The molecular simulations are adopted to investigate the separation of H2S/CH4 mixture by the graphenenanotube hybrid structure (GNHS). The effects of pressure, temperature and H2S mole fraction on the adsorption and separation behaviors are examined. The results show that the separation performance of the GNHS can be enhanced by reducing the adjacent carbon nanotubes (CNTs) distance. The selfdiffusivity of H2S molecules in the GNHS is 1.83 x 10(-8) m(2) s(-1) which is less than that of CH4. Therefore, enlarging the diffusivity discrepancy of the two components can improve the separation performance of the GNHS. (C) 2014 Elsevier B.V. All rights reserved.