Quiz Time: How much CO2 comes out of a tank of petrol?

Just wondering how much forum members know about how much CO2 is produced when we run our cars.

So. A quick quiz.

If I fill my car with 60 litres of petrol (this would weigh around 45 kgs) how much CO2 by weight would be produced when I've emptied the tank ?

Good luck

Re: Quiz Time: How much CO2 comes out of a tank of petrol ?

Um, 50kgs??

Because the oxygen comes from outside the tank.

Re: Quiz Time: How much CO2 comes out of a tank of petrol ?

:sleeping:

Re: Quiz Time: How much CO2 comes out of a tank of petrol ?

Petrol would be around 90% carbon (rest mainly being hydrogen).

Atomic weight of carbon = 12
Atomic weight of oxygen = 16
Atomic weight CO2 = 12 + (16*2) = 44
therefore CO2 is 3.6667 times the mass of C.

90% of 45kg = 40.5kg C
Therefore mass CO2 from 45kg petrol = 40.5 * 3.6667 = 148.5kg.

basilio said:

Just wondering how much forum members know about how much CO2 is produced when we run our cars.

So. A quick quiz.

If I fill my car with 60 litres of petrol (this would weigh around 45 kgs) how much CO2 by weight would be produced when I've emptied the tank ?

Good luck

Click to expand...

I have always believed cars emit carbon monoxide and not CO2.

If you want to commit hare karrie you hook up the exhaust to a hose and then to the inside of the car, breath in deep and its all over in minutes.

Assuming we're talking about regular unleaded petrol (91 RON) and that the engine is operating correctly then I'd estimate a total of about 169 kg of CO2 would be produced.

138 kg as direct emissions from combustion of the petrol in the vehicle.

14 kg from refining the oil, transporting petrol to the service station, electricity to run the pumps and so on.

17 kg from upstream oil industry operations to explore, drill, extract oil etc and transport it to refineries.

Those figures will vary depending on location (due to transport distances etc) but are my best estimates for a typical Australian situation.

What volume of dry ice does it make ?

Hint:
Density of dry ice ~ 1.5g/cubic cm.

I threw up this quiz on the forum to create some interest in a very useful blog site I found yesterday.

The writer. Tom Murphy, is a an Associate Professor of Physics at the University of California. His brilliance in my view is making quite big ideas accessible to most people through some clear but simplified maths and an engaging writing style. And he is interesting enough to check out for his invention skills alone.

The article I'm quoting from is called

"Recipe for climate change in two easy steps ".

Anyway his discussion on the amount of CO2 we produce included the following as the chemical formula for the amount of CO2 produced through a cars engine.

(I havn't mastered scientific notation on my computer so please bear with the awkward scripts. Alternatively check out the URL )


C8 H18 + 12.5 O2 --- 9 H2o + 8 CO2 + 11.5 kcal
1g 3.51 g 1.42g 3.09g

Each reaction has been scaled for one gram of input fuel. Notice that all three produce about 3 g of CO2 for every gram of input fuel. This 3:1 ratio applies to any mass/weight measure you care to use, and is easy to remember.

So the 45 kg from 60 litres of Petrol would produce (roughly) 139.05 kg of CO2 !!
(Isn't that is a lot of gas from just one smallish tank of petrol ?!!)

It looks like Smurf76 takes the prize with bonus points for calculating the additional CO2 expended in producing and transporting the fuel.

For full details of the story check out
http://physics.ucsd.edu/do-the-math/2011/08/recipe-for-climate-change/

___________________________________________________________________

I decided to follow up this question after i saw a quite useful program on SBS looking at solutions to climate change. One of the ways the program used to illustrate how much carbon an average family in America used was to dump the tons of carbon at their feet. Quite effective.

Post 2636 Climate Hysteria
http://player.sbs.com.au/programs#/p...Surge-Full-Ep/

but it depends upon the engine.

Not all fuel is burned completely, and not all to CO2,

so, good rough guestimates, but no real science/chemistry is gained from back of a pad calculations.

The real question is :


How many extra people can be fed, globally, due to Australia's emissions over a 12 month period??

In calculating so-called carbon footprint, isn't it the carbon that counts and not the oxygen ?

It's a bit harsh counting the oxygen. Without it, life on Earth would be, well, be a little different.

drsmith said:

In calculating so-called carbon footprint, isn't it the carbon that counts and not the oxygen ?

It's a bit harsh counting the oxygen. Without it, life on Earth would be, well, be a little different.

Click to expand...

As would the human body / life without carbon.

Tom Murphy who wrote the "Recipe for Climate Change" was not trying to detail to the last decimal point how much CO2 was produced from a tank of petrol. But his calculations are accurate enough to demonstrate on the big picture how much extra CO2 we put into the atmosphere with our cars and trucks

I believe almost every person would be very surprised to realise that each tank of fuel ends up as roughly 3 times weight of CO2

Yes of course carbon is critical for life and CO2 is naturally circulated through plants and animals. But our capacity to turn billions of tons of old carbon into fresh CO2 which can't be recycled is the issue.

The analysis of how Water vapour, CO2 and other greenhouse gases warms the atmosphere is well written and quite illuminating.

basilio said:

Just wondering how much forum members know about how much CO2 is produced when we run our cars.

Click to expand...

CO2 isn't the poison. Super fine exhaust particles do damage longer term or short term in greater quantities and billions of people around the world (including me) emit these poisonous particles almost every day.

While we're doing some figures...

If we replaced all the petrol used in Australia with ethanol then we'd need enough food to feed about 250 million people in order to do it. And that's assuming we convert food to fuel at 100% efficiency which, of course, we won't.

And that's just petrol so not including diesel, kero (aviation fuel), LPG, coal, natural gas...

Biofuels have a role to play but they're no silver bullet at least not with present technology.