Hydrogen sulfide dissociation using reactive sulfur species
The disclosure relates to methods of irradiating a gas containing hydrogen sulfide (H 2 S) with high energy light to photolytically cleave some of the hydrogen sulfide in the gas to form sulfur-containing reactive species. The sulfur-containing reactive species act as autocatalysts that react with some of the remaining hydrogen sulfide in the gas to generate hydrogen gas and one or more sulfur-containing products. The methods remove hydrogen sulfide from the gas and produce hydrogen gas. The methods can be implemented in a component of a hydrocarbon producing well (e.g., a wellhead, a flow line, a production casing, a production tubing), a component used to transport the gas mixture produced by the well (e.g., a transportation pipeline), a gas treatment system (e.g., a tail gas treatment system), a borehole and/or an underground formation.
1 . A method, comprising:
irradiating a gas mixture comprising first and second portions of hydrogen sulfide (H 2 S) with light to photolytically cleave the first portion of the hydrogen sulfide in the gas mixture, thereby generating a sulfur-containing reactive species, the gas mixture being in a member selected from the group consisting of at least one component of a hydrocarbon producing well, at least one component configured to transport a hydrocarbon produced by a hydrocarbon producing well, a gas treatment system, a borehole and an underground formation; and
reacting the sulfur-containing reactive species with the second portion of the hydrogen sulfide in the gas mixture to generate a sulfur-containing product,
wherein the first portion of the hydrogen sulfide is different from the second portion of the hydrogen sulfide, and the light has a wavelength of at most 380 nanometers (nm).
2 . The method of claim 1 , wherein the member comprises at least one component selected from the group consisting of a wellhead, a flow line, a production casing, a production tubing, a tail gas treatment system, a borehole, a transportation pipeline and an underground formation.
3 . The method of claim 1 , wherein the sulfur-containing reactive species comprises at least one member selected from the group consisting of an HS x radical, where x=1-8.
4 . The method of claim 1 , wherein the sulfur-containing product comprises at least one member selected from the group consisting of polysulfanes and elemental sulfur.
5 . The method of claim 1 , wherein at least one of the following holds:
the sulfur-containing product adsorbs at least one species selected from the group consisting of hydrogen sulfide, polysulfides, sulfites, polysulfanes, CS 2 , SO 2 and heavy metals; and
the sulfur-containing product absorbs at least one species selected from the group consisting of hydrogen sulfide, polysulfides, sulfites, polysulfanes, CS 2 , SO 2 and heavy metals.
6 . The method of claim 1 , wherein the wavelength of the light is from 100 nanometers (nm) to 380 nm.
7 . The method of claim 1 , wherein a power of the light is from 1 milliwatt to 1 megawatt.
8 . The method of claim 1 , further comprising:
irradiating the sulfur-containing product with light having a wavelength of at least 380 nm to generate a reactive species; and
reacting the reactive species with hydrogen sulfide to generate additional sulfur-containing product.
9 . The method of claim 1 , wherein at least one of the following holds:
irradiating the gas mixture with light to photolytically cleave the first portion of the hydrogen sulfide in the gas mixture generates hydrogen radicals; or
the sulfur-containing reactive species comprises a first portion of sulfur-containing reactive species and a second portion of sulfur-containing reactive species different from the first portion, and the first portion of the sulfur-containing reactive species reacts with the second portion of the sulfur-containing reactive species to generate a sulfur-containing product.
10 . The method of claim 1 , further comprising:
reacting the sulfur-containing reactive species with a ceramic species to form a ceramic-sulfur species; and
reacting the ceramic-sulfur species with an additional portion of hydrogen sulfide in the gas mixture to provide additional sulfur-containing reaction product.
11 . The method of claim 10 , wherein:
the member comprises at least one component selected from the group consisting of a wellhead, a flow line, a production casing, a production tubing, a tail gas treatment system a borehole, a transportation pipeline and an underground formation; and
the ceramic species is disposed on a surface of the member.
12 . The method of claim 10 , wherein the ceramic species comprises at least one member selected from the group consisting of Fe, Cr, Mg, Mn, Ca, Ce, Zn, Na, Sb, Bi, V, Ba, Sr, CaC, Zn, V, Na 2 C, Sb, Si, Al, Li, Na, K and a lanthanide.
13 . The method of claim 10 , wherein the ceramic-sulfur species comprises at least one member selected from the group consisting of FeS x , CrS x , MgS x , MnS x , CaS x , CeS x , ZnS x , NaS x , SbS x , BiS x , VS x , BaS x O 4-y , SrS x O 4-y , FeS x O y , CrS x O y , MgS x O y , MnS x O y , CaS x O y , CeS x O y , CaCS x O y , ZnS x O y , VS x O y , Na 2 CS x O y , SbS x O y , SiS x O y , lanthanide sulfides, lanthanide oxysulfides, and lanthanide sulfites.
14 . The method of claim 10 , wherein the sulfur-containing reactive species comprises at least one member selected from the group consisting of an HS x radical, where x=1-8, and HS − .
15 . The method of claim 10 , wherein the sulfur-containing product comprises at least one member selected from the group consisting of polysulfanes, elemental sulfur and a product containing both the ceramic and sulfur.
16 . The method of claim 10 , wherein at least one of the following holds:
the sulfur-containing product adsorbs at least one species selected from the group consisting of hydrogen sulfide, polysulfides, sulfites, polysulfanes, CS 2 , SO 2 and heavy metals; or
the sulfur-containing product absorbs at least one species selected from the group consisting of hydrogen sulfide, polysulfides, sulfites, polysulfanes, CS 2 , SO 2 and heavy metals.
17 . The method of claim 10 , wherein:
the ceramic species comprises Fe 2 O 3 ;
the ceramic-sulfur species comprises Fe 2 O x S y ; and
the sulfur-containing product comprises at least one member selected from the group consisting of elemental sulfur, polysulfanes, and Fe 2 S 3-x .