Some help on alternative fuel vehicles presentation

[Slicks]

Hydrogen fuel (Liquid hydrogen), yes, is impractical. Hydrogen fuel cells, however, appear to be much more efficient.

 

[Keef]

Efficient in what way? It's hydrogen gas compressed at 15,000+ psi in rounded tanks that waste a lot of space because of their shape. You might be able to get half the potential power as gasoline within the same space required by that particular volume of gasoline. The only benefit you get is clean combustion. The deficiencies you get are wasted space, less power, shorter range...

 

[Rogue Ssv]

They also only get around 200 miles a tank, and it really pissed me off when some (SENIORS!!!!) idiot wrote that 'because of their amazing efficiency--they get more than 200 miles per gallon--they seem like a good idea. But when they emit water, wont it flood the world?' in the school science magazine. (BLEEEP)ing IDIOT!!!!
Anyway there are some ways to extract hydrogen without using energy but these are impractical for large amounts, and fuel cells as you can see are not that efficient, although they at least wont 'flood the world with water vapor'. Unfortunately he graduated (how did they let him?!) so I couldnt track him down and curse him out.

 

[Slicks]

My mistake, I was under the impression that hydrogen fuel cells (that use electrolysis to separate two elements) were different from compressed hydrogen (The inefficient method you speak of).
I believe there are two methods that we're thinking of - compressed hydrogen for in internal combustion engine, and hydrogen fuel cells to produce electricity.

What I think you're thinking of:
http://www.greencar.com/index.cfm?content=features22
What I'm thinking of:
http://science.howstuffworks.com/fuel-cell1.htm

 

[Rogue Ssv]

Thats true, slix, but dont you still need hydrogen to run a fuel cell? therefore inefficient, to some point.

 

[Slicks]

To some point, yes. Nowhere near as bad as the other type. Everything, compared to gasoline, is going to be inefficient. This is simply because we already have the raw material for gasoline, and it just has to be refined. The raw material (be it electricity, corn, or hydrogen) for everything else has to be created or harnessed, and then refined.

[And, with that, I'm out for the night. I've got to get some sleep.]

 

[Omnis]

Thats true, slix, but dont you still need hydrogen to run a fuel cell? therefore inefficient, to some point.

Water. If something wasn't inefficient at all, we wouldn't need to improve technology. Remember, we aren't looking for something better than petroleum, we're just looking for alternatives.

 

[Kylehnat]

Efficient in what way? It's hydrogen gas compressed at 15,000+ psi in rounded tanks that waste a lot of space because of their shape. You might be able to get half the potential power as gasoline within the same space required by that particular volume of gasoline. The only benefit you get is clean combustion. The deficiencies you get are wasted space, less power, shorter range...

I think you should do some actual, objective research before you take your own words as gospel.

 

[Keef]

Slicks, I often confuse hydrogen IC engines with fuel cells. Hydrogen IC engines can't produce the power that their gasoline counterparts can, and it's difficult to package an amount of hydrogen within the space of a gas tank that will get you the same range.
Fuel cells also require hydrogen in the same types of tanks--it is required to react with the oxygen in the air, after all.
Both methods are very clean, but neither would perform as well in a go-fast or go-far situation like a regular old gasoline mill. With some packaging work and some cost cutting they may be able to match gas, but car makers don't fancy making their cars slower. Look at Lexus--they got better mileage from their 3.5L V6, but they used that saved gas to make 306 horsepower. Course, most of the buyers never use that power, so I guess they didn't lose too much mileage

 

[Famine]

As for the cost, if you eliminate the fact that farmers need to work hard to make it grow and all the things, the principal needs are seeds, sun, water and rich ground.

Sure - and if you eliminate the fact that riggers need to work hard to get oil out of the ground and all the things, the principal needs are dead trees and a hole.

The farmer needs to:
Plough fields (needs a plough - runs on gasoline/diesel)
Plant the seeds (needs a seed spreader - runs on gasoline/diesel)
Water the seeds (needs a pump - runs on gasoline/diesel)
Fertilise the seeds (needs a muck-spreader - runs on gasoline/diesel)
Reap the harvest (needs a harvester - runs on gasoline/diesel)
Collect the harvest (needs a tractor - runs on gasoline/diesel)
Ship the harvest to be refined into bioethanol (needs big lorries or actual ships - run on gasoline/diesel)

All the machinery is needed for large-scale growing because it's large-scale. And the reason all of this machinery runs on gasoline and/or diesel rather than bioethanol is because the ethanol they make is actually too expensive both monetarily and in terms of energy efficiency.

Just because you can make fuel out of growing something doesn't make it "costless", and that doesn't even begin to take into account the fact that half of the Earth's land surface is needed - including things like Siberia, the Sahara, the Nevada Desert, Australia and, lest we forget, Antarctica. More than half of the Earth's land isn't actually habitable on any scale, let alone arable. You'd have just as much luck on the Moon.

The real cost of Bioethanol is 75% MORE per gallon (US) than it costs to make gasoline/petrol - and a gallon (US) of gasoline/petrol gives 138,500BTUs of thermal energy, compared to the 77,000BTUs per gallon (US) of bioethanol.

 

[Rogue Ssv]

Yes, and Gas is actually the CHEAPEST liquid per gallon. Poland Spring is like $10, Coke is like $15 or something, and fancy perfume is more than 1K
So, despite being much worse off then we were a few years ago, we're actually getting a really good deal.
Famine--good point, Ill be honest and say I didnt think of that.
Did anyone see the World News Tonight story on Brazil or something converting all of their cars to Ethanol (or whatever that corn oil stuff is called; Im having a temporary brain blank)? Did anyone believe it? I think that it would be quite hard to do that, as they would have to modify every single car's engines. Unfortunately they didnt state what the ratios were, but if, as my mom, the anchorwoman, and most people who watch WNT now think, we were to convert the world to veggie oil, (no not biodiesel, I THINK ethanol. Anyway its what the FlexiFuel GM cars use), wouldnt that be very hard, and require to modify every engine?

 

[dylansan]

Maybe a slide at the beginning about the history of fuel and engines, to show how far we've come, and a diagram of how a hybrid works. Oh and there were a few misspellings. Other than that it was 👍!