Superpants Posted March 23, 2007 Share Posted March 23, 2007 Every molecule of petrol burnt needs 12.5 molecules of O2 to burn fully, so the mass expelled is greater than the mass of fuel put in. There is a way of working out the volume of gas this would produce, but my memory is'nt good enough at the moment- I'll have to look it up. Maybe if I'm feeling enthusiastic I will look it up. Quote Link to comment Share on other sites More sharing options...
Orange Posted March 23, 2007 Share Posted March 23, 2007 BLIMEY....!!! Nail.......head..... If only you knew the full story Quote Link to comment Share on other sites More sharing options...
Simon Smith Posted March 23, 2007 Share Posted March 23, 2007 So as the O2 bit came from the air anyway, and most of the C bit on a diesel comes out as carbon (soot) then the CO2 output of a diesel must be less than the calculation says? Quote Link to comment Share on other sites More sharing options...
Superpants Posted March 23, 2007 Share Posted March 23, 2007 Most of the emissions on a diesel still come out as CO2 and H2O. The percentage that escapes as particulates is pretty small, so although it will affect the calculation a little, it will probably be in the order of a few percent- struggling to find details on the web in a useful set of units (g/kWh will be awkward to convert to something meaningful like g/l) to back this up though! By the way- thanks Adrian! Quote Link to comment Share on other sites More sharing options...
Superpants Posted March 23, 2007 Share Posted March 23, 2007 Returning to the actual volume of gas released: 1 mole of gas at Standard Temperature and Pressure (1 atmosphere- 1 Bar nominally, and O Degrees C) occupies 22.4 litres. Therefore as for 1 litre of Petrol releases, 6.46 x (8 + 9) = 109.82 Mols of gas, The volume will be 109.82 x 22.4 = 2460 litres of gas If the temperature is higher (as it will be in an exhaust or in real world driving), then the volume will increase. On the issue of particulate matter, the limit value in the Euro III legislation is 0.1 g/km. Compared to the several hundred grams of CO2, this quantity is tiny, and would have no significant impact on the CO2 emissions. I should probably adopt the mad scientist picture as an avatar Quote Link to comment Share on other sites More sharing options...
Turbocharger Posted March 23, 2007 Share Posted March 23, 2007 Surely to calibrate these equations, we can just use the published MPG and CO2 specs for any (or a range of) new vehicles to see which correlates closest? Being a maintenance engineer I've identified the problem and generated a process, but not actually done anything to solve it. Quote Link to comment Share on other sites More sharing options...
white90 Posted March 23, 2007 Share Posted March 23, 2007 Vals TD5 does 24.5mpg around town and approx 28 on the motorway =305 g/km to manufactures spec of 299 g/km so around town slightly worse on the motorway better. Quote Link to comment Share on other sites More sharing options...
bill van snorkle Posted March 24, 2007 Share Posted March 24, 2007 Seeing as how CO2 makes up less than 1% of greenhouse gasses and H2O,ie water vapor 95% wouldn't it be more appropiatefor the eco Nazi's to calculate how much water vapor a particular engine produces for each litre of fuel consumed ? And is water vapor necessarily a bad thing to have floating around in the air anyway ? I know we could certainly use a bit more over here. Bill. Quote Link to comment Share on other sites More sharing options...
Guest WALFY Posted March 24, 2007 Share Posted March 24, 2007 No chemist either but my take on the subject is the explosion of the fuel driving the piston down must mean the fuel /air mix grows.like the detonation of any explosive small amount of explosive material grows many times as a gas. Tony Without getting to techy on you. When an Explosive explodes it turns from a solid to a gas. And it is this rapid expansion that does the damage. IIRC most explosives change in volume by a min of 25,000 it's original volume. Hence when you spectacular video clips you will sometimes see a white ring move out from the seat of the explosion. Think of the clip from the A bomb tests, you see the white mist. This is just a wave of pressure, This is what causes the damage, that and the other debris picked up and thrown around. Hopefully that'll be the 1 thing you learn today Quote Link to comment Share on other sites More sharing options...
white90 Posted March 24, 2007 Share Posted March 24, 2007 oo hark at you the scientist Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.