A spherical droplet of methane (2cm in diameter) is burned in pure oxygen atmosphere at 2000 K and 3 atm. Oxygen is transferred to the surface by diffusion, where it is consumed by the reaction:
CH4 + 2O2 → 2H2O+CO2
This surface reaction can be assumed to be instantaneous. At 2000 K, the diffusion coefficient for each of the species (H2O, CO2 and O2) in the remaining species can be assumed constant at 3.54 x 10-4 m2/s. Assume ideal gas behavior, a one-dimensional diffusion with constant properties, negligible CH4 evaporation and negligible convection. Calculate the steady-state O2molar consumption rate in mol/s.