Embodiments of the disclosure provide a method and system for sulfur recovery. A Claus tail gas stream is fed to a hydrogenation reactor to produce a hydrogenated gas stream. The hydrogenated gas stream is fed to a quench tower to produce a quenched gas stream. The quenched gas stream is fed to a first stage adsorption vessel of first stage adsorption unit to produce a first outlet gas stream. The first outlet gas stream is fed to a second stage adsorption vessel of a second stage adsorption unit to produce a second byproduct gas stream. The first stage adsorption vessel is regenerated to produce a first byproduct gas stream. The second stage adsorption vessel is regenerated to produce a second outlet gas stream including hydrogen sulfide. Optionally, a portion of the second byproduct gas stream or nitrogen can be fed to the first stage adsorption vessel or the second stage adsorption vessel for regeneration. Optionally, a sales gas can be fed to the second stage adsorption vessel for regeneration. Optionally, vacuum can be applied to the first stage adsorption vessel or the second stage adsorption vessel for regeneration.

Methods and systems for converting ammonium waste streams into certifiably Organic ammonium salts having a variety of uses in greenhouse gas-reducing activities are herein described. The resulting ammonium salt compositions can be used to enhance crop yield.

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.

The system is provided with: a first heat exchanger which is interposed at an intersection between a rich solution supply line and a lean solution supply line, which has absorbed CO.sub.2 and H.sub.2S extracted from a bottom portion of an absorber, and a regenerated absorbent; a second heat exchanger which is interposed at an intersection between a semi-rich solution supply line and a branch line branched at the branch portion C from the lean solution supply line, and the lean solution; a merging portion which merges a branch line configured to supply the lean solution after heat exchange with the lean solution supply line; and a flow rate adjusting valve which is interposed in the lean solution supply line to adjust the distribution amount of the lean solution.

Systems and methods for removing hydrogen sulfide from an ammonia stream in the NH3 purification and liquefaction stage of a conventional two-column sour water stripping system using an adsorbent bed.

The system includes: an absorber which brings an introduction gas into contact with an absorbent that absorbs CO.sub.2 and H.sub.2S; an absorbent regenerator which releases CO.sub.2 or the like to regenerate the absorbent; a second supply line which returns a regenerated absorbent to the absorber from the regenerator; a third supply line which extracts a semi-rich solution from the vicinity of a middle stage of the absorber, and introduces the semi-rich solution to the vicinity of the middle stage of the regenerator; and a semi-rich solution heat exchanger which is interposed at an intersection between the third supply line and the second supply line to perform the heat exchange between the semi-rich solution and the lean solution.

Disclosed are systems and methods which provide a process stream comprising a gaseous component, capture the gaseous component from the process stream by an ionic liquid solvent of a separator, and recover a captured gaseous component from the ionic liquid solvent in a regenerator. A second gaseous component from the process stream may be captured by the ionic liquid solvent of the separator, and the second gaseous component may be recovered from the ionic liquid solvent in the regenerator. Alternatively, the second gaseous component from the process stream may be uncaptured by the ionic liquid solvent, and the uncaptured second gaseous component may be recovered from a membrane unit.

An absorbent for absorbing CO.sub.2 or H.sub.2S, or both of CO.sub.2 and H.sub.2S in a gas contains, as components, (a) a secondary linear monoamine, (b) a tertiary linear monoamine, and (c) a secondary cyclic diamine. When the concentration of the secondary linear monoamine (a) is more than 30% by weight and less than 45% by weight and the concentration of the tertiary linear monoamine (b) is more than 15% by weight and less than 30% by weight, absorbability of CO.sub.2 or H.sub.2S, or both of CO.sub.2 and H.sub.2S is good, and releasability of CO.sub.2 or H.sub.2S that have been absorbed during regeneration of the absorbent is good. The amount of steam of a reboiler used during regeneration of the absorbent in a CO2 recovery unit can be thus reduced.

Embodiments of the disclosure provide a method and system for sulfur recovery. A Claus tail gas stream is fed to a hydrogenation reactor to produce a hydrogenated gas stream. The hydrogenated gas stream is fed to a quench tower to produce a quenched gas stream. The quenched gas stream is fed to a first stage adsorption vessel of first stage adsorption unit to produce a first outlet gas stream. The first outlet gas stream is fed to a second stage adsorption vessel of a second stage adsorption unit to produce a second byproduct gas stream. The first stage adsorption vessel is regenerated to produce a first byproduct gas stream. The second stage adsorption vessel is regenerated to produce a second outlet gas stream including hydrogen sulfide. Optionally, a portion of the second byproduct gas stream or nitrogen can be fed to the first stage adsorption vessel or the second stage adsorption vessel for regeneration. Optionally, a sales gas can be fed to the second stage adsorption vessel for regeneration. Optionally, vacuum can be applied to the first stage adsorption vessel or the second stage adsorption vessel for regeneration.

A composite amine absorbent according to the present invention is an absorbent for absorbing CO.sub.2 or H.sub.2S, or both of CO.sub.2 and H.sub.2S in a gas. The absorbent is obtained by dissolving (1) a linear monoamine, (2) a diamine, and (3) propylene glycol alkyl ether, for example, represented by the following chemical formula (I) in water. In the composite amine absorbent, the components complexly interact, and the synergistic effect thereof provides good absorbability of CO.sub.2 or H.sub.2S, or both of CO.sub.2 and H.sub.2S and good releasability of CO.sub.2 or H.sub.2S absorbed during regeneration of the absorbent. Furthermore, the amount of water vapor in a reboiler 26 used during regeneration of the absorbent in a CO.sub.2 recovery unit 12 can be reduced.
R.sup.1—O—(R.sup.2—O).sub.n—R.sup.3  (I)