What about the stuff that gets left in the bottom of the processor?

[waterdude]

My first batch had a good seperation, but I still got some of the glycerin/soap in my wash tank with the fuel. So, now my batch looks milky and needs help to separate.

Now that the batch is out of the processor, what about the residual bio-diesel at the bottom of my appleseed processor?

Do any of you tilt your processors to drain completely?

--Hugh

[RickHredf250]

I piped mine with air from a shop comporessor so I can blow it all out.
I always end up with a little water/bd in the bottom of the wash tank, just dump the next batch on top of it. If it gets too bad, I do clean it out.
Rick H...

[Spencnaz]

The glycerin is going to come out first and then the biodiesel on top of that is going to flush out any glycerin still in the reactor's plumbing.

If there is anything left in the reactor, it will be biodiesel left behind. Remember too, that water heaters have a slightly inclined bottom to them allowing all the contents to be drained.

Also, if your reactor is up on a pedestal or trailer (such as mine), gravity will do all the work.

[scottefontay]

Remember too that wet biodiesel can have a honey cream look before it is dried. That's the magic part when it goes from creamy to crystal sparkles [img]/ubbthreads/images/graemlins/cool.gif[/img]

[waterdude]

Hello all,

It is separating slowly...ssssslooooooooooooowly.

What about some gentle heat to help it define itself?

--Hugh

[macinco]

Heat always helps (emulsions, washing, settling, drying, etc.)

Sounds crazy (but ot does work and many others can attest to it), adding ~10 water to the end of you reaction and continuing to pump/stir/circulate for a few minutes) makes washing AT LEAST twice as easy with AT LEAST half the risk of having promblems/difficulty washing/emulsion. Just makes a little more glycerine/stuff. All the water you add settles out with the glycerin.

And.... however you do it.... make sure you are doing as good as you can with regards to not getting settled glycerin into your wash tank.

Keep brewin.....(and washing and drying)....you will get good at it.

[scottefontay]

Hugh, is your biodiesel gooey and curdy or is it still thin, just creamy looking?

[waterdude]

Thanks Marky, I'll keep at it...for sure. Running my truck on biodiesel right now (20 gallons at $3.60/gallon)

Scott, my fuel is settling supper slow, but I know that I have glycerine in the wash tank. Adding 6 extra gallons of warm/hot water did nothing to clear it up. I'm guessing that that warm water just sunk straight down to the water layer and didn't warm the batch at all.

I'm going to try heating the upper fuel layer and hope that it does the trick. As it is separating now, clear fuel on top two inches with yellow mixed layer below.

I haven't drained any water off the bottom yet.

--Hugh

[scottefontay]

Hugh, what I'm asking is whether or not the "mixed layer" is thick or thin. I ask because wet biodiesel is not clear, its creamy colored. Whereas an emulsion is thick in a gooey, curdy sort of way I freaked out themy first couple batches too, until I dried them. What did your oil titrate to?

[waterdude]

Update 3/16/06: I heated the biodiesel layer last night for 90 minutes, while stirring occasionally and talking on the phone. This morning, the biodiesel looks much much better, a darker and clearer honey brown color (thinner), rather than a orange milkshake (thicker and milky looking). I think the heat helped a lot.

Yesterday, I bought a 110 volt water heater element and two prong 16 guage power cord at the hardware store. Connected the wires and dropped it right into the washtank. I was careful to only heat the fuel layer and not the water layer on the bottom.

Tonight, I plan to drain the 1st wash water and then add fresh water do a second bubble wash.

Batch Process on 3/1/06: I used KOH: 7.0 gram base + 3.0 gram titration in 22% methanol, reaction time 90 minutes.

Questions: How long are people bubble washing during each stage?

Should I add warm wash water or just use cold?

Thanks much,

Hugh

[scottefontay]

I've found that the first wash water gets staturated pretty quick, within 3 or four hours and the more water used the better. Warm water will work better than cold as it will dissolve more solute. I usually do a wash cycle over nite and one while at work that way I can get two in one day. If you are having trouble washing I recommend doing the prewash, adding 5-7% water in directly at the end of the initial mixing process and mixing for 30 seconds or so. Makes life easier.


In the future you may want to pump the products of the reaction directly into your conebottomed wash tank, before it settles, so you can more easily seperate the glycerin

[waterdude]

Greetings all,

My second wash last night looks a million times better than the first wash [img]/ubbthreads/images/graemlins/laugh.gif[/img] , this biodiesel newbie doesn't know much yet.

Other than checking pH of the wash water, what else are people looking at? Straight clarity?

My first bubble wash was only 1 hour, second wash was 3 hours of bubbling. Maybe these are too short on time? Still figuring things out.

--Hugh

[waterdude]

[ QUOTE ]
Hugh, is your biodiesel gooey and curdy or is it still thin, just creamy looking?

[/ QUOTE ]

Now that I'm through the second wash, I would say that the bio-junk that I was looking at was thin and creamy. Maybe that is what it is supposed to look like on the first wash?

--Hugh

[scottefontay]

Well, it really shouldn't be any more viscous than the biodiesel. It should still be thin, just cream colored (there should be no goo). If it is thicker with an actual creamy consistency than you have a mild emulsion. If it looks like chunks or gobs of butter at the top than you have a serious emulsion and believe me those are not fun. Its important that the first wash be very gentle, so if you don't have any control on your air pump you should get a small valve at the petstore.

As far as the pH of the wash water, removing the alkalinity should coincide with the clearing of the water and the absence of that "slimy" feel to the water. It takes a couple times and a few mistakes buyt its pretty straight forward once you know what to look for.

[biobenz]

Many water heater based biodiesel reactors do not drain clean and what is left on the bottom is glycerine, that being heavier than the biodiesel itself. This is a sure fire way of getting glyerine into the wash cycle and causing wash problems.
I explained this in my reactor page on this and the two work arounds to it; one being a tilt and recycle and resettle one and the simpler, and one we use, one is to transfer the whole lot to a seperate settling tank with the Stand Pipe design ( http://www.biodieselcommunity.org/standpipewashtank/ ). This later allows to drain out the biodiesel FIRST and then drain out the glycerine, virtually eliminating the potential for glycerine in the wash cycle, unless the reaction is not yet completed and there is still some left to settle out but that is another matter. If you settle for at least 4 hours or better 6 to 8 then you can be sure that all the glycerine has dropped out of a fully converted batch.
Some have had superior results using warmish to hot water for washing; one idea is to do the first wash a static wash. IE: just let the BD sit opn top of some hot water for awhile and this will help many of the soaps to drop out. Change water before further washing. Some will mist, some will bubble, some use other less widely used methods, but the initial wash is where most of the soaps are going to come out, so do it gently whatever method you use.
http://www.biodieselcommunity.org/mainpage/ has tutorial instruction on this and other aspects of biodiesel production at the home level.
Happy brewing.