Wrong......Used oil has organics in it that WILL hold water, and it can turn your batch into a congealed mess. Just settling will not always remove the suspended water. There are two things that quality biodiesel won't tolerate, water, and mixing with air. Water in the bio will cause corrosion, and mixing air with bio will cause oxydation of the bio. I've got several test containers of biodiesel I made over 7 years ago, and it is just as good as the day I made it, BUT, I have it in sealed containers with NO air in it.

 

same thing happened the one time we tried to water-wash our bio. ended up with an emulsion. It was a pain to deal with and ended our water washing attempts.

 

Hmmmmm, so by using this method you don't really even need to test for the amount of water in your oil? If you take the time and steps to let the water settle and use the process you speak of.
So your processor tank is the tank in which you mix your oil and methanol etc.? correct?
Could you explain the up flow system and what kind of filtration you use to get the water out?

 

AH. Didn't think of that. So what rushmore is referring to would be filtration of the organics that hold the water. yes? no?
Settling will take care of the excess water that the organics in the oil cannot absorb and filtration will take care of the organics? Is this close to being correct?
Any good write ups on upflow filtration systems??
I really wanted to go with the washing method because water is essentially free and air is free after the innitial expense of the pumps and hosing and air stones.
With the drying method you must continue to buy magnesol which adds to your cost per gallon really, only reason i didn't wanna use that method.

 

You still need to monitor the water in your oil BEFORE you process. Magnasol is used AFTER the batch is made. I use vacuum to remove most of the soap BEFORE I mix in the Magnasol. This requires half of the Magnasol that would normally be used.

You should at least try a "pan test" on the oil before you process. This is just putting about a quarter inch of the oil in a pan and heating it up. If it bubbles, there's water in it. The more bubbles, the more water. Excess water can be adjusted for by adding more KOH, or NaOH, but you need to know about the water first, or you could wind up with an emulsion. Not fun......

 

Using Magnasol is the cheepest part of the process, and produces the best result with the least amount of problems. I wouldn't even attempt making bio without it....

 

Used oil can absorb water. And, used oil is almost always useable. It just depends on how much time and energy you want to put into it to make it useable. It can hold enough suspended/absorbed moisture, still look clear enough, and cause problems in reaction and washing. There are many different ways to dry the oil, but it depends on how wet it is when you get it. My method is by heating it in my settling drum to 130F-140F, shutting off the heat and allowing it to settle a couple days. Then I drain out a few cloudy gallons off the bottom, pour a cubie of glycerin from the previous batch, stir and settle. The glycerin will grab onto whatever moisture is left and sink to the bottom. Now I have crystal clear oil that is always 300-400ppm or less water. You can make biodiesel with oil that has 100ppm or more, but you will likely make a lot of soap, and/or create an emulsion which will take many extra steps, time, and energy to wash.

My best advice to you is two things: 1.) Read as much as you can at the site I gave you the link to in an earlier post. (Then come back here if something doesn't make any sense).
2.) Google 'Dr.Pepper Technique', and make a few 2 litre bottle test batches with new and used cooking oil. This will greatly help you understand how it all works, by learning how to titrate, react, and wash. Better to make mistakes at this level than at a larger scale. This is what I did several times until I knew I understood the process. It helped me understand what I needed to build my reactor and wash tank.

 

Yes i saw the Dr pepper test on your link.
I understand titration but one thing i am uncertain about is fabman you said water can be accounted for by adding extra KOH.
Is this the same step done when titrating and determining how much extra KOH is to be added per litre?

 

No. What I'm talking about is after the reaction starts. I use an "open" style of processor, not the appleseed style, and once in a while the reaction is not progressing along as it should, I can add more KOH and force the reaction to completion. Not really possable in the appleseed type, but it will save a batch.......

 

right i wont have an "appleseed" type i will have open tanks
how do you determine the amount to add in order to save the batch and when do you determine that it needs more?

 

I watch the batch for the first 30 min. When it turns almost black it's got good conversion. The "black" color is the suspended glycerol. If it doesn't change color I add a half pound of KOH and wait to see a color change. If no change to black, I add another 1/2 pound. Never had to add more than a pound to get it to convert, but has saved many batches!

I also don't use a pump for mixing. I use a mechanical mixer ( elect motor with a shaft and "prop" on the bottom). Mixes MUCH faster, and takes less time to process.

If you go to the main forum page in this forum and search under my screen name, you will find several thousand pages on the biodiesel process.......

 

All this talk about the process is getting me fired up about making batches again. My sources dried up for the winter, but tourist season will be starting up again and the oil will once again be flowing...

 

Like i said fellas. this new project really interests me and gets me excited to experiment, but i hear on and off about these conversions required to run WVO, i could understand in the newer models with the emissions systems and more specific fuel delivery systems.
But my truck is an 86 6.9l, i have heard many storys about people running these trucks just fine on WVO with no conversion. Starting on diesel but running on WVO.
How many agree or disagree and why or why not? thanks. Really wouldn't be interested in jerry rigging some alternative fuel system. Fuel i will change and mess with if it is burnable and proven to work, Fuel SYSTEMS i will not, they put it on at the factory for a reason.

 

I've made 1300 gallons of bio and run it in my 2 diesels. With Biodiesel there are no conversions just put it in. It does have a higher gel point then regular diesel, and produces about 93% of the power. I had to change fuel filters more often at first as it cleaned out the fuel system but that's about it.

There are others here who have made and used a lot more than me without issues also...

 

Okay thats the answer i was hoping fod, people telling me to add a whole seperate tank and lines and inline selection valves and fuel heaters, thats a big waste of time and money for something that is supposed to save you money