It's Roland the Plogger again, wrong as usual.

It's been possible to convert cellulose to ethanol using enzymes for a while now. The problem is that making the enzymes is still too expensive for this to be useful as a fuel process. This Wikipedia article [wikipedia.org] provides some background on that. It's a good idea. If the cost of making the enzymes can be brought down, there's plenty of agricultural waste (straw, bagasse, corn cobs, wood chips) available at low or even negative (it costs money to dispose of it) cost. Venture capital is going into developing cost-effective processes.

But it's not likely to be done in a car's fuel tank. Something more like a brewery scaled up to oil refinery size is more like it.

Why, in a big tank [google.com] of course. Doesn't your local grocery store have one of these in the cereal aisle?

Not that you'd have each customer filling their gas tank, from empty, every day. But sure, figure a thousand tanks per week - that's only 6 an hour for a 24-hr 'starch station', and you'd have to fill a 12' x 16' tank [watertanks.com] every week full of starch. Not to mention the hassle of loading your car's tank with a powder. Are they really suggesting you'd buy off-the-shelf from a grocery store? What are you going to do, spoon it in, one tablespoon at a time? 3328 tablespoons later.... [google.com]

That should curb obesity in this country. But then we have all this energy already stored as fat on our bodies. Well, we'll just have to design a car that runs on human fat. Just cut that love handle, toss it in a gas/fat tank and there you go, drive to the store and buy more Twinkies to put that lost chunk of fat back and keep going...

That coal/oil burning/swamping CO2 into the atmosphere in what? 2 centuries or so of accumulated solar energy which took maybe millions of years to build up is exactly what the dilemma of global warming causes (some still dispute that it is actually happening or discredit any argument towards it).

Now you want to put all kinds of dirty burning junk into your "converter" to accelerate over a ton of steel and plastic and move one human body over some distance?

Not sure either what those hydrogen-from-starch inventors are dreaming about. Besides developing a completely new fuel system, if they want to take the hydrogen with enzymes away from starch (carbohydrate, made of C6H12O6 chunks), what's going to happen with the carbon and oxygen? That's not clear at all from that article. Doesn't production of CO2 defeat the purpose of using hydrogen? Ideal would be to generate hydrogen from renewable resources and burn it to gain energy. Maybe its because the CO2 would come from a renewable resource - starch grown now with plants?

One other thing to consider is the viability of having this enzyme process run in the tank of a vehicle. Even the most robust kinds of these reactions require a relatively stable environment. It might be possible to do this in a reactor in one's garage, but not in a vehicle that gets parked in the hot sun or below zero winter temperatures vehicles encounter. Additionally, is this process throttleable? It doesn't seem so. In other works, when you dump your starch in the tank, it begins producing H2 and continues until all the consumables are gone. If you park your car for a few days, the H2 produced is going to have to be stored. That means tanks and pumps.

This might work as the basis of a hydrogen fuel system, where the H2 is the product being pumped into your car. It might have a definite advantage over other fuel technologies in that the production process, being relatively benign environmentally, will promote the establishment of local starch refineries. They would seem to make for much more suitable neighbors than petrochemical plants. This will, in turn undermine the monopoly that the major producers have on production and distribution of fuel and keep profit margins within reasonable range. We might even see a combination of retail H2 outlets and home production equipment. If the prices spike up, you can switch to your backup stash of potatoes. Try storing a supply of gasoline at home when it goes on sale at Costco and see what your local fire department has to say.