The present disclosure provides a method for generating higher hydrocarbon(s) from a stream comprising compounds with two or more carbon atoms (C.sub.2+), comprising introducing methane and an oxidant (e.g., O.sub.2) into an oxidative coupling of methane (OCM) reactor. The OCM reactor reacts the methane with the oxidant to generate a first product stream comprising the C.sub.2+ compounds. The first product stream can then be directed to a separations unit that recovers at least a portion of the C.sub.2+ compounds from the first product stream to yield a second product stream comprising the at least the portion of the C.sub.2+ compounds.

A fuel vapor processing apparatus may include a first adsorption chamber, a second adsorption chamber and a third adsorption chamber that are connected in series with respect to a flow of gas. A ratio of a length to a diameter of the second adsorption chamber may be larger than that of the first adsorption chamber. A cross sectional area of each of the second and third adsorption chambers may be smaller than a cross sectional area of the first adsorption chamber.

Disclosed is a method of sequentially separating and recovering one or more NGLs (129, 229) from a natural gas feedstream (3). Specifically, a raw natural gas feedstream (3) is passed through two or more NGLs separation unit (100, 200) wherein each separation unit removes one or more NGLs from the natural gas feedstream to provide a methane-rich natural gas supply (205). Each separation unit employs an adsorption media and has an adsorption step and a media regeneration step wherein the regeneration step may be operated as a batch process, a semi-continuous process, or a continuous process. One embodiment of this method provides for the use of a different regenerable adsorbent media in each separation unit.

A chemical substance concentrator includes a tubular body, and a plurality of adsorption parts provided with predetermined intervals on a surface of the tubular body facing an inside of the tubular body. The chemical substance concentrator can cause a sample to easily pass through the chemical substance concentrator.

Process and apparatuses for purifying a feed stream containing CO.sub.2 and predominantly hydrogen are provided. In an embodiment, the process includes passing the feed stream through a multilayer adsorbent bed comprising a first adsorbent section, a second adsorbent section downstream from the first adsorbent section and a third adsorbent section downstream from the second adsorbent section. The first adsorbent section comprises an activated carbon layer, the second adsorbent section comprises a layer of molecular sieve of the faujasite structure type with a Si/Al atomic ratio of from 1.5 to 8.0 and the third adsorbent section comprises a layer of molecular sieve of the faujasite structure type with a Si/Al atomic ratio of from 1.0 to 1.5. At least one of N.sub.2, CO.sub.2, CH.sub.4 and CO is adsorbed from the feed stream and a purified hydrogen product is recovered from the multilayer adsorbent bed.

An adsorption module and associated processes for conducting advanced separations processes such as sorption enhanced water-gas shift (SEWGS). The adsorption module contains at least one angled baffle to create at least two tapered adsorbent beds within the adsorption module. The taper is such that the adsorbent beds' cross-sections within the adsorption module decrease in the direction of feed flow, thereby taking advantage of increased product purity and process efficiency provided by tapered adsorption beds.

A CO.sub.2 adsorption and recovery system including an intake unit, a first purification/adsorption/regeneration unit, a second purification/adsorption/regeneration unit, a three-way valve switching unit, a vacuum drawing unit and an exhaust unit is provided. The first and second purification/adsorption/regeneration units have a hollow fiber bundle impurity adsorption column, a hollow fiber bundle CO.sub.2 adsorption column and two heating devices. One set of adsorption columns performs purification and adsorption procedures to the inlet gas in a normal or high pressure condition, and the other set of adsorption columns performs desorption and regeneration procedures in a high temperature condition when the adsorption columns are heated by the heating devices. The three-way valve switching unit exchanges the purification and adsorption procedures with the regeneration procedure to the first and second units. The vacuum drawing unit draws CO.sub.2 desorbed from the CO.sub.2 adsorption columns alternatively. The exhaust unit drains a purified product gas out.

A chemical substance concentrator is configured to concentrate a chemical substance in a gaseous object. The chemical substance concentrator includes a channel in which a gaseous object flows, an adsorbent being conductive and configured to adsorb the chemical substance, and a pair of electrodes configured to cause a current to flow in the adsorbent.

A method for hydrogen production by pressure swing adsorption that can increase the recovery efficiency of an adsorption target component while enabling an off-gas to be appropriately supplied to a combustion device is provided that can achieve a cost reduction and an increase in the efficiency of the combustion operation.

Natural gas may be purified by removing C.sub.3+ hydrocarbons and CO.sub.2 in respective one or more separation units to yield conditioned gas lower in C.sub.3+ hydrocarbons and CO.sub.2 in comparison to the un-conditioned natural gas. Notably, the feed gas need not be subjected to joule-thomson expansion and molecular sieve dehydration performed by conventional processes. Rather, any water-rich reject stream from the separation unit(s) is dried downstream with a smaller compressor and smaller molecular sieve or gas separation membrane dehydration unit before it may be re-injected deep underground or deep under the sea bed.