Gas separation modules

J. Lemanski and G.G. Lipscomb, Effect of Fiber Variation on the Performance of Counter-current Hollow-fiber Gas Separation Modules, 7. Membr. Sci. 167, 241 (2000). 

The hollow fiber membranes are the optimum choice for gas separation modules due to their very high packing density (up to 30,000 m /m may be attained [1]). Figure 4.21 shows alternative configurations for such modules [108]. Modifications of this configuration exist, where possibility for introduction of sweep gas on permeate side is included, or fibers may be arranged transversal to the flow in order to minimize concentration polarization [109,110]. The hollow fiber membranes are usually asymmetric polymers, but composites also exist. Carbon molecular sieve membranes may easily be prepared as hollow fibers by pyrolysis. 

Lipscomb, G.G. Sonalkar, S. Sources of nonideal flow distribution and their effect on the performance of hollow fiber gas separation modules. Separation and Purification Technology 2004, 33 (1), 1-36. 

Gas-separation-module assembly is typically an operator-machine interactive process, because the scale of operation cannot justify the type of automation necessary for the high-volume dialysis and filter-module assembly lines. This also has some advantages in enabling products to be sized and tailored to the application. 

J. Lemanski, G. G. Lipscomb, Effect of shell-side flows on hollow-fiber gas separation modules, J. Membr. Sci., 195, 215-228 (2001). 

Table 5.2 Features and applications of the diiferent gas separation modules" ...

For high pressure air drying specially designed four port gas separation modules were used. " High pressure wet feed air enters the shell side of the module and the sweep gas is used on the bore side which is vented in the atmosphere. When feed gas is not available at high pressure, a dehydration process with permeate compression and recycle is used. In this process all the moisture leaves the system as condensate on the compressor/cooler system, thus conserving air loss. 

Non-porous polymeric membranes are usually employed for gas separation, although porous ones can also be used. Composite polymeric membranes developed in the 1970s made the separation of gas streams commercially feasible. The first large-scale gas separation modules were developed by DuPont in early 1970s, but the first successful commercial membrane gas separation processes (PRISM) were announced by Monsanto in late 1970s. 

This chapter details (1) the polyimides used in the membranes, (2) preparation method of the membranes, (3) design of gas separation module, and (4) practical applications of the gas separation membranes. 

Ma, Y. H., Mardilovich, I. P., and EngwaU, E. E. (2004b). Composite gas separation modules having high Tamman temperature intermediate layers. U.S. Patent application 20040244590. 

Ma YH. and Guazzone F. (2006), Composite gas separation modules having a layer of particles with a uniform binder distribution, US Patent 7,172,644. 

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