JP-2026076123-A - Gas separation method, gas separation equipment, and gas production method

Abstract

[Problem] To provide a gas separation control method, gas separation equipment, and gas production method that can maximize the recovery rate of the target gas component. [Solution] The gas separation method according to the present invention is a gas separation method that separates and recovers a target gas component from a raw gas containing the target gas component by a pressure swing adsorption method, wherein the time t for adsorbing the target gas component onto the adsorbent is determined using the flow rate of the raw gas, the volume concentration of the target gas component in the raw gas, the amount of adsorbent, and the adsorption capacity of the adsorbent. [Selection Diagram] Figure 1

Inventors

• 沖田 智之
• 紫垣 伸行

Assignees

• ＪＦＥスチール株式会社

Dates

Publication Date

20260511

Application Date

20251010

Priority Date

20241023

Claims (11)

1. A gas separation method for separating and recovering a target gas component from a source gas containing the target gas component by pressure swing adsorption method, A gas separation method in which the time t for adsorbing the target gas component onto the adsorbent is determined using the flow rate of the raw material gas, the volume concentration of the target gas component in the raw material gas, the amount of the adsorbent, and the adsorption capacity of the adsorbent.
2. The gas separation method according to claim 1, wherein the time t for adsorbing the target gas component is within the range of the following formula (1), where tb is the time (s) for the adsorbent to reach its adsorption capacity. 0.27 ≦ t/tb ≦ 0.43 (1) tb=(M×y)/(F×x) (2) Here, Flow rate of the aforementioned raw material gas: F ( Nm³ /s) Volume concentration of the target gas component in the source gas: x(-) Amount of the adsorbent: M (kg) The adsorption capacity of the adsorbent is y ( Nm³ /kg).
3. The gas separation method according to claim 1 or 2, wherein the adsorption capacity y of the adsorbent is a function of the temperature of the adsorbent.
4. The gas separation method according to claim 3, wherein the adsorption capacity y of the adsorbent is given by the following formula (3). y=-1.7×10 -6 ×T 2 +9.0×10 -5 ×T+0.034 (3) Here, the temperature of the adsorbent is T (°C).
5. The gas separation method according to claim 1 or 2, wherein the target gas component is carbon dioxide.
6. The gas separation method according to claim 1 or 2, wherein the raw material gas is blast furnace gas.
7. A gas separation apparatus for separating and recovering a target gas component from a source gas containing the target gas component by pressure swing adsorption method, An adsorption tower filled with an adsorbent that adsorbs the aforementioned target gas component, A raw material gas introduction unit for introducing the raw material gas into the adsorption tower, An off-gas discharge section discharges off-gas containing non-adsorbed gas components that were not adsorbed by the adsorbent from the adsorption tower, A depressurization section for reducing the pressure inside the adsorption tower in order to desorb the raw material gas adsorbed on the adsorbent, A recovery unit for recovering the target gas component desorbed in the aforementioned depressurization unit, A flow rate measuring unit for measuring the flow rate of the aforementioned raw material gas, A concentration measuring unit for measuring the volume concentration of the target gas component in the raw material gas, A control unit controls the time t for adsorbing the target gas component onto the adsorbent, using the flow rate of the raw material gas measured by the flow rate measuring unit and the volume concentration of the target gas component in the raw material gas measured by the concentration measuring unit. A gas separation facility equipped with the following features.
8. The gas separation apparatus according to claim 7, further comprising a pressure relief section having a pressure relief pipe and a valve for releasing gas from the adsorption tower.
9. The system further includes a temperature measuring unit for measuring the temperature of the adsorbent, The gas separation apparatus according to claim 7 or 8, wherein the control unit controls the time t for adsorbing the target gas component onto the adsorbent using the temperature of the adsorbent measured by the temperature measuring unit.
10. A gas production method comprising using the gas separation method described in claim 1 or 2, wherein the raw material gas is a gas containing carbon dioxide, and the target gas component is carbon dioxide, and carbon dioxide gas is produced from the raw material gas.
11. A gas production method comprising producing hydrogen gas from a raw material gas using the gas separation method described in claim 1 or 2, wherein the raw material gas is a gas containing hydrogen and the target gas component is an impurity component other than hydrogen.

Description

This invention relates to a gas separation method, a gas separation apparatus, and a gas production method. Conventionally, the pressure swing adsorption method (PSA method) has been used to separate specific gas components contained in raw material gases. The PSA method utilizes the fact that the amount of gas component adsorbed by an adsorbent varies depending on the gas type and its partial pressure. It is applied in various fields and is often used to produce high-concentration gases by adsorbing a specific component contained in the raw material gas. To improve the separation performance of the PSA method (such as the volume concentration and recovery rate of the target gas component), a method of controlling the temperature of the adsorbent (see Patent Document 1) has been proposed. Patent No. 7207626 specification This figure shows an example of a gas separation facility according to the present invention.This figure shows the relationship between the ratio t/tb (the time t required for the adsorbent to adsorb the target gas component (carbon dioxide)) to the time tb required for the adsorbent to reach its adsorption capacity, and the recovery rate of the target gas component (carbon dioxide). The embodiments of the present invention will be described below with reference to the drawings. Figure 1 shows an example of a gas separation apparatus according to the present invention. The gas separation apparatus 1 shown in Figure 1 is an apparatus for separating and recovering a gas containing a target gas component (e.g., carbon dioxide) from a raw material gas by a pressure swing adsorption method. It comprises two adsorption towers 2 filled with an adsorbent that adsorbs the target gas component, a raw material gas introduction section 3 for introducing the raw material gas into the adsorption towers 2, and an off-gas discharge section 4 for discharging off-gas containing unadsorbed gas components from the adsorption towers 2. Note that the gas separation apparatus 1 does not include a cleaning gas supply pipe for supplying a portion of the target gas discharged from the other adsorption tower 2 as cleaning gas to the adsorption tower 2. The raw material gas introduction section 3 includes a raw material gas supply pipe L1 for introducing the raw material gas into the adsorption tower 2 during the adsorption process, and a valve V1 for controlling the flow of the raw material gas in the raw material gas supply pipe L1. Furthermore, the raw material gas supply pipe L1 is equipped with a raw material gas flow meter (flow rate measuring unit) 9 for measuring the flow rate of the raw material gas, and a raw material gas concentration meter (concentration measuring unit) 10 for measuring the volume concentration of the target gas component in the raw material gas. The off-gas discharge section 4 comprises an off-gas discharge pipe L2 and a valve V2. During the adsorption process, when the raw material gas is introduced into the adsorption tower 2, the off-gas containing unadsorbed gas components is discharged from the adsorption tower 2. Furthermore, the gas separation equipment 1 comprises a pressure reduction unit 5, a recovery unit 6, and a control unit 7. The pressure reduction unit 5 includes a vacuum pump VP that sucks gas from inside the adsorption tower 2 to reduce pressure, a vacuum pump intake pipe L3 from the adsorption tower 2 to the vacuum pump VP, and a valve V3. It reduces the pressure inside the adsorption tower 2 to desorb the target gas components adsorbed on the adsorbent. The recovery unit 6 has a valve V4 on the discharge side of the vacuum pump VP that switches between desorption of the target gas component and desorption of other gas components, and a gas recovery pipe L4. It recovers the target gas containing the target gas component desorbed in the pressure reduction unit 5, as well as gases containing other gas components. The control unit 7 controls the time t for adsorbing the target gas component onto the adsorbent, using the flow rate of the raw material gas, the volume concentration of the target gas component in the raw material gas, the amount of adsorbent, and the time tb for reaching the adsorption capacity calculated from the adsorption capacity of the adsorbent. The control unit 7 is connected to a raw material gas flow meter 9 and a raw material gas concentration meter 10 that measures the volume concentration of the target gas component in the raw material gas. The control unit 7 is configured to receive data on the flow rate of the raw material gas measured by the raw material gas flow meter and data on the volume concentration of the target gas component in the raw material gas measured by the raw material gas concentration meter 10. The above-mentioned "time t for adsorbing the target gas component onto the adsorbent" refers to the time spent in the adsorption process, where the raw material gas is introduced into the adsorption tower 2, the target gas component con