JP2009001454A - Method for separating hydrogen-containing gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for separating hydrogen-containing gases whereby the generation of excessively highly pure hydrogen can be automatically inhibited without altering the number of the hydrogen separation membranes of a hydrogen separation membrane apparatus when highly pure hydrogen is separated from a hydrogen-containing gas comprising a reformer gas and a sweet gas and produced in a petroleum refining company (petroleum refining process) A. <P>SOLUTION: A second hydrogen-containing gas is passed through a hydrogen-containing gas pressure regulation means to regulate its pressure and is combined with a first hydrogen-containing gas. When the combined hydrogen-containing gas obtained by combining the first hydrogen-containing gas with the second hydrogen-containing gas is introduced into a hydrogen separation membrane apparatus, the temperature of the combined hydrogen-containing gas is regulated by a temperature regulation means, and the pressure of the highly pure hydrogen leaving the hydrogen separation membrane apparatus is regulated by means of a hydrogen-containing gas pressure regulation means, and at the same time, the energy used in the hydrogen-containing gas pressure regulation means and the temperature regulation means is minimized by regulation by a load regulation means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for separating a hydrogen-containing gas, and more specifically, a hydrogen-containing gas obtained from a petroleum refining process and a hydrogen-containing gas obtained from a petrochemical process are separated into high-purity hydrogen and off-gas. The present invention relates to a method of using these separated high-purity hydrogen and off-gas in an oil refining process.

Conventionally, in a petrochemical complex, many companies such as oil refining companies and petrochemical companies are located adjacent to each other.
FIG. 5 and FIG. 6 are schematic block diagrams showing the processes of the petroleum refining company (petroleum refining process) A and the petrochemical company (petrochemical process) B in these petrochemical complexes, and FIG. 5 shows the petrochemical complex. FIG. 6 is a schematic block diagram showing a process of an oil refinery company (petroleum refining process) A, and FIG. 6 is a schematic block diagram showing a process of a petrochemical company (petrochemical process) B in the petrochemical complex.

In these drawings, for convenience of explanation, a part is omitted for easy understanding.
By the way, in the oil refining company (oil refining process) A, as shown in FIG. 5, the crude oil transported by the crude oil tanker and stored in the crude oil tank is separated by distillation using the atmospheric distillation apparatus 100. Separated into gas, LPG, naphtha, kerosene, light oil and atmospheric residue.

Of these, the gas is used as a fuel gas in an oil refining company, and LPG recovers propane and butane via the LPG recovery device 102. In addition, naphtha uses a naphtha desulfurization apparatus 104 to remove hydrogen by desulfurization reaction by adding hydrogen and changing the sulfur content to hydrogen sulfide (H ₂ S). The catalytic reforming reaction is carried out using a catalyst in the presence. By this catalytic reforming reaction, hydrogen, methane, ethane, LPG and the like are obtained as by-products in addition to the reformed gasoline mainly composed of aromatic hydrocarbons.

  The reformed gasoline is mixed with another gasoline base material (for example, desulfurized naphtha, cracked gasoline obtained from a fluid catalytic cracking device, etc.) via the gasoline adjusting device 106 to produce gasoline.

  As shown in FIG. 7, the catalytic reformer 110 has a catalytic reformer reactor 111 and a gas separator 112, and through the gas separator 112, hydrogen, methane, ethane, LPG, Separated into reformate gasoline. Among these, the first hydrogen-containing gas containing hydrogen, methane, ethane, etc. is called “reformer gas” (hydrogen purity of about 70 to 80%) (hereinafter referred to as “reformer gas”). .

  In addition, the reformer gas separated by the gas separator 112 of the catalytic reformer 110 is used as a fuel gas in an oil refinery company in addition to being recycled for the reforming reaction in the catalytic reformer, and is changed to LPG. Quality gasoline is separated in the LPG separation tower.

Further, kerosene and light oil are removed by using a kerosene desulfurization device 108 and a light oil desulfurization device 114 to remove sulfur by a desulfurization reaction in which hydrogen is added and the sulfur content is changed to hydrogen sulfide (H ₂ S). Kerosene and diesel oil are manufactured.

Further, the atmospheric residue is separated into a vacuum gas oil and a vacuum residue by performing distillation separation using the vacuum distillation apparatus 116. The vacuum gas oil thus separated is removed by a fluid catalytic cracking device 101 after removing the sulfur content by desulfurization reaction using a heavy oil indirect desulfurization device 118 to add hydrogen and change the sulfur content to hydrogen sulfide (H ₂ S). Cracked gasoline and cracked light oil are produced.

On the other hand, the vacuum residue separated using the vacuum distillation apparatus 116 becomes a raw material for asphalt.
In addition, a part of the atmospheric residue is removed using a heavy oil direct desulfurization unit 120, after removing the sulfur content by desulfurization reaction by adding hydrogen and changing the sulfur content to hydrogen sulfide (H ₂ S). Via the apparatus 103, it is mixed with other heavy oil base materials (for example, cracked light oil, heavy oil direct desulfurization residue oil, etc.) to produce heavy oil.

The hydrogen, methane, hydrogen sulfide (hydrogen sulfide obtained by the desulfurization reaction by these desulfurization apparatuses, that is, the naphtha desulfurization apparatus 104, the kerosene desulfurization apparatus 108, the light oil desulfurization apparatus 114, the heavy oil indirect desulfurization apparatus 118, and the heavy oil direct desulfurization apparatus 120 ( The gas containing H ₂ S) is supplied to the gas cleaning device 122 as shown in FIGS.

In this gas cleaning device 122, only hydrogen sulfide (H ₂ S) is removed by contacting with an amine such as monoethanolamine or diisopropanolamine, and the second hydrogen-containing gas containing the remaining methane, hydrogen, etc. The so-called “sweet gas” (hydrogen purity of about 60%) is used as a fuel gas (hereinafter referred to as “sweet gas”).

  On the other hand, as shown in FIG. 5 and FIG. 6, in the petrochemical company (petrochemical process) B, the naphtha obtained in the oil refinery company (petroleum refining process) A is used as a raw material naphtha for petrochemicals. In addition to ethylene, propylene and the like, butane fraction, cracked gasoline and the like are obtained by the cracking and separating device 124.

  In the petrochemical company (petrochemical process) B, after purifying butylene from the butane fraction obtained by the naphtha cracking separation device 124, methyl ethyl ketone, secondary butyl alcohol, and the like are produced using the methyl ethyl ketone synthesizer 126. .

  By the way, in the oil refining company (oil refining process) A, high-purity hydrogen is used in the desulfurization apparatus, in particular, the light oil desulfurization apparatus 114, the heavy oil indirect desulfurization apparatus 118, the heavy oil direct desulfurization apparatus 120 and the isomerization apparatus. .

  For this reason, petroleum refining company (petroleum refining process) A requires a large amount of high-purity hydrogen. Although not shown in the drawing, using a hydrogen production device separately, high-purity hydrogen (hydrogen purity of about 97%) is used. This high-purity hydrogen is produced and used in the above desulfurization apparatus and isomerization apparatus.

  On the other hand, the reformer gas (hydrogen purity of about 70 to 80%) obtained by the catalytic reformer 110 is used in the naphtha desulfurizer 104, the kerosene desulfurizer 108, etc. as a hydrogen-containing gas other than the hydrogen production apparatus. However, since the hydrogen purity is low, it cannot be used for other desulfurization apparatuses. In addition, since the sweet gas (hydrogen purity of about 60%) obtained by the gas cleaning device 122 has low hydrogen purity and low pressure, it cannot be used as hydrogen for the desulfurization device in this state. For this reason, for example, it is used as a fuel gas for a heating furnace such as the atmospheric distillation apparatus 100, the vacuum distillation apparatus 116, and the desulfurization apparatus, or high purity hydrogen is separated through a hydrogen separation membrane apparatus, and the above desulfurization is performed again. Used in the device.

Conventionally, when high-purity hydrogen is separated through a hydrogen separation membrane device, the hydrogen separation membrane device is operated with a constant inlet pressure, outlet pressure, and inlet temperature in order to keep the hydrogen purity constant. It was. For this reason, when the hydrogen purity or flow rate of the reformer gas or sweet gas changes, the purity of hydrogen obtained by increasing or decreasing the number of hydrogen separation membranes of the hydrogen separation membrane device is kept constant.
JP 2003-327969 A

    However, in order to keep the hydrogen purity constant in the method of increasing / decreasing the number of hydrogen separation membranes, it is necessary to frequently switch the number of separation membranes in response to flow rate fluctuations, which increases the complexity of the work on site and improves. It was desired.

  In view of such a current situation, the present invention provides a hydrogen separation membrane device for separating high-purity hydrogen from a hydrogen-containing gas comprising reformer gas and sweet gas obtained in an oil refinery company (oil refinery process) A. An object of the present invention is to provide a hydrogen-containing gas separation method capable of automatically obtaining a certain hydrogen purity without increasing or decreasing the number of hydrogen separation membranes.

The present invention was invented in order to achieve the above-described problems and objects in the prior art, and the hydrogen-containing gas separation method of the present invention comprises a first hydrogen-containing gas obtained from a petroleum refining process. A hydrogen-containing gas separation method for separating a second hydrogen-containing gas having a pressure lower than that of the first hydrogen-containing gas into high-purity hydrogen and off-gas through a hydrogen separation membrane device,
Using the hydrogen-containing gas pressure adjusting means, the pressure of the second hydrogen-containing gas is adjusted and merged with the first hydrogen-containing gas,
When the hydrogen-containing combined gas obtained by combining the first hydrogen-containing gas and the second hydrogen-containing gas is introduced into the hydrogen separation membrane device, the temperature of the hydrogen-containing combined gas is adjusted using temperature adjusting means. ,
While adjusting the pressure of the high purity hydrogen obtained through the hydrogen separation membrane device using the high purity hydrogen pressure adjusting means,
The hydrogen-containing gas pressure adjusting means, the temperature adjusting means, and the high-purity hydrogen pressure adjusting means are controlled so as to minimize the energy used. In an oil refining company (oil refining process) A, reformer gas (first hydrogen-containing gas) obtained by the catalytic reformer 110 and sweet gas (second hydrogen-containing gas) obtained by the gas cleaning device 122 It can be separated into high-purity hydrogen and off-gas through a hydrogen separation membrane device.

  Furthermore, adjustment of the pressure (membrane inlet pressure) of the second hydrogen-containing gas (sweet gas) using the hydrogen-containing gas pressure adjusting means, and mixing of the hydrogen-containing combined gas (reformer gas and sweet gas) using the temperature adjusting means Gas) temperature (membrane inlet temperature), high-purity hydrogen pressure (membrane outlet pressure) adjustment using high-purity hydrogen pressure adjusting means, hydrogen-containing gas pressure adjusting means, temperature adjusting means, high purity Since it is controlled to minimize the energy used in the hydrogen pressure adjusting means, even if the hydrogen purity or flow rate of the reformer gas or sweet gas changes, the hydrogen separation membrane of the hydrogen separation membrane device Without increasing or decreasing the number, the purity of hydrogen can be kept constant, and the energy required for separating the hydrogen-containing gas can be automatically minimized. It is possible to reduce the Kosuto.

In the method for separating a hydrogen-containing gas according to the present invention, when the hydrogen purity of the first hydrogen-containing gas or the second hydrogen-containing gas is changed,
Adjusting the pressure of the second hydrogen-containing gas by the hydrogen-containing gas pressure adjusting means;
Adjustment of the temperature of the hydrogen-containing combined gas by the temperature adjusting means, or
One of the adjustments of the pressure of the high purity hydrogen by the high purity hydrogen pressure adjusting means is selectively performed.

Further, the method for separating a hydrogen-containing gas of the present invention, when the flow rate of the first hydrogen-containing gas or the second hydrogen-containing gas changes,
Adjusting the pressure of the second hydrogen-containing gas by the hydrogen-containing gas pressure adjusting means;
Adjustment of the temperature of the hydrogen-containing combined gas by the temperature adjusting means, or
One of the adjustments of the pressure of the high purity hydrogen by the high purity hydrogen pressure adjusting means is selectively performed.

  By comprising in this way, adjustment of the pressure (film inlet pressure) of the second hydrogen-containing gas (sweet gas) using the hydrogen-containing gas pressure adjusting means, and hydrogen-containing combined gas (reformer gas) using the temperature adjusting means Of the gas (mixed gas of gas and sweet gas) and the pressure of the high purity hydrogen (membrane outlet pressure) using the high purity hydrogen pressure adjusting means can be selectively performed. Optimum adjustment can be performed with respect to changes in the hydrogen purity and flow rate of the gas and sweet gas, and the purity of the hydrogen obtained through the hydrogen separation membrane device can be kept constant.

  Furthermore, in view of the cost required for adjusting the membrane inlet pressure, adjusting the membrane inlet temperature, and adjusting the membrane outlet pressure, adjust the membrane inlet pressure, the membrane inlet temperature, and the membrane outlet pressure as appropriate. Since it can be performed, the cost required to separate the hydrogen-containing gas can be reduced.

  Further, in the method for separating a hydrogen-containing gas of the present invention, high-purity hydrogen separated through the hydrogen separation membrane device is supplied to either a desulfurization step or an isomerization step in a petroleum refining step. It is configured.

  By comprising in this way, the high purity hydrogen separated through the hydrogen separation membrane device can be effectively used in the desulfurization process of the petroleum refining process and the isomerization process of isomerizing normal paraffin into isoparaffin. It is possible to reduce the operation of the hydrogen production equipment in the oil refining process.

The method for separating a hydrogen-containing gas according to the present invention is characterized in that the off-gas separated through the hydrogen separation membrane device is supplied to a petroleum refining process.
By configuring in this way, off-gas, which is a fuel gas composed of, for example, methane, ethane, etc., separated through the hydrogen separation membrane device, is converted into, for example, atmospheric distillation at an oil refinery company (oil refinery process) A. It can be effectively used as fuel gas for heating furnaces such as the apparatus 100, the vacuum distillation apparatus 116, and the desulfurization apparatus.

In the method for separating a hydrogen-containing gas of the present invention, the first hydrogen-containing gas is a hydrogen-containing gas obtained from the catalytic reforming step of the petroleum refining step.
In the method for separating a hydrogen-containing gas of the present invention, the second hydrogen-containing gas is a hydrogen-containing gas obtained from a desulfurization step of the petroleum refining step.

  By comprising in this way, the reformer gas (1st hydrogen containing gas) (hydrogen purity about 70-80%, pressure about 3.0MPa) obtained by the catalytic reformer 110, and the gas washing after a desulfurization process High purity hydrogen can be obtained from the sweet gas (second hydrogen-containing gas) obtained by the apparatus 122 (hydrogen purity: about 60%, pressure: about 0.3 MPa).

According to the present invention, in an oil refining company (oil refining process) A, from reformer gas (hydrogen purity of about 70 to 80%) obtained by the catalytic reformer 110 and sweet gas obtained by the gas scrubber 122. When separating the low purity hydrogen-containing gas into high purity hydrogen and off-gas through the hydrogen separation membrane device, the hydrogen separation membrane device is adjusted by adjusting the inlet pressure, outlet pressure, and inlet temperature of the hydrogen separation membrane device. A certain hydrogen purity can be obtained without increasing or decreasing the number of hydrogen separation membranes in the apparatus.

  As a result, even when the hydrogen purity or flow rate of the reformer gas or sweet gas changes, there is no need to switch the number of hydrogen separation membranes in the hydrogen separation membrane device, so that the work efficiency can be improved.

  In addition, the pressure (membrane inlet pressure) of the second hydrogen-containing gas (sweet gas) using the hydrogen-containing gas pressure adjusting means, the hydrogen-containing combined gas (mixed gas of reformer gas and sweet gas) using the temperature adjusting means ) Temperature (membrane inlet temperature) and high-purity hydrogen pressure (membrane outlet pressure) using a high-purity hydrogen pressure adjusting means can be selectively adjusted, so hydrogen in reformer gas and sweet gas Optimal adjustments can be made to changes in purity and flow rate, and the purity of hydrogen obtained through the hydrogen separation membrane device can be kept constant.

  Furthermore, in view of the cost required for adjusting the membrane inlet pressure, adjusting the membrane inlet temperature, and adjusting the membrane outlet pressure, adjust the membrane inlet pressure, the membrane inlet temperature, and the membrane outlet pressure as appropriate. Since it can be performed, the cost required to separate the hydrogen-containing gas can be reduced.

Hereinafter, embodiments (examples) of the present invention will be described in more detail with reference to the drawings.
FIG. 1 is a schematic block diagram of a hydrogen-containing gas using the method for separating a hydrogen-containing gas of the present invention. FIG. 2 is a schematic diagram of separation of sweet gas from the desulfurization step of FIG. It is a schematic block diagram which shows the outline of isolation | separation by the hydrogen separation membrane apparatus of the reformer gas from the contact reforming process of this.

In FIG. 1, the code | symbol 10 has shown the separation method of the hydrogen-containing gas of this invention as a whole.
In the method for separating a hydrogen-containing gas of the present invention, in the schematic block diagram shown in FIG. 5, in an oil refinery company (oil refinery process) A, naphtha is added with hydrogen using a naphtha desulfurization unit 104 to add sulfur content. After removing the sulfur content by a desulfurization reaction that converts hydrogen to hydrogen sulfide (H ₂ S), hydrocarbon gas of hydrogen, methane, and ethane obtained by the catalytic reformer 110 is used.

  That is, as shown in FIG. 2, the reformed gasoline reformed by the catalytic reformer 110 and the hydrocarbon gas obtained as a by-product are converted into methane, ethane, hydrogen, etc. via the gas separator 112. It is separated into a hydrogen-containing gas (hydrogen purity of about 70 to 80%, pressure of about 3.0 MPa), so-called “reformer gas” containing LGP, and reformed gasoline.

  In the method for separating a hydrogen-containing gas of the present invention, the reformer gas containing hydrogen, methane, ethane, etc. is used. As shown in FIG. In FIG. 11, first, the water is introduced into the washing tower 14 via the opening / closing valve 16. In the water washing tower 14, the reformer gas 12 is brought into AC contact with water to remove impurity gas such as chlorine gas contained in the reformer gas 12.

  Then, the reformer gas 12 from which the impurity gas has been removed by the water washing tower 14 is adjusted to a constant flow rate by a flow control valve (flow rate adjusting valve) 18, and is passed through the reformer gas introduction path 11. After merging with a sweet gas introduction path 20 which will be described later, it is introduced into the filter device 22.

On the other hand, in the schematic block diagram shown in FIG. 5, it was obtained by a desulfurization reaction by a desulfurization apparatus, that is, a naphtha desulfurization apparatus 104, a kerosene desulfurization apparatus 108, a light oil desulfurization apparatus 114, a heavy oil indirect desulfurization apparatus 118, and a heavy oil direct desulfurization apparatus 120. , Hydrogen, methane, ethane, hydrogen sulfide (H ₂ S) containing gas is brought into contact with an amine such as monoethanolamine or diisopropanolamine in the gas scrubber 122 as shown in FIG. Only hydrogen sulfide (H ₂ S) is removed to obtain a hydrogen-containing gas (hydrogen purity of about 60%, pressure of about 0.3 MPa) called “Sweet Gas” containing methane, ethane, hydrogen and the like. It is done.

  In the method for separating a hydrogen-containing gas according to the present invention, a sweet gas containing methane, ethane, hydrogen, or the like is used. As shown in FIG. First, the water is introduced into the washing tower 28 via the opening / closing valve 26. In this water-washing tower 28, the sweet gas 24 is brought into AC contact with water, whereby impurity gases such as ammonia gas and chlorine gas contained in the sweet gas 24 are removed.

  Then, since the pressure of the sweet gas 24 from which the impurity gas has been removed by the water washing tower 28 is a low pressure of about 0.3 MPa, the pressure is equivalent to about 3.0 MPa that is the pressure of the reformer gas 12. After the pressure is increased through the compressor (compressor) 30, the flow rate is adjusted to a constant flow rate by a flow rate adjusting valve (flow control valve) 32, and the above-described re-flow is set via the sweet gas introduction path 20. It is introduced into the filter device 22 together with the reformer gas 12 joined through the former gas introduction path 11.

  The sweet gas introduction path 20 is controlled so that a part of the sweet gas 24 pressurized by the compressor 30 is returned via the sweet gas recirculation path 36 and the pressure regulating valve 38, and the pressure of the sweet gas 24 is controlled. It is controlled to be constant.

  The hydrogen-containing gas composed of the reformer gas 12 and the sweet gas 24 introduced into the filter device 22 contains moisture by passing through the washing towers 14 and 18 in the filter device 22, and the scale is in the pipe. In order to prevent accumulation, dust such as moisture and scale is removed.

  In this way, the hydrogen-containing gas from which moisture and dust have been removed in the filter device 22 passes through the heat exchanger 40 and is heat-exchanged by low-pressure steam (about 0.3 MPa, 140 ° C.), and the hydrogen-containing gas. Is adjusted to be about 60 to 90 ° C. In the heat exchanger 40, the flow rate of the low-pressure steam is adjusted by the temperature control valve 42 so that the temperature of the hydrogen-containing gas is about 60 to 90 ° C.

  By passing through the heat exchanger 40 in this way, the hydrogen-containing gas maintained at a temperature of about 60 to 90 ° C. is introduced into the hydrogen separation membrane device 46 via the hydrogen separation membrane introduction path 44. It has become.

  Note that the number of the hydrogen separation membranes 48 of the hydrogen separation membrane device 46 can be appropriately changed according to the amount of the hydrogen-containing gas to be processed. In this embodiment, two hydrogen separation membranes 48 are used in consideration of the processing amount, but, of course, the number of hydrogen separation membrane devices 48 is not limited at all, and one or three or more hydrogen separation membrane devices 48 are used. There may be.

  The hydrogen separation membrane 48 of the hydrogen separation membrane device 46 is composed of, for example, a polymer hollow fiber membrane module, and hydrogen molecules with small molecules permeate the membrane, and other molecules such as methane with large molecules, for example, The gas does not permeate the membrane, and is configured so that hydrogen can be recovered with high purity.

High purity hydrogen (97% or more) separated by the hydrogen separation membrane 48 is introduced into the hydrogen supply path 54 constituting the hydrogen supply apparatus via the hydrogen recovery path 52.
In the hydrogen supply path 54, high-purity hydrogen is cooled to, for example, 40 ° C. by the heat exchanger 56. The high-purity hydrogen cooled by the heat exchanger 56 has been reduced in pressure to about 0.2 MPa, so that the pressure is increased through the compressor 58 so that the pressure is about 1.8 MPa. Thereafter, the flow rate is adjusted by the flow rate adjusting valve 60 so that the flow rate is constant, and is introduced into the high purity hydrogen header 62.

  If the pressure or flow rate of the high purity hydrogen flowing through the hydrogen supply path 54 becomes too high, the pressure control valve 64 is opened and a portion of the high purity hydrogen is incinerated via the high purity hydrogen disposal path 65. It can be disposed of.

  The hydrogen supply path 54 is controlled so that a part of the high-purity hydrogen boosted by the compressor 58 is returned via the hydrogen gas recirculation path 66 and the pressure regulating valve 68, and is introduced into the high-purity hydrogen header 62. The pressure of the high-purity hydrogen produced is controlled to be constant.

  The high-purity hydrogen introduced into the high-purity hydrogen header 62 in this manner is supplied to the oil refining company (petroleum refining process) A for the desulfurization reaction in the desulfurization unit and the isomerization process for isomerizing normal paraffin to isoparaffin. Can be done.

  On the other hand, the off gas containing other gases such as methane and ethane separated by the hydrogen separation membrane 48 is adjusted to a constant flow rate by the pressure adjustment valve 72 via the fuel gas recovery path 70. Thus, the gas is introduced into the off-gas supply path 74 constituting the off-gas supply device.

  In the off gas supply path 74, the off gas is cooled to, for example, 40 ° C. by the heat exchanger 76 and introduced into the fuel gas header 80. In the figure, reference numeral 78 denotes an open / close valve.

  The off-gas introduced into the fuel gas header 80 in this manner is converted into fuel gas, for example, heating at an oil refinery company (oil refinery process) A such as an atmospheric distillation apparatus 100, a vacuum distillation apparatus 116, and a desulfurization apparatus. It can be used as furnace fuel gas.

  The compressor 30, the flow rate adjustment valve 32, the temperature control valve 42, the pressure adjustment valve 72, the compressor 58, and the pressure adjustment valve 68 are automatically operated by a hydrogen separation membrane facility load control system 90 that performs load control of the hydrogen separation membrane facility. Controlled.

Hereinafter, a control method when the hydrogen purity or flow rate of the reformer gas 12 or the sweet gas 24 is changed will be described with reference to FIGS.
(1) Case where the flow rate is constant and the hydrogen purity is lowered FIG. 3 shows that the hydrogen purity of the high purity hydrogen obtained through the hydrogen separation membrane device 46 is constant when the hydrogen purity of the reformer gas 12 or the sweet gas 24 is lowered. It is a flowchart which shows the control step for maintaining.

  First, as shown in S100, when only the hydrogen purity is lowered while the flow rate of the reformer gas 12 or the sweet gas 24 is kept constant, the hydrogen gas is passed through the hydrogen separation membrane 48 as shown in S101. The hydrogen purity of the high purity hydrogen obtained will be reduced.

  Therefore, control is performed so that the hydrogen purity of the high-purity hydrogen is increased by taking any of the adjustment methods of S102, S108, and S113. Below, the process in which the hydrogen purity of high-purity hydrogen increases by each adjustment method will be described.

(A) Membrane inlet pressure adjustment case As shown in S102, by opening the pressure adjustment valve 72, the pressure of the reformer gas 12 and the sweet gas 24 is lowered as in S103, and the hydrogen separation membrane introduction path 44 The pressure drops. As a result, as shown in S104, the flow rate adjusting valves 18 and 32 are closed in order to keep the flow rates of the reformer gas 12 and the sweet gas 24 constant.

  On the other hand, since the pressure in the hydrogen recovery passage 52 is constant due to the decrease in the inlet pressure of the hydrogen separation membrane 48, the membrane differential pressure in the hydrogen separation membrane 46 is reduced, and hydrogen gas passes through the hydrogen separation membrane and the hydrogen recovery passage 52. However, as shown in S105, a gas other than hydrogen, for example, gas such as methane or ethane flows to the off-gas supply path 74 side without passing through the hydrogen separation membrane, thereby increasing the flow rate, as shown in S106. The flow rate of the hydrogen recovery path 52 decreases.

  This is because other gases such as methane and ethane do not easily pass through the hydrogen separation membrane 48 because the hydrogen molecules are smaller than other gases such as methane and ethane contained in the off-gas.

By controlling in this way, it is possible to increase the hydrogen purity of the high-purity hydrogen flowing through the hydrogen recovery path 52 as shown in S107.
In this embodiment, when the pressure on the suction port side of the compressor 58 is increased to reduce the compression ratio of the compressor 58, the power of the compressor 58 is reduced, that is, when the hydrogen-containing gas is separated. However, the present invention is not limited to this, and may be controlled so as to reduce the compression ratio of the compressor 30 or reduce the amount of low-pressure steam flowing into the heat exchanger 40. You may control as follows.

(B) Membrane outlet pressure adjustment case As shown in S108, the suction pressure of the compressor 58 rises by opening the pressure control valve 68, and the hydrogen recovery path 52 on the permeate side of the hydrogen separation membrane 46 as shown in S109. The flow rate decreases. Thereby, since the pressure of the hydrogen separation membrane introduction path 44 is constant, the membrane differential pressure of the hydrogen separation membrane 46 decreases.

  Here, when the membrane differential pressure of the hydrogen separation membrane 46 decreases, gases other than hydrogen that have permeated the hydrogen separation membrane 48 and flowed into the hydrogen recovery path 52, for example, other gases such as methane and ethane, are recovered off-gas. It flows to the path 74 side, and the flow rate of the off-gas supply path 74 increases as shown in S110.

This is because the molecules of other gases such as methane and ethane contained in the off-gas are larger than the hydrogen molecules, so that it is difficult for the hydrogen separation membrane 48 to permeate.
By controlling in this way, it is possible to increase the hydrogen purity of the high-purity hydrogen flowing through the hydrogen recovery path 52 as shown in S111.

(C) Membrane inlet temperature adjustment case As shown in S112, the pressure control valve 72 remains constant, and the temperature control valve 42 is closed to reduce the amount of low-pressure steam flowing into the heat exchanger 40, thereby separating hydrogen. The temperature of the hydrogen-containing gas flowing through the film introduction path 44 is lowered.

  When the temperature of the hydrogen-containing gas is low and other gases such as methane and ethane other than the hydrogen gas are inactivated, the hydrogen separation membrane 48 is less likely to be transmitted, and the temperature of the hydrogen-containing gas is reduced. Will pass through the hydrogen separation membrane 48 and the hydrogen purity of the high purity hydrogen flowing through the hydrogen recovery path 52 will increase.

By controlling in this way, it is possible to increase the hydrogen purity of the high-purity hydrogen flowing through the hydrogen recovery path 52 as shown in S113.
As described above, when only the hydrogen purity is lowered while the flow rate of the reformer gas 12 or the sweet gas 24 is kept constant, the membrane inlet pressure and the membrane outlet pressure are controlled by the hydrogen separation membrane equipment load control system 90. Any of the membrane inlet temperatures is selectively adjusted. For this reason, the hydrogen purity of the high purity hydrogen obtained through the hydrogen separation membrane 48 is kept constant.

  Note that which of the membrane inlet pressure, membrane outlet pressure, and membrane inlet temperature is adjusted is determined by the hydrogen separation membrane equipment load control system 90 by minimizing the power of the compressor 30 and the compressor 58, and the heat exchanger. 40 is selected to minimize the amount of low pressure steam used.

  In addition, by inputting the unit price of low-pressure steam and the unit price of power into the hydrogen separation membrane facility load control system 90 in advance, based on the amount of power used by the compressors 30 and 58 and the amount of steam used by the heat exchanger 40. The membrane inlet pressure, membrane outlet pressure, membrane inlet temperature can be adjusted so that energy costs are minimized.

  Furthermore, in any case of (a) membrane inlet pressure adjustment case, (b) membrane outlet pressure adjustment case, and (c) membrane inlet temperature adjustment case, adjustment is performed by the hydrogen separation membrane equipment load control system as in S114. The optimum adjustment means is selected based on the subsequent membrane inlet pressure, membrane outlet pressure, and membrane inlet temperature, and the membrane inlet pressure, membrane outlet pressure, and membrane inlet temperature are adjusted recursively.

  Thus, by recursively adjusting the membrane inlet pressure, membrane outlet pressure, and membrane inlet temperature, the hydrogen purity of high-purity hydrogen can be kept constant and the energy required for the separation of the hydrogen-containing gas can be automatically Can be minimized.

(2) Case of constant hydrogen purity and reduced flow rate Next, in order to keep the hydrogen purity of high-purity hydrogen constant when only the flow rate is lowered while the purity of reformer gas 12 or sweet gas 24 is kept constant. The control steps will be described with reference to FIG.

  First, as shown in S200, when only the flow rate is reduced while the hydrogen purity of the reformer gas 12 or the sweet gas 24 is kept constant, the hydrogen gas is passed through the hydrogen separation membrane 48 as shown in S201. The hydrogen purity of the high purity hydrogen obtained will be reduced.

  Therefore, control is performed so that the hydrogen purity of the high-purity hydrogen is increased by taking one of the adjustment methods of S202, S208, and S213. Below, the process in which the hydrogen purity of high-purity hydrogen increases by each adjustment method will be described.

(A) Membrane inlet pressure adjustment case As shown in S202, by opening the pressure adjustment valve 72, the pressure of the reformer gas 12 and the sweet gas 24 is lowered as in S203, and the hydrogen separation membrane introduction path 44 is The pressure drops. As a result, as shown in S204, the flow rate adjusting valves 18 and 32 are closed in order to keep the flow rates of the reformer gas 12 and the sweet gas 24 constant.

  On the other hand, since the pressure in the hydrogen recovery passage 52 is constant due to the decrease in the inlet pressure of the hydrogen separation membrane 48, the membrane differential pressure in the hydrogen separation membrane 46 is reduced, and hydrogen gas passes through the hydrogen separation membrane and the hydrogen recovery passage 52. However, as shown in S205, a gas other than hydrogen, for example, gas such as methane or ethane, flows through the off-gas supply path 74 without passing through the hydrogen separation membrane, thereby increasing the flow rate, as shown in S206. The flow rate of the hydrogen recovery path 52 decreases.

  This is because other gases such as methane and ethane do not easily pass through the hydrogen separation membrane 48 because the hydrogen molecules are smaller than other gases such as methane and ethane contained in the off-gas.

By controlling in this way, it is possible to increase the hydrogen purity of the high-purity hydrogen flowing through the hydrogen recovery path 52 as shown in S207.
In this embodiment, when the pressure on the suction port side of the compressor 58 is increased to reduce the compression ratio of the compressor 58, the power of the compressor 58 is reduced, that is, when the hydrogen-containing gas is separated. However, the present invention is not limited to this, and may be controlled so as to reduce the compression ratio of the compressor 30 or reduce the amount of low-pressure steam flowing into the heat exchanger 40. You may control as follows.

(B) Membrane outlet pressure adjustment case As shown in S208, the suction pressure of the compressor 58 rises by opening the pressure control valve 68, and the hydrogen recovery path 52 on the permeate side of the hydrogen separation membrane 46 as shown in S209. The flow rate decreases. Thereby, since the pressure of the hydrogen separation membrane introduction path 44 is constant, the membrane differential pressure of the hydrogen separation membrane 46 decreases.

  Here, when the membrane differential pressure of the hydrogen separation membrane 46 decreases, gases other than hydrogen that have permeated the hydrogen separation membrane 48 and flowed into the hydrogen recovery path 52, for example, other gases such as methane and ethane, are recovered off-gas. It flows to the path 74 side, and the flow rate of the off-gas supply path 74 increases as shown in S210.

This is because the molecules of other gases such as methane and ethane contained in the off-gas are larger than the hydrogen molecules, so that it is difficult for the hydrogen separation membrane 48 to permeate.
By controlling in this way, it is possible to increase the hydrogen purity of the high-purity hydrogen flowing through the hydrogen recovery path 52 as shown in S211.

(C) Membrane inlet temperature adjustment case As shown in S212, the pressure control valve 72 is kept constant, and the temperature control valve 42 is closed to reduce the amount of low-pressure steam flowing into the heat exchanger 40, thereby separating hydrogen. The temperature of the hydrogen-containing gas flowing through the film introduction path 44 is lowered.

  When the temperature of the hydrogen-containing gas is low and other gases such as methane and ethane other than the hydrogen gas are inactivated, the hydrogen separation membrane 48 is less likely to be transmitted, and the temperature of the hydrogen-containing gas is reduced. Will pass through the hydrogen separation membrane 48 and the hydrogen purity of the high purity hydrogen flowing through the hydrogen recovery path 52 will increase.

By controlling in this way, it is possible to increase the hydrogen purity of the high-purity hydrogen flowing through the hydrogen recovery path 52 as shown in S213.
As described above, when only the flow rate is reduced while the hydrogen purity of the reformer gas 12 or the sweet gas 24 is kept constant, the membrane inlet pressure, By adjusting either the membrane outlet pressure or the membrane inlet temperature, the hydrogen purity of the high purity hydrogen obtained through the hydrogen separation membrane 48 can be controlled to be kept constant.

  Note that which of the membrane inlet pressure, the membrane outlet pressure, and the membrane inlet temperature is adjusted is determined by the hydrogen separation membrane equipment load control system 90 and used in the power of the compressor 30 and the compressor 58 and in the heat exchanger 40. Is selected to minimize the amount of low pressure steam used.

  In addition, by inputting the unit price of low-pressure steam and the unit price of power into the hydrogen separation membrane facility load control system 90 in advance, based on the amount of power used by the compressors 30 and 58 and the amount of steam used by the heat exchanger 40. The membrane inlet pressure, membrane outlet pressure, membrane inlet temperature can be adjusted so that energy costs are minimized.

  Further, in any case of (a) membrane inlet pressure adjustment case, (b) membrane outlet pressure adjustment case, and (c) membrane inlet temperature adjustment case, as shown in S214, hydrogen separation membrane equipment load control system 90 Thus, the optimum adjusting means is selected based on the adjusted membrane inlet pressure, membrane outlet pressure, and membrane inlet temperature, and the membrane inlet pressure, membrane outlet pressure, and membrane inlet temperature are adjusted recursively.

  Thus, by recursively adjusting the membrane inlet pressure, membrane outlet pressure, and membrane inlet temperature, the hydrogen purity of high-purity hydrogen can be kept constant and the energy required for the separation of the hydrogen-containing gas can be automatically Can be minimized.

  As described above, when the hydrogen purity or flow rate of the reformer gas 12 or the sweet gas 24 changes, the hydrogen separation membrane equipment load control system 90 adjusts the membrane inlet pressure, the membrane outlet pressure, and the membrane inlet temperature. The hydrogen purity of the high purity hydrogen obtained through the hydrogen separation membrane 48 can be kept constant.

  For this reason, since it is not necessary to increase or decrease the number of the hydrogen separation membranes 48 according to changes in the hydrogen purity and flow rate of the reformer gas 12 and the sweet gas 24 as in the prior art, the working efficiency can be improved.

  The hydrogen separation membrane equipment load control system 90 automatically adjusts the membrane inlet pressure, the membrane outlet pressure, and the membrane inlet temperature based on the unit price of the low-pressure steam, the unit price of power, the amount of power used by the compressor, and the like. Since the adjustment can be performed selectively, the cost can be reduced.

  In this embodiment, only the case where the hydrogen purity or flow rate of the reformer gas 12 or the sweet gas 24 is reduced has been described. However, when the hydrogen purity or flow rate of the reformer gas 12 or the sweet gas 24 is increased, Even when the hydrogen purity and flow rate of the former gas 12 and the sweet gas 24 change at the same time, the membrane inlet pressure, the membrane outlet pressure, and the membrane inlet temperature are appropriately and selectively adjusted by the hydrogen separation membrane equipment load control system 90. As a result, the purity of hydrogen obtained through the hydrogen separation membrane 48 can be kept constant.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to this. For example, in the above embodiment, only the oil refining company (oil refining process) A is taken into consideration. , Petrochemical company (petrochemical process) B, other chemical companies, steel companies, etc., high purity hydrogen, off-gas which is the fuel obtained by the present invention is also used in the facilities of companies that require fuel Various modifications can be made without departing from the object of the present invention.

FIG. 1 is a schematic block diagram of the method for separating a hydrogen-containing gas of the present invention. 2 is a schematic block diagram showing an outline of separation of the sweet gas from the desulfurization process of FIG. 1 by the hydrogen separation membrane apparatus and an outline of separation of the reformer gas from the catalytic reforming process of FIG. 1 by the hydrogen separation membrane apparatus. It is. FIG. 3 is a flowchart showing control steps for keeping the hydrogen purity of the high purity hydrogen obtained through the hydrogen separation membrane device 46 constant when the hydrogen purity of the reformer gas 12 or the sweet gas 24 is lowered. is there. FIG. 4 is a flowchart showing control steps for keeping the hydrogen purity of the high purity hydrogen obtained through the hydrogen separation membrane device 46 constant when the flow rate of the reformer gas 12 or the sweet gas 24 is lowered. . FIG. 5 is a schematic block diagram showing a process of an oil refinery company (oil refinery process) A in a petrochemical complex. FIG. 6 is a schematic block diagram showing a process of a petrochemical company (petrochemical process) B in a petrochemical complex. FIG. 7 is a schematic block diagram showing an outline of separation of the reformer gas from the catalytic reforming step by the hydrogen separation membrane device. FIG. 8 is a schematic block diagram showing an outline of separation of the sweet gas from the desulfurization process by the hydrogen separation membrane device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Hydrogen-containing gas separation method 11 Reformer gas introduction path 12 Reformer gas 14 Flushing tower 16 On-off valve 18 Flow control valve 20 Sweet gas introduction path 22 Filter device 24 Sweet gas 26 On-off valve 28 Flushing tower 30 Compressor 32 Flow rate adjustment Valve 36 Sweet gas recirculation path 38 Pressure adjustment valve 40 Heat exchanger 42 Temperature control valve 44 Hydrogen separation membrane introduction path 46 Hydrogen separation membrane device 48 Hydrogen separation membrane 52 Hydrogen recovery path 54 Hydrogen supply path 56 Heat exchanger 58 Compressor 60 Flow rate Adjustment valve 62 High-purity hydrogen header 64 Pressure adjustment valve 65 High-purity hydrogen disposal path 66 Hydrogen gas recirculation path 68 Pressure adjustment valve 70 Fuel gas recovery path 72 Pressure adjustment valve 74 Off-gas supply path 76 Heat exchanger 78 Open / close valve 80 Fuel gas header 90 Hydrogen separation membrane equipment load control system 100 Atmospheric distillation apparatus 101 Fluid catalytic cracking apparatus 102 Recovery apparatus 103 Heavy oil adjustment apparatus 104 Naphtha desulfurization apparatus 106 Gasoline adjustment apparatus 108 Kerosene desulfurization apparatus 110 Contact reformer 111 Contact reformer reactor 112 Gas separator 112 Gas separator 114 Gas oil desulfurization unit 116 Vacuum distillation unit 118 Heavy oil indirect desulfurization unit 120 Heavy oil direct desulfurization unit 122 Gas scrubber unit 124 Naphtha cracking separation unit 126 Methyl ethyl ketone synthesis unit

Claims (7)

Hydrogen that separates the first hydrogen-containing gas obtained from the petroleum refining process and the second hydrogen-containing gas having a pressure lower than that of the first hydrogen-containing gas into high-purity hydrogen and off-gas through a hydrogen separation membrane device. A method for separating contained gas, comprising:
Using the hydrogen-containing gas pressure adjusting means, the pressure of the second hydrogen-containing gas is adjusted and merged with the first hydrogen-containing gas,
When the hydrogen-containing combined gas obtained by combining the first hydrogen-containing gas and the second hydrogen-containing gas is introduced into the hydrogen separation membrane device, the temperature of the hydrogen-containing combined gas is adjusted using temperature adjusting means. ,
While adjusting the pressure of the high purity hydrogen obtained through the hydrogen separation membrane device using the high purity hydrogen pressure adjusting means,
Hydrogen controlled using load control means so as to minimize energy used in the hydrogen-containing gas pressure adjusting means, the temperature adjusting means, and the high purity hydrogen pressure adjusting means Method for separating contained gas. When the hydrogen purity of the first hydrogen-containing gas or the second hydrogen-containing gas changes,
Adjusting the pressure of the second hydrogen-containing gas by the hydrogen-containing gas pressure adjusting means;
Adjustment of the temperature of the hydrogen-containing combined gas by the temperature adjusting means, or
2. The method for separating a hydrogen-containing gas according to claim 1, wherein any one of the adjustment of the pressure of the high purity hydrogen by the high purity hydrogen pressure adjusting means is selectively performed. When the flow rate of the first hydrogen-containing gas or the second hydrogen-containing gas changes,
Adjusting the pressure of the second hydrogen-containing gas by the hydrogen-containing gas pressure adjusting means;
Adjustment of the temperature of the hydrogen-containing combined gas by the temperature adjusting means, or
3. The method for separating a hydrogen-containing gas according to claim 1, wherein either of the adjustment of the pressure of the high purity hydrogen by the high purity hydrogen pressure adjusting means is selectively performed.   The high-purity hydrogen separated through the hydrogen separation membrane device is configured to be supplied to either a desulfurization step or an isomerization step of a petroleum refining step. 4. The method for separating a hydrogen-containing gas according to any one of 3 above.   5. The method for separating a hydrogen-containing gas according to claim 1, wherein the off-gas separated through the hydrogen separation membrane device is supplied to a petroleum refining process.   The method for separating a hydrogen-containing gas according to any one of claims 1 to 5, wherein the first hydrogen-containing gas is a hydrogen-containing gas obtained from a catalytic reforming step of the petroleum refining step.   The method for separating a hydrogen-containing gas according to any one of claims 1 to 6, wherein the second hydrogen-containing gas is a hydrogen-containing gas obtained from a desulfurization step of the petroleum refining step.

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