Gas separation hydrogen enrichment

Methanol is produced from carbon monoxide, carbon dioxide, and hydrogen. The proper feed composition is achieved by combining the hydrogen-enriched syngas from the shift reactor and the hydrogen-carbon monoxide stream from the gas separation unit. The feed stream... 

The nozzle separation process utilizes the centrifugal forces which occur upon diversion of a gas stream. A gas stream of uranium(VI) fluoride, helium and hydrogen is directed along a curved wall and then split by a peeling off plate into two gas streams with enrichment of the heavier and lighter isotopes respectively. 

Carbon dioxide-methane separation Solvent vapor recovery Hydrogen and carbon dioxide recovery from steam-methane reformer off-gas Hydrogen recovery from refinery off-gas Carbon monoxide-hydrogen separation Alcohol dehydration Production of ammonia synthesis gas Normal-isoparaffin separation Ozone enrichment... 

Apphcations of SLM, ELM, and BOHLM configurations for gas separations are reviewed. These are production of oxygen enriched air carbon dioxide separation from various gas streams, including carbon dioxide from nitrogen, unsaturated hydrocarbons, and sugars from aqueous solutions olefin, sulfur dioxide separation from various gas streams hydrogen production and separation. Author presents state-of-the-art information for both the novice and practitioner. 

Gas separation membrane technologies are extensively used in industry. Typical applications include carbon dioxide separation from various gas streams, production of oxygen enriched air, hydrogen recovery from a variety of refinery and petrochemical streams, olefin separation such as ethylene-ethane or propylene-propane mixtures. However, membrane separation methods often do not allow reaching needed levels of performance and selectivity. Polymeric membrane materials with relatively high selectivities used so far show generally low permeabilities, which is referred to as trade-off or upper bound relationship for specific gas pairs [1]. 

Sweep diffusion is a form of mass diffusion column in which the screen separating the counterflowing light and heavy streams is not present. Cichelli et al. [C4] developed the theory of such a column and used it to separate hydrogen from natural gas and to enrich air. Table... 

Gas permeation (GP) was described in detail in Examples 9.2 and 9.3. Since the early 1980s, applications of GP with dense polymeric membranes have increased dramatically. Applications include (1) separation of hydrogen from methane (2) adjustment of the H2/CO ratio in synthesis gas (3) oxygen enrichment of air (4) nitrogen enrichment of air (5) removal of C02 (6) drying of natural gas and air (7) removal of helium and (8) removal of organic solvents from air (Seader and Henley, 2006). 

Of the two developing membrane processes Usted in Table 3, gas separation and pervaporation, gas separation is the more developed. At least 20 companies worldwide offer industrial membrane-based gas separation systems for a variety of applications. In gas separation, a mixed gas feed at an elevated pressure is passed across the surface of a membrane that is selectively permeable to one component of the feed. The membrane separation process produces a permeate enriched in the more permeable species and a residue enriched in the less permeable species. Important, well-developed applications are the separation of hydrogen from nitrogen, argon, and methane in ammonia plants the production of nitrogen from air the separation of carbon dioxide from methane in natimal gas operations and the separation and recovery of organic vapors from air streams. Gas separation is an area of considerable current research interest the munber of applications is expected to increase rapidly over the next few years. 

In the last three decades, membrane-based gas separation has become a well-established unit operation for a variety of important applications. Gas separation membranes operate in the chemical industry in hydrogen separation, monomer recovery, the enrichment of nitrogen from air, and natural gas treatment. Recovery of hydrogen from the purge gas of an ammonia reactor was established around 1980. Vinylchloride monomer recovery from the PVC production process was started up about 10 years later. Recently, the recovery of propylene from polypropylene purge bins became feasible. The removal of sour gases from natural gas as well as biogas operates reliably, today. ... 

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