Gas separation cryogenic

Even though most chemical purification methods are not carried out at low temperatures, they are useful in several cryogenic gas separation systems. Ordinarily water vapor is removed by refrigeration and adsorption methods. However, for small-scale purification, the gas can be passed over a desiccant, which removes the water vapor as water of crystallization. In the krypton-xenon purification system, carbon dioxide is removed by passage of the gas through a caustic, such as sodium hydroxide, to form sodium carbonate. 

Using Non-Cryogenic Absorption to Reject Nitrogen From Subquality Namral Gases - The Mehra Process Alternative, Gas Separation International Conference, Austin, TX, Apr. 22 - 24, 1991. 

ATR is used widely, although costs are relatively high due to the high capital and energy costs related to the cryogenic air separation plant (approx. 40% of the total capital costs). For large-scale plants, however, such as gas-to-liquid plants, but also possibly natural gas based power stations with pre-combustion C02 capture, ATR becomes more economic than SMR [7]. 

Many of our chronic diseases (asthma, lung cancer, emphysema, and bronchitis) could result from air pollution or be directly influenced by air pollution. Air samples can be very complex mixtures and GC is easily adapted to the separation and analyses of such mixtures. Two publications concerned with the adaptation of cryogenic gas chromatography to analyses of air samples illustrate this adaptation (34,35). 

D.R Paul and Y.P. Yampol skii, Polymeric gas separation membranes, CRC Press inc, 1994 L.M. Lehman, Cryogenic Purification of Hydrogen Energy Progress 3 (1983), 7... 

As for a comparison of membrane gas separation technologies, such as pressure swing absorption (PSA) and low-temperature or cryogenic separations, the last chapter in (Paul and Yam-pol skii, 1994) must remain somewhat inconclusive, given the... 

Air (methyl, dimethyl mercury) Preconcentration of sample onto graphitized carbon substrate separation by cryogenic gas chromatography GC/CVAFS 0.3 pg (mercury, dimethyl mercury) 0.4 pg (diethyl mercury) 2 pg (methyl mercury chloride) 91-105 Bloom and Fitzgerald 1988... 

The market for gas separation applications is considered to be potentially very important. In 1993 the total membrane (polymeric) sales for gas separation are about US 75 million, which is expected to grow by a factor of three in the year 2000 [4]. Many gas membrane applications are envisaged (Table 13.1 in Ref. [7]). The market for N2 or O2 production especially is expected to grow for non-cryogenic and membrane applications (in 1993 this was 3-5%). According to Thorogood [9], membrane applications will particularly be found in medium... 

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