Behavior of Separative Desorption of Hydrogen, Helium, and Methane from Cryosorption Pump

Mixed Desorption of He, H2, and CH4Adsorbed on Charcoal Maximally Cooled at 10K

“…The experimental apparatus is the same as that shown in our previous study. 5,6) The vacuum chamber has a volume of 3.2 L. The chamber is composed of three parts; (i) activated carbon adsorbent that is cooled around at 10 K, (ii) a cryopanel part that is cooled at around 10 K, and (iii) a baffle-panel part cooled around at 80 K. Cooling is performed using two-stage cooling units, which can cool maximally down to 10 K. The cryopanel is coated with a thin activated charcoal film as adsorbent. The temperature is measured using Chromel-AuFe (0.07%) thermocouples.…”

“…Here, the relative nitrogen pressure at liquid nitrogen temperature is defined as p/p 0 , in which p 0 =1.0133x10 5 Pa. The pore volume determined is distributed in the range from 1.5 to 25 nm as seen in the figure.…”

“…In addition, it is necessary to use a surge tank in order to operate the fuel purification process smoothly. Although the desorption of various gases proceeds selectively at different temperatures 5) according to their respective vapor pressures or interaction energies between adsorbent and adsorbate, the information on selective gas desorption from the adsorbent is lost when the desorption gas is stored in a surge tank together. If the information on the selective gas desorption is efficiently utilized in the following fuel purification process, the scale of the fuel purification process, such as the number of Pd-Ag membrane tubes, can be decreased.…”

“…Previously, there was some research to investigate processes of adsorption and desorption of a single component of He or H 2 and two-component mixtures on activated carbon utilized for cryosorption pumps. 5,6) In addition, the performance of gas adsorption in a large-scale cryosorption pump was experimentally investigated by the ITER group. 7,8) The basic adsorption and desorption mechanism and the isotherm of activated carbon for various gaseous molecules were investigated previously.…”

“…7,8) The basic adsorption and desorption mechanism and the isotherm of activated carbon for various gaseous molecules were investigated previously. 5,6,8,9) However, there is no analytical or experimental study on the adsorption and desorption behavior of multicomponent gas mixtures on the adsorbent. In the present study, experimental results and analytical equations for the three-component gas adsorption and desorption of He, H 2 , and CH 4 are presented.…”