Back to the Future 3: Making Gasoline
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Archived from the IMDb Discussion Forums — Back to the Future Part III
TMC-4 — 9 years ago(December 31, 2016 09:27 PM)
NOTE: If you're familiar with the movie, you can skip to the factual question under the ////////s
In the movie
Back to the Future III
, Marty inadvertently punctures the fuel line, spilling all the Delorean's gas into a bear's cave in September of 1885.
This is the main problem in getting Marty back to the future in this film, since the Delorean must reach 88 mph in order for the flux capacitor/time-circuits to do their thing (they still had a working Mr. Fusion to create the 1.21 gigawatts).
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In the film, they have less than a week to overcome this problem: How to get the Delorean up to 88 mph in a world where gasoline is rare, if non-existent.
Yet, petroleum was around.
How plausible might it have been, for someone with a PhD in chemistry, to obtain enough petroleum and convert it into gasoline so the Delorean can accelerate to the required 88 mph, in the wild west of mid-1885?* -
TxMike — 9 years ago(January 01, 2017 08:26 AM)
Not plausible at all.
If you simply distil crude oil and capture the gasoline fraction it would have a very low octane rating, close to zero. Very nice for Jet fuel but not very good for modern high-compression car engines.
The engine of the DeLorean may be able to actually start on such low-octane fuel but if so it would run very poorly right before it blew itself up from excessing knock.
If Doc Brown had a PhD in Chemistry and if he had studied refining and fuel production, a very long shot at that, he would know that he could use the low-octane fuel along with proper catalysts, high-pressure reaction vessels, and a distillation column to make a small amount of high-octane fuel. He might be able to enlist the help of the local blacksmith to make the hardware but he still would not have a source for the catalysts required for the chemical reactions to convert low-octane saturates into high-octane aromatics and branched alkanes like isooctane.
Yes, I am a Chemist and my career was largely in the fuels business, mostly gasoline and jet fuels.
.... TxMike ....