Friday, April 20, 2012

Where Does Gasoline Go?

It's not unusual for an American to put about 10 gallons of gas into his or her car each week. At the end of the week, that gasoline is seemingly just gone, but we know from middle school science class that matter can neither be created nor destroyed, only changed in form.

This post illuminates the story of how gasoline changes in form and expands an earlier telling of that story on this blog.

Today's post is mostly in the form of the video below, Where Does Gasoline Go? I expect that most readers of this blog know the basic answer to that question: Gasoline becomes carbon dioxide in the atmosphere. That's right, of course, but it's not the whole story, and the video highlights more of the story of carbon as it is transforms from being part of the hydrocarbons that make up gasoline and become atmospheric carbon dioxide.

The combustion reaction that combines the gasoline with oxygen from the air also produces water vapor, and a bit of other stuff too. That's closer to the whole story, but the video is intended to give a deeper understanding of all that and more.

Check it out, either in the narrated version immediately below, or in the interactive downloadable version here, where you control the video. I recommend the interactive version, where you can be your own narrator. The interactive version was also updated in 2017, using the most recent available data.

We're using a little more gasoline and a lot less coal than we were when the video was produced.




In addition to showing how much carbon dioxide is produced by weight from burning a gallon of gasoline, the video also shows the volume of the carbon dioxide released -- in gallon-sized balloons. How many balloons do you think are needed to contain the carbon dioxide from burning one gallon of gas?


The video is largely an exposition of basic chemistry, and I think a powerful exposition that should give us pause. It closes with a simple idea that has proven very difficult to act upon. What is your response? What will you do?

Please share by commenting below.

Don Duggan-Haas

Production notes:
The video was originally created as an interactive video, meaning that it advanced when you clicked the play button to the next transition. Unfortunately, once embedded in the blog it didn't play that way, so I've add narration. You can download the video in an interactive format for Mac and PC here. The downloadable .mov file plays a presentation in which you control transitions with the click of a mouse. Unfortunately, software updates (that are really down-dates) eliminate exporting to interactive movies, so that option applies to the 2012 video. A new version of the silent video is here, with automatic transitions. Note that this is a large (134.5 MB) .m4v file. The presentations were created using Keynote, a presentation software only available for Mac OS. A Keynote version of the presentation is available here. You can see a similar animation for methane (natural gas's primary component) here