And the reason I want to get hydrogen from ethanol is...?

You should be able to get H2 and CO then gas shift the CO to CO2 and get more H2. It is the implementation using microwaves that seems unique.

This is significant if you want to run a PEM fuel cell with a liquid fuel and all you have is ethanol..preferably the lower cost wet ethanol.

what does it means in case of a reformer that the "energy conversion of efficiency is 80%"

How does it compares with the tradionnal methanol catalytic reformer ?

Thats great , the world is mad , one unsustainable is made from
another unsustainable fuel !

Hope they don't need too much Rhodium it is ten time rarer than platinum...

Has Toyota found a hundred trillion tonnes of ethanol buried under their car park?

EtOH 80% -> H2 Fuel Cell 60% -> E-Motor 95% -> 45% efficiency,

2 twice us much then ICE with EtOH?

Wait a minute,"...0.92 liters of hydrogen can be obtained from 1ml of a 50-50 ethanol-water mixture".

Hydrogen is obtained from 50/50 ethanol-water mixture - that's good - but 0.92 liter from 1ml?

That about 2mol of hydrogen for every 1mol of ethanol.

andrew rose:

You have a good point.

However, if this process can be made to work cheaply and as efficiently with handling friendly butanol and if the price of fuel cells can be reduced by 10x, it may have a niche market as part of the ground transportation mix.

The only thing I could figure about the 0.92 liter of H2 is that is volume at 1 atmosphere. H2 is low weight but high volume, so you have to compress it to 10k psi to get it to fit on the car. Since this is on demand and not stored, there would be no need to compress, which takes energy anyway.

The 1 ml of ethanol/water to 0.92 liters of H2 would make 1 liter of ethanol/water to 920 liters of H2 at 1 atmosphere. I do not know what 920 liters of H2 at 1 atmosphere weighs, but from an energy standpoint, what they are saying is 1000 BTUs of ethanol will make 800 BTUs of H2, I guess. (or more if you take into account the microwave generator energy)

If you could get a blend at the pump with wet ethanol, you would have a pump that says E100, but is 95% ethanol and 5% water. Since getting the last bit of water out is energy intensive this could be a good thing. I would guess in this case you would selected 50/50 water ethanol and fill your tank.

I assume that the 80% includes the power required for the microwave generator, which could be quite a bit. You still have to get the ethanol to the station by tanker truck which would not be as convenient as SNG by pipe, but I guess you can not have everything.

itsme

60% for the fuel cell is optimistic 50% is more realistic, but anyway a diesel series hybrid can return close to 50% efficiency as well without such a complicated technoly as microwave reformer put together with a fuel cell. I don't believe in a hydrogen economy but a fuel cell + reformer why not since you don't have the infrastructure problem to manage. But so far the reformer approach has been abandonned by almost everebody. But well Toyota is good at succeeding where everybody gave up... :)

30% efficiency to the wheels with Otto cycle combustion would be pretty optimistic. Perhaps running E100 with 20 pounds of boost in a 1 liter with series hybrid configuration, where the ICE can run more efficiently.

So now you take that gallon of E100 starting with 100 energy units (abstract to make the math easy) and get 80 units of H2 and put it in a 50% efficient PEM, that brings you down to 40%. Now you have inverter and motor, which brings you down to 32% (.4 x.9 x .9) You have the inverter and motor in a series hybrid as well.

So about 30% either way, but no combustion with the fuel cell and no NOX, CO and other nasties. Which brings up the topic of CO2. I assume that they just vent the CO2 created during the process, or use one of those fancy CO2 collector canisters. But if the ethanol is made from plants, the CO2 is neutral anyway.

Consifrtomh jomdas fc is 60^ eff already and the goal of just 2012 is 75 id say its very realistic and in fact low for when fv cars actualy pop up.

What this realy means is disel generator replacement will go alot faster and that any gas station with h2 can not only use cheap night time power but also fall back on e100 if they have it sat after 2nd and 3rd and 4th gen biofuel tech...

As for why? Well in 40 tears motors not engines will run cars and this converts ethenol to power much better then any genset could.

You could always vaporized the ethanol and put it directly into an SOFC stack to get more efficiency than this. An SOFC runs 50% efficient, with an output turbine it can reach 70%. That is twice the efficiency of a ICE running the same gallon of ethanol.

By my calculations, 1 ml of 50/50 EtOH is about .45 grams of EtOH, or roughly 0.01 moles.  This makes 0.92 liters of H2, or .041 moles.  My best guess about the stoichiometry looks like this:

C2H5OH + O2 + H2O -> 2 CO2 + 4 H2

Producing hydrogen from ethanol has plenty of uses besides fuel cells:

• Hydrogen as a burn-rate modifier for liquid fuels.
• Hydrogen to run SCR NOx traps.