The present invention relates to an additive composition for scavenging hydrogen sulfide in hydrocarbons, wherein said additive composition comprises a combination of (a) glyoxal and (b) at least one aliphatic tertiary amine or oxide treated derivative thereof, or a mixture of the aliphatic tertiary amine and the oxide treated derivative thereof. In one embodiment it also relates to a method for scavenging hydrogen sulfide in hydrocarbons, and in another embodiment it relates to a method of using an additive composition of the present invention for scavenging hydrogen sulfide in hydrocarbons. In yet another embodiment it relates to a composition for scavenging hydrogen sulfide in hydrocarbons comprising (A) a hydrocarbon and (B) a hydrogen sulfide scavenging additive composition of the present invention.

Natural gas liquefaction process in combination with a synthesis gas production process, where the steam derived from the synthesis gas production process is used as a heating source for the implementation of the pre-treatment step for eliminating the impurities liable to freeze during the natural gas liquefaction process.

Disclosed is a process comprising: step a) contacting a feed stream comprising a contaminant with an absorbent stream in a counter-current flow to produce a contaminant depleted product stream depleted in the molar quantity of the contaminant relative to the molar quantity of said contaminant in the feed stream, and a contaminant enriched absorbent stream enriched in the molar quantity of the contaminant relative to the molar quantity of said contaminant in the absorbent stream; and step b) treating the contaminant enriched absorbent stream to form a gaseous stream comprising said contaminant and a regenerated absorbent stream lean in the molar quantity of said contaminant relative to the molar quantity of said contaminant in the contaminant enriched absorbent stream; herein said absorbent stream comprises at least 15 wt. % of at least one compound (A) of general formula (I) or a mixture (M) comprising at least one compound (B) of general formula (II) and at least one compound (C) of general formula (III).

A cryogenic distillation tower for separating a feed stream. The tower includes a distillation section. A controlled freeze zone section is situated above the distillation section and forms a solid from the feed stream. The controlled freeze zone section includes a spray assembly in an upper section and a melt tray assembly in a lower section. The melt tray assembly includes at least one vapor stream riser that directs the vapor from the distillation section into liquid retained by the melt tray assembly, and one or more draw-off openings positioned to permit a portion of the liquid to exit the controlled freeze zone section. The portion of the liquid indirectly exchanges heat with a heating fluid. One or more return inlets return the portion of the liquid to the melt tray assembly after it has been heated in the heat exchanger.

A co-current contacting system for removing impurities from a gas stream is described herein. The co-current contacting system includes a co-current contactor configured to co-currently flow a gas stream including impurities and a liquid stream through the co-current contactor. The co-current contactor is also configured to incorporate liquid droplets formed from the liquid stream into the gas stream, such that the impurities from the gas stream are absorbed by the liquid droplets. The co-current contacting system also includes a separator configured to remove the gas stream from the liquid droplets including the impurities, generating a purified gas stream and a rich liquid stream. The co-current contacting system is configured to recycle the rich liquid stream for reuse as a portion of the liquid stream flowing into the co-current contactor.

This disclosure relates to CO.sub.2-philic crosslinked polyethylene glycol membranes useful for natural gas purification processes. Also provided are methods of using the membranes to remove CO.sub.2 and H.sub.2S from natural gas.

In a method for capturing carbon, sulfur, and/or nitrogen from a target source, a matrix including activated metal dispersed in a metal activating agent is provided. The target source may be or include a carbon, sulfur, and/or nitrogen target compound. The target source is contacted with the matrix, wherein the activated metal reacts with the target source to produce elemental carbon, elemental sulfur, elemental nitrogen, and/or one or more compounds transformed from the target compound(s). The matrix may be produced by contacting a metal with the metal activating agent, and maintaining contact between the metal and the metal activating agent for a period of time sufficient for metal atoms from the solid metal to disperse in the metal activating agent. The reaction may also produce a metal compound. The activated metal may also be utilized in alkylation and other synthesis processes.

Provided is a composition for removing a sulfur-containing compound present in liquid or vapor, the sulfur-containing compound being hydrogen sulfide, an —SH group-containing compound or a mixture thereof, the composition containing an α,β-unsaturated aldehyde represented by the following general formula (1) as an active ingredient; ##STR00001##
wherein R.sup.1 and R.sup.2 each independently represent an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms or an aryl group having 6 to 12 carbon atoms, or are connected to each other to represent an alkylene group having 2 to 6 carbon atoms; and R.sup.3 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, or is connected to R.sup.1 to represent an alkylene group having 2 to 6 carbon atoms.

Provided are high-performance gas desulfurizing agent and desulfurizing method each of which has a high desulfurizing ability even at low temperatures and keeps its desulfurizing performance for an extended period of time. The gas desulfurizing agent includes zinc oxide, aluminum oxide, and copper, the desulfurizing agent further including nickel in an amount of 1.0% by mass to 10% by mass and rhenium in an amount of 0.1% by mass to 1.0% by mass. The gas desulfurizing method includes bringing the desulfurizing agent into contact with gas in coexistence of hydrogen to decompose a sulfur compound in the gas and remove the sulfur compound from the gas.

An apparatus and method to desulfurize a biogas containing sulfur. Since biogas is produced by an anaerobic digester from human, animal, kitchen and agriculture's wastes, it is a short term recycled product from the photosynthesis of CO.sub.2, and has a net zero carbon emission. The sulfur compounds in the biogas can be removed by the following steps: (1) converting all sulfur compounds into H.sub.2S by the hydrogen produced from the biogas over Pt group metal catalysts; (2) adsorbing the H.sub.2S at high temperature by the regenerable Pt group metal catalyst and adsorbents. The desulfurized biogas is further converted by an ATR/CPO reformer or a steam generating reformer to produce various reformates.