Alternate fuels, Biodiesel

[cranetruck]

The 5-micron sock filters came from this store on ebay, but I don't see them listed now.

http://stores.ebay.com/Clean-Grease

I need more now so I'll let you know when I find them. They are 5 inches in diameter and about 16 inches long. The filter hangs inside a perforated tube with legs to stand on a typical 5-gallon bucket. Don't know where this one came from, it belongs to my neighbor/chemist Ms Wetzel. She also produces fuel grade ethanol (moonshine) for use in gas powered cars and as a substitute for methanol when making biodiesel.

Coking of the injectors may become an issue with long term use of large percentages of cooking oil. One more thing to research...

 

[cranetruck]

Here is another source for filter socks:

http://filterbag.com/items/PONG5P4P.html

They seem to have every size thinkable.

 

[cranetruck]

Does anybode here know if commercially made biodiesel bought at a service station produces the same "french fries" smelling exhaust as homemade stuff? I'm beginning to think about the legal concerns and if the homemade BD can be identified by smell.

 

[ken]

What legal concerns? Do you mean untaxed fuel on the road?

 

[cranetruck]

Yes. There are some pretty hefty fines for driving on the highways with dyed diesel or kerosene. Don't know how often anybody actualy checkes the fuel, but the smell of french fries is a dead givaway.
Of course, if the commercial biodiesel has the same aroma as homemade, then I guess there is less of a problem, just carry a receipt for a purchase of the commercial BD. A Jerry can of commercial BD should do it.

 

[mangus580]

Bjorn, if you do some digging, you will find there is a tax exemption for BD if you blend under 400 gallons per quarter (I think thats the #'s).

 

[Recovry4x4]

For me anyway, I assume that if the laws don't say that I can't do it, I'll assume that I can. I've not been able to find anything that says I can't burn fryoil in my vehicles. When they pass that law, I'll get oil from someplace that doesn't cook fries.

 

[ken]

If there is comm biodiesel how much is it per gallon?

 

[mangus580]

From what I have seen posted places online, comm BD runs slightly higher then dino diesel in most places. But with some new blending tax breaks, I hear that it is getting better.

 

[cranetruck]

In North Carolina it's about $3.29/gallon (including tax)...

Here is my latest procedure for making a batch of 9 gallons of biodiesel.
Time to mix and stir is about 2 hrs.

Since the oil from the deli is mostly clear and free flowing at room temp, I decided to
try a batch without heating.

1) Prepare the sodium methoxide by dissolving 30 teaspoons into 2 gallons of methanol.
I did this 1/2 liter at a time in 15 batches (2 gallons is just over 7 liters). I may increase the batch size for this next time. Dissolving the lye (Red Devil sodium hydroxide) into the methanol produces some heat, that's why the smaller batches. This is done on the porch/outside.

2) Pour the 2 gallons of sodium methoxide into 8 gallons (30 liters) of used clear cooking oil while stiring.
Continue to stir for 1/2-3/4 hour. The mix becomes uniformly cloudy after 1/2 hour or so.
I use clear 10 gallon storage tubs for this. They are available at Walmart, the brand name is Sterilite.
These tubs are kept in the basement where I have a ventilating fan (our old darkroom).

3) Let sit for several days. An aprox 1-inch layer of glycerine will settle out and light amber biodiesel is on top.
The glycerine represents about 1 gallon and is not used.

4) The biodiesel is now essentially ready for use. I just filter it through a 5-micron filter sock and pour into the fuel tank of the deuce.
It may still have a small residue of methanol and lye and would not meet ASTM standards without "washing". This residue is the reason for the pH value of 8 (as close as I can determine it). The effect of the residue may be a bit of a boost for the engine (methanol) and the lye may have a corrosive effect on some parts of the fuel system in the long run. How much I don't know, but according to the book "From the fryer to the fuel tank" by Joshua Tickell, no problem has ever been experienced by using unwashed biodiesel (page 71).

The total cost for the 9 gallons of biodiesel is about $6.00 or $0.66/gallon.

The batch prepared like this last week turned out very well, did another yesterday.

The part of the waste cooking oil that requires heating is saved for later. It settles at the bottom of the storage containers and represents about 20% of the oil I get from the deli.

Later,

 

[mangus580]

Bjorn, I was under the impression the heating was required to make the reaction happen properly.

Also is your glycerin still liquied when you are done?

 

[cranetruck]

Mike, I'm not sure about the heating part. The glycerine is like a slime right now in batch from last week and about an inch thick in the tub. The "biodiesel" on top is light amber in color and the density is 0.84 ( the waste cooking oil I started with has a density of 0.87).

When the used cooking oil settles it forms a layer (approx 20%) of an off-white colored thicker oil/grease on the bottom. When I heated it to about 120 F, it turned into the same color and consistence as the upper layer. I guess heating would be required to process the thicker stuff, but since I only used the clear top layer this time I figured room temp would be ok. Maybe I'm wrong, although the result looks good to the untrained eye.

Still learning...

Thanks for your comments!

 

[cranetruck]

Mike, I do have one question about the sodium methoxide (methanol with lye ).
I often see statements like "use right away" or "mix immediately" with the oil. In my case, it was an hour between mixing the first portion of the 2 gallon batch and the last before mixing it with the cooking oil. Is one hour too long? The container was covered.

 

[mangus580]

Its my understanding that if its in a sealed container, it doesnt matter how long you wait. I have seen suggestions of mixing it hte night before even.

The reason I asked about the glycerine, was that if you start using a processor type setup kinda like mine, you will have some slight problems with the 'solid' glycerine. This can be avoided by using KOH instead of NaOH (potassium hydroxide I think is what it is). the KOH leaves the glycerine in a liquid form, but does require a little more to be used.

 

[cranetruck]

Mike, I googled it and it appears that room temperature is ideal for the reaction (transesterification) to take place.
I guess as long as it's an oil and not a grease the waste "oil" (WVO) doesn't have to heated.

When I pick up the WVO from the deli, about half of it is very hot, right from the kitchen. They keep it at 360 F when in use and it was still 265 when I got home. I use a steel trash can for the hot stuff.
My plan now is to dilute the hot oil with some cold to reduce the temp to about 120 or so and process it as soon as I get home when still warm. That way even the grease will be processed.

 

[cranetruck]

Completed another run to the sawmill this mornng. It's a 45 mile roundtrip on a country road with lots of hills.
This time the fuel was about 75% homemade biodiesel and I could swear that the EGT is lower than it used to be. I really have to work to get it up to 1,100 F. In some hills, I didn't have to ease off the "gas" pedal at all, where with 100% petro diesel, I had to watch it to keep from hitting the 1,200 mark. Power is about the same, so I could keep a higher average speed for the run.
Biodiesel rules!

 

[Opie]

"My plan now is to dilute the hot oil with some cold to reduce the temp to about 120 or so and process it as soon as I get home when still warm. "


And you don't need to go to the trouble (and expense) to heat it and get it all over the kitchen floor like in your first experiment, you lucky duck!

 

[cranetruck]

Start checking your local restaurants, you can all do the same. Ask for the empty oil containers, this deli used to toss them in the trash dumpster, they solved my oil storage problem!

One other thing, the fuel consumption has gone up. No numbers yet, but instead of 8-9 mpg it's more like 6-7 for a given run.

Have a great day!

 

[ken]

I'm guessing with the lower EGT's and higher fuel comsumption there is less BTU's in biodiesel?

 

[Desert Rat]

I'm figuring that's the case.