[jd90]

Hi everyone.

So I'm a mechanical engineering student so i have limited knowledge of chemistry besides some basic combustion.

The unit g / KW H    is slightly confusing me, what is it actually measuring, produce of substance for a certain amount of energy produced?

Watt = J/s         therefore can I convert g/KW H into g/J    as multiplying the hours by 3600 to get seconds which would cancel it from the j/s (from Watts)







Basically I have say 5 g/KWH of carbon monoxide produced from a vehicle. Can I show this as 1.389 x10^-6 g/j    ?





I understand this may seem pointless, but I then want to use this to calculate how much CO is produced for a certain amount of fuel used.   I can easily get the J/L for propane and the usage per day.

Initially I wanted to represent 5 g/ KWH in ppm but of course they are measuring different things so Im trying to relate them somehow. Once I have the grams per joule I can then divide this by the volume of air in the building to give mg/m^3    (per day) then this will give me ppm (per day) as a guidline of concentration that should be present with a vehicle burning a certain amount of propane at 5 g/KWH of CO.

[magician4]

Can I show this as 1.389 x10^-6 g/j    ?

yes, you can
however, I would keep with the specifics and make this 1.389 µg CO / J

regards

Ingo

[Borek]

The unit g / KW H    is slightly confusing me, what is it actually measuring, produce of substance for a certain amount of energy produced?

Yes, it tells you how many grams of something were produced per each kWh of energy produced.

Once I have the grams per joule I can then divide this by the volume of air in the building to give mg/m^3    (per day) then this will give me ppm (per day) as a guidline of concentration that should be present with a vehicle burning a certain amount of propane at 5 g/KWH of CO.

You don't know enough yet. You will need to know how many kWh the vehicle uses per day, plus, you should know how effective the ventilation is (how often is the air in the building exchanged). But yes, with this kind of information it should be possible to give some rough estimate of possible CO concentrations.

[jd90]

 seeing as i now have μg CO/J, could I use J/ litre and the volume of fuel? rather than power consumption

[Borek]

These should be equivalent approaches, many ways of skinning that cat.

None of them exact though.