
A bus that runs on formic acid - happy-go-lucky
http://www.bbc.com/news/business-40403351
======
jimrandomh
It has an energy density of 1.77 kWh/L and 1.22 g/cm^3, or 1.45 kWh/kg
([http://pubs.acs.org/doi/pdf/10.1021/acsenergylett.6b00574](http://pubs.acs.org/doi/pdf/10.1021/acsenergylett.6b00574)).
Compare to gasoline at 12.9 kWh/kg
([https://en.wikipedia.org/wiki/Energy_density](https://en.wikipedia.org/wiki/Energy_density))
and li-ion batteries at 0.1-0.3 kWh/kg
([https://en.wikipedia.org/wiki/Lithium-
ion_battery](https://en.wikipedia.org/wiki/Lithium-ion_battery)).

~~~
digi_owl
Honestly nothing can beat gasoline up front.

but here we have something that can match li-ion, but that can be refueled as
easily as one refuel a gasoline car. Can be stored for long periods on simple
containers. And can be produced from atmospheric gasses.

~~~
ams6110
Looks like it's up to about 10x better than li-ion.

~~~
digi_owl
Gah, sorry for the brainfart.

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p1mrx
Formic acid contains 53 g/L of hydrogen[1]. The Mirai has a 500 km range,
using 5 kg of hydrogen[2]. So you would need 95 L (116 kg) of formic acid to
get the same range. The actual tanks on the Mirai (87.5 kg, 122 L) are
physically larger, but weigh less.

[1]
[http://large.stanford.edu/courses/2013/ph240/yoo1/](http://large.stanford.edu/courses/2013/ph240/yoo1/)

[2]
[https://en.wikipedia.org/wiki/Toyota_Mirai#Fuel_economy_and_...](https://en.wikipedia.org/wiki/Toyota_Mirai#Fuel_economy_and_range)

~~~
bluejekyll
Seems like a decent tradeoff. The extra weight would reduce the range, but the
gained tank space might make that ok?

~~~
twic
I imagine the formic acid also has safety advantages: it's stored at room
pressure rather than under pressure, so the tank can't explode, and if there's
a leak, it won't vapourise.

On the other hand, it's reasonably nasty stuff, although far from Things I
Won't Work With levels of nasty:

[https://www.cdc.gov/niosh/ipcsneng/neng0485.html](https://www.cdc.gov/niosh/ipcsneng/neng0485.html)

~~~
vacri
Also, imagine how many ants you'd have to milk to get just one liter of this
stuff!

 _cough_

~~~
qbrass
Hope that cough isn't because you tried to find out and now have pulmonary
edema from inhaling the fumes.

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andmarios
Very interesting work. What they developed essentially is a way to store
renewable energy.

They take CO2, H2O and electricity from renewable sources to create their
fuel. The secret here is the catalyst they developed. The fuel is liquid, thus
stored easily.

In order to use it they use a reverse chemical process which creates H2 and
CO2. The H2 burns with oxygen (and releases part of the stored energy) to
produce H2O and thus they end with the elements they used in the first step.

If in its currrent capacitiy can be used for transportation, it probably can
be used for many other things as well.

~~~
overcast
So the catalyst isn't renewable. How much of that do they need? What are the
costs, and energy put into that?

~~~
detaro
> _So the catalyst isn 't renewable_

Is it not? Not being used up is kind of the definition of "catalyst" though,
so while it might need maintenance/recycling (due to mechanical changes, or
contamination) it probably can be reused after processing.

------
userbinator
_" The tailpipe emissions are only CO2 and water," explains Mr van Cappellen.
"No other harmful gases like nitric oxides, soot or sulphuric oxides are
emitted."_

The same is true of the complete combustion of petrol and other hydrocarbon
fuels. I remember the same was said of propane when it became the popular
alternative fuel several decades ago.

~~~
dthal
The CO2 is also an input; it originally comes from the environment, so this is
net-zero emissions in the same way that biofuels are. From the article:

    
    
       Although the bus emits CO2, Team Fast argues that the original CO2 used to create the hydrozine is 
       taken from existing sources, such as air or exhaust fumes, so that no additional CO2 is produced
        - it's a closed carbon cycle in the jargon.

------
FLUX-YOU
>The fuel, which the team has dubbed hydrozine (not to be confused with
hydrazine)

/facepalm

Why would you cozy up your name next to a horribly carcinogenic rocket fuel?
This a nomenclature foot-gun.

~~~
vacri
Seems reminiscent of the hyper/hypo issue in medical jargon. Not something you
want to screw up.

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jws
Making up a name "Hydrozine" instead of just calling it "formic acid" makes
this quite confusing. Maybe it works for marketing.

~~~
kabdib
Yeah, that was a little too subtle. I had to check it a few times before I
realized they weren't talking about hydrazine (toxic, probably carcinogenic if
it doesn't kill you right away, and definitely not something you want putting
around on public roads).

If I were their marketing, I'd pick something else, fast. Something a good
hamming-distance away from anything requiring special suits for handling, and
that doesn't include steps in release protocols like "evacuate nearby towns".

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rini17
Formic acid freezes at 8°C. Hooray.

------
tambourine_man
Interesting. What's the catalyst made of? I remember they used to require
platinum and other expensive elements.

Also, using CO2 from factories is nice but eventually we need to get rid of
them altogether. I imagine taking CO2 from the atmosphere at its natural
concentration should be incredibly inefficient.

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awjr
Doesn't this solve the battery storage issue for renewables? I mean you can
produce lakes of this stuff and 'burn it' when needed.

Strategically could be worth shipping/piping from a high sun/wind/geothermal
area.

The key is that it is a way to store renewable energy easily and cheaply.

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darkmarmot
I can't imagine the horrible smell... just one angry ant is enough to make me
ill. An engine full of the stuff would be a nightmare.

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nimish
No mention of handling issues around liters of irritating acid...getting stung
by ants is bad enough

~~~
alkonaut
How strong an acid is this?

If it's not extreme then handling shouldn't be much worse than petroleum fuels
which are mildly irritating, toxic, and flammable. We have built
infrastructure to let people handle those products (rather) safely.

~~~
petre
It's a weak acid similar to acetic acid (vinegar contains 9% acetic acid) but
weaker.

[https://en.m.wikipedia.org/wiki/Formic_acid#Safety](https://en.m.wikipedia.org/wiki/Formic_acid#Safety)

~~~
twic
On the other hand, it's 100%, not 9%. I'd say it's about as nasty as anything
you're likely to come across at home (bleach, white spirit, etc), but small
potatoes as an industrial chemical:

[https://www.cdc.gov/niosh/ipcsneng/neng0485.html](https://www.cdc.gov/niosh/ipcsneng/neng0485.html)

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exabrial
Isn't formic acid a main ingredient in wasp or bee venom?

~~~
joss82
Formic comes from the Latin word for ant.

It's what ants spray at an intruder when upset.

It's also hallucinogenic.

Good stuff.

~~~
kabdib
> It's also hallucinogenic.

That's one way to get people to ride the bus more often ... :-)

"The driver said my downtown stop was the one with all the candy-canes, but
all I see are walruses with briefcases."

