A new membrane module design with disc geometry for the separation of hydrogen using Pd alloy membranes

Long-term hydrogen permeation tests of Pd–Cu–Ni/PNS with temperature cycles from room temperature to 773K

“…The hydrogen permeation flux of the present membrane was approximately half that of the previous membrane, because the former was 2.4 times as thick as the latter, as shown in Table 2. The hydrogen permeation flux linearly depended on the pressure with an exponent of 0.8 at the different temperatures of 673, 723, and 773 K. In the previous study, the n-value increased from 0.72 to 0.91 as the temperature was increased from 623 to 773 K [15]. We concluded that the reason for this was the increase of the support resistance with increasing temperature.…”

“…The Pd-Cu-Ni alloy film was 12 m in thickness, which is 2.4 times as thick as the previous membranes, because the Pd and Cu sputtering times of the present membranes were 2.25 and 3.0 times those of the previous membranes, respectively. In the previous study, the n-value increased with increasing temperature [15] and we concluded that the reason for this was the increase of the support resistance with increasing temperature. In this work, we tried to minimize the effect of the support resistance and maximize the dependency of the hydrogen permeation on the membrane film.…”

“…The details of the fabrication methods are shown in previous papers [13,14]. In this paper, the durations of Pd and Cu sputtering were 2.25 and 3.0 times longer than those used in the fabrication of the membranes referred to in these previous studies, respectively, and the Cu-reflow temperature was 973 K rather than 923 K. The newly designed plate-and-frame type membrane module and apparatus described in our previous paper [15] were used to measure the permeation of hydrogen through the membranes. The unit cell of the membrane module was made of Inconel 600, because its thermal expansion coefficient is closer to those of palladium and nickel than that of 316 L stainless steel, as shown in Table 1.…”

Preparation of palladium membrane on Pd/silicalite-1 zeolite particles modified macroporous alumina substrate for hydrogen separation

“…This result is deviated from Sievert's law, in which the n value is 0.5. In fact, many studies reported that the n-value might be affected by several factors, such as preparation technique, thickness, surface activity, membrane microstructure and transport resistance [27,36,37]. For a Pd composite membrane, the total transfer resistance through the membrane is the summation of each layer in series [38e40], while the resistance of gas transport is defined as the reciprocal of the gas permeance.…”

Formation of a defect-free Pd–Cu–Ni ternary alloy membrane on a polished porous nickel support (PNS)

“…As shown in Table 1, the base metals of most Pd-based membranes are palladium, palladium-copper, palladium-silver, and palladium-copper-nickel [50][51][52][53][54]. The utilization of composite structures which consist of a thin membrane film and porous substrate reduces the material cost, as well as offering a high hydrogen permeation rate, because an ultra thin membrane film can be prepared.…”