Gas hydrogen recovery

Hydrogen and Carbon Dioxide Production from Steam-Methane Reformer Off Gas Production of Ammonia Synthesis Gas Hydrogen Recovery fiom Refinery Off Gases Methane-Carbon Dioxide Separation from Landfill Gas... 

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... 

Fig. 2.8 Methanol purge-gas hydrogen recovery system showing water-scrubbing tower (right) and membrane elements (center). (Used with permission of Air Products and Chemicals, Inc.).

The main revamp options of the ammonia synthesis loop are the installation of molecular sieves for drying of the make-up gas, installation of a purge gas hydrogen recovery system, and improvements in the ammonia synthesis converter system. 

Hydrogen Hydrogen recovery was the first large commercial membrane gas separation. Polysulfone fiber membranes became available in 1980 at a time when H9 needs were rising, and these novel membranes qiiickly came to dominate the market. Applications include recovery of H9 from ammonia purge gas, and extraction of H9 from petroleum crackiug streams. Hydrogen once diverted to low-quahty fuel use is now recovered to become ammonia, or is used to desulfurize fuel, etc. H9 is the fast gas. 

Assume that 1 kmol of gas occupies 22.4 m3 at standard temperature and pressure (STP). For stage-cut fractions from 0.1 to 0.9, calculate the purity of hydrogen in the permeate, the membrane area and the fractional hydrogen recovery for a single-stage membrane. 

Gas separation through membranes achieved commercialization after the introduction of the Prism process by Monsanto a decade ago. Originated for hydrogen recovery, high area membrane equipment is now used for other gases, notably C02 [1]. Hydrogen, carbon dioxide, and other components are now being removed from mixtures on an industrial scale [2, 3],... 

Mehra (2) [Named after the inventor] A gas separation process utilizing absorption in a solvent at moderate pressures. Developed by Advanced Extraction Technologies and applied to hydrogen recovery, nitrogen rejection, and recovery of natural gas liquids. 

Metal Hydride Process for Ammonia Purge Gas, The metal hydride process will be illustrated using the case of hydrogen recovery from an ammonia purge gas stream generated during ammonia manufacture. 

Figure 15. Applications map for hydrogen recovery process A, ammonia purge gas B, refinery stream C, coal conversion recycle gas D, ethylene plant cracked gas E, FCC minus gas...

SEPAREX delivered a hydrogen recovery system, utilizing 4-in. diameter spiral-wound elements, in early 1982 The system will recover hydrogen from the off-gas of a unit utilizing UOP s ButamerR process in a LPG processing complex. 

Recently two widely divergent process variations of PSA have been commercialized by Union Carbide Corporation The first of these is called POLYBED PSA, which Is used for hydrogen recovery (17-21) Plants with capacities of up to about 1 2 x 10 NM /day of hydrogen have been built Hydrogen recoveries of 86 percent vs 70-75 percent for other PSA processes have been demonstrated, as well as purities of 99 999 mole percent (20) POLYBED PSA involves the use of five or more beds, with extensive gas Interchanges and pressure equalizations between the beds One process embodiment (17) is shown In Figure 3 ... 

Adding a carbon dioxide (C02) wash system to a PSA hydrogen plant will improve the hydrogen recovery of the PSA. Hydrogen recovery can be improved by 3% to 5% because both the total feed gas volume and the C02 content of the feed gas are reduced. The incremental hydrogen benefit is not sufficient to make this option economically attractive unless die recovered C02 has value. A liquid or gaseous C02 market must be available172. 

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