Science Buddies: "Ask an Expert"

For my science fair experiment i'm trying to figure out which type of automobile gasoline causes the least amount of damage to our environment. I wanted to do this by measuring the amount of C02 emitted by each type of gasoline. The problem is, I need precision gas detection tubes for carbon dioxide and my high school doesn't have this equipment. I tried ordering CO2 sensor online, but they're very expensive.

Is there any other way I can measure the CO2 emitted? Or is there any other way to figure out which gasoline is the least harmful?

Hi Abby,

That's an interesting question, but what do you mean by different 'types' of gasoline? Different brands? Regular vs high-test?

Why do you think there's enough of a difference in CO2 emission to matter? I thought all gasoline was chemically about the same and when they are burned they will produce about the same amount of CO2. Is that not true?

If you compared gasoline to diesel, maybe there is a difference in CO2 production, but then you would have to factor in the difference in energy yield per gallon.

Working with flammable liquids like gasoline is dangerous and I would advise against it. You can determine the amount of CO2 produced from burning by knowing the chemical composition of the fuel. You don't need to actually burn it and measure the CO2 directly.

You could also calculate how much CO2 would be emitted from gasoline containing 10% ethanol vs gas with no ethanol and see if there's a benefit to having ethanol present. But there again, you need to consider the energy output. If it takes more of a certain kind of fuel to go a certain distance then the total amount of CO2 produced may be greater and there will be no advantage to using it.

I would be curious to know how much CO2 is produced by a power plant in generating electricity to charge an electric vehicle. EVs produce no CO2 themselves, but unless the electricity is generated by photovoltaic cells, there is some CO2 produced by an electric generating plant. That would be another type of fuel calculation that you could include in your comparison.

Hope this helps!

Sybee