Ethanol is not a good long-term solution.  It would take a hell of a lot of farmland to power all of our vehicles.  Also, is it really a good idea to use up farmland for growing gas?  No matter how well you manage the land, you'll always take more than you put back.

ahh see thats where technology comes in... ethanol can be made from more then just corn these days... other, more energy dense and land friendly crops could be used/bioengineered... actually the big push is to be able to make it from any biomass, things that would otherwise wind up in the trash could be used to make fuel... it's really a win win

Well...we already use most our land to make feed for cows.....So I don't see how it could get any worse 




BTW....if I wanted to use ethenol in my bike...do I just buy it (err...where would I buy it) and use it instead of gas...or do I mix it with gas?

Any crop will decimate farmland, though some more than others.  You're still taking nutrients out of the soil and eventually it will be used up.  Personally, I'd like to save farmland for food.  

As far as using trash, it's already being done.  It's called thermal depolymerization.  The cost per barrel is almost to the point where it can compete with fossil fuels, though it's not a solution because there's just not enough trash.  It would solve the landfill problem though.  

The real solution is to find a catalyst that will separate hydrogen and oxygen, or come up with a way to cheaply, energy efficiently, and environmentally responsibly produce solar cells.  If you can do either of those, you'll be a Nobel Prize winner for sure, and will solve our energy problems.  

Quote from: Egaeus on May 07, 2006, 08:45:13 PMThe real solution is to find a catalyst that will separate hydrogen and oxygen

There's no cheating physics. Hydrogen is a good storage form for energy; it's not a source. Ain't no such thing as freely available combustible hydrogen on Earth; you will always have to split it off somewhere, which will take more energy than you gain (Not talking bout methane here; that might work.)

I have also just today read an article on Ethanol, which stated that Ethanol uses up to 70% of the energy that can be won by burning it for production first. So you can reduce emissions only by about a third. Oil seeds for diesel are more efficient, but also these need massive acreage to feed our hunger for energy.

Energy is a tough issue, but i think that ethanol is one of the more exciting movements in a long while. It is a technology that will develope because it is simple and doesn't take re-engineering the whole system, just a few minor tweaks here and there. To convert to electric power the entire infrastructure would have to accommodate people plugging in at every parking space. Hydrogen fuel/cells would take having to create hydrogen stations of some sort, a huge PITA and not something easily done with what we've got. Ethanol may only reduce the bad stuff by a third or whatever current statistics say, however, it is a relatively easy step in the correct direction.

Oh and as far as farmland goes, doesn't the gov't already subsidize wheat production to help regulate the price in a sort of farmland wellfare type program? I've heard of or read about this controversial practice somewhere anyone back me up on that? Anyway, the point I'm looking to make is that if we're using tax dollars to grow wheat we don't eat, why not use the same cash to grow energy crops that we will use.

Quote from: EMTkid on May 08, 2006, 10:45:17 AM
Anyway, the point I'm looking to make is that if we're using tax dollars to grow wheat we don't eat, why not use the same cash to grow energy crops that we will use.

Because that might cut into Big Oil's annual profits.  As long as we have an oil baron in the Whitehouse we'll never see a real shift away from petroleum in this country.

Quote from: Mandres on May 08, 2006, 01:09:40 PM

Quote from: EMTkid on May 08, 2006, 10:45:17 AM
Anyway, the point I'm looking to make is that if we're using tax dollars to grow wheat we don't eat, why not use the same cash to grow energy crops that we will use.

Because that might cut into Big Oil's annual profits.  As long as we have an oil baron in the Whitehouse we'll never see a real shift away from petroleum in this country.

ehh... not saying I agree or disagree, but there has been a lot of great E85 and other alternative energy legislation in the past couple years because of the current administration.  There are now all kinds of tax incentives and government funding for developing, producing, selling, and using E85 that have made production increase more and more each year.

Quote from: MarkusN on May 08, 2006, 01:58:25 AM
There's no cheating physics.

No, but you can sometimes trick it into doing what you want.  That's what engineers do all the time, but ChemE isn't my field.

Farm subsidies are a completely different can of worms.  However, wasteful government practices don't justify more wasteful practices, and exhausting farmland for fuel is about as wasteful as it gets.  I love the idea of ethanol and biodiesel.  It's relatively clean-burning and it doesn't contribute to global warming.  However, it has its drawbacks that need to be carefully considered before we plant the entire country in sugar cane, corn and soybeans.

Hydrogen is where it's at.  The lack of infrastructure is insignificant.  The gas stations on every corner didn't just pop up overnight.  It's just that we need to be able to produce it efficiently, or more likely have enough clean energy to be able to not worry about how inefficient its production is.  You solve that problem, and the filling stations will take care of themselves.

Some of my fellow engineering buddies and I regularly discuss how hydrogen is just a bad idea.  Sure it's nice and pretty, but it's just not a solution to any problem, and if anything it will create problems.  First off there is no tricking physics, physics is a set of laws that don't bend, ever.  In this case, energy can not be made or destroyed, it can only change forms.  In order to make hydrogen from separating water, you NEED to add energy to the equation.  There is no getting around it.  Hydrogen just isn't an energy source (unless we get a really long straw that can handle 10k degrees F and stick it in the sun), it is a way to store energy just as a battery would store energy.  You still need to make the energy in another way, either by burning a fossil fuel or splitting atoms (yeah there's wind, solar, hydro, and geothermal power, but they're all limited).  Most hydrogen used today is produced by carbon stripping natural gas, and therefore still depends on a fossil fuel.  When you include the process of creating the hydrogen, hydrogen fuel cells are no more efficient or environment friendly then running on gasoline.  I honestly think the only viable way to cheaply and cleanly produce hydrogen in the long run is with nuclear power, and we all know a lot of people wouldn't be happy with that.

Next there's the logistics of carrying hydrogen around in your car.  IMO everyone driving around with a couple hundred cubic feet of hydrogen pressurized to some 3000 psi is not a very good idea.  I can only imagine the size of the explosion if one of those tanks were to be punctured in an accident.  Not to mention you lose a good part of your trunk space to store all this hydrogen and still can only drive 100 miles before you need to refuel.

I think the wrinkles with using ethanol are a lot easier to overcome then the wrinkles with hydrogen.  The first thing is it has to be made using something other the our current crops.  There are several plants out there that are more energy dense then corn or sugar beets and can be grown in places no other crop can.  Most of the technology we need is already there, all it would take would be determined industry to come up with a viable solution with minimal short comings. 

I read a study from MIT recently that found a small displacement, heavily turbocharged engine with direct ethanol injection is about 30% more efficient then current gasoline engines.  Engines like that combined with hybrid cars would blow hydrogen out of the water in the big efficiency picture.

http://www.switch2hydrogen.com/

A company has been working on a kit that you can put in any gasoline powered car.
They have a solar powered generator that splits the hyrdrogen from the water.
As far as the carrying hydrogen around, if you bind it to a chemical, you can transport it safely. This company shot their storage tank with incindiary bullets and all it did was smolder a little.

But, alas, the Consumer Product Safety Commission raided their labs and took all their stuff and are fighting them in court....

I always like these debates because it brings out a lot of great points of view and some really smart people that also happen to be cool because they like bikes 

I think that if the argument against wasteful energy crops is addressed, then clearly current wasteful farmland usage is part of the same can of worms. If we are currently operating under poor a poor land management plan then wouldn't that mean that better use (although possibly still not perfect) would be an improvement?

Damn literalists....

Lima, you're a computer engineer, right?  So you got a Computer Engineering degree, right?  So you took at least one communications class?  Remember Shannon's capacity theorem?  It's based in chaos theory and is a fundamental limit on how fast you can transfer data in noise.  However, on the surface, new modulation schemes like OFDM seem to exceed that fundamental limit.  It's not that engineers broke the laws of physics on which Shannon based his theorem, they just figured out how how to "cheat" it through a good understanding of those laws and a lot of clever thinking.  Clear enough?

You can't cheat physics, but sometimes you can do things a little easier than previously thought possible.

Quote from: Mandres on May 08, 2006, 01:09:40 PM

Quote from: EMTkid on May 08, 2006, 10:45:17 AM
Anyway, the point I'm looking to make is that if we're using tax dollars to grow wheat we don't eat, why not use the same cash to grow energy crops that we will use.

Because that might cut into Big Oil's annual profits.  As long as we have an oil baron in the Whitehouse we'll never see a real shift away from petroleum in this country.

not just the whitehouse lol but in the usa

I see what you're saying, and I'm sorry I thought you were thinking there could be a way to turn water into hydrogen by just running it through some sort of catalyst.  A lot of people just don't understand you can't just pull hydrogen out of no where and think it is an energy source.  A solar powered catalyst is a good idea, and that is in no way tricking or cheating physics, that's just using another energy source to create the hydrogen.  Yes, I've taken a course in data communications (not one of my fav's to say the least), but I don't think that is a good analogy to physics.  Data comm is applied probability and statistics to guestimate how something will behave in the real world and is all theory and no law.  Theories can be stretched, but laws can't.  That's beside the point, the point is ethanol is still awesome 

United Nuclear has some cool stuff, I do check out their website every now and then.  They have all these great chemicals and materials that I could get in soooo much trouble with; I'm not surprised they're having problems with the law.  Anyway, their method of storing hydrogen is a good idea, and solves a lot of the problems with moving hydrogen.  I wonder if they use something like this for fuel cells yet?  I don't know if I like the idea of running an internal combustion engine on hydrogen though.  I would think there would be serious issues with detonation and the ignition timing would have to be pulled way back to get it to run right.  I didn't see anything about performance, but I'd bet it would drop significantly.  But hey, I can convert any EFI car to run on ethanol for <$300, which is a little less then the $7-10k they want for thier hydrogen kit.

Now to back up my bro ethanol. The newest thing is cellulosic ethanol.  Currently, ethanol is produced only from the kernels from the corn, but with cellulosic ethanol the entire plant can be used.  This means something like 3-4 times as much net fuel per area of land.  Not to mention being able to turn all biomass wastes like grass clippings, leaves, and all kinds of farm wastes into fuel.  According to wikipedia, we could replace up to 30% of our energy needs by recycling wastes that are otherwise disposed.  To make up the difference, crops like switchgrass can be grown instead of corn for fuel.  Better  ethanol production methods combined with more efficient engines (the high octane rating of ethanol allows for more efficient engines) make ethanol very viable as our main energy source.   If you want to do some more reading check here: http://www.harvestcleanenergy.org/enews/enews_0505/enews_0505_Cellulosic_Ethanol.htm

What does an engine require to run on ethenol? Just a higher compression ratio like diesel engines or something?

No, just increase the fuel injector pulse width / larger carb jetting and advance the ignition timing.  For modern cars this can be as easy as pluging a computer into the cars ODBII port and remapping the fuel and ignition tables.  Ideally you would throw on a turbocharger to take advantage of the higher octane rating and increase engine efficiency.

That's what I get for playing fast and loose with terminology.  I was thinking of that article with my first response.  However, I used terminology incorrectly. 

yeah well we engineers are anal retentive when it comes to our physics

I'm not that anal retentive, but yeah, if someone claimed to break thermodynamic laws, I'd have something to say too.

Anyway, maybe a better example is the Von Neumann - Landauer limit.  It's a fundamental (as opposed to practical) limit on the speed of computers due to the fact that the dissipation of the energy stored in a bit adds a finite amount of entropy to the universe.  However, through the concept of reversible computing, that energy doesn't have to be dissipated like it is in a typical CMOS microprocessor.  Therefore, the Von Neumann-Landauer limit wouldn't apply.  Now, making a reversible computer is another problem in itself, and that's where I get lost.  I'm too afraid to take that class.  The concept sounds nice though.