WO2017169690A1 - Appareil de production de gaz à adsorption modulée en pression - Google Patents

Appareil de production de gaz à adsorption modulée en pression Download PDF

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Publication number
WO2017169690A1
WO2017169690A1 PCT/JP2017/009956 JP2017009956W WO2017169690A1 WO 2017169690 A1 WO2017169690 A1 WO 2017169690A1 JP 2017009956 W JP2017009956 W JP 2017009956W WO 2017169690 A1 WO2017169690 A1 WO 2017169690A1
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Prior art keywords
gas
pressure
adsorption
adsorption tower
flow rate
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PCT/JP2017/009956
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English (en)
Japanese (ja)
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田中啓
横山晃太
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大阪瓦斯株式会社
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Publication of WO2017169690A1 publication Critical patent/WO2017169690A1/fr

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/02—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography
    • B01D53/04—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography with stationary adsorbents
    • B01D53/047—Pressure swing adsorption
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/22—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by diffusion
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/50—Carbon dioxide
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C7/00—Purification; Separation; Use of additives
    • C07C7/12—Purification; Separation; Use of additives by adsorption, i.e. purification or separation of hydrocarbons with the aid of solids, e.g. with ion-exchangers
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C7/00—Purification; Separation; Use of additives
    • C07C7/144—Purification; Separation; Use of additives using membranes, e.g. selective permeation
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C9/00—Aliphatic saturated hydrocarbons
    • C07C9/02—Aliphatic saturated hydrocarbons with one to four carbon atoms
    • C07C9/04—Methane

Definitions

  • the present invention is a form in which an adsorbent that adsorbs the miscellaneous gas from a source gas containing the gas to be purified and other miscellaneous gas is filled, and the source gas supply path is connected to one end side to discharge the gas to be purified
  • An operation control unit that sequentially performs the operation cycle including the desorption process with different phases is provided,
  • a membrane separation unit comprising a separation membrane that allows the miscellaneous gas to pass through the offgas discharge passage faster than the gas to be purified, and a membrane in the membrane separation unit for offgas discharged from the adsorption tower in the de
  • a booster is provided for boosting and supplying to the membrane separator for separation;
  • the present invention relates to a pressure fluctuation adsorption gas production apparatus provided with a recycle gas return path for returning a recycle gas that does not pass through the separation membrane to the raw material gas supply path.
  • a membrane separation unit for separating the miscellaneous gas from the off-gas is provided, and the miscellaneous gas is separated.
  • the off-gas is returned to the raw material gas supply path as a recycle gas, thereby improving the production efficiency of the purification target gas while reducing the load on the adsorption tower.
  • Patent Document 1 a hydrogen-containing gas containing hydrogen as a purification target gas as a source gas and oxygen dioxide or methane as a miscellaneous gas is described.
  • Patent Document 1 the hydrogen-containing gas after passing through the membrane separation unit is supplied to the carbon dioxide separation membrane, and the hydrogen-containing gas from which carbon dioxide has been separated is returned to the source gas supply path as a recycle gas. It is configured.
  • the internal pressure of the off-gas discharge path is reduced in the avoidance of adversely affecting the pressure-increasing unit due to the operation in the idling state where no off-gas exists or in the desorption process.
  • the amount of off-gas discharged from the adsorption tower every time the desorption process is performed and the amount sent out by the pressurizing unit after another adsorption tower starts the desorption process after the adsorption tower starts the desorption process. It can be considered that the sending amount of the booster is determined so as to be equal.
  • the raw material gas supplied through the raw material gas supply path is combined with the recycle gas and supplied to the adsorption tower.
  • the concentration of the purification target gas of the raw material gas supplied to the adsorption tower is the same as that of the raw material gas itself. It changes when the concentration of the gas to be purified changes, or the flow rate of the recycle gas or the concentration of the gas to be purified of the recycle gas changes.
  • the concentration of the gas to be purified of the raw material gas itself decreases, the amount of off-gas discharged from the adsorption tower increases, and when the amount of off-gas increases in this way, it is returned to the raw material gas supply path.
  • the amount of recycled gas increases, and the amount of miscellaneous gas returned to the raw material gas supply path through the recycled gas return path increases.
  • the recycle gas is an off gas after the miscellaneous gas is separated in the membrane separation unit, and therefore, the miscellaneous gas amount is reduced as compared with the off gas discharged from the adsorption tower, but includes the miscellaneous gas amount.
  • the amount of recycle gas returned to the source gas supply path increases, the amount of miscellaneous gas returned to the source gas supply path increases.
  • the source gas purification target gas supplied to the adsorption tower Inconveniently, the concentration of the gas to be purified that is exhausted from the adsorption tower is greatly reduced from the proper concentration. There is a risk of inviting.
  • the present invention has been made in view of the above circumstances, and its object is to purify the gas to be purified discharged from the adsorption tower regardless of the decrease in the concentration of the gas to be purified of the raw material gas supplied to the adsorption tower. It is in the point which provides the pressure fluctuation adsorption type gas manufacturing apparatus which can suppress the fall of the density
  • the pressure fluctuation adsorption type gas production apparatus of the present invention is a form in which an adsorbent that adsorbs the miscellaneous gas from a source gas containing a gas to be purified and other miscellaneous gases is filled, and the source gas supply path is on one end side.
  • An adsorption step of adsorbing the miscellaneous gas from the source gas supplied through the source gas supply path and discharging the purification target gas through the purification target gas discharge path, and discharging the miscellaneous gas through the off-gas discharge path An operation control unit that sequentially performs the operation cycle including the desorption process with different phases is provided, A membrane separation unit comprising a separation membrane that allows the miscellaneous gas to pass through the offgas discharge passage faster than the gas to be purified, and a membrane in the membrane separation unit for offgas discharged from the adsorption tower in the desorption step.
  • the concentration of the gas to be purified of the raw material gas supplied to the adsorption tower decreases, the supply flow rate of the raw material gas is corrected to the decrease side, and the purification target of the raw material gas to be supplied to the adsorption tower
  • the raw material gas adjusting unit is adjusted to correct the supply flow rate of the raw material gas to the increasing side.
  • the internal pressure of the off-gas discharge path is excessively increased while avoiding the adverse effect on the pressure-up section because the off-gas does not exist in the flow path portion located between the adsorption tower and the pressure-up section in the off-gas discharge path.
  • the desorption process it is possible to prevent the desorption process from being performed properly.
  • the operation control unit adjusts the raw material gas adjustment unit to reduce the supply flow rate of the raw material gas supplied to the adsorption tower. Therefore, when the concentration of the gas to be purified of the raw material gas decreases, an increase in the amount of off-gas discharged from the adsorption tower is suppressed. And by suppressing the increase in the amount of off-gas in this way, the increase in the amount of recycle gas returned to the source gas supply path is suppressed, and the amount of miscellaneous gas returned to the source gas supply path through the recycle gas return path is reduced. The increase is suppressed.
  • the concentration of the purification target gas of the source gas supplied to the adsorption tower increases, the supply flow rate of the source gas is corrected to the increase side, so that the reduction in the purification amount of the purification target gas is suppressed. Can do.
  • the concentration of the purification target gas discharged from the adsorption tower regardless of the decrease in the concentration of the purification target gas of the raw material gas supplied to the adsorption tower. Can be suppressed.
  • the operation control unit is configured to perform the adsorption based on at least one of the flow rate of the recycle gas and the concentration of the gas to be purified of the recycle gas.
  • column may be discriminate
  • the characteristic configuration of the pressure fluctuation adsorption gas production apparatus of the present invention it is possible to satisfactorily discriminate between a decrease and an increase in the concentration of the gas to be purified of the source gas supplied to the adsorption tower.
  • a further characteristic configuration of the pressure fluctuation adsorption gas production apparatus of the present invention is that the operation control unit supplies the adsorption tower based on the concentration of the gas to be purified of the raw material gas before the recycle gas joins. It is configured to discriminate a decrease and an increase in the concentration of the purification target gas of the raw material gas.
  • the operation control unit discriminates a decrease and an increase in the concentration of the purification target gas of the raw material gas supplied to the adsorption tower based on the concentration of the purification target gas of the raw material gas before the recycle gas joins. Therefore, the decrease and increase in the concentration of the purification target gas of the raw material gas supplied to the adsorption tower can be well determined based on the concentration of the purification target gas of the raw material gas before the recycle gas joins.
  • the characteristic configuration of the pressure fluctuation adsorption gas production apparatus of the present invention it is possible to satisfactorily discriminate between a decrease and an increase in the concentration of the gas to be purified of the source gas supplied to the adsorption tower.
  • a further characteristic configuration of the pressure fluctuation adsorption type gas production apparatus of the present invention is provided with an off gas tank for storing off gas discharged from the adsorption tower at a location upstream of the pressure increasing unit in the off gas discharge path,
  • the boosting unit is configured to supply the off-gas stored in the off-gas tank to the membrane separation unit.
  • the desorption process can be improved by setting the internal pressure of the offgas tank to a low pressure suitable for the desorption process. It can be carried out. That is, since the off gas is temporarily stored in the off gas tank, and the stored off gas is boosted by the pressurizing unit and supplied to the membrane separation unit, the off gas can be stored in the off gas tank at a sufficiently low pressure. Therefore, the desorption process can be performed satisfactorily.
  • the operation control unit changes the supply flow rate of the off gas supplied from the booster unit to the membrane separation unit, the amount of off gas discharged from the adsorption tower every time the desorption process is performed, and another time after the adsorption tower starts the desorption process.
  • the internal pressure of the off-gas tank becomes excessive by adjusting the off-gas adjusting unit so that the amount of off-gas supplied to the membrane separation unit becomes equal until the adsorption tower starts the desorption process. Therefore, the internal pressure of the off-gas tank becomes excessive and the desorption process cannot be performed properly, or the internal pressure of the off-gas tank becomes excessive and adversely affects the boosting section.
  • the desorption process can be performed satisfactorily while avoiding this.
  • the desorption process of the adsorption tower can be performed satisfactorily.
  • a further characteristic configuration of the pressure fluctuation adsorption gas production apparatus of the present invention is that the raw material gas is a methane-containing gas containing 40% or more of methane as the purification target gas, and is discharged through the purification target gas discharge passage.
  • the purification target gas is a product gas containing 80% or more of methane.
  • a methane-containing gas containing 40% or more of methane as a purification target gas can be efficiently purified to a product gas containing 80% or more of methane.
  • a methane-containing gas containing 40% or more of methane as a purification target gas can be efficiently purified into a product gas containing 80% or more of methane.
  • the biogas as the raw material gas G is mainly composed of methane and carbon dioxide, and has a methane content of about 60%.
  • the pressure fluctuation adsorption type gas manufacturing apparatus of this embodiment is comprised so that the gas purification for obtaining the product gas H containing 80% or more of methane may be performed.
  • a tower, B tower, C tower, and D tower are provided as four adsorption towers 1, and the lower end side of the four adsorption towers 1 is provided with a compressor 2 as a raw material booster.
  • a source gas supply path 3 that supplies the pressurized source gas G and an offgas discharge path 4 that discharges offgas are connected.
  • the compressor 2 is provided with a back pressure valve 2A for maintaining the supply pressure at a set value (for example, 750 kPaG).
  • a raw material gas adjusting unit MG for adjusting the raw material gas supply amount to the target supply amount is provided.
  • the source gas adjusting unit MG is configured using a mass flow controller, detects the flow rate of the source gas G flowing through the source gas supply path 3, and the detected flow rate is an operation control unit F (see FIG. 2) described later.
  • the flow rate of the raw material gas G is controlled so as to be the target flow rate commanded from (1). Since details of the mass flow controller are well known, detailed description is omitted in this embodiment.
  • source gas supply valves A1, B1, C1, D1 for opening and closing the source gas supply path 3, and off gas discharge valves A5, B5 for opening and closing the off gas discharge path 4, C5 and D5 are provided.
  • a raw material side concentration sensor SG for detecting a methane gas concentration (a methane concentration in the raw material gas) that is a concentration of the gas to be purified of the raw material gas G is provided.
  • a product gas delivery path 5 as a purification target gas discharge path for delivering the product gas H is provided, and the product gas H is stored in the product gas tank 6 through the product gas delivery path 5. It is configured to be.
  • a tower communication passage 7 for connecting the four adsorption towers 1 to each other is connected to the upper part of the four adsorption towers 1.
  • product gas delivery valves A 2, B 2, C 2, D 2 that open and close the product gas delivery path 5, and communication on / off valves A 4, B 4 that open and close the tower communication path 7, C4 and D4 are provided.
  • the product gas delivery path 5 is provided with a product side concentration sensor SH for detecting the methane gas concentration (the methane concentration in the product gas) which is the concentration of the gas to be purified of the product gas H, and the methane concentration in the product gas is Whether or not the concentration is appropriate can be monitored.
  • the methane gas concentration the methane concentration in the product gas
  • the off-gas discharge path 4 is provided with a membrane separation unit 9 having a separation membrane 9A, and a booster pump 10 as a boosting unit that boosts off-gas and supplies it to the membrane separation unit 9.
  • the booster pump 10 is provided with a pump back pressure valve 10A for maintaining the supply pressure at a set target value (for example, 780 kPaG).
  • a set target value for example, 780 kPaG.
  • an offgas tank T for storing offgas is provided at a location upstream of the booster pump 10 in the offgas discharge path 4, and the booster pump 10 supplies the offgas stored in the offgas tank T to the membrane separation unit 9. It is configured as follows.
  • a material that permeates a miscellaneous gas mainly composed of carbon dioxide faster than methane as a purification target gas is used.
  • methane as the gas to be purified hardly permeates or does not substantially permeate, and carbon dioxide in the off-gas stored in the off-gas tank T.
  • the miscellaneous gas mainly composed of carbon is separated as the membrane permeation gas J.
  • Examples of such a separation membrane 9A include cellulose acetate, polyamide, polyimide, polysulfone, polytetrafluoroethylene, polyethersulfone, carbon membrane, microporous glass composite membrane, DDR type zeolite, multi-branched polyimide silica, and polydimethylsiloxane.
  • a material mainly composed of at least one selected material is used.
  • the off-gas adjusting unit MR is configured using a mass flow controller similarly to the raw material gas adjusting unit MG, and detects the flow rate of the recycle gas flowing through the recycle gas return path 11, and the detected flow rate is an operation described later. It is configured to control the flow rate of the recycle gas so that the target flow rate is commanded from the control unit F (see FIG. 2). That is, the operation control unit F is configured to command a target flow rate based on detection information of the pressure sensor 14 that detects an internal pressure of the offgas tank T (hereinafter referred to as an offgas tank pressure). It will be described later.
  • the supply flow rate of the off gas supplied from the booster pump 10 to the membrane separation unit 9 can be adjusted by adjusting the flow rate of the recycle gas. As the amount increases, the amount of the gas passing through the membrane increases in a direct proportional relationship. Therefore, the supply flow rate of the off gas and the flow rate of the recycle gas are in a direct proportional relationship.
  • each of the four adsorption towers 1 is configured to sequentially execute an operation process determined in a form in which an operation cycle is divided into 16 steps with phases different from each other.
  • the operation cycle will be described on behalf of the tower A.
  • Steps 1 to 3 the source gas supply valve A1 and the product gas delivery valve A2 corresponding to the A tower are opened, and the source pressure and adsorption corresponding to the adsorption process are performed. That is, miscellaneous gas is adsorbed by the adsorbent while increasing the internal pressure of the tower A, and the product gas H is discharged through the product gas delivery path 5.
  • the communication on / off valve A4 and off-gas discharge valve A5 are closed.
  • step 4 the open / close valves A ⁇ b> 4 and B ⁇ b> 4 of the A tower and the B tower are opened, and the adsorption pressure equalization AB corresponding to the first-stage pressure equalizing step for pressure reduction for supplying the internal gas of the A tower to the B tower is performed.
  • the raw material gas supply valve A1, the product gas delivery valve A2, and the off-gas discharge valve A5 are closed.
  • the meaning of “AB” in the adsorption pressure equalization AB means that the internal gas of the high-pressure side A tower described above is supplied to the low-pressure side B tower described later, and so on. .
  • step 5 all valves associated with Tower A are closed and waited.
  • step 6 open / close valves A ⁇ b> 4 and C ⁇ b> 4 of the A tower and the C tower are opened, and pressure equalization AC corresponding to a middle pressure equalizing step for pressure reduction for supplying the internal gas of the A tower to the C tower is performed.
  • the raw material gas supply valve A1, the product gas delivery valve A2, and the off-gas discharge valve A5 are closed.
  • Step 7 the pressure on and off valves A4 and D4 of the A tower and the D tower are opened, and the pressure equalization AD corresponding to the final pressure equalizing step for pressure reduction for supplying the internal gas of the A tower to the D tower is performed.
  • the raw material gas supply valve A1, the product gas delivery valve A2, and the off-gas discharge valve A5 are closed.
  • Steps 8 to 10 the off-gas discharge valve A5 of the A tower is opened, and pressure reduction corresponding to the desorption process is performed. Incidentally, in this desorption process, the raw material gas supply valve A1, the product gas delivery valve A2, and the communication on / off valve A4 are closed.
  • step 11 the pressure equalization BA corresponding to the first-stage pressure equalization step for boosting is performed by opening the communication on / off valves A4 and B4 of the A tower and the B tower and supplying the internal gas of the B tower to the A tower.
  • the raw material gas supply valve A1, the product gas delivery valve A2, and the off-gas discharge valve A5 are closed.
  • steps 12 and 13 all valves associated with Tower A are closed and waited.
  • step 14 open / close valves A ⁇ b> 4 and C ⁇ b> 4 of the A tower and the C tower are opened, and pressure equalization CA corresponding to the middle pressure equalizing process for pressurization for supplying the internal gas of the C tower to the A tower is performed.
  • the middle pressure equalizing step for boosting the raw material gas supply valve A1, the product gas delivery valve A2, and the off gas discharge valve A5 are closed.
  • step 15 all valves associated with Tower A are closed and waited.
  • step 16 the adsorbing pressure equalization DA corresponding to the final pressure equalizing step for pressurization is performed by opening the communication on / off valves A4 and D4 of the A column and the D column and supplying the internal gas of the D column to the A column.
  • the raw material gas supply valve A1, the product gas delivery valve A2, and the off-gas discharge valve A5 are closed.
  • the operation control unit F performs the adsorption process, the first pressure equalization process for pressure reduction, the middle pressure equalization process for pressure reduction, the final pressure equalization process for pressure reduction, the desorption in a state where the phases of the four adsorption towers 1 are different.
  • An operation cycle including a process, an initial pressure equalizing process for boosting, a middle pressure equalizing process for boosting, and a final pressure equalizing process for boosting is sequentially executed.
  • the operation control unit F sequentially executes an operation cycle including an adsorption process, a pressure-lowering pressure equalizing process, a desorption process, and a pressure-boosting pressure equalizing process in a state where the phases of the four adsorption towers 1 are different from each other. Is configured to do.
  • the step times of Step 1, Step 5, Step 9, and Step 13 are times corresponding to the adsorption time correction value X for changing and adjusting the adsorption time for performing the adsorption process.
  • the adsorption time correction value X is set to 100 (seconds), for example.
  • the raw material gas adjustment section MG for adjusting the raw material gas supply amount is provided in the upstream portion of the compressor 2 in the raw material gas supply path 3, and the raw material gas adjustment section MG passes through the raw material gas supply path 3.
  • the flow rate of the flowing raw material gas G is detected, and the raw material gas supply amount is controlled so that the detected flow rate becomes the target flow rate instructed from the operation control unit F. Details thereof will be described later.
  • the driver commands the operation control unit F from the operation command unit 16 to the target flow rate of the recycle gas flowing through the recycle gas return path 11 to control the operation.
  • the operation control unit F instructs the off-gas adjusting unit MR to send the target flow rate to the off-gas adjusting unit MR.
  • the off gas discharged when one adsorption tower 1 performs the desorption process is stored in the off gas tank T, and the desorption process of one adsorption tower 1 is started using the stored off gas. Then, it is necessary to discharge from the off-gas tank T until another adsorption tower 1 starts the next desorption process.
  • the supply flow rate of off gas supplied from the booster pump 10 to the membrane separation unit 9 (off gas discharge flow rate discharged from the off gas tank T) can be adjusted by adjusting the flow rate of the recycle gas.
  • the off-gas supply flow rate (off-gas discharge flow rate) increases, the off-gas supply flow rate (off-gas discharge flow rate) and the recycle gas This is because the flow rate is directly proportional.
  • the operation control unit F is configured to adjust the off-gas adjusting unit MR so as to maintain the relationship with the amount of recycle gas returned to the source gas supply path 3 in the relationship of the following equation (1).
  • Recycle gas amount Off gas amount-Membrane permeation gas amount -------- (1)
  • the off-gas tank pressure which is the internal pressure of the off-gas tank T, increases as each of the four adsorption towers 1 performs the desorption process. As the off-gas is discharged through the path 8, it will decrease. If the relationship of the above equation (1) is maintained, the off-gas tank pressure increases and decreases while maintaining the appropriate minimum pressure (minimum value) and the appropriate maximum pressure, as shown in FIG. Will be repeated.
  • the off gas tank pressure gradually increases as shown in FIG. 5, and the depressurization process cannot be performed properly. If the amount of recycle gas is larger than “off gas amount ⁇ membrane permeating gas amount”, the off gas tank pressure gradually decreases as shown in FIG. 6, and the off gas tank pressure of the off gas tank T is too low (negative pressure). This may cause inconveniences such as damaging the booster pump 10.
  • the operation control unit F sets the minimum pressure (minimum value) of the offgas tank pressure to the target pressure (for example, 2 kPaG) based on the pressure detection information of the pressure sensor 14 that detects the offgas tank pressure.
  • the target flow rate is obtained, and the obtained target flow rate is commanded to the off-gas adjusting unit MR, whereby the relationship of the above formula (1) is maintained.
  • the unit MR is configured to command.
  • the corrected flow rate is obtained as a larger flow rate as the differential pressure Pt increases in a state where it is obtained as a value of 1 NL / min.
  • the minimum pressure (minimum value) is larger than the target pressure, the differential pressure Pt becomes positive, and a positive correction flow rate is obtained.
  • the minimum pressure (minimum value) is smaller than the target pressure, the differential pressure Pt is negative. Thus, a negative correction flow rate is obtained.
  • the minimum pressure (minimum value) of the off-gas tank pressure is configured to approach the target pressure (for example, 2 kPaG) by correcting the target flow rate of the recycled gas.
  • the target pressure for example, 2 kPaG
  • FIG. 8 the case where the relationship between the differential pressure Pt and the correction flow rate is set as a primary equation is illustrated, but the relationship between the differential pressure Pt and the correction flow rate is set as a secondary equation. The relationship with the correction flow rate can be variously changed.
  • the recycle gas flowing through the recycle gas return path 11 from the operation command unit 16 to the operation control unit F by the driver during the start-up operation of the pressure fluctuation adsorption gas production apparatus is commanded.
  • a target flow rate at which the minimum pressure (minimum value) of the off-gas tank pressure becomes a target pressure is commanded.
  • the operation control unit F when an automatic operation command is commanded from the operation command unit 16 when the minimum pressure (minimum value) of the off-gas tank pressure reaches a target pressure (for example, 2 kPaG), the operation control unit F, as described above, The target flow rate is set while obtaining the correction flow rate based on the differential pressure Pt, and the set target flow rate is commanded to the off-gas adjusting unit MR. Even during the start-up operation of the pressure fluctuation adsorption gas production apparatus, the operation control unit F sets the target flow rate while obtaining the correction flow rate based on the differential pressure Pt as described above, and the set target flow rate is set to off gas. You may implement with the form commanded to the adjustment part MR.
  • the operation command unit 16 is configured to instruct the operation control unit F of a target relationship between the methane gas concentration of the raw material gas G and the target supply amount before the recycle gas joins.
  • the operation control unit F then supplies the source gas G based on the target relationship between the instructed methane gas concentration and the target supply amount and the methane gas concentration (methane concentration in the source gas) detected by the source side concentration sensor SG.
  • the target supply amount is obtained, and the obtained target supply amount is instructed to the raw material gas adjustment unit MG.
  • the target supply amount is increased as the methane gas concentration is higher than the reference value.
  • the relationship is set such that the target supply amount decreases as the value becomes lower than the reference value.
  • the amount by which the target supply amount is reduced is set in view of the increase amount of the recycle gas amount that increases as the methane gas concentration decreases.
  • the operation control unit F corrects the supply flow rate of the source gas G to the decrease side, and when the methane gas concentration of the source gas G increases, the source gas G
  • the raw material adjusting unit MG is adjusted so as to correct the supply flow rate to the increase side.
  • the average methane gas concentration of the methane concentration in the raw material gas during the adsorption process is obtained.
  • the average methane gas concentration is obtained by sampling the detection information of the raw material side concentration sensor SG every set time (for example, 500 ms) and obtaining the average value of the sampled detection values.
  • the target supply amount is obtained based on the obtained average methane gas concentration and the target relationship between the methane gas concentration and the target supply amount, and when the adsorption process is performed next, the raw material gas is obtained at the obtained target supply amount. It is configured to supply G.
  • the off-gas tank T is omitted, and the internal pressure (hereinafter referred to as the flow passage portion) between the adsorption tower 1 and the booster pump 10 in the off-gas discharge passage 4 is omitted.
  • a flow path pressure sensor 15 for detecting a flow path pressure) is provided.
  • the flow path pressure detected by the flow path pressure sensor 15 increases as each of the four adsorption towers 1 performs the desorption process, similarly to the off gas tank pressure, the off gas is not transmitted through the off gas delivery path 8. It will decrease by being discharged. If the relationship of the above expression (1) is maintained, the flow path pressure is maintained at an appropriate minimum pressure (minimum value) and an appropriate maximum pressure, as in the off-gas tank pressure shown in FIG. , Will increase and decrease repeatedly.
  • the target flow rate for the operation control unit F to set the minimum pressure (minimum value) of the channel pressure to the target pressure based on the pressure detection information of the channel pressure sensor 15 that detects the channel pressure. Is obtained, and the obtained target flow rate is commanded to the off-gas adjusting unit MR, so that the relationship of the above formula (1) is maintained.
  • the operation control unit F obtains a differential pressure between the minimum pressure (minimum value) and the target pressure. Then, based on the obtained differential pressure, a correction flow rate of the target flow rate commanded to the off gas adjustment unit MR is obtained, and the flow rate obtained by correcting the currently commanded target flow rate with the correction flow rate is set as a new target flow rate. It is configured to command the MR.
  • the corrected flow rate is obtained as a larger flow rate as the differential pressure increases in a state where it is obtained as a value of 1 NL / min. become.
  • the off-gas adjusting unit MR that adjusts the supply flow rate of off-gas is provided at the downstream side of the membrane separating unit 9, but the booster pump 10 and the membrane separating unit 9 are provided. You may implement in the form which installs the off gas adjustment part MR in the location corresponded between.
  • the average methane gas concentration of the methane concentration in the raw material gas from the start of the adsorption step until the set initial time (for example, 10 seconds) elapses.
  • the target supply amount is obtained based on the obtained average methane gas concentration and the target relationship between the methane gas concentration and the target supply amount.
  • the raw material gas G may be supplied with the calculated
  • the off-gas adjusting unit MR is configured using a mass flow controller.
  • the booster pump that configures the boosting unit while detecting the gas flow rate with the flow rate sensor.
  • the off-gas adjusting unit MR may be configured in such a manner that the discharge amount of 10 is adjusted.
  • the case where the source gas G is a biogas containing methane as the gas to be purified and carbon dioxide or the like as the miscellaneous gas is exemplified.
  • a gas modified from city gas that is, hydrogen as a gas to be purified, and various gases such as carbon dioxide, carbon monoxide, and nitrogen containing gases are used as source gas G It can be done.
  • the raw material gas supply path 3 and the off-gas discharge path 4 are connected to the lower end side as one end side of the adsorption tower 1 and the other end side of the adsorption tower 1 is used.
  • the raw material gas supply path 3 and the off-gas discharge path 4 are connected to the upper end side as one end side of the adsorption tower 1, and adsorption
  • the purification target gas discharge path 5 may be connected to the lower end side as the other end side of the tower 1.
  • the location where the off-gas discharge path 4 is connected to the adsorption tower 1 is connected to the end of the adsorption tower 1 to which the purification target gas discharge path 5 is connected, or to the intermediate portion in the longitudinal direction of the adsorption tower 1. In short, what is necessary is just to connect the off-gas discharge path 5 to the adsorption tower 1.
  • the desorption process is performed by integrating the detection value of the flow sensor that detects the flow rate of the off gas flowing through the flow path portion between the adsorption tower 1 and the booster pump 10 as the booster in the offgas discharge channel 4.
  • the amount of off-gas discharged from the adsorption tower 1 is calculated and the amount of off-gas is divided by the time from when the adsorption tower 1 starts the desorption process until when another adsorption tower 1 starts the desorption process.
  • the target value of the off gas supply flow rate may be obtained.
  • the operation control unit F is supplied to the adsorption tower 1 based on the concentration of the gas to be purified (methane) of the source gas G before the recycle gas joins.
  • the adsorption tower 1 is based on at least one of the flow rate of the recycle gas and the concentration of the recycle target gas of the recycle gas. Decrease and increase in the concentration of the purification target gas of the source gas G supplied to the gas may be determined, and further, the adsorption may be performed based on the concentration of the purification target gas of the source gas G after the recycle gas has joined. You may make it discriminate
  • Adsorption tower 3 Raw material gas supply path 4 Off-gas discharge path 5 Purification target gas discharge path (product gas delivery path) 9A Separation membrane 9 Membrane separation unit 11 Recycle gas return path 12 Off-gas adjustment unit 15 Material gas adjustment unit F Operation control unit G Material gas (biogas) H Gas to be purified (product gas) T off gas tank

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Analytical Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Water Supply & Treatment (AREA)
  • General Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Separation Of Gases By Adsorption (AREA)
  • Carbon And Carbon Compounds (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)

Abstract

L'invention concerne un appareil de production de gaz à adsorption modulée en pression, qui peut empêcher une réduction de concentration d'un gaz purifié qui est évacué d'une tour d'adsorption indépendamment d'une réduction de concentration du gaz purifié dans un gaz de charge d'alimentation. Une unité de séparation par membrane 9, qui a une membrane de séparation 9A à travers laquelle un gaz divers passe rapidement par rapport à un gaz purifié, et une unité d'amplification de pression 10 qui amplifie la pression d'un gaz d'échappement et fournit le gaz d'échappement à l'unité de séparation par membrane 9, sont disposées sur un trajet d'évacuation de gaz d'échappement 4 relié à une tour d'adsorption 1. Un trajet de retour de gaz de recyclage 11 qui renvoie un gaz de recyclage, qui ne passe pas à travers la membrane de séparation 9A, vers un trajet d'alimentation en gaz de charge d'alimentation 3 est fourni. Une unité de commande de fonctionnement définit la vitesse d'alimentation à laquelle le gaz d'échappement est fourni par l'unité d'amplification de pression 10 à l'unité de séparation par membrane 9 à un débit auquel la quantité de gaz d'échappement évacuée de la tour d'adsorption 1 pendant chaque étape de désorption est égale à la quantité de gaz d'échappement fournie à l'unité de séparation par membrane 9 entre le début d'une étape de désorption au niveau de la tour d'adsorption 1 et le début d'une étape de désorption au niveau d'une tour d'adsorption distincte 1. Si la concentration d'un gaz purifié dans un gaz de charge d'alimentation G diminue, l'unité de commande de fonctionnement corrige le débit d'alimentation du gaz de charge d'alimentation G vers le côté réduit.
PCT/JP2017/009956 2016-03-31 2017-03-13 Appareil de production de gaz à adsorption modulée en pression WO2017169690A1 (fr)

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KR101385977B1 (ko) * 2012-10-31 2014-04-16 한국전기연구원 자기부상 및 자기베어링 시스템용 전자석 액추에이터의 pwm 구동 시스템
CN113877228B (zh) * 2021-09-30 2023-04-18 河南平高电气股份有限公司 一种六氟化硫回收气体精馏提纯系统

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JPS5651223A (en) * 1979-06-18 1981-05-08 Monsanto Co Selective adsorbing method
JPS6391119A (ja) * 1986-10-01 1988-04-21 ザ・ビーオーシー・グループ・インコーポレーテッド ガス拡散バリヤーを使用するｐｓａ法および装置
JPS6447421A (en) * 1987-08-16 1989-02-21 Kansai Coke & Chemicals Pressure alteration type absorbing separation system
JPH0312212A (ja) * 1989-06-08 1991-01-21 Nippon Sanso Kk 圧力変動吸着分離装置の運転制御方法
US5753010A (en) * 1996-10-28 1998-05-19 Air Products And Chemicals, Inc. Hydrogen recovery by pressure swing adsorption integrated with adsorbent membranes
JP2008247632A (ja) * 2007-03-29 2008-10-16 Nippon Oil Corp 水素製造および二酸化炭素回収方法ならびに装置
WO2014104196A1 (fr) * 2012-12-28 2014-07-03 大阪瓦斯株式会社 Appareil de raffinage de gaz

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5651223A (en) * 1979-06-18 1981-05-08 Monsanto Co Selective adsorbing method
JPS6391119A (ja) * 1986-10-01 1988-04-21 ザ・ビーオーシー・グループ・インコーポレーテッド ガス拡散バリヤーを使用するｐｓａ法および装置
JPS6447421A (en) * 1987-08-16 1989-02-21 Kansai Coke & Chemicals Pressure alteration type absorbing separation system
JPH0312212A (ja) * 1989-06-08 1991-01-21 Nippon Sanso Kk 圧力変動吸着分離装置の運転制御方法
US5753010A (en) * 1996-10-28 1998-05-19 Air Products And Chemicals, Inc. Hydrogen recovery by pressure swing adsorption integrated with adsorbent membranes
JP2008247632A (ja) * 2007-03-29 2008-10-16 Nippon Oil Corp 水素製造および二酸化炭素回収方法ならびに装置
WO2014104196A1 (fr) * 2012-12-28 2014-07-03 大阪瓦斯株式会社 Appareil de raffinage de gaz

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