A process for the removal of hydrogen sulfide and sulfur recovery from a H.sub.2S-containing gas stream by catalytic direct oxidation and Claus reaction through two or more serially connected catalytic reactors, wherein a specific control of the oxygen supplement is operated. The control and improvement of the process is obtained by complementing, in each major step of the process, the H.sub.2S-containing gas stream by a suitable flow of oxygen, namely before the H.sub.2S-containing gas stream enters the Claus furnace, in the first reactor of the process and in the last reactor of the process. Especially in application in a SubDewPoint sulfur recovery process the H.sub.2S/SO.sub.2 ratio is kept constant also during switch-over of the reactors R1 and R by adding the last auxiliary oxygen containing gas directly upstream the last reactor R so that the H.sub.2S/SO.sub.2 ratio can follow the signal of the ADA within a few seconds.

A feed stream is flowed to a catalytic reactor. The catalytic reactor includes a non-thermal plasma and a catalyst. The feed stream includes hydrogen sulfide and carbon dioxide. The feed stream is contacted with the catalyst in the presence of the non-thermal plasma at a reaction temperature, thereby converting the hydrogen sulfide and the carbon dioxide in the feed stream to produce a product. The product includes a hydrocarbon and sulfur. The product is separated into a product stream and a sulfur stream. The product stream includes the hydrocarbon from the product. The sulfur stream includes the sulfur from the product.

A method for cleaning an off-gas from viscose production, essentially containing H.sub.2S and CS.sub.2, comprises passing the gas through a catalytic reactor containing a direct oxidation type catalyst, such as V.sub.2O.sub.5 on silica, to convert H.sub.2S in the gas to elemental sulfur, SO.sub.2 or mixtures thereof, either via the oxygen present in the gas or via oxygen added to the gas stream. Elemental sulfur and SO.sub.2 are removed from the effluent gas from the catalytic reactor, and the unconverted CS.sub.2 is recycled to the viscose production process.

A method of generating electricity in a body of water includes providing a colony of sulfur-reducing bacteria, a colony of sulfur-oxidizing bacteria, and a colony of denitrifying bacteria submerged in the body of water. The colony of sulfur-reducing bacteria can be used to convert at least a portion of sulfates present in the body of water to hydrogen sulfide. The colony of sulfur-oxidizing bacteria can be used to convert the hydrogen sulfide to sulfuric acid, which can react with manganese to produce hydrogen gas. The colony of denitrifying bacteria can be used to convert at least a portion of nitrogen oxides in the body of water to nitrogen gas, which can be bubbled through a portion of water from the body of water to remove dissolved oxygen gas. The hydrogen gas and oxygen gas can be combined in a fuel cell generator to generate electricity.

A method of generating hydrogen gas includes providing a colony of sulfur-reducing bacteria and a colony of sulfur-oxidizing bacteria. The colonies can be submerged in a body of water. The colony of sulfur-reducing bacteria can be used to convert at least a portion of sulfates present in the body of water to hydrogen sulfide. The colony of sulfur-oxidizing bacteria can be used to convert the hydrogen sulfide to sulfuric acid. The sulfuric acid can react with manganese to produce hydrogen gas and manganese sulfate.

A method of separating oxygen from a body of water includes providing a colony of denitrifying bacteria submerged in the body of water. The colony of denitrifying bacteria can be used to convert at least a portion of nitrogen oxides present in the body of water to nitrogen gas. The method can also include collecting the nitrogen gas and bubbling the nitrogen gas through a portion of water from the body of water to remove dissolved oxygen from the portion of water. This can form a mixture of the nitrogen gas and oxygen gas.

Techniques for generating electric power for well site operations include processing a hydrocarbon fluid produced from a subterranean formation, through a wellbore, and to a terranean surface into at least one acid gas; processing the at least one acid gas into hydrogen; generating, with the hydrogen, electrical power from a hydrogen engine; and providing the generated electrical power for use or storage to power at least one electrically-operated machine to perform at least one well site operation.

A process for recovering sulfur in a sulfur recovery unit comprising the steps of reacting hydrogen sulfide and oxygen in the reaction furnace at a minimum reaction temperature to produce a reaction effluent; reducing the temperature of the reaction effluent from the minimum reaction temperature to a boiler section outlet temperature to produce a cooled effluent, the cooled effluent comprises hydrogen sulfide, sulfur dioxide, and sulfur-containing contaminants; reacting the hydrogen sulfide, sulfur dioxide, and sulfur-containing contaminants in the catalytic extension to produce a boiler catalytic effluent; reducing the boiler catalytic effluent temperature such that the elemental sulfur condenses to form liquid sulfur and a gases stream; reacting the hydrogen sulfide and sulfur-containing contaminants with the oxygen to produce an oxidizer outlet stream comprises sulfur dioxide; and separating the sulfur dioxide in the scrubbing unit to produce a recycle stream and an effluent gases, the recycle stream comprises sulfur dioxide.

A system and method for removing sulfur compounds from gas, including discharging tail gas having sulfur compounds from a sulfur recovery unit (SRU) to a non-thermal plasma (NTP) catalytic unit including an NTP reactor, providing oxidant to the NTP reactor and placing the oxidant in an NTP state in the NTP reactor to give an oxidative reactive species formed from the oxidant, converting (oxidizing) the sulfur compounds with the oxidative reactive species and catalyst in the NTP catalytic unit into sulfur oxides (SO.sub.x) to discharge the tail gas as treated having the formed SO.sub.x without the sulfur compounds that were converted. The SO.sub.x is absorbed into water in a quench tower to give the tail gas beneficially having only small amounts (e.g., less than 200 ppmv) of sulfur compounds. SO.sub.x may be degassed from water discharged from the quench tower and sent to the SRU furnace.

A method for cleaning an off-gas from viscose production, essentially containing H.sub.2S and CS.sub.2, comprises passing the gas through a catalytic reactor containing a direct oxidation type catalyst, such as V.sub.2O.sub.3 on silica, to convert H.sub.2S in the gas to elemental sulfur, SO.sub.2 or mixtures thereof, either via the oxygen present in the gas or via oxygen added to the gas stream. Elemental sulfur and SO.sub.2 are removed from the effluent gas from the catalytic reactor, and the unconverted CS.sub.2 is recycled to the viscose production process.