Driving on Starch

Roland Piquepaille writes "Using sugar contained in corn or potatoes to build hydrogen-powered fuel cells has already been done. But now, a team of U.S. researchers has developed a new sugar-to-hydrogen technology. Why not put the starch inside the tank of your car? With the help of 13 specific enzymes, 'a car with an approximately 12-gallon tank could hold 27 kilograms (kg) of starch, which is the equivalent of 4 kg of hydrogen. The range would be more than 300 miles, estimates one of the researchers. One kg of starch will produce the same energy output as 1.12 kg (0.38 gallons) of gasoline.' The beauty behind this idea is that no special infrastructure would be needed. Starch could be distributed by your local grocery store."

Comments

Re:Hay

[CrazyJim1]

I want my car to burn hay!

I have one that burns rice.

Question

[VanHalensing]

Wouldn't that be a lot of starch? I mean, wouldn't we then have a shortage of it? I know it's more renewable than gas, but could they even produce enough? They're having a hard enough time with 10% corn for gas. 12 gallons of starch is like, 110 or so bags of starch at the store...

Re:Question

[gad_zuki!]

>The beauty behind this idea is that no special infrastructure would be needed. Starch could be distributed by your local grocery store.

Yeah, someone isnt thinking energy alternatives through again. 1,000 people a day probably visit my grocery store. How are they going to pull 13 gallons of starch each? Where will by store put 13,000 gallons a day. In the cereal aisle?

  You will need a gas station like place to move this much product.

Secondly, where is this stuff coming from? etc etc etc

Re:Question

[stoolpigeon]

There is a little confusion on both your parts. It doesn't matter how many people visit the grocery store a day right now. Because right now that number has nothing to do with how much gas they use.
 
The question is - how many gas stations are there and how many grocery stores are there. Then find out how many people go to the gas stations and fill up every day - then look at what kind of traffic that means for the grocery store. I'm willing to bet that the gp is right in that the number is large.
 
What do people normally buy at the grocery store in 12 or 13 gallon quantities right now?
 
And when you say do those people drive 300 miles a day - that's not accurate either. I don't think too many people go to the grocery store every day. I go 1 or 2 times a week. We fill our car about once a week. So in my case, the number of trips to a gas station and grocery store are similar now. But when I buy gas - there are 3 or 4 gas stations near where I live - and one grocery store.
 
The numbers are all guesses, but like I said, the intent of the gp is probably pretty much right. The current distribution system for groceries (in the US anyway) is not sufficient to handle also providing fuel needs for the public on top of the food.

Re:Question

[mcrbids]

The numbers are all guesses, but like I said, the intent of the gp is probably pretty much right. The current distribution system for groceries (in the US anyway) is not sufficient to handle also providing fuel needs for the public on top of the food.

Perhaps you don't realize how little that actually matters. It's one thing to build an infrastructure that's inherently incompatible with existing infrastructure. It's another thing entirely to extend and amplify an existing infrastructure.

Let's take your "tank a week" scenario. It's roughly on par with Gasoline per unit of weight (Kg) so we're talking about a 10-gallon tank in your average 4-5 seater car. Gasoline weighs about 6 pounds per gallon, so that's about 60 lbs per week to meet a not-atypical situation. I buy a 50-lb bag of dogfood every other week thanks to my large golden retriever.

What's important is the cost of entry - not the total cost. It doesn't really matter what the total cost is, as long as the initial cost can be made up in profits quickly. Once the enterprise is profitable, it doesn't really matter much what the costs are, since the enterprise is, by definition, profitable and thus has the means to grow.

Here, we're talking about starch as merely an additional product that I can buy, along with the 50-lb bag of dog food. The initial cost of entry to sell starch to early adopters is so low as to be inconsequential.

Compare/contrast that with typical hydrogen scenarios, with expensive retrofits of existing fuel stations, special tanks, special dispensation stations, etc. See the difference?

Yes, your local grocery mart probably isn't going to provide enough fuel for everybody in town next to the dog food aisle. But they can start there, and then as the profits grow, roll out more specialized stations as the demand justifies it. See the difference?

Re:Question

[PapayaSF]

The beauty behind this idea is that no special infrastructure would be needed. Starch could be distributed by your local grocery store.

Yeah, someone isnt thinking energy alternatives through again. 1,000 people a day probably visit my grocery store. How are they going to pull 13 gallons of starch each? Where will by store put 13,000 gallons a day. In the cereal aisle?

I think you're a bit unfair here. What I think he means to say is "The starch could be distributed by your local grocery store," or "It could be starch distributed by your local grocery store." The point is not that all vehicle fuel will henceforth be bought at grocery stores, but that the substance is already widely available, and wouldn't need a new, special infrastructure the way mass distribution of hydrogen would.

Re:Question

[Romancer]

Starch is also used for a wide variety of purposes currently. The food industry alone uses it to make the molds for almost all the jelly like candies on the market. It's used as an additive for most mixes that thicken, and quite a few quick recipies that are becomming more and more popular. The bulk rate at which these companies currently buy and consume starch is astonishing. We pay mostly for the carton and shipping when we buy a box. It's quite close to a surplus waste item right now. If the demand rises, the extraction would easily be ramped up and production trippled in a matter of months. This gives the infrastructure of vehicles that can run on it a chance to grow easier than any other alternative fuel besides wall chargeable electric cars.

My one fear is the process that releases the hydrogen gas might not be as fast as we can demand it from a red light and once the process is started can we shut off the car and not have it wasted. If there is a storage tank that meters in hydrogen to keep a constant reserve available for quick use and a way to store the excess after pulling into the driveway, then it might be ok. This all adds weight and complexity not discussed in the article. They make it sound like all you'd have to have is a tank full of starch. Where are the reacting agents stored and how do we refill those? What waste products to the chemical reactions give off and are they containable or toxic? What about the liquids that would be needed to move the starch and reactive agents around the system, or are we dealing with pellets of starch and have to have a hopper system like in pellet stoves? I think that these are the concerns that people should be asking rather than will Walmart have enough starch to run my new starch SUV. That's jumping the gun a bit in my opinion. Or in slashdot pun style, putting the cart before the horse.

from the article

[wizardforce]

The abbreviations are: PPP, pentose phosphate pathway; G1P, glucose-1-phosphate; G6P, glucose-6-phosphate; 6PG, 6-phosphogluconate; Ru5P, ribulose-5-phosphate; and Pi, inorganic phosphate. The enzymes are: #1, glucan phosphorylase; #2, phosphoglucomutase; #3, G-6-P dehydrogenase; #4, 6-phosphogluconate dehydrogenase, #5 Phosphoribose isomerase; #6, Ribulose 5-phosphate epimerase; #7, Transaldolase; #8, Transketolase, #9, Triose phosphate isomerase; #10, Aldolase, #11, Phosphoglucose isomerase: #12, Fructose-1, 6-bisphosphatase; and #13, Hydrogenase.
it looks like they built it like this: starch=>glucose [amylase]=>glycolysis=>pyruvate decarboxylation=>TCA cycle and finally liberating the hydrogen from protons and electrons from the TCA. I wonder from this is how they deal with the enzyme's need for cofactors, corrosion, stability of enzymes and side reactions. it looks promising for sure but it looks like they have a lot of work ahead of them. there is also the problem of the starch settling in the tank and thus being unavailable for the reaction unless that is where it happens in that case what about H2 build up? lastly, with the problem of corn shortages being possible for ethanol, what exactly will happen when starch is used instead as it is also taken from food plant sources?

Food

[McGiraf]

Now that oil is getting near to being all used the big plan is to use food crops to run you cars? Brilliant, what can go wrong?

Roland the Plogger again

[Animats]

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 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.

Re:External combustion engines

[koreth]

Yuck. Go visit beautiful downtown Beijing and then we'll talk about what a fabulous idea it is for everyone to own their own little coal plants.

Very impressive.

[Gibbs-Duhem]

Now, I know this probably will never get seen by anyone, but none of the posts so far were appropriate to reply to.

I am actually a bioengineer, and I'm actually working in this field, trying to convert ethanol into hydrogen.

And I can say, this process looks excellent. Finding natural enzymes that do the conversion makes everything enormously easier.

Here's the deal. Ethanol has slightly more energy than straight sugar, because the fermentation adds energy to the system. That added energy is negligible in comparison to the total energy. However, you lose a butt-load of energy because you have to heat the sugar up in order to ferment it, deal with transportation costs for the crops, and if you're using it as an additive (instead of reforming 20-25% ethanol in water directly), distill it to 100%, which uses a ridiculous amount of energy (10 times more to get it from 95-100 than from 20-95). However, the plus side is that ethanol is a pretty high energy density liquid, about 85% that of gasoline, and much higher energy density than compressed hydrogen gas. So, with an ethanol+water mixture, you end up getting 6 H2 out of every one etOH molecule. Pretty durn good. (if you think I'm an idiot because I have more hydrogen coming out than are on an ethanol molecule, look up steam reforming instead of making yourself look like a fool)

However, at the end of the day, it's extremely questionable whether or not ethanol itself is net energy positive, because of all the energy that goes into producing it (even though the liquid itself increases in energy density). Sugar, however, is less refined, and so less energy goes into making it. The idea is this -- if the net energy is negative, then you're still using more fossil fuels than you save. But if sugar is energy positive, then you can use 1kg of sugar to produce 2kg of sugar, and use that to make 4kg of sugar, and so on.

Sure, you have to pay attention to the problems of rising food costs. But starch? Don't worry about it, it'll be more efficient than gasoline, and it'll be more efficient than ethanol. You're talking a 3x fold improvement on efficiency right off the bat because it's a fuel cell instead of an I.C.E. Now, your sugar production has to be net energy positive, so multiply that factor (guess would be around 2-3) times the 3x fold efficiency improvement in the fuel cell and you're using 6-9 times less energy to produce the same amount of work. The economy will figure out the rest -- hell, you can get starch out of all sorts of crop waste way more easily than you can get ethanol out of them.

The only infinite resource is "human stupidity"

[Joce640k]

The only infinite resource we have is "human stupidity". When we figure out how to split water molecules using stupidity we'll have the problem licked fer sure.

I'm sure a breakthrough can't be too far away, most modern SUVs are already running on 50% stupidity, we just need to improve the yield.