초록 ▼

The invention relates to a method for transferring mass between a flow of a first fluid, preferably a gas phase such as a combustion flue gas, and flow of a second fluid, preferably a liquid phase, where the first fluid is contacted with the outer surface of porous (semi-permeable) membranes, e.g. P

The invention relates to a method for transferring mass between a flow of a first fluid, preferably a gas phase such as a combustion flue gas, and flow of a second fluid, preferably a liquid phase, where the first fluid is contacted with the outer surface of porous (semi-permeable) membranes, e.g. Polytetrafluoroethylene (PTFE, Teflon.RTM.) membranes, in the form of hollow fibers having gas-containing pores and containing the second fluid with the inner surface of the membranes. Useful membranes are characterized in that they e.g. have a porosity (.epsilon.) of at least 0.50, a mass transfer coefficient of e.g. at least 3 cm/s, and a tortuosity factor of e.g. at the most 1.4/.epsilon. when the porosity .epsilon. is lower than 0.80 and at the most 1.3/.epsilon. when the porosity .epsilon. is 0.80 or higher. The membranes may also be arranged in hollow tubular members where the mass transfer coefficient of the membranes is at least on tenth of the mass transfer coefficient of the gas phase. The invention also relates to an apparatus for the above-mentioned mass transfer having a tubular conduit with an open inlet end, where a part of the wall of the conduit comprises a plurality of hollow tubular members defining array(s) with interstices between the members allowing flow of the gas phase. The invention further relates to a process for absorption or desorption where porous membranes, e.g. the above-characterized membranes, are utilized and where an exceptionally low membrane area per cubic meter of gas handled is required.

대표청구항 ▼

[ What is claimed is:] [1.]1. A method for transferring mass between a flow of a first fluid and a flow of a second fluid, one of the fluids being a gas phase and the other being a liquid phase, comprising contacting the first fluid with the outer surface of at least one porous membrane in the form

[ What is claimed is:] [1.]1. A method for transferring mass between a flow of a first fluid and a flow of a second fluid, one of the fluids being a gas phase and the other being a liquid phase, comprising contacting the first fluid with the outer surface of at least one porous membrane in the form of at least one hollow fibre of a poly(halogenated olefins), the pores of which membranes are gas-containing and have an average pore size between 0.2 and 1 .mu.m, and contacting the second fluid with the inner surface of said membranes, the maximum pore size of said membranes being such as to prevent direct mixing of the two fluids, the membranes having a porosity (.epsilon.) of at least 0.50 and at most 0.90, the tortuosity factor of the membranes being at the most 1.4/.epsilon. when the porosity .epsilon. is lower than 0.80 and at the most 1.3/.epsilon. when the porosity .epsilon. is 0.80 or higher, the liquid phase resistance with respect to the mass being transferred in the liquid (1/k.sub.i,l) being substantially negligible and the mass transfer coefficient of the membranes with respect to the mass being transferred in the liquid (1/k.sub.i,l) being at least 3 cm/s, wherein the thickness of the membrane is in the range of 5-200 .mu.m.