consider I have a mixture of Hydrogen and Natural Gas.

The volumetric mixture is $\varphi_{H_2} = 70 \%$ and $\varphi_{NG} = 30 \%$.

So the $H_2$ makes up a mass fraction of

$$w_{H_2} = \frac{\rho_{H_2}\cdot\varphi_{H_2}}{\rho_{H_2}\cdot\varphi_{H_2}+\rho_{NG}\cdot\varphi_{NG}} = 21.2 \%$$

with $\rho_{H_2} = 0.0899 \frac{kg}{m_n^3}$ and $\rho_{NG} = 0.780 \frac{kg}{m_n^3}$.

How much CO2-Emissions does the combustion of $1 kWh$ of my mixture produce, if the combustion of Natural Gas produces $0.200 \frac{kg}{kWh}$? How does the calculation work out?

  • 3
    $\begingroup$ What have you done so far? This is not a free homework solution site. $\endgroup$
    – Solar Mike
    May 6, 2021 at 15:14

1 Answer 1


assuming full combustion, CO2 coming out is

  • none from the H2
  • 1:1 mole ratio from the CH4

So mass of CO2 =

( mass of CH4 ) x ( molar mass of CO2 ) / ( molar mass of CH4)

Add a slight adjustment for Ethane content of the natgas, if you want.

You also need the heating value of the H2 to figure out the total mass, so you can get the mass of CH4.


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