Helium recovery

Helium-neon Helium-neon lasers Helium neon lasers Heliumpiping Helium recovery Hellebrin [13289-18-4]... 

Cryogenic distillation has been used extensively ia the processiag of natural gas for nitrogen removal and for helium recovery (22—23). Two basic processes are now used for nitrogen rejection from natural gas— the single-column heat-pumped process and the double-column process. Eadier processes utilized multistage flash columns for helium recovery from natural gas (24). 

The liquid helium evaporates in the heat exchanger and thus cools dovm the cryopanel. The waste gas which is generated (He) is used in a second heat exchanger to cool the baffle of a thermal radiation shield vi/hich protects the system from thermal radiation coming from the outside. The cold helium exhaust gas ejected by the helium pump is supplied to a helium recovery unit. The temperature at the cryopanels can be controlled by controlling the helium flow. 

In fulfillment of the contract requirements with the Navy, a hypothetical helium recovery system was designed based on the limited data available from the test program. These calculations were performed to put the test results in perspective. They are not, however, intended to describe a system that Westinghouse has for market. Westinghouse has no plans to market such a system. 

More detailed data concerning the effects of humidity, membrane area and lower helium concentrations in the feed stream on helium recovery must be obtained before a final design can be performed with confidence. 

Pressure swing adsorption (PSA) processes are widely applied industrially for gas separations. Applications are numerous and include hydrogen and helium recovery and purification, air drying, the production of oxygen from air, and the separation of normal paraffins from isoparaffins. 

Figure 3.38 Early plate-and-frame design developed by Stern et al. [110] for the separation of helium from natural gas. Reprinted with permission from S.A. Stem, T.F. Sinclaire, P.J. Gareis, N.P. Vahldieck and P.H. Mohr, Helium Recovery by Permeation, Ind. Eng. Chem. 57, 49. Copyright 1965, American Chemical Society and American Pharmaceutical Association...

For gas separation membranes, for example, He, O2, and N2 gas transport properties of CA/poly(methyl methacrylate) (PMMA) blends have been measured [108]. This article reported that CA/PMMA blends exhibited phase separation with limited intermiscibility between the components, but they were possibly useful as membrane materials to produce high-purity helium gas streams combined with high helium recovery. 

Helium He/HC He/N2 Helium recovery from gas wells Helium recovery from diving air mixtures Small market Feasible small market Low He concentration requires staging... 

On the other hand, actual binary mixture tests using porous alumina and glass membranes show separation factor values for helium recovery from oxygen that are lower than what Knudsen diffusion provides, as indicated in Table 7.15. Only Koresh and Soffer [1983a 1983b] show an ideal separation factor of 20 to 40 with a low permeability of 1.2x10 barrers when molecular sieve membranes with a reported pore diameter of 0.3 to 0.5 nm are used. 

Includes solvent recovery, dehumidification, pervaporation, and helium recovery membranes. 

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