Author Topic: Higher energy fuels through biology?  (Read 404 times)

Offline LouScheffer

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Higher energy fuels through biology?
« on: 07/11/2018 01:07 PM »
Bicyclobutane (two carbon triangles with a common side) looks like a great rocket fuel.  Due to the energy in the strained bonds, it has an ISP +19 seconds bettter than RP-1, a huge improvement.  (According to this NASA report HIGH ENERGY-DENSITY LIQUID ROCKET FUEL PERFORMANCE).  But the highly strained bonds make it very hard and expensive to synthesize.

However, scientists at Caltech have recently coaxed E. Coli to produce bicyclobutane enzymatically, at room temperature and pressure.  (See Enzymatic construction of highly strained carbocycles .  And if  bicyclobutane could be harvested, rather than directly synthesized, then the cost could potentially become practical.

Online speedevil

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Re: Higher energy fuels through biology?
« Reply #1 on: 07/11/2018 02:21 PM »
I could not find a density for the compound in question, the NASA list oddly misses it off.
Of course, CH4 is already in several rocket designers pipelines, which is even better.

If it's not a simple drop-in for RP1 (and the boiling point of 8C seems to question that), you're redesigning anyway - and at that point - why not methane?

Offline Asteroza

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Re: Higher energy fuels through biology?
« Reply #2 on: 07/12/2018 12:23 AM »
8C is slightly annoying but it isn't a cryogen. Wonder how the system trades work out for it in terms of end-to-end biofuel production of rocket propellant with some oxidizer (assuming you wanted a near room temperature oxidizer to compare with cryogenic LOX/CH4)

Offline Proponent

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Re: Higher energy fuels through biology?
« Reply #3 on: 07/14/2018 09:40 PM »
I could not find a density for the compound in question, the NASA list oddly misses it off.
Of course, CH4 is already in several rocket designers pipelines, which is even better.

If it's not a simple drop-in for RP1 (and the boiling point of 8C seems to question that), you're redesigning anyway - and at that point - why not methane?

Except for its high cost, cyclopropane appears to be a very attractive fuel, better than methane (see Bruce Dunn's work: 3rd attachment to this post).  I would guess that bicyclobutane has still better density than cyclopropane and maybe a bit more specific impulse.

By the way, here is Caltech's press release on the matter.
« Last Edit: 07/14/2018 09:42 PM by Proponent »

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