Modeling of the membrane extraction of extra-pure hydrogen from chemically noninteracting multicomponent gaseous mixtures

Abstract

A. B. Vandyshev, L. L. Murav'ev, V. M. Makarov, and I'. B. Usova UDC 534.544:621.593Production of extra-pure hydrogen (EPH) using thin continuous metallic membranes is one of the urgent trends in hydrogen power generation and technology [ 1 ]. The membrane method of producing EPH is based on the high permeability and selectivity with respect to hydrogen of membranes formed from palladium-based alloys at 773-873 K and makes it possible to produce hydrogen with a purity of 99.9999% and higher.High-temperature membrane vessels and assemblies have come into rather widespread use in foreign [2] and domestic practice [3]. For further development of membrane equipment and the procedure used to produce EPH, it is necessary to refine model representations of the process of the membrane separation of hydrogen-containing gaseous media. Different aspects of the membrane extraction of EPH primarily from binary hydrogen-containing gaseous H2-N 2 and H2-H20 mixtures have been examined in previously proposed mathematical models [4][5][6][7][8][9]. It is interesting to develop a simple mathematical model suitable for description of laws governing the membrane separation of multicomponent hydrogen-containing gaseous mixtures, the com-0009-2355/99/0102-0003522.00 9Kluwer Academic/Plenum Publishers

Raising efficiency of special-purity hydrogen production from nitrogen-hydrogen gas mixtures

“…Initially, at the fixed values X 1 0 = 0.75, p h = 1.0 MPa, p l = 0.125 MPa, γ = 3.79⋅10 -10 m 2 ⋅sec -1 ⋅Pa -1/2 , F = 12.4 m 2 , and δ = 0.1 mm in the range Q 0 = 0-220 m 3 /h in accordance with the ideal expulsion model [5], we calculated the dependence of Q p on Q 0 (Fig. 1, curve 1) that satisfactorily describes the experimental data in [3] in the range Q 0 = 60-100 m 3 /h as well as the maximally attained throughput of the apparatus DB-100 [3], which is 78 m 3 /h at Q 0 = 218 m 3 /h (Fig.…”

“…In this work, the characteristics of the apparatus DB-100 have been analyzed more thoroughly (in comparison with [4,5]), taking account of the maximally attained SPH throughput, and the scope for raising the throughput and efficiency of the membrane apparatus has been determined.…”

“…For ideal expulsion models [5], the relationship between the key technological and design parameters of the membrane apparatus is described by the following expressions:…”

Analysis of flow-rate characteristics of high-output membrane equipment for the production of ultra-pure hydrogen

“…% and higher) on the one hand, and energy-and resource-conserving production processes in the metallurgical, chemical, and other branches of industry on the other [1]. The energy outlays required for the production of 1 m 3 of UPH by the membrane-separation method is calculated to be several times lower than those by the electrochemical method, and the purity of the product is substantially higher.In the 1980s, an experimental-industrial plant based on membrane equipment with a large unit output (300-1050 m 3 /h) in which chemically non-interacting hydrogen-containing gaseous mixtures were used as an initial feedstock, was developed in Russia within the framework of the program adopted by the State Committee of the Council of Ministers for Science and Technology of the USSR regarding hydrogen; these gaseous mixtures were the waste gases of ammonium synthesis and spent electrolytic hydrogen after "bright annealing" of transformer and electrical-sheet steels [1][2][3][4][5][6].Considering the fact that for mathematical description of the separation of chemically non-interacting hydrogen-containing gaseous mixtures in membrane equipment with palladium membranes, a model of ideal substitution has been found most suitable [7,8], and analysis of the flow-rate characteristics of the above-indicated membrane equipment with a high unit output, and assessment of possible means of improving the efficiency and economy of equipment, as well as consideration of possible trends in practical application of the results obtained are of interest within the framework of this model.In the case of the ideal-substitution model [7,8], which accounts for variation in hydrogen concentration as the gas mixture passes over the surface of the membrane, the interrelation between basic production and structural parameters of a …”

“…Considering the fact that for mathematical description of the separation of chemically non-interacting hydrogen-containing gaseous mixtures in membrane equipment with palladium membranes, a model of ideal substitution has been found most suitable [7,8], and analysis of the flow-rate characteristics of the above-indicated membrane equipment with a high unit output, and assessment of possible means of improving the efficiency and economy of equipment, as well as consideration of possible trends in practical application of the results obtained are of interest within the framework of this model.…”