A system and method for sulfur recovery, including hydrogenating Claus tail gas, quenching the hydrogenated gas, adsorbing water and hydrogen sulfide from the quenched gas, and regenerating adsorbent with carbon dioxide and/or nitrogen and heating the adsorbent in a regeneration temperature ramp to desorb primarily hydrogen sulfide in a first part of the temperature ramp.

An object of the present invention is to provide a hydrogen sulfide production method enabling efficient recovery of sulfur. The production method is a method for producing hydrogen sulfide from sulfur and hydrogen comprising (1) a reaction step of reacting sulfur and hydrogen to obtain a crude hydrogen sulfide gas, (2) a purification step of purifying the crude hydrogen sulfide gas by bringing the crude hydrogen sulfide gas into contact with aliphatic lower alcohol in a packed tower to precipitate sulfur contained in the crude hydrogen sulfide gas, (3) a discharge step of discharging from inside the packed tower a suspension of sulfur in aliphatic lower alcohol obtained in the purification step, and (4) a filtration step of filtering the aliphatic lower alcohol suspension of sulfur with a filter to obtain a sulfur cake, and the filter 20 is a rotary filter 22 or a leaf filter.

A system and method for sulfur recovery, including hydrogenating Claus tail gas, quenching the hydrogenated gas, adsorbing water and hydrogen sulfide from the quenched gas, and regenerating adsorbent with carbon dioxide and/or nitrogen and heating the adsorbent in a regeneration temperature ramp to desorb primarily hydrogen sulfide in a first part of the temperature ramp.

An object of the present invention is to provide a hydrogen sulfide production method enabling efficient recovery of sulfur. The production method is a method for producing hydrogen sulfide from sulfur and hydrogen comprising (1) a reaction step of reacting sulfur and hydrogen to obtain a crude hydrogen sulfide gas, (2) a purification step of purifying the crude hydrogen sulfide gas by bringing the crude hydrogen sulfide gas into contact with aliphatic lower alcohol in a packed tower to precipitate sulfur contained in the crude hydrogen sulfide gas, (3) a discharge step of discharging from inside the packed tower a suspension of sulfur in aliphatic lower alcohol obtained in the purification step, and (4) a filtration step of filtering the aliphatic lower alcohol suspension of sulfur with a filter to obtain a sulfur cake, and the filter 20 is a rotary filter 22 or a leaf filter.

Disclosed are processes for purifying feed streams containing hydrogen sulfide and sulfur-containing impurities by removing sulfur-containing impurities, such as elemental sulfur and polysulfanes, using solid catalytic sorbents. Also disclosed are processes for producing hydrogen sulfide.

A process for recovering sulfur from a tail gas stream comprising the steps of providing a tail gas stream to a chemical looping combustion (CLC) unit, the tail gas stream comprising a sulfide component, providing an oxygen carrier to the CLC unit, the oxygen carrier comprising a calcium carbonate, providing an air stream to the CLC unit, the air stream comprising oxygen, and reacting the sulfide component in the CLC unit with the calcium compound and the air to produce a product effluent, the product effluent comprising calcium sulfate.

A process for simultaneous removal of hydrogen sulfide (H.sub.2S ) and heavy metals from mixture includes charging a contaminated aqueous composition containing heavy metal ions to a reactor. The process also includes passing a H.sub.2S -containing gas composition via a plurality of gas spargers through the contaminated aqueous composition present in the reactor to form a H.sub.2S-containing contaminated aqueous composition and a purified gas composition. The process further includes reacting the H.sub.2S from the H.sub.2S -containing contaminated aqueous composition with the heavy metal ions in the H.sub.2S -containing contaminated aqueous composition to form a metal sulfide precipitate in a metal-sulfide-containing contaminated aqueous composition. In addition, the process includes at least partially introducing the metal-sulfide-containing contaminated aqueous composition to a solid-liquid separator and removing the metal sulfide precipitate from the metal-sulfide-containing contaminated aqueous composition to form a purified aqueous composition.

A process for recovering sulfur from a tail gas stream comprising the steps of providing a tail gas stream to a chemical looping combustion (CLC) unit, the tail gas stream comprising a sulfide component, providing an oxygen carrier to the CLC unit, the oxygen carrier comprising a calcium carbonate, providing an air stream to the CLC unit, the air stream comprising oxygen, and reacting the sulfide component in the CLC unit with the calcium compound and the air to produce a product effluent, the product effluent comprising calcium sulfate.

A process for recovering sulfur from a tail gas stream comprising the steps of providing a tail gas stream to a chemical looping combustion (CLC) unit, the tail gas stream comprising a sulfide component, providing an oxygen carrier to the CLC unit, the oxygen carrier comprising a calcium carbonate, providing an air stream to the CLC unit, the air stream comprising oxygen, and reacting the sulfide component in the CLC unit with the calcium compound and the air to produce a product effluent, the product effluent comprising calcium sulfate.

The present invention relates to a hydrogen sulfide purification method including removing a lithium raw material from a mixed gas which is generated in a process of producing lithium sulfide by a reaction of hydrogen sulfide and the lithium raw material and which includes unreacted hydrogen sulfide and the lithium raw material.