Deli Luo

The permeation behavior of deuterium through 1Cr18Ni9Ti stainless steel with TiN+TiC-TiN multiple films

Abstract TiN+TiC+TiN multiple films are deposited on the surface of 1Cr18Ni9Ti stainless steel by ion-beam assisted deposition technology. The characteristics of films are tested by XPS, SEM and XRD, which showed that the film are compact and uniform with a thickness of about 15μm, and have a good adherence with the substrate below 773 K. The diffraction peaks in the XRD patterns for TiC and TiN are broadened, implying that the multiple films are deposited on the surface of 1Cr18Ni9Ti stainless steel. Meanwhile, the C-H bonded CH4-appears in the infrared spectra of multiple films, suggesting that the CH4- is in a static state, so hydrogen atom cannot migrate from the site bonded with carbon to a neighboring site. The deuterium permeability in 1Cr18Ni9Ti stainless steel coated with multiple films is 2-3 orders of magnitude lower than that in pure 1Cr18Ni9Ti stainless steel substrate from 473 K to 773 K.

Hydrogen Isotope Separation Factor Measurement for Single Stage Hydrogen Separators and Parameters for a Large-Scale Separation System

A Concept design for large-scale hydrogen ISS based on a single Pd alloy membrane separator cascade has been presented. Separators to investigate the feasibility of the Pd membrane separator cascade concept have been designed and the separation performance of the separators is given. Results show that the separation factors, which are between 1.4 and 1.8 at the operation temperature, are large enough for a practical separation system design. Estimation results indicate that a 2.0m2 Pd membrane is needed for a 20mol/h and 12 stages batch ISS, and an approximately 50m2 Pd membrane is needed for a 200mol/h and 26 stages ISS. It is clear that the separator cascade concept is both reasonable and practicable for large-scale hydrogen isotope separation.

Simulation and Optimization of Hydrogen Displacement Adsorption Process for Hydrogen Isotope Enrichment/Separation

Abstract For hydrogen isotope enrichment/separation applicable to fusion fuel processing, environmental tritium safety confinement, or recovery of tritium from heavy water reactors, a hydrogen displacement adsorption process system is recommended using molecular sieve 5A as the separation material. For simulation and optimization of the process, mathematical models and a solving method are provided to calculate the breakthrough curves during the displacement adsorption, in which various parameters including pressure drop and mass transfer coefficients are allowed to be changeable. Based on the calculated results, the effects of the column size, the flow rate, and the outlet pressure on the enrichment factor, the recovery ratio and the separation ability of the column are comprehensively analyzed. The conclusions have some theoretical guiding significance for the development of hydrogen isotope separation by the displacement adsorption method.

Improved hydrogen adsorption of 5A molecular sieves by enhancing its thermal conductivity

Understanding the hydrogen adsorption of porous materials is crucial to the design of high-efficiency hydrogen isotope separation materials. Much importance has been attached to tailoring the structures of materials, while the thermal management during the adsorption is often ignored. Here, we have experimentally found that the hydrogen adsorption capacity of a 5A molecular sieve (5A) is improved by enhancing its thermal conductivity. It can be facilely achieved by constructing rich and firm thermally conductive networks by filling graphite. 5A with 30 wt. % graphite shows a high thermal conductivity of 0.97 W m−1 K−1 and a fast thermal response. Notably, it also displays an enhancement of 15.6 ml/g normalized hydrogen adsorption capacity compared to the neat 5A. This indicates that there is a close relationship between thermal conductivity and hydrogen adsorption. The above demonstrations show that thermal management plays a significant role in hydrogen adsorption and should be seriously considered for designing the materials of hydrogen isotope separation.Understanding the hydrogen adsorption of porous materials is crucial to the design of high-efficiency hydrogen isotope separation materials. Much importance has been attached to tailoring the structures of materials, while the thermal management during the adsorption is often ignored. Here, we have experimentally found that the hydrogen adsorption capacity of a 5A molecular sieve (5A) is improved by enhancing its thermal conductivity. It can be facilely achieved by constructing rich and firm thermally conductive networks by filling graphite. 5A with 30 wt. % graphite shows a high thermal conductivity of 0.97 W m−1 K−1 and a fast thermal response. Notably, it also displays an enhancement of 15.6 ml/g normalized hydrogen adsorption capacity compared to the neat 5A. This indicates that there is a close relationship between thermal conductivity and hydrogen adsorption. The above demonstrations show that thermal management plays a significant role in hydrogen adsorption and should be seriously considered for d...