The process of the present invention provides high recovery and low capital cost giving it an economic advantage over previously known purification processes. The present process has particular applicability to the purification of synthesis gases comprising at least hydrogen (H.sub.2), carbon monoxide (CO), methane (CH.sub.4), CO.sub.2, and H.sub.2O to obtain a gas stream including at least H.sub.2, CO, and CH.sub.4, that is substantially free of H.sub.2O and CO.sub.2. The process also has applicability to the purification of natural gases inclusive of at least CH.sub.4, N.sub.2, CO.sub.2, and H.sub.2O to produce a gas stream including at least CH.sub.4 and N.sub.2, but which is substantially free of H.sub.2O and CO.sub.2.

The present invention relates to a process for removing carbon dioxide from synthesis gas using a hygroscopic, physical absorption medium. The process includes cooling the absorption medium and the synthesis gas; water is at least partially removed from the synthesis gas by condensation; carbon dioxide is removed from the cooled synthesis gas via the cooled absorption medium in a physical absorption step at elevated pressure; laden absorption medium is treated in a plurality of serially arranged flash stages, wherein co-absorbed carbon monoxide and hydrogen are removed from the laden absorption medium in at least one first flash stage, and carbon dioxide is removed from the laden absorption medium in a flash stage arranged downstream of the first flash stage. The process features a high rate of separated carbon dioxide and a pure and dry (anhydrous) carbon dioxide product. The invention further relates to a plant for performing the process.

The present invention relates to a process for producing hydrogen and for separating carbon dioxide from synthesis gas using a physical absorption medium. The process comprises the steps where the synthesis gas and the absorption medium are cooled; carbon dioxide is removed from the cooled synthesis gas via the cooled absorption medium in a physical absorption step at elevated pressure; laden absorption medium is treated in a plurality of flash stages, wherein co-absorbed carbon monoxide, hydrogen and carbon dioxide are separately removed from the laden absorption medium; hydrogen is separated from synthesis gas freed of carbon dioxide in a physical separation step, wherein hydrogen as product gas and an offgas comprising hydrogen, carbon monoxide and carbon dioxide are obtained; product gas hydrogen and carbon dioxide are discharged from the process. The invention further relates to a plant for performing the process.

An integrated amine and redox gas treatment system is configured to treat an influent hydrocarbon containing stream. The system includes a reduction oxidation unit connected directly downstream of an amine unit. The amine unit is configured to separate the influent fluid stream into a first amine effluent stream including hydrocarbons and a second amine effluent stream including a connection pressure and comprising CO.sub.2. The reduction oxidation unit is configured to receive the second amine effluent stream from the amine unit and operate at the connection pressure while releasing a reduction oxidation effluent stream including purified CO.sub.2. The connection pressure includes a single pressure or a plurality of pressures at which both the amine unit and the reduction oxidation unit are configured to operate.

The invention relates to a process and plant for purifying a raw synthesis gas containing hydrogen and carbon monoxide as target components and carbon dioxide and sulfur components as disruptive components by gas scrubbing with a physically acting, liquid scrubbing medium selective for carbon dioxide and sulfur components. The process/the plant comprise an absorption apparatus, a hot regeneration apparatus, a preferably multistage flash regeneration apparatus and a reabsorber column supplied with the first portion of a stripping gas. According to the invention the flash regeneration apparatus is supplied with the second portion of the stripping gas.

Systems and methods for preventing formation of carbonyl sulfide in the production of sweet gas using an amine-lean aqueous solution and metal oxide adsorbent material. In embodiments, a method may include producing, via an amine absorption column supplied with a raw gas stream that includes fractions of hydrogen sulfide (H.sub.2S), carbon dioxide (CO.sub.2), and carbon monoxide (CO), (1) a sweet gas stream that includes the fractions of the CO and (2) an amine-rich aqueous solution that includes the H.sub.2S and CO.sub.2. The method may include heating the amine-rich aqueous solution to produce a heated amine-rich aqueous solution. The method may include producing, via an amine regenerator supplied with the heated amine-rich aqueous solution (1) an acid gas stream that includes the H.sub.2S and CO.sub.2 and (2) an amine-lean aqueous solution. The method may include producing, via adsorption in a metal oxide adsorbent vessel, an effluent stream that includes the CO.sub.2.

A system and method for processing unconditioned syngas first removes solids and semi-volatile organic compounds (SVOC), then removes volatile organic compounds (VOC), and then removes at least one sulfur containing compound from the syngas. Additional processing may be performed depending on such factors as the source of syngas being processed, the products, byproducts and intermediate products desired to be formed, captured or recycled and environmental considerations.

An aminated siliceous adsorbent, which is the reaction product of dried acidified rice husk ash having disordered mesopores and an amino silane, wherein amine functional groups are present on an external surface and within the mesopores of the dried acidified rice husk ash, and wherein the aminated siliceous adsorbent has a carbon content of 24 to 30 wt. %, based on a total weight of the aminated siliceous adsorbent. A method of making the aminated siliceous adsorbent and a method of capturing CO.sub.2 from a gas mixture with the aminated siliceous adsorbent.

The invention provides a system for removing target moieties from gas streams, the system comprising a supersonic expander coaxially positioned within an array of oblique shock inducers. Also provided is a method for removing target moieties from gas streams, the method comprising simultaneously subjecting the streams to supersonic expansion and oblique shock compression.

The invention relates to a gas scrubbing process and plant for purifying raw synthesis gas by physical absorption in methanol. A raw synthesis gas stream which includes hydrogen and carbon monoxide as desired constituents and water and acid gases as undesired constituents is admixed with methanol and subsequently cooled below the freezing point of water. According to the invention a liquid phase including methanol and water is separated from the cooled raw synthesis gas stream. Acid gases are removed from the remaining gaseous phase by physical absorption in methanol at elevated pressure. Separating the water from the raw synthesis gas stream before the absorption of the acid gases prevents larger amounts of water passing into the methanol circuit of the gas scrubbing process. This achieves savings in resources and certain plant parts may be smaller than is customary.