure, and then the pressure is further reduced to vacuum. Note that when the pressure is reduced to atmospheric pressure, a part of it may be recovered as intermediate product gas (b) and the remainder may be removed as purge gas (d).

The degree of vacuum in this step (3) is O-? 760torr
n) Set as appropriate to match the adsorption amount, desorption amount, or desorption rate of CO, CO, and N2 from the range.

Step 1 Step (4) is a clinobutyrolite-based adsorbent packed column (A
) Before introducing the intermediate product gas (b) derived from the porous adsorbent packed tower (B), the intermediate product gas (b) derived from the porous adsorbent packed tower (
It consists of the step of pressurizing the porous adsorbent packed column CB) with the Hλ-rich gas (e) derived from B). Note that this gas (e) may be used instead of the above H-rich gas (e).
), the intermediate product gas (b) itself may be used for pressurization.

This pressure increase is necessary for effective adsorption and concentration of hydrocarbon components onto the porous adsorbent.

The pressure in this pressure increasing step (4) is 1 to 50 kg/a
m'LG can be selected from a range of 5 to 10 kg/cm2G, but considering problems such as increase in energy cost for gas compression, it is preferable to set it to 5 to 10 kg/cm2G.

The second LAJ step (5) is a clinobutyrolite-based adsorbent packed column (A
) is introduced into the porous adsorbent-packed tower (B).
), as well as adsorbing hydrocarbon components contained in H,
It consists of a step of deriving a gas (e) rich in .

This process is carried out in the following steps.

Porous adsorbent packed tower CB pressurized in the previous step (4)
), the intermediate product gas (b) derived from the clinobutyrolite-based adsorbent packed column (A) is introduced, and the hydrocarbon components are adsorbed onto the porous adsorbent, and at the same time, the H2 component is concentrated.

and H-rich gas (e) derived from the column (B).
For example, when CH+ is detected in the intermediate product gas (
Stop introducing b).

In addition, H2. derived from the column (B). gas rich in (e)
A part is used for pressurizing the column (B) in the above-mentioned step (4), and the remainder is purged.

The Nisei Uyu step (6) consists of a step in which the hydrocarbon components adsorbed in the porous adsorbent packed tower (B) are desorbed by a pressure reduction operation and recovered as a product gas (c).

That is, first, the pressure in the column (B) is reduced from a predetermined pressure to atmospheric pressure, and then the pressure is further reduced to vacuum. Note that a part of the gas desorbed during depressurization may be purged as Hz-rich gas (e), and the remainder may be recovered as product gas (c).

The degree of vacuum in this step (3) is θ ~ 760 torr
The amount of adsorption and desorption of hydrocarbon components from the range of .

Alternatively, it is appropriately set to match the desorption rate.

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

In addition, in step (3), the CO1CO2, N, and concentrated gas desorbed from the column (A) by the pressure reduction operation becomes a purge gas (d) and is used as a chemical raw material.

Similarly, H derived from column CB) in step (5)
The gas (e) rich in , is used as a chemical raw material, etc.

Function In the present invention, the raw material gas (a) is
From Co, Co2. , N2 components and intermediate product gas (b) are separated, and hydrocarbon components and H are separated from intermediate product gas (b) by pressure swing operation in the porous adsorbent packed tower (B).

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

Example 1 Example 1 shows the case where the first half of the process of the present invention is implemented, that is, a clinobutyrolite-based adsorbent packed column (A
) shows the case where the PSA cycle was performed.

The first clinobutyrolite-based adsorbent packed tower (A) is filled with commercially available naturally occurring clinobutyrolite as an adsorbent.
Raw material gas (a) having the composition shown in the raw material gas column of the table
was introduced, and the PSA cycle was repeated under the following operating conditions.

Operating conditions Gas flow rate 800 cc/win Filling amount
240 cc (21 layers ■φ x 690-H) Pressure 7 kg/am G tower internal temperature
Room temperature PSA cycle pressure increase 80 torr −+ 7 kg/cm G
(Using intermediate product gas (b)) Adsorption 16 in Atmospheric pressure reduction 7 kg/cm"G + Okg/cm'LG Vacuum pressure reduction Okg/cm"G → 80 torr cycle implementation 2
Clinobutyrolite-based adsorbent packed tower (A)
The composition of intermediate product gas (b) derived from 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 introduced into a column packed with a commercially available zeolite adsorbent MS-5A as an adsorbent, and two PSA cycles were carried out under exactly the same conditions as in Example 1. Table 1 also shows the results obtained when the test was repeated twice.

Table 1 Note: The unit of gas composition is molz. The unit of gas calorie is kca 1/Nm."As seen from Table 1, in Example 1, CO is 100%,
N, was removed by 5G%, resulting in an increase in the calorie content of the intermediate product gas (b). On the other hand, in Comparative Example 1 using MS-5A as the adsorbent, 100% of coz was removed, but the adsorption of N was poor, and CH1,000 and CzH (which should be recovered as intermediate product gas (b)) were removed. As a result, the calorie of the intermediate product gas (b) is actually lower than the calorie of the raw material gas (a).

Example 2 Example 2 shows the case where the latter step of the method of the present invention was carried out, that is, the case where a PSA cycle was carried out in a packed column CB) using activated carbon as a porous adsorbent.

Using commercially available activated carbon as a porous adsorbent, an intermediate product gas (b) having the composition shown in the intermediate product gas column of Table 2 is introduced into a porous adsorbent packed tower (B) filled with this activated carbon. Then, the PSA cycle was repeated under the following operating conditions. Note that the total amount of gas desorbed during atmospheric pressure reduction and vacuum reduction was defined as product gas (c).

Operating conditions Gas flow rate 400 cc/win Filling amount
240 cc (21 layers ■φ x 890m rise H) Pressure 8 kg/cm"G tower internal temperature
30℃ PSA cycle pressure increase 200 torr + 8kg/cs”G(H
(using z-rich gas (e)) Adsorption 221n Purge 8 kg/cm'LG + 4 kg/cm
Product gas (c ) is shown in the product gas column of Table 2.

Note to Table 2: The unit of gas composition is Maol % The unit of gas calorie is kca 1/Nm'' As can be seen from Table 2, hydrocarbon gas is concentrated from 75% to 83%, and the gas calorie is 877011? It was a remarkable improvement from al/Nrn' to 10,490kcal/Ngo.

Example 3 Example 3 shows the implementation of all steps of the method of the present invention.

A third clinobutyrolite-based adsorbent packed tower (A) filled with naturally occurring clinobutyrolite as an adsorbent is
Raw material gas (&) having the composition shown in the raw material gas column of the table
was introduced and a PSA cycle was conducted under the following experimental conditions, and the intermediate product gas (b') derived from the tower (A) was transferred to a porous adsorbent-packed tower (B) filled with commercially available activated carbon as an adsorbent. was introduced, and a PSA cycle was performed under the following operating conditions. Note that the total amount of gas desorbed from the porous adsorbent packed tower (B) at atmospheric pressure and during vacuum depressurization is defined as the product gas (c
).

Operating conditions of tower (A) Gas flow rate 800 cc/sin Filling rate
240 cc (21mmφx 890mmH) Pressure 7 kg/cm G tower internal temperature
Room temperature (approximately 20℃) PSA cycle pressure increase 60 torr →7 kg/cm G (using intermediate product gas (b)) Adsorption ICI sin Atmospheric pressure reduction 7 kg/cm1G + Okg/ci+”G
Vacuum pressure reduction Okg/c+s”G + 80 torr Operating conditions of tower (B) Gas flow rate 400 cc/sin Filling amount
240 cc (2111!IΦX 890mmH) Pressure 8 kg/cmzG tower internal temperature
30℃ PSA cycle pressure increase 200 torr + El kg/cm G
(Using gas (e) rich in H2) Adsorption 22 win 8 kg/cmzG → 4 kg/cm"G atmospheric pressure reduction 4 kg/cm'LG + Okg/c+szG vacuum reduction Okg/c+a"G + 200 torr The composition of the intermediate product gas (b) derived from the clinobutyrolite-based adsorbent-packed tower (A) at the fifth time of the cycle, and the porous adsorbent-packed tower (at the fifth depression of the cycle)
Table 3 shows the composition of the product gas (c) recovered from B).

Table 3 Note: The unit of gas composition is Maol Z. The unit of gas calorie is kca 1/N. %, 80% of NZ was removed. Also,
The recovery rate of product gas (c) (recovery rate of hydrocarbon components) is 8
0%, gas calories range from 7810 to 10320
kcal/Nrn”.

Example 4 Example 4 shows the case where all steps of the method of the present invention were carried out.

An experiment was conducted under the same operating conditions as in Example 3, except that commercially available molecular sieving carbon (MSC) was used as the porous adsorbent and this MSC was packed into a porous adsorbent packed column CB). However, the adsorption time in the column (B) (the time when CH is first observed in the gas (e) derived from the column (B)) was 12 minutes.

The composition of the intermediate product gas (b) derived from the clinobutyrolite-based adsorbent-packed tower (A) at the fifth depression of the cycle, and the composition of the porous adsorbent-packed tower (B) at the fifth depression of the cycle. Table 4 shows the composition of the product gas (e) recovered from ).

Note to Table 4: The unit of gas composition is Maol % The unit of gas calorie is kca 1/N. Compared to activated carbon, the adsorption time is shorter because the adsorption capacity is smaller, and the N2 removal rate and product gas (c) recovery rate (hydrocarbon recovery rate) tend to be slightly lower than activated carbon. As for 761
0kcal/Nrn' to 10000kcal/Nm
It can be seen that the method of the present invention is superior.

Example 5 Example 5 shows the implementation of all steps of the method of the present invention.

Commercially available molecular sieve MS-5 as a porous adsorbent
A, this MS-5A was transferred to a porous adsorbent packed column (B).
The experiment was carried out under the same operating conditions as in Example 3, except that the liquid was filled in the container. However, the adsorption time in the column (B) (the time when CH+ was first observed in the gas (e) derived from the column (B)) was 10 minutes.

The composition of the intermediate product gas (b) derived from the clinobutyrolite-based adsorbent-packed tower (A) at the fifth depression of the cycle, and the composition of the porous adsorbent-packed tower (B) at the fifth depression of the cycle. Table 5 shows the composition of the product gas (c) recovered from ).

Table 5 Note: The unit of gas composition is m at 1 The unit of gas calorie is kca As can be seen from Table 5 and Example 3.4, MS-5A
When filled with carbon, the adsorption time is shorter because the adsorption capacity is smaller than that of activated carbon and MSC, and the removal rate of N and the recovery rate of product gas (c) (hydrocarbon recovery Although there is a tendency that the rate) is slightly lower, the gas calorie is 7E110kcal/Nr.
n'' to 9710 kcal/Nm', which shows that the method of the present invention is superior.

Effects of the Invention Since the present invention consists of the above-described process sequence, each process operation can be performed smoothly and efficiently, and the target high-calorie product gas can be recovered with a high yield.

Therefore, by implementing the method of the present invention, H2, C
It has great industrial significance because high-calorie gas can be produced at low cost from hydrocarbon gas containing O2CO2, Nz, etc. through a process that is simpler than before.

In addition, during the production of high-calorie product gas, CO and C are separated from the clinobutyrolite-based adsorbent packed column (A).
Gases rich in Oλ, N, concentrated gas, and H derived from the porous adsorbent-packed tower (B) can all be used as chemical raw materials, so they are 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, C&)...source gas, (b)...intermediate product gas, (c)...product gas, (d)...purge gas, (e)...H2-rich gas patent Applicant Kansai Thermal Chemical Co., Ltd. Figure 1

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 a clinobutyrolite-based adsorbent. An intermediate product gas (b) is produced by passing through a pressure swing adsorption tower (A) filled with the gas, and then this intermediate product gas (b) is passed through a pressure swing adsorption column filled with a porous adsorbent having organic gas adsorption properties. A method for producing a high-calorie gas, which comprises introducing the gas into a column (B) and performing a pressure swing operation to produce a high-calorie product gas (c). 2. Claim 1, wherein the clinobutyrolite adsorbent is made from naturally occurring clinobutyrolite or from synthetically obtained clinobutyrolite. manufacturing method. 3. 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. 4. 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 subjected to pressure swing adsorption filled with a clinobutyrolite adsorbent. An intermediate product gas (b) is produced by passing through the column (A), and then this intermediate product gas (b) is introduced into a pressure swing adsorption column (B) filled with a porous adsorbent having organic gas adsorption properties. (1) Before introducing the raw material gas (a) into the clinobutyrolite-based adsorbent-packed column (A), Step of pressurizing the column (A) with the intermediate product gas (b) derived from (A) or the raw material gas (a) itself; (2) Pressure of the raw material gas (a) into the clinobutyrolite-based adsorbent packed column ( A step in which the CO, CO_2, and N_2 components contained in the raw material gas (a) are adsorbed by introducing into the raw material gas (a), and the intermediate product gas (b) from which these components have been removed is led out from the same column (A). (3) A step of desorbing CO, CO_2, and N_2 components adsorbed in the clinobutyrolite-based adsorbent packed column (A) by decompression operation and removing them as a purge gas (d). (4) The intermediate product gas (b) derived from the clinobutyrolite adsorbent packed tower (A) is transferred to the porous adsorbent packed tower (B).
) of pressurizing the porous adsorbent packed column (B) with the H_2-rich gas (e) or intermediate product gas (b) itself derived from the porous adsorbent packed column (B), prior to introduction into the porous adsorbent packed column (B); (5) The intermediate product gas (b) derived from the clinobutyrolite adsorbent packed tower (A) is transferred to the porous adsorbent packed tower (B).
) to adsorb the hydrocarbon components contained in the intermediate product gas (b) and to derive the H_2-rich gas (e); (6) in the porous adsorbent packed column (B); The adsorbed hydrocarbon components are desorbed by a reduced pressure operation to produce a product gas (c).
The manufacturing method according to claim 1, characterized in that the step of recovering as