Simulation of quantum separation of binary hydrogen isotope mixtures in carbon slit pores

Abstract

The carbon slit pore has been investigated as a medium for low temperature hydrogen isotope mixture separation. It is shown that the path integral formalism with Silvera-Goldman potential provides the most accurate results for the adsorption simulations. At 40 K, an operating pressure of 1.0 bar and carbon slit width of 0.56 nm is found to be optimal for efficient quantum separation. Simulations for practical separation processes using a 99.95% H₂ and 0.05% D₂ bulk composition H₂/D₂ mixture, using the optimal carbon slit pore at 40 K and 1.0 bar, demonstrate that the deuterium mole fraction increases from 0.05 to 50.3% after three separation steps. The results show highly efficient equilibrium separation of binary H₂/D₂ mixtures in narrow carbon slit pores, indicating the potential of molecular sieving carbon materials for hydrogen isotope separations.