Diesel fuel-cell APU

2 major issues.

Using diesel is still using diesel. Getting more efficient is great, but its a tiny step. If you want to really hit tailpipe pollution and oil use you need to switch fuels. Dropping 6kwh of batteries in the truck and a plug would certainly be cheaper, and then you could make it a phev and use regen braking to charge the battery. Alternatively lng (more expensive) would greatly reduce oil use in a truck and make it cheaper to fuel

If we do want these things to have fuel cells, methanol from natural gas or renewable means is certainly better in a separate tank, and requires a simpler reformer. Truck stops now all have urea, they could easily add methanol.

 

China is the leader in methanol for transportation right now. Methanol CH3OH is also a much easier feedstock for a reformer, and we have many methanol direct fuel cells, but reform + hydrogen fuel cell makes much more sense in transportation than diesel, when we are taking about trucks. It is relatively easy to have methanol available at truck stops just like urea for SCR of NOx.

In the US, IMHO the picken's plan of lng for trucks makes the most sense, but that is likely North America only.

In Europe, at least using methanol not diesel for the APU would decrease imported oil.

But you have to ask why not go batteries and a plug.

Just spit balling. A 6 kwh will likely provide a full 3kw for 1.5 hours. If there is a plug, great, no need to run the ice at all. Otherwise it just needs to run every 1.5 hours to charge batteries. Add one motor for regen, we are probably talking $5K, The fuel cell and reformer has to cost a lot more than that. Making it a full hybrid would cost more, but the fuel cell APU is only supplying electricity.

This APU be an attempt to prove the tech though and then switch to methanol. The pem cell and batteries would be the same. The reformer and fuel would be less expensive with methanol, but without methanol infrastructure they may be going diesel.

 

Toshiba was the company that seems to have pushed cost down the most, this was in 2009
Toshiba Launches Methanol Fuel Cell Charger | PCWorld
[quoteThe Dynario, a charger that can replenish the batteries in gadgets like cell phones and digital cameras via USB, went on sale on Thursday on Toshiba's Web store. Sales will be limited to 3,000 units and each will cost ¥29,800 (US$328)[/quote]

The tech is far better than beta, the problem they ran into, is lithium batteries improved fast enough that the methanol fuel cells were not needed. Its a simple matter of cost and efficiency.

Direct methanol fuel cells cost too much for most applications. The efficiency really is not any better than if the methanol was burned directly in a flex fuel engine in a phev, if that was a turbo ice designed to burn both e10 and methanol. For that reason the fuel cell lobby is pushing hydrogen - its more efficient once on the car. An alternative making refueling easier is methanol with a reformer and a cheaper hydrogen fuel cell that would get poisoned by methanol.

The fuel cell lobby wants to push fuel cells into applications where batteries may be more cost effective, using government incentives. I'm all for the R&D, but that can be accomplished on fork lifts and busses for mobile applications. We can use small fixed fuel cell generators which can run hotter, using natural gas, methane (more purified than what comes out of the pipeline) and methanol. If proton exchange memberane (hydrogen) fuel cells become cheap enough, then it may be cost effective to do methanol + on board reformer then PEM, instead of dirrect methanol fuel cells for transport.

Today's tech for these APUs though is pretty straight forward. You put a bigger battery and a plug in the truck. that way you can run the ice at higher than idle to charge the battery (more efficient) if you can't plug in, and you can shut off the ice. Better would be to add regen braking to charge the battery, but you don't even need to go there to be better than a diesel reformer + fuel cell.

 

Thinking about this again today, I think costs are probably low enough to try a methanol -> reformer -> fuel cell APU.

I don't really know costs but here are guestimates. Diesel APU is about $9K. retail Methanol is about $1.50/gallon, and diesel about $3.75 gallon. Diesel has about twice the energy as methanol, but a diesel apu is about 30% efficient, methanol fuel cells should from the quote be at least 40% (higher than diesel). That gives methanol a cost of around 23 cents/kwh for methane, 35 cents/kwh for diesel.

I don't think they have it all down but ZnO + ZnPd seem to be good catalysts for converting CH3OH + H2O (cheap to make methanol has water in it) to H2 + CO2 and leaves the water alone, but some CO is produced. That could be burned in the diesel engine later if stored and separated. DOE is funding research as are the European equivallence.

If the diesel APU produces a peak of 5kw but sustained 3kw, You could probably combine 4kwh of batteries and 4kw of reformer+ fc + plug. weight of batteries is tiny compared to the weight of a truck. If batteries cost $500/kwh and fc+reformer $1000/kw, then we are talking about around $6K, double it for other costs and we are at $12K. Add $2K for a 15 gallon methanol tank and a burner for heat (less waste heat, may want to heat the cabin cheaper with burning than converting), and cost could be around $14K or $5000 more than a diesel APU, and these costs are being driven down quickly. If the government is subsidising fuel cells, then cost to the trucker is even less. Costs to convert airconditioning, power steering, etc to electricity is going down, so if these apus start selling +plug+ methanol power will get more substituted for diesel. The other advantage of electric airconditioning and power steering is they require less maintenance, which make it an easier sell. These little 3kw fuel cells are in lots of fork lifts, so the tech is proven. Looking toyota builds the biggest fork lift fuel cell at 30kw, but typical size is 12 kw.