Note that the CO2 consumption rate, 𝑟 , is identical to the formation rate of methane, since we assume no by-product formation. The catalyst mass 𝑚 can now be calculated according to Eq. ( ) and a value of about 56 kg is derived. Improvements of the specific methane formation rate by an order of magnitude is realistic by increasing the Ru-loading from 1 wt.-% to above 10 wt.-% and by rising the operation temperature to 220 °C .