Desulfurization method, desulfurization apparatus, hydrogen generation apparatus, and fuel cell system

Abstract

To provide a technique suitable for desulfurization of a gas containing carbon sulfide.SOLUTION: The desulfurization process includes first contacting the source gas 50 with an amine-bearing agent 102 to reduce carbon sulfides in the source gas 50. The amine-bearing agent 102 has an amine as a functional group. The desulfurization method includes reducing hydrogen sulfide generated by the first contact in the source gas 50.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a desulfurization method, a desulfurization device, a hydrogen generation device, and a fuel cell system. [Background technology]

[0002] Desulfurization has been studied in the past. Patent Document 1 discloses a method for removing carbon disulfide from hydrocarbons. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-20765 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides techniques suitable for desulfurizing gases containing carbon sulfide. [Means for solving the problem]

[0005] The present disclosure provides: reducing carbon sulfide contained in the feed gas by first contacting the feed gas with an amine-containing agent having an amine as a functional group; reducing hydrogen sulfide produced by the first contact in the feed gas.

[0006] From another perspective, the present disclosure provides: A desulfurization apparatus for desulfurizing a raw material gas, a first filled section filled with an amine retaining agent that has an amine as a functional group and reduces carbon sulfide; The desulfurization device is configured to reduce hydrogen sulfide generated in the amine-retaining agent. [Effects of the Invention]

[0007] The technology disclosed herein is suitable for desulfurizing gases containing carbon sulfide. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a configuration diagram of a fuel cell system according to an embodiment. [Figure 2] FIG. 2 is a configuration diagram of a desulfurization device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] (Findings that formed the basis of this disclosure) Raw material gases such as city gas, liquefied petroleum (LP) gas, and natural gas contain lower hydrocarbon gases such as methane, ethane, propane, butane, etc. Raw material gases are used not only as industrial fuels and household fuels, but also as raw materials for producing hydrogen.

[0010] Steam reforming is a well-known industrial method for producing hydrogen. In one example of the steam reforming method, a lower hydrocarbon gas is reformed by adding steam in the presence of a catalyst. This produces a reformed gas primarily composed of hydrogen. In the steam reforming method, the feed gas may contain sulfur compounds. Therefore, the catalyst used in the steam reforming method may be poisoned by the sulfur compounds, resulting in a decrease in its catalytic function.

[0011] Furthermore, in some fuel cell systems, reformed gas from a reformer is supplied to a fuel cell. In such cases, not only the catalyst in the reformer but also the electrode catalyst in the power generation cell of the fuel cell may be poisoned by sulfur compounds.

[0012] Pure hydrogen fuel cell systems are known as fuel cell systems that do not require a reformer. In these systems, a hydrogen-containing gas with a high hydrogen concentration is supplied to the fuel cell from a hydrogen source such as a hydrogen storage tank. The sulfur compounds contained in the hydrogen-containing gas may also poison the electrode catalyst in the power generation cells of the fuel cell.

[0013] Incidentally, Patent Document 1 describes a method for removing carbon disulfide. In this method, carbon disulfide is removed by contacting a hydrocarbon containing carbon disulfide with a weakly basic anion exchange resin having a polyamine as a functional group. However, this method can produce hydrogen sulfide from carbon disulfide.

[0014] In order to suppress deterioration of devices such as reformers and fuel cells, it is effective to not only reduce carbon sulfide but also reduce all substances containing sulfur atoms, including hydrogen sulfide. The present inventors have obtained this finding through extensive research. The present disclosure is based on this finding.

[0015] Hereinafter, embodiments will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of already well-known matters or redundant description of substantially the same configuration may be omitted. The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0016] (Embodiment) Hereinafter, the embodiment will be described with reference to FIGS.

[0017] [1-1.Configuration] FIG. 1 is a configuration diagram of a fuel cell system 30 according to an embodiment.

[0018] The fuel cell system 30 includes a hydrogen generator 20 and a fuel cell 5. The hydrogen generator 20 includes a desulfurizer 10 and a reformer 4. The desulfurizer 10 includes a first charging section 2 and a second charging section 3. The first charging section 2, the second charging section 3, the reformer 4, and the fuel cell 5 are connected in this order.

[0019] The desulfurization device 10 desulfurizes the raw material gas 50. The reformer 4 reforms the raw material gas 50 desulfurized by the desulfurization device 10. This produces a hydrogen-containing gas 60. The fuel cell 5 generates power using the hydrogen-containing gas 60.

[0020] Specifically, the fuel cell system 30 is configured with a raw material gas supply path 1a and a hydrogen-containing gas supply path 1b. Along the raw material gas supply path 1a, a raw material gas 50 passes through a first filling section 2 and a second filling section 3 in this order to be desulfurized, and is then supplied to the reformer 4. Along the hydrogen-containing gas supply path 1b, a hydrogen-containing gas 60 is supplied from the reformer 4 to the fuel cell 5.

[0021] The source gas 50 contains carbon sulfide and hydrocarbons. Specifically, the source gas 50 contains carbon sulfide as an impurity. Here, an impurity is a substance unintentionally contained in a target substance. In this embodiment, the carbon sulfide is carbon disulfide. However, the carbon sulfide may also be carbon monosulfide.

[0022] The hydrocarbon content of the source gas 50 is, for example, 80% by volume or more and 100% by volume or less. The hydrocarbon content of the source gas 50 may be 97% by volume or more and 100% by volume or less. The carbon sulfide content of the source gas 50 is, for example, more than 0 ppm by volume and 0.5 ppm by volume or less. The carbon sulfide content of the source gas 50 may be 0.002 ppm by volume or more and 0.35 ppm by volume or less.

[0023] The hydrocarbons in the raw material gas 50 include, for example, at least one selected from the group consisting of methane, ethane, propane, and butane. The hydrocarbons in the raw material gas 50 may be city gas, liquefied petroleum gas, or natural gas.

[0024] FIG. 2 is a configuration diagram of the desulfurization device 10 according to the embodiment.

[0025] The desulfurization apparatus 10 is an apparatus for desulfurizing a raw material gas 50. In the desulfurization apparatus 10, the first packed section 2 is packed with an amine retention agent 102. The amine retention agent 102 has an amine as a functional group. The amine retention agent 102 reduces carbon sulfide contained in the raw material gas 50. However, when reducing carbon sulfide, the amine retention agent 102 may generate hydrogen sulfide. The desulfurization apparatus 10 is configured to reduce hydrogen sulfide generated in the amine retention agent 102. The desulfurization apparatus 10 is suitable for desulfurizing gases containing carbon sulfide.

[0026] Specifically, in the desulfurization device 10, the second filled section 3 is filled with the material 103. The material 103 reduces the hydrogen sulfide contained in the raw material gas 50.

[0027] The desulfurization method includes a first step of contacting the raw material gas 50 with the amine carrier 102 (hereinafter referred to as the first contact). The first contact reduces carbon sulfide contained in the raw material gas 50. On the other hand, the first contact may produce hydrogen sulfide. The desulfurization method includes a second step of reducing hydrogen sulfide contained in the raw material gas 50. In this way, the raw material gas 50 is desulfurized. This configuration is suitable for desulfurizing gases containing carbon sulfide.

[0028] Specifically, in the second step, the source gas 50 is brought into contact with the material 103 (hereinafter referred to as the second contact). By the second contact, the hydrogen sulfide contained in the source gas 50 is reduced.

[0029] Specifically, the amine retention agent 102 reduces the concentration of carbon sulfide in the raw material gas 50. Then, the desulfurization apparatus 10 reduces the concentration of hydrogen sulfide in the raw material gas 50. In the first step, the raw material gas 50 is first contacted with the amine retention agent 102 to reduce the concentration of carbon sulfide in the raw material gas 50. In the second step, the concentration of hydrogen sulfide in the raw material gas 50 is reduced.

[0030] As shown in FIG. 2 , the desulfurization apparatus 10 according to this embodiment includes an accommodation space 150, an inlet 151, and an outlet 152. The accommodation space 150 accommodates the first packed section 2 and the second packed section 3. In the desulfurization apparatus 10, the inlet 151, the first packed section 2, the second packed section 3, and the outlet 152 are arranged in this order. The inlet 151 allows the raw material gas 50 to flow from the outside of the desulfurization apparatus 10 into the first packed section 2. The raw material gas 50 flowing out of the first packed section 2 flows into the second packed section 3. The outlet 152 allows the raw material gas 50 to flow out of the desulfurization apparatus 10 from the second packed section 3. In this way, the raw material gas 50 passes through the first packed section 2 filled with the amine retention agent 102 and the second packed section 3 filled with the material 103, in this order.

[0031] In this embodiment, the material 103 includes an adsorbent. The adsorbent reduces hydrogen sulfide. Desulfurization involving reduction of hydrogen sulfide using an adsorbent can be performed more easily than hydrodesulfurization.

[0032] The amine retention agent 102 includes at least one selected from the group consisting of primary amines, secondary amines, and tertiary amines. Examples of primary amines include monoethanolamine and ethylenediamine. Examples of secondary amines include dimethylamine and N-methylethanolamine. Examples of tertiary amines include dimethylaminoethanol and triethanolamine. Note that "the amine retention agent 102 includes at least one selected from the group consisting of primary amines, secondary amines, and tertiary amines" encompasses an embodiment in which the amine retention agent 102 includes a complex amine formed from at least two selected from the group consisting of primary amines, secondary amines, and tertiary amines. An example of a complex amine is diethylenetriamine. Diethylenetriamine is a complex amine formed from a primary amine and a secondary amine. As can be understood from the above example, the amine contained in the amine retention agent 102 is not limited to a primary amine alone, a secondary amine alone, or a tertiary amine alone, but may also be a complex amine formed from at least two of a primary amine, a secondary amine, and a tertiary amine.

[0033] An example of the material 103 is activated carbon. Examples of raw materials for activated carbon include coconut shells, coal (anthracite, bituminous coal, etc.), wood flour, peat charcoal, and bamboo charcoal. A specific example of the material 103 is modified activated carbon. The modified activated carbon is, for example, activated carbon supporting a metal. Examples of the metal include copper, nickel, cobalt, zinc, magnesium, tungsten, silver, manganese, iron, chromium, molybdenum, etc. Other examples of the material 103 include iron oxide, sodium hydroxide, and zeolite. Zeolite may support a metal such as silver.

[0034] In a typical example of this embodiment, the composition of the amine-carrying agent 102 is different from the composition of the material 103. Also, in a typical example of this embodiment, the material 103 does not contain an amine.

[0035] Various techniques can be applied to the above-described embodiments. Examples 1 to 3 will be described below. Unless there is a particular contradiction, any technique according to the above-described embodiments can be combined with any technique according to Examples 1, 2, and / or 3.

[0036] (Example 1) In a first example, the source gas 50 contains carbon sulfide and hydrogen. Specifically, the source gas 50 contains carbon sulfide as an impurity. In the first example, the carbon sulfide may be carbon disulfide or carbon monosulfide. In a typical example of the first example, the carbon sulfide is carbon disulfide.

[0037] In a first example, the hydrogen content in the source gas 50 is, for example, 20% by volume or more and 100% by volume or less. The hydrogen content in the source gas 50 may be 98% by volume or more and 100% by volume or less. The carbon sulfide content in the source gas 50 is, for example, more than 0 ppm by volume and 0.5 ppm by volume or less. The carbon sulfide content in the source gas 50 may be 0.002 ppm by volume or more and 0.35 ppm by volume or less.

[0038] In the first example, the fuel cell 5 generates power using a raw material gas 50 that has been desulfurized by the desulfurization device 10. The fuel cell system 30 does not require a reformer. The raw material gas 50 can be supplied from a hydrogen source such as a hydrogen storage tank.

[0039] (Example 2) In the second example, the desulfurization apparatus 10 does not necessarily have the material 103 separate from the amine retention agent 102. In the second example, the amine retention agent 102 is a predetermined material modified with an amine. In the second example, the amine retention agent 102 having an amine as a functional group is configured in this manner. The predetermined material is, for example, activated carbon. Examples of raw materials for activated carbon include those described as raw materials for activated carbon as material 103 in the above-described embodiment. The amine retention agent 102 of the second example combines the functions of the amine retention agent 102 and material 103 described in the above-described embodiment into a single material. The first packed section 2 of the second example combines the first packed section 2 and second packed section 3 described in the above-described embodiment into a single packed section.

[0040] In the first filling unit 2 according to the second example, the amine carrier 102 reduces carbon sulfide contained in the source gas 50 due to the contribution of the modified amine. Meanwhile, when reducing carbon sulfide, the amine carrier 102 may generate hydrogen sulfide. The hydrogen sulfide thus contained in the source gas 50 is reduced due to the contribution of the predetermined material in the amine carrier 102.

[0041] In the second example, in the first contact between the source gas 50 and the amine carrier 102, the carbon sulfide contained in the source gas 50 is reduced due to the contribution of the modified amine. Meanwhile, hydrogen sulfide may be generated by the first contact. The hydrogen sulfide thus contained in the source gas 50 is reduced due to the contribution of the predetermined material in the amine carrier 102.

[0042] (Example 3) In the third example, the amine retention agent 102 and the material 103 are separate materials. Both the amine retention agent 102 and the material 103 are filled in the first filling section 2. Specifically, the amine retention agent 102 and the material 103 are filled in a mixed state in the first filling section 2.

[0043] (Addendum) The present disclosure provides the following techniques.

[0044] (Technology 1) reducing carbon sulfide contained in the feed gas by first contacting the feed gas with an amine-containing agent having an amine as a functional group; reducing hydrogen sulfide produced by the first contact in the feed gas.

[0045] (Technology 2) The desulfurization method according to claim 1, wherein the amine-containing agent comprises at least one selected from the group consisting of a primary amine, a secondary amine, and a tertiary amine.

[0046] (Technology 3) The raw material gas is passed through a first packed section filled with the amine retaining agent and a second packed section filled with a material in this order; 3. The desulfurization method according to claim 1, wherein the hydrogen sulfide is reduced by second contact of the raw material gas with the material.

[0047] (Technology 4) 4. The desulfurization method according to claim 3, wherein the material comprises an adsorbent.

[0048] (Technology 5) 5. The desulfurization method according to any one of techniques 1 to 4, wherein the carbon sulfide is carbon disulfide.

[0049] (Technology 6) 6. The desulfurization method according to any one of Techniques 1 to 5, wherein the raw material gas is a gas containing hydrocarbons.

[0050] (Technology 7) 7. The desulfurization method according to any one of Techniques 1 to 6, wherein the raw material gas is a gas containing hydrogen.

[0051] (Technology 8) A desulfurization apparatus for desulfurizing a raw material gas, a first filled section filled with an amine retaining agent that has an amine as a functional group and reduces carbon sulfide; The desulfurization device is configured to reduce hydrogen sulfide generated in the amine-retaining agent.

[0052] (Technology 9) 9. The desulfurization apparatus according to claim 8, wherein the amine carrier comprises at least one selected from the group consisting of a primary amine, a secondary amine, and a tertiary amine.

[0053] (Technology 10) 10. The desulfurization device according to claim 8 or 9, further comprising a second packed section packed with a material that reduces hydrogen sulfide.

[0054] (Technology 11) The first filling section; the second packed portion into which the source gas flowing out from the first packed portion flows; an inlet for allowing the source gas to flow into the first packed section; an outlet for allowing the source gas to flow out from the second packed section; The desulfurization apparatus according to technology 10, comprising:

[0055] (Technology 12) 12. The desulfurization apparatus according to claim 10 or 11, wherein the material includes an adsorbent.

[0056] (Technology 13) 13. The desulfurization apparatus according to any one of claims 8 to 12, wherein the carbon sulfide is carbon disulfide.

[0057] (Technology 14) 14. The desulfurization apparatus according to any one of claims 8 to 13, wherein the raw material gas is a gas containing hydrocarbons.

[0058] (Technology 15) 15. The desulfurization apparatus according to any one of claims 8 to 14, wherein the raw material gas is a gas containing hydrogen.

[0059] (Technology 16) A desulfurization device according to Technical 14; a reformer that reforms the raw material gas desulfurized by the desulfurization device to generate a hydrogen-containing gas.

[0060] (Technology 17) The hydrogen generating device according to Technology 16; a fuel cell that generates electricity using the hydrogen-containing gas generated by the hydrogen generation device.

[0061] (Technology 18) A desulfurization device according to technique 15; a fuel cell that generates electricity using the raw material gas desulfurized by the desulfurization device.

[0062] (Technology 19) reducing carbon sulfide in the feed gas by first contacting the feed gas with an amine-containing agent; reducing hydrogen sulfide produced by the first contact in the feed gas; The desulfurization method, wherein the amine retention agent comprises at least one selected from the group consisting of a primary amine, a secondary amine, and a tertiary amine.

[0063] As described above, Techniques 3 to 7 can be directly and / or indirectly applied to Technique 1. Similarly, Techniques 3 to 7 can be directly and / or indirectly applied to Technique 19.

[0064] (Technology 20) A desulfurization apparatus for desulfurizing a raw material gas, a first filled section filled with an amine retainer that reduces carbon sulfide; the desulfurization device is configured to reduce hydrogen sulfide generated in the amine-containing agent; The desulfurization apparatus, wherein the amine retention agent comprises at least one selected from the group consisting of a primary amine, a secondary amine, and a tertiary amine.

[0065] As described above, Techniques 10 to 18 can be directly and / or indirectly applied to Technique 8. Similarly, Techniques 10 to 18 can be directly and / or indirectly applied to Technique 20. [Industrial Applicability]

[0066] The desulfurization technology according to the present disclosure is applicable to fuel cell power generation and the like. [Explanation of symbols]

[0067] 1a Raw material gas supply route 1b Hydrogen-containing gas supply route 2. First filling section 3 Second filling section 4 Reformer 5 fuel cell 10 Desulfurization equipment 20 Hydrogen generator 30 Fuel Cell System 50 Raw material gas 60 Hydrogen-containing gas 102 Amine retaining agent 103 Material 150 storage space 151 Entrance 152 Exit

Claims

1. reducing carbon sulfide contained in the feed gas by first contacting the feed gas with an amine-containing agent having an amine as a functional group; reducing hydrogen sulfide produced by the first contact in the feed gas.

2. 2. The desulfurization method according to claim 1, wherein the amine retention agent comprises at least one selected from the group consisting of a primary amine, a secondary amine, and a tertiary amine.

3. The raw material gas is passed through a first packed section filled with the amine retaining agent and a second packed section filled with a material in this order; 2. The desulfurization method of claim 1, wherein the hydrogen sulfide is reduced by second contact of the feed gas with the material.

4. The method of claim 3 , wherein the material comprises an adsorbent.

5. 2. The desulfurization method according to claim 1, wherein the carbon sulfide is carbon disulfide.

6. The desulfurization method according to claim 1 , wherein the raw material gas is a gas containing hydrocarbons.

7. The desulfurization method according to claim 1 , wherein the raw material gas is a gas containing hydrogen.

8. A desulfurization apparatus for desulfurizing a raw material gas, a first filled section filled with an amine retaining agent that has an amine as a functional group and reduces carbon sulfide; The desulfurization device is configured to reduce hydrogen sulfide generated in the amine-retaining agent.

9. The desulfurization apparatus according to claim 8 , wherein the amine retention agent comprises at least one selected from the group consisting of a primary amine, a secondary amine, and a tertiary amine.

10. The desulfurization device according to claim 8 , further comprising a second packed section filled with a material that reduces the hydrogen sulfide.

11. The first filling section; the second packed section into which the source gas flowing out from the first packed section flows; an inlet for allowing the source gas to flow into the first packed section; an outlet for allowing the source gas to flow out from the second packed section; The desulfurization device according to claim 10, comprising:

12. The desulfurization apparatus of claim 10 , wherein the material comprises an adsorbent.

13. The desulfurization device according to claim 8 , wherein the carbon sulfide is carbon disulfide.

14. The desulfurization apparatus according to claim 8 , wherein the raw material gas is a gas containing hydrocarbons.

15. The desulfurization apparatus according to claim 8 , wherein the raw material gas is a gas containing hydrogen.

16. The desulfurization device according to claim 14; a reformer that reforms the raw material gas desulfurized by the desulfurization device to generate a hydrogen-containing gas.

17. The hydrogen generation device according to claim 16; a fuel cell that generates electricity using the hydrogen-containing gas generated by the hydrogen generation device.

18. The desulfurization device according to claim 15; a fuel cell that generates electricity using the raw material gas desulfurized by the desulfurization device.

Images