The Problem with Biofuels

[M-SIL 2]

Originally posted by: Duke87

As for biofuel, I wouldn't rule it out as completely stupid, though I do think it is unwise to just take crops and make them into ethanol or whatever. If you're going to make biofuel, it should be done with what would otherwise be trash, such as agricultural waste. quote>

I do agree. I think is extremely inefficient to grow crop in order to make fuel. The most viable that I know to make biodiesel is pond slime (aka Algae) because it grow extremely fast and produces the most oil per acre.

[Duke87 1,070]

Originally posted by: sam

Originally posted by: Easy Bakes

So your saying that this  waste cooking oil dosent have to be processed in order to be burned

in  a vehicle?

Wouldnt the particles of food and such suspended in the oil clog the fuel filter and injectors?

quote>

It does have to be processed, partly for the reason you suggest (filtration and various chemical methods to clean it), and also because the oil has to be chemically converted to a fuel that can be combusted by vehicles. Unfortunately the processing method used in backyard operations is rather hazardous and I don't recommend it. I heard the cleaning of the fuel lines and engines using it was also rather a time consuming process, as the fuel is very heavy and sticky.quote>

Actually, no. A gasoline-powered car could never run on this. We're talking diesel, here. Diesel engines can burn almost anything combustible if you can get it in liquid form. So they can just burn the used cooking oil with zero processing. As for the particles suspended in it, my guess would be they probably just put a filter in the fuel line which you'd probably have to clean out regularly, I'm not sure. But I do know that it is literally just take the oil, put it in the tank, and you're good to go. No cleaning or processing involved.

But this only works with diesel. If, for instance, you wanted to use it as an additive for gasoline, then you would have to process and clean it.

Also, since when is cooking oil heavy and sticky? It's lighter than water. It's a bit more viscous than water at room temperature, but when it gets heated up (like in the engine), it flows quite freely.

[Sam 163]

Originally posted by: Duke87

Originally posted by: sam

Originally posted by: Easy Bakes

So your saying that this  waste cooking oil dosent have to be processed in order to be burned

in  a vehicle?

Wouldnt the particles of food and such suspended in the oil clog the fuel filter and injectors?

quote>

It does have to be processed, partly for the reason you suggest (filtration and various chemical methods to clean it), and also because the oil has to be chemically converted to a fuel that can be combusted by vehicles. Unfortunately the processing method used in backyard operations is rather hazardous and I don't recommend it. I heard the cleaning of the fuel lines and engines using it was also rather a time consuming process, as the fuel is very heavy and sticky.quote>

Actually, no. A gasoline-powered car could never run on this. We're talking diesel, here. Diesel engines can burn almost anything combustible if you can get it in liquid form. So they can just burn the used cooking oil with zero processing. As for the particles suspended in it, my guess would be they probably just put a filter in the fuel line which you'd probably have to clean out regularly, I'm not sure. But I do know that it is literally just take the oil, put it in the tank, and you're good to go. No cleaning or processing involved.

But this only works with diesel. If, for instance, you wanted to use it as an additive for gasoline, then you would have to process and clean it.

Also, since when is cooking oil heavy and sticky? It's lighter than water. It's a bit more viscous than water at room temperature, but when it gets heated up (like in the engine), it flows quite freely.quote>

Actually it was biodiesel I was referring to. I've certainly seen reference to the notion that "biodiesel is the only alternative fuel that runs in any conventional, unmodified diesel engine." (http://www.biodiesel.org.au/)

Wikipedia has this to say about vegetable oils used as fuels: "Many vegetable oils have similar fuelproperties to diesel fuel, except for higher viscosity and lower oxidative stability. If these differences can be overcome, vegetable oil may substitute for #2 Diesel fuel, most significantly as engine fuel or home heating oil."

Originally posted by: Duke87

Also, since when is cooking oil heavy and sticky? quote>

I'll try to remember that the next time I have to wash up my frypan

[coolotter88 2]

well, I don't think the deep frying oil really gets stuck onto pans and stuff.

[Barbarossa 51]

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  Edited September 7, 2012 by Barbarossa  

[hym 358]

I bet it would probably be laxative abuse if anything.

[Duke87 1,070]

Originally posted by: sam

Originally posted by: Duke87

Also, since when is cooking oil heavy and sticky? quote>

I'll try to remember that the next time I have to wash up my frypan quote>

Your washing troubles come not because the oil is sticky, but rather because it's hydrophobic. Again, water is polar, oil is not. They don't mix too well. Keep in mind that a bit of dish detergent makes it a lot easier. Time for some numbers:

Kinematic viscosity of water (40 ºC): 6.58x10^-7 m²/s

Kinematic viscosity of cooling oils (38 ºC): ~2.7x10^-5 to 3x10^-4 m²/s (mostly in the lower end of that range)

Kinematic viscosity of diesel fuel (38 ºC): 2.7x10^-6 m²/s

So both are considerably more viscous, but still not in the range of something really sticky like, say honey (2.2x10^-3 m²/s). So yes, oil is a bit sticky, but not oppressively so.

Density of water: 1000 kg/m³

Density of cooking oils: ~910 to 930 kg/m³

Density of diesel fuel: 850 kg/m³

Your "heavy" statement is completely unfounded.