EP-4739622-A1 - METAMATERIAL-ENHANCED PHOTOCATALYTIC CONVERSION OF HYDROGEN SULFIDE

Abstract

Metamaterials may be utilized to facilitate conversion of hydrogen sulfide into elemental hydrogen and elemental sulfur in the presence of suitable photocatalyst particles. Photoreactor systems utilizing metamaterials may comprise a flow-through reaction space having at least one metamaterial-catalyst surface. The at least one metamaterial-catalyst surface comprises a metamaterial surface having a plurality of resonators patterned thereon and a plurality of photocatalyst particles located upon at least a portion of the resonators, within a gap between a first region and a second region of one or more resonators, or within a gap between adjacent resonators. The plurality of photocatalyst particles comprise at least one photocatalyst effective to convert hydrogen sulfide into elemental hydrogen and elemental sulfur upon exposure to electromagnetic radiation.

Inventors

• SEREN, Huseyin R.
• SANTRA, ASHOK
• BOMMAREDDY, SAMPATH K.

Assignees

• Saudi Arabian Oil Company

Dates

Publication Date

20260513

Application Date

20240628

Claims (19)

1. 1. A method comprising: providing a gas stream comprising hydrogen sulfide; interacting the gas stream in a flow-through reaction space with at least one metamaterialcatalyst surface, the at least one metamaterial-catalyst surface comprising a metamaterial surface having a plurality of resonators patterned thereon and a plurality of photocatalyst particles located upon at least a portion of the resonators, within a gap between a first region and a second region of one or more resonators, or within a gap between adjacent resonators; wherein the plurality of photocatalyst particles comprise at least one photocatalyst effective to convert hydrogen sulfide into elemental hydrogen and elemental sulfur upon exposure to electromagnetic radiation; exposing the at least one metamaterial-catalyst surface to electromagnetic radiation while interacting the at least one metamaterial-catalyst surface with the gas stream; and obtaining elemental hydrogen and elemental sulfur after interacting the gas stream with the at least one metamaterial-catalyst surface.
2. 2. The method of claim 1, wherein the electromagnetic radiation comprises ultraviolet electromagnetic radiation, visible electromagnetic radiation, infrared electromagnetic radiation, or any combination thereof.
3. 3. The method of any preceding claim, wherein the electromagnetic radiation is received from a solar source, an artificial source, or any combination thereof.
4. 4. The method of any preceding claim, wherein the artificial source is present and located adjacent to the flow-through reaction pathway, and at least a portion of the electromagnetic radiation is received from the artificial source.
5. 5. The method of any preceding claim, wherein the artificial source is a light emitting diode array.
6. 6. The method of any preceding claim, wherein the at least one metamaterial-catalyst surface is interacted with the gas stream at a temperature ranging from about 135°C to about 155°C.
7. 7. A method comprising: providing a feed stream comprising hydrogen sulfide; interacting the feed stream in a flow-through reaction space with at least one metamaterial surface comprising a plurality of resonators patterned thereon; exposing the at least one metamaterial surface to a plurality of photocatalyst particles while interacting the feed stream with the at least one metamaterial surface; wherein the plurality of photocatalyst particles comprise at least one photocatalyst effective to convert hydrogen sulfide into elemental hydrogen and elemental sulfur upon exposure to electromagnetic radiation; exposing the at least one metamaterial surface to electromagnetic radiation while interacting the at least one metamaterial surface with the feed stream; and obtaining elemental hydrogen and elemental sulfur after interacting the feed stream with the at least one metamaterial surface.
8. 8. The method of claim 7, w herein the feed stream comprises a gas stream or a liquid stream.
9. 9. The method of claim 7, wherein the plurality of photocatalyst particles is introduced to the flow-through reaction space concurrently with the feed stream.
10. 10. The method of claim 7, wherein the at least one metamaterial surface receives electromagnetic radiation from a solar source, an artificial source, or any combination thereof.
11. 11. The method of claim 7. wherein the artificial source is present and located adjacent to the flow-through reaction pathw ay, and at least a portion of the electromagnetic radiation is received from the artificial source.
12. 12. A photoreactor sy stem comprising: a flow-through reaction space having at least one metamaterial-catalyst surface, the at least one metamaterial-catalyst surface comprising a metamaterial surface having a plurality of resonators patterned thereon and a plurality of photocatalyst particles located upon at least a portion of the resonators, within a gap between a first region and a second region of one or more resonators, or within a gap between adjacent resonators; wherein the plurality of photocatalyst particles comprise at least one photocatalyst effective to convert hydrogen sulfide into elemental hydrogen and elemental sulfur upon exposure to electromagnetic radiation.
13. 13. The photoreactor system of claim 12, wherein the flow -through reaction space is connected to a gas inlet for receiving a gas stream comprising hydrogen sulfide, a gas outlet for discharging elemental hydrogen, and a liquid outlet for discharging elemental sulfur.
14. 14. The photoreactor system of claim 12, wherein the at least one metamaterial-catalyst surface receives electromagnetic radiation from a solar source, an artificial source, or any combination thereof.
15. 15. The photoreactor system of claim 13, wherein the artificial source comprises a lightemitting diode array.
16. 16. The photoreactor system of claim 11, wherein the at least one metamaterial-catalyst surface is present upon (1) a substrate that is at least partially transparent to solar radiation, such that the at least one metamaterial-catalyst surface receives a first input of electromagnetic radiation as solar radiation from a first face of the substrate and a second input of electromagnetic radiation from the artificial source or (2) a substrate that is opaque to solar radiation or is blocked from transmitting solar radiation to the plurality of resonators, such that the solar radiation is converted to heat and heating of the flow-through reaction space takes place when exposure to solar radiation occurs.
17. 17. The photoreactor system of claim 11, wherein the at least one metamaterial-catalyst surface is present upon a first face of a substrate and a second plurality of resonators are located upon a second face of the substrate opposite the first face, the second plurality of resonators being capable of interacting with solar radiation, such that the solar radiation is converted to heat by the second plurality of resonators and heating of the flow-through reaction space takes place when exposure to solar radiation occurs.
18. 18. The photoreactor system of claim 11 , wherein the at least one metamaterial -catalyst surface is present upon a membrane resonator comprising a substrate having plurality of holes or slits defined therein, the membrane resonator dividing the flow-through reaction space into a first flow-through reaction space and a second flow-through reaction space.
19. 19. The photoreactor system of claim 11, wherein the plurality of resonators are located upon a substrate that is (1) substantially planar or and the flow-through reaction space or a portion thereof is linearly interposed between the substrate and the artificial source or (2) substantially non-planar and the artificial source is also substantially non-planar, and the flow-through reaction space or a portion thereof defines an annulus between the substrate and the artificial source.

Description

METAMATERIAL-ENHANCED PHOTOCATALYTIC CONVERSION OF HYDROGEN SULFIDE FIELD OF THE DISCLOSURE [0001] The present disclosure relates generally to hydrogen sulfide processing and, more particularly, to methods and systems for converting hydrogen sulfide into elemental hydrogen and elemental sulfur. BACKGROUND OF THE DISCLOSURE [0002] Acid gases such as hydrogen sulfide (H2S) and carbon dioxide (CO2), for example, are often present in combination with hydrocarbon gases produced from a subterranean formation. Natural gas is but one example of a hydrocarbon gas that may contain acid gases. [0003] To make hydrocarbon gases suitable for further use, acid gases may be removed using amine-based absorbents. Eventually, the amine-based absorbents are processed to discharge the acid gases therefrom and regenerate the free amine. Carbon dioxide liberated from the amine-based absorbents may be released into the atmosphere, although carbon capture strategies are becoming increasingly common and oftentimes are mandated by local regulations. Hydrogen sulfide, in contrast, is a highly toxic gas, and is not usually released into the atmosphere without first being converted into a more benign form. [0004] At present, hydrogen sulfide is most frequently processed by the Claus process, which converts the hydrogen sulfide into elemental sulfur and water through partial oxidation and a subsequent catalytic reaction of the remaining hydrogen sulfide with sulfur dioxide. High temperatures are utilized in the Claus process, and rigorous process control is usually required to avoid excessive oxidation. [0005] An alternative reaction pathway for processing hydrogen sulfide to form elemental hydrogen as a more valuable product would be highly desirable, as hydrogen is an environmentally benign, clean energy storage resource or fuel. Although some progress has been made in the conversion of hydrogen sulfide into elemental hydrogen and elemental sulfur through methane reforming, thermal conversion, plasma decomposition, or electrochemical decomposition, current technologies are rather energy intensive and occur at high temperatures with only low conversion to products. In addition, accumulation of elemental sulfur upon reaction surfaces may be problematic in some instances, such as upon electrodes in electrochemical processes, thereby compromising the conversion process. Photochemical conversion of hydrogen sulfide into elemental hydrogen and elemental sulfur has also been explored, but the conversion efficiency remains rather poor. [0006] In view of the foregoing, improved processes for converting hydrogen sulfide into elemental hydrogen and elemental sulfur would be highly desirable. SUMMARY OF THE DISCLOSURE [0007] Various details of the present disclosure are hereinafter summarized to provide a basic understanding. This summary is not an exhaustive overview of the disclosure and is neither intended to identify certain elements of the disclosure, nor to delineate the scope thereof. Rather, the primary purpose of this summary is to present some concepts of the disclosure in a simplified form prior to the more detailed description that is presented hereinafter. [0008] According to some embodiments consistent with the present disclosure, photoreactor systems comprise: a flow-through reaction space having at least one metamaterial-catalyst surface, the at least one metamaterial-catalyst surface comprising a metamaterial surface having a plurality of resonators patterned thereon and a plurality of photocatalyst particles located upon at least a portion of the resonators, within a gap between a first region and a second region of one or more resonators, or within a gap between adjacent resonators; wherein the plurality of photocatalyst particles comprise at least one photocatalyst effective to convert hydrogen sulfide into elemental hydrogen and elemental sulfur upon exposure to electromagnetic radiation. [0009] In other embodiments consistent with the present disclosure, methods for processing hydrogen sulfide comprise: providing a gas stream comprising hydrogen sulfide; interacting the gas stream in a flow-through reaction space with at least one metamaterial-catalyst surface, the at least one metamaterial-catalyst surface comprising a metamaterial surface having a plurality of resonators patterned thereon and a plurality of photocatalyst particles located upon at least a portion of the resonators, within a gap between a first region and a second region of one or more resonators, or within a gap between adjacent resonators; wherein the plurality of photocatalyst particles comprise at least one photocatalyst effective to convert hydrogen sulfide into elemental hydrogen and elemental sulfur upon exposure to electromagnetic radiation; exposing the at least one metamaterialcatalyst surface to electromagnetic radiation while interacting the at least one metamaterial-catalyst surface with the gas stream; and obtaining elemental hydrogen and ele