Demonstrating the CO2 Weight of a Gallon of Gasoline




Introduction: Demonstrating the CO2 Weight of a Gallon of Gasoline

About: Long time bicyclist, bike commuter, bike tourer, recent bike builder/experimenter. I'm an energy consultant for hydro electric, solar and other renewable energy generation.

Fun Earthday Activity that teaches us with muscular exertion.

Or Kinesthetic learning...

It is a powerful demonstration of the potential burden of CO2.

After participants lift the 26 lbs of CO2 for a few seconds.....

Remind them the atmosphere will carry it for hundreds of years until enough plants can capture it and sequester it.

Step 1: Very Fun and Informative Demonstration of the Weight of CO2 Associated With a Single Gallon of Gasoline

This Simple Demonstration has the participants experience the weight of CO2 associated with a single gallon of Gasoline by lifting 4 jugs partially filled with water simulating:

The 6.3 pounds of gasoline in a gallon

Another 14.3 pounds of oxygen that is combusted in the car engine with the Gasoline to make the O2 in CO2

And another 6 pounds of CO2 emissions Upstream of the gas station (drilling, pumping, shipping, refining, and trucking it to the gas station)

Step 2: The Participants Enjoy the Fun Challenge

The challenge has two parts:

1) to understand what each jug is simulating as they lift them one by one ....

2) to physically lift all 26 pounds of simulated CO2 off the ground even for a few seconds.

Step 3: Luckily I Found Super-Heros to Help Lift the Massive CO2 Weight of a Gallon of Gas

This is a very fun Earthday Demo and We provide the calculations in the attached Spreadsheet.

You can do your own research and get more precise answers and simulation results.

We just derived this with a few facts and internet searches.

A gallon of Gas weighs 6.3 lb. A gallon of Water weighs 8.34 lb.

Gasoline is about 84% carbon by Weight so it has 5.4 lb. Carbon

CO2 tailpipe emissions of gasoline combustion is 19.64 lb./gal

(So 14.2 lb. of the 19.64 lb. must be coming from atmospheric O2 combining with the 5.4 lb. of carbon)

Molecular weights: Hydrogen =1, Carbon = 12, Oxygen = 16

Step 4: I Used a Scale to Weigh in the Amounts of Water Into the Simulation Jugs

You can use a scale or measure volumes into the jugs as the spreadsheet provides in quarts and ounces.

Or you can uses your semi calibrated "good" eye to eyeball about where I drew the line on these gallon jugs and make yours at the same places on your gallon jugs.

The Gasoline Jug is to be filled with 6.3 pounds of water (up to that line).

The 2 Oxygen Jugs are each filled with 7.1 pounds of Water representing the O2 in the air combusted with the gasoline in the engine. (I call the Jugs O-One and O-Two (Dr. Seussian reference) :)

The upstream CO2 emissions are coincidentally about the same weight as the gallon of gas itself (~6 lbs.) and a similar mark can be made on the fourth jug for 6 lbs. of Upstream emissions.

( If you want to represent upstream emissions for "Tar Sands" refined gasoline you may need to completely fill the upstream jug and get another pint to go with it. This is because Tar Sands is a sticky difficult to manage resource and there are lots of high emissions in the added steps required.

Step 5: Here a Driver Struggles Shoulder the Responsibility for a Gallon

This can be fun! I use a strap or rope tying the jugs together so first the participant....

1) First lifts just the 6.3 pound gallon of Gasoline....

2) Then they lift higher to pick up the Oxygen that makes CO2 in the engine,

3) Then finally they grapple with the upstream emissions of CO2 that got their precious gallon of gasoline from the oil in the ground to the convenient refined delicate product at their local gas pump.

Step 6: Refinements

You could mark your Gasoline Jug with the 6.3 pound mark and the two sub component marks at 5.4 pounds of Carbon and 0.9 pounds of Hydrogen that primarily make up Gasoline ( Octane Rings are C8 H18 )

You can separate the Upstream emissions into a 6 lb jug for conventional oil exploration, drilling, pumping, shipping, refining, and trucking to the station.

And you can offer an alternative 9 pound upstream emission jug(s) (slightly more than and 8.3 pound gallon jug can hold) to represent the more complex and energy intensive emissions associated with the massive effort involved with scraping forests away and mining tar sands under them and melting the tar off the sand and refining the tar into gasoline etc.

You could add some Orange food coloring to the "Gasoline" jug

You could add some Blue food color to the Oxygen jugs

You could add some Brown (orange plus blue?) color to the ugly upstream process emissions jug



    • Fix It! Contest

      Fix It! Contest
    • Metalworking Contest

      Metalworking Contest
    • Creative Misuse Contest

      Creative Misuse Contest

    15 Discussions

    Thanks for sharing this informative exercise -- and all the steps needed to make it a great lesson for students, boy/girl scouts -- and everyone!

    Some commenters are pointing out the important benefits of CO2.

    Some are pointing out that they think CO2 is an unimportant greenhouse gas.

    Some are pointing out that they think the climate is stable and all is well.

    MY instructable is just about demonstrating the weight of CO2 emissions associated with a gallon of gasoline, regardless of our opinions about the merits of adding more CO2 to the atmosphere than it has contained in the history of human beings.


    2 years ago

    seems like there are a lot of apparently misinformed comments here,

    Why are there 26 pounds of stuff when you burn a gallon of petrol? Because thats what happens. The 'C' turns into CO2, the H turns into H2O.

    H20 isn't significant in the troposphere. Whats the point arguing its abundant somehere down low?

    CO2 concentrations were higher in the past? yes, millions of years ago. How is that relevant?

    Try taking look at real current temperature and rainfall data, and then see if you can support the pretence that nothing is going on.

    because thats

    1 reply

    OK looking at the satellite measurements there has been no discernible warming at any level of the atmosphere for roughly 18.5 years there has been some recent warming (less than .03 degrees Celsius) due to the massive El Nino that is now fading and heading to La Nina. but lets talk about the troposphere that is not where we measure Co2 we measure it lower in the atmosphere near Mount Kilauea at an observation station that is where we get the PPMV. As far as what past levels show us it shows us that Co2 can be much much higher and have next to no effect, there is no warming in the troposphere which according to the models there was supposed to be a large area of higher temps near the equator but that has not happened and rainfall data where I am at we are having a wet spring which happens in an El Nino year there are other areas that are having dry spells but looking at the historic records nothing that is happening right now is outside of natural variation.......well there is one thing that is outside of the last 100 years but that is the exact opposite of what climate models predict when the hurricane season for 2016 starts we will have gone just over 3800 days without a major hurricane (class 3-5) hitting the U.S. in fact the ACE (Accumulated Cyclone Energy this is for the world) has dropped to record low levels according to Dr Ryan Maue in fact global hurricane numbers have been on a downward trend for the last 30 years the exact opposite of what the models predict, real world observations show that temperature has been far below what the models that all the hysteria is based on are off; about 3 degrees too high and extreme weather has gone down worldwide of course to see that you would have to look at real world numbers not models.

    When I went to school, hydrocarbons broke down to CO2 and H2O (in a perfect world). Where is the weight of water in you experiment? It should be over half the weight of the CO2 emissions. Secondly please check out the emissions pumped out by refineries in California and compare those to the "tar sands", tar sands are cleaner in all respects. Good idea, please recheck your equations and facts.


    2 years ago

    Carbon dioxide (CO2) is an important trace gas in Earth's atmosphere currently constituting about 0.04% (400 parts per million) of the atmosphere.

    Even in tropical air, water vapor in the atmosphere approaches 4% in the air.

    So it seems water vapor is many many times more prevalent in our atmosphere then CO2. And therefore water vapor has a much great effect of holding in heat and being a greenhouse heat trapping gas then CO2 will ever be. Just the facts.

    2 replies

    CO2 is heavier than air, but without any logic, it's considered as a heat trapping gas. Discussions about global pollution always lead to anger as people don't want, not to change their mind, but simply to open it.

    I don't think it's the density of a gas that creates its heat trapping capability, since Methane (CH4 molecular wt 16) is considered to have 84 times the greenhouse warming impact of Carbon Dioxide (CO2 at almost 3 times the density with a molecular wt 44). This link shows an explanation relating to the number of atomic connections in the molecule.

    I support having an open mind. I try to keep mine open.


    2 years ago

    seems like there are a lot of apparently misinformed comments here,

    Why are there 26 pounds of stuff when you burn a gallon of petrol? Because thats what happens. The 'C' turns into CO2, the H turns into H2O.

    H20 isn't significant in the troposphere. Whats the point arguing its abundant somehere down low?

    CO2 concentrations were higher in the past? yes, millions of years ago. How is that relevant?

    Try taking look at real current temperature and rainfall data, and then see if you can support the pretence that nothing is going on.

    because thats


    2 years ago

    I have to say this is very questionable and equally misleading because you arbitrarily use other gases and chemicals combined with one gallon of gas to make it appear to be 26 pounds of output gases and material. But if you seriously think this isn't really fooling the folks that participated in your claimed gasoline example, why don't you do one with batteries for electric vehicles. And if you also include everything it takes to make the batteries and then dispose of them after the fact, even you may be enlightened at how much waste and energy it take to run electric vehicles. You're not going to like those statistics for sure. JMHO!

    1 reply

    I don't think my demonstration is very questionable or very misleading as you call it. As I understand Chemistry: Each Carbon atom in fully combusting gasoline (about 5.4 pounds of them in a 6.3 pound gallon) is bonding with two oxygen atoms (about 14.3 pounds of them from the air taken into the engine) to produce about 19.7 pounds of tailpipe CO2. I have also heard that around another 6 pounds of upstream emissions of CO2 occur in the drilling, pumping shipping, refining, and trucking of gasoline to the stations where I buy it. Rather than ignore the upstream emissions, I include them as a separate jug in the demonstration. I include a downloadable spreadsheet in the instructable so readers can follow the logic, chemistry and math I try to convey. And maybe they can refine the calculations in their own experiments.

    what a lot of superhero shirts :')

    I have to agree with the other poster, co2 is the absolute least of our concerns. Heavy metals and industrial products causing mass cancer rates is more detrimental than that maybe +.05 degrees farenheit a year

    Not sure why we are worried about a trace gas that without which there would be no life on this planet if we drop 150 PPMV certain plants start shutting down, another 75 PPMV trees die and another 25 PPMV the last of the grasses die we would be gone as a species between 150 PPMV and 200 PPMV throughout earths history Co2 levels have been far higher than currently and have fluctuated massively at times Co2 has been well over 800 PPMV during glacial periods (we are currently depending on the day at 390-405 PPMV) Co2 has also been over 1000 PPMV never in all that time have we had a runaway warming Co2 as a greenhouse gas is overwhelmed by water vapor. yes if we didn't have Co2 the earth would be unlivable for 2 reasons first no plants second it does have a warming effect but that is logarithmic in function meaning for ever increment of warming that the last 100 PPMV did we need roughly 10 times that amount to get the same warming and at this point Co2 is near its heat saturation point in fact there are several scientists that have said that no matter how much Co2 that is in the atmosphere from this point onward we will most likely not get even another degree of temperature change so rather than Co2 worry about real environmental issues like what to do with all those mercury laden light bulbs that everyone wants us to use.

    Please try this for your Earthday events and comment back here to tell us how it went and what the reactions were!