Hello,
I am trying to find out the CO2 equivalent of 10 tonnes of rapeseed derived HEFA biofuels. I already have the CO2e (GWP) of the HEFA which is measured as grams of CO2 equivalent per Megajoule of fuel.
Conversion
The problem is I want to find out the CO2 equivalant of using 10 tonnes (not 10 Megajoules) of this HEFA fuel. Obviously you cannot simply convert a unit of energy to a unit of mass without additional information. That said, I have found the specific energy of the HEFA, which is 40MJ/kg. With this information is the following conversion from 'gCO2 eq/MJ' to 'gCO2 eq/tonne' correct?
Because 40MJ of energy is in 1kg of HEFA I divided the 125gCO2 eq/MJ by the 40MJ to get 3.125gCO2 eq/kg
I then multiplied the 3.125gCO2 eq/kg by 1000 to get 3,125gCO2 eq/tonne
The result is a conversion of 125g CO2eq/MJ to 3125g CO2 eq/tonne assuming HEFA has a specific energy of 40MJ/kg.
GWP
One last question for anyone familiar with GWP calculations: is it correct to assume that the GWP (expressed as CO2e) for a liquid fuel can be simply multiplied by the mass of fuel to get the CO2eq of the specified mass?
For example, I can take 3,125gCO2 eq/tonne and multiply it by 10 to get 31,250g/CO2 eq; so 10 tonnes of HEFA has a CO2 equivalent of 31250g (if my calculations were correct).
Thanks for the help!
I am trying to find out the CO2 equivalent of 10 tonnes of rapeseed derived HEFA biofuels. I already have the CO2e (GWP) of the HEFA which is measured as grams of CO2 equivalent per Megajoule of fuel.
Conversion
The problem is I want to find out the CO2 equivalant of using 10 tonnes (not 10 Megajoules) of this HEFA fuel. Obviously you cannot simply convert a unit of energy to a unit of mass without additional information. That said, I have found the specific energy of the HEFA, which is 40MJ/kg. With this information is the following conversion from 'gCO2 eq/MJ' to 'gCO2 eq/tonne' correct?
Because 40MJ of energy is in 1kg of HEFA I divided the 125gCO2 eq/MJ by the 40MJ to get 3.125gCO2 eq/kg
I then multiplied the 3.125gCO2 eq/kg by 1000 to get 3,125gCO2 eq/tonne
The result is a conversion of 125g CO2eq/MJ to 3125g CO2 eq/tonne assuming HEFA has a specific energy of 40MJ/kg.
GWP
One last question for anyone familiar with GWP calculations: is it correct to assume that the GWP (expressed as CO2e) for a liquid fuel can be simply multiplied by the mass of fuel to get the CO2eq of the specified mass?
For example, I can take 3,125gCO2 eq/tonne and multiply it by 10 to get 31,250g/CO2 eq; so 10 tonnes of HEFA has a CO2 equivalent of 31250g (if my calculations were correct).
Thanks for the help!