We now explain why the capillary condensation and evaporation of CO2 and CH4 can be found in this 3 nm width slit-pore at 300 K with in the presence of water. Figure 8 shows the adsorption-desorption of CO2/CH4/H2O mixture in 3 nm width slit-pores at 300 K. The hysteresis loop of water is Type H1. The condensation and evaporation of CO2 and CH4 are found at the same pressure of water.