Compare the total annual CO2 emissions of a coal-fired power plant to those of a natural gasfired power plant with the same power generation capacity, assuming (1) the power generation efficiency of the coal-fired power plant is 38%, whereas the power generation efficiency of the gas-fired power plant 48%, (2) annually, each power plant produces 630 hours of electricity at its capacity of 2000 MW, (3) the heating value of the coal is 30 MJ/kg and the carbon content of the coal is 75 wt%, (4) natural gas is assumed to be the mixture of 94 vol% of CH4 and 6 vol% of C2H6. The heating values of CH4 and C2H6 are known to be 50.10 MJ/kg and 47.54 MJ/kg, respectively