Disclosed is a process for regenerating a hybrid solvent used to remove contaminants from a fluid stream and to provide an improved yield of purified fluid. Said process comprises at least one purification unit (12) and at least one regeneration unit (40) wherein condensed water (72) from the regeneration unit is combined with the regenerated lean hybrid solvent (55) prior to reuse in the purification unit and none of the condensed water is recycled into the regeneration unit.

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.

The invention relates to a process and a plant for staged separation of concomitants from a raw synthesis gas stream to produce synthesis gas and a sulfur-free naphtha product as a by-product, To remove naphtha compounds and sulfur-containing concomitants, raw synthesis gas is treated with a scrubbing medium in a prescrubbing stage and withdrawn from the prescrubbing stage, and the laden scrubbing medium is mixed with water to bring about a phase separation into a scrubbing medium-water mixture and naphtha, wherein sulfur-containing concomitants are in solution in naphtha. To remove the sulfur-containing concomitants the naphtha is heated to obtain sulfur-free naphtha as a by-product of the gas scrubbing.

In a process for separating a mixture containing carbon monoxide, hydrogen and carbon dioxide, the mixture cooled in a heat exchanger is contacted by a stream of liquid methanol at a temperature below 40 C. to produce carbon dioxide enriched methanol and a carbon dioxide depleted gas relative to the cooled mixture, the carbon dioxide depleted gas is cooled in the heat exchanger and is sent to a separation unit to produce a carbon monoxide enriched stream and a hydrogen enriched stream and the streams enriched in carbon monoxide and hydrogen are heated in the heat exchanger by exchanging heat with the mixture.

The disclosure provides seven integrated methods for the chemical sequestration of carbon dioxide (CO.sub.2), nitric oxide (NO), nitrogen dioxide (NO.sub.2) (collectively NO.sub.x, where x=1, 2) and sulfur dioxide (SO.sub.2) using closed loop technology. The methods recycle process reagents and mass balance consumable reagents that can be made using electrochemical separation of sodium chloride (NaCl) or potassium chloride (KCl). The technology applies to marine and terrestrial exhaust gas sources for CO.sub.2, NOx and SO.sub.2. The integrated technology combines compatible and green processes that capture and/or convert CO.sub.2, NOx and SO.sub.2 into compounds that enhance the environment, many with commercial value.

The invention relates to a process for aftertreatment of gas streams in which unwanted components are present in an amount that varies irregularly in a periodic manner or over time and/or in a varying concentration, by means of an absorption or gas scrubbing process. For this purpose, during the entry of the desorption peak into the gas scrubbing apparatus, the amount of scrubbing medium is increased proceeding from a normal value during a first phase and, after the end of the desorption peak, the amount of scrubbing medium is returned back to the normal value during a second phase, wherein the laden scrubbing media are collected in different intermediate vessels during the two phases, mixed and released as a mixture to a downstream scrubbing medium regeneration apparatus.

The invention relates to a process for removal of unwanted, in particular acidic, gas constituents, for example carbon dioxide and hydrogen sulfide, from a crude synthesis gas containing metal carbonyls by gas scrubbing with a scrubbing medium. According to the invention water is added directly into the feed conduit of the methanol water mixture containing metal sulfides before the introduction thereof into the methanol-water separating column and/or water is injected directly into the methanol-water separating column at at least one point. This avoids deposits or encrustations of metal sulfide particles in the methanol-water separating column.

The invention relates to a process and a plant for removal of acidic gas constituents from synthesis gas by absorption in a physical scrubbing medium. A first scrubbing medium laden with at least carbon dioxide (CO.sub.2) is supplied to a decompression vessel for depressurization from a first absorption apparatus via a first feed conduit. Furthermore, a second scrubbing medium laden with at least carbon dioxide (CO.sub.2) is supplied to the decompression vessel for depressurization from a second absorption apparatus via a second feed conduit. The carbon dioxide concentration in the first laden scrubbing medium is higher than the carbon dioxide concentration in the second laden scrubbing medium. According to the invention it is provided that an at least partial commixing of the first and the second laden scrubbing medium is effected in the decompression vessel, wherein the commixing and depressurization affords a partially regenerated scrubbing medium and the first feed conduit and the second feed conduit are arranged such that carbon dioxide desorbed from the first laden scrubbing medium by the depressurization is at least partially absorbed by the second laden scrubbing medium.

A CO.sub.2 recovery system used in a vehicle includes a CO.sub.2 recovery device recovering CO.sub.2 contained in inflowing gas; and a flow rate control device controlling flow rates of gases present in a plurality of different regions of the vehicle flowing into the CO.sub.2 recovery device. The gases present at the plurality of different regions include at least any two among air at an outside of the vehicle, air at an inside of the vehicle, and exhaust gas discharged from a body of an internal combustion engine of the vehicle.

A process for sweetening a syngas stream, the process comprising the steps of: providing a syngas stream to a nonselective amine absorption unit, the sour syngas stream comprising syngas, carbon dioxide, and hydrogen sulfide; separating the syngas stream in the nonselective amine absorption unit to obtain an overhead syngas stream and an acid gas stream; introducing the acid gas stream to a membrane separation unit, the acid gas stream comprising hydrogen sulfide and carbon dioxide; separating the acid gas stream in the membrane separation unit to produce a retentate stream and a permeate stream, wherein the retentate stream comprises hydrogen sulfide, wherein the permeate stream comprises carbon dioxide; introducing the retentate stream to a sulfur recovery unit; processing the retentate stream in the sulfur recovery unit to produce a sulfur stream and a tail gas stream, wherein the sulfur stream comprises liquid sulfur.