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Author Topic: Waste Motor Oil Refining  (Read 49182 times)

dieseldave

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Re: Waste Motor Oil Refining
« Reply #45 on: January 30, 2008, 03:18:44 AM »

    Dieselcraft Centrifuge?  ???    Where can I get one and how much$$$$.  ::)  I live in Edmonton Alberta. ;D

rbodell

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Re: Waste Motor Oil Refining
« Reply #46 on: January 30, 2008, 06:06:09 AM »
I use a dieselcraft centrifuge. Works great. The dirtier the oil the more often you have to clean out the gunk, but no filters to buy and ti does get the wattery goo out. just catch it in a cup when you shut it down.

Do you heat your feed stock ? What temperature ?
I was thinking it would be nice to just have a pump and one of these centrifuges going more or less continually for a few days on a drum of product but Dieselcraft indicates heating will be required which could potentially add substantial expense (although I have never worked out the exact cost).

Jens

At first I heated the oil to a temperature that I couldn't hold my hand on a pipe in the system. Don't know the exact temp. I installed a 1450 watt 125 volt water heater element in the side of a 15 gallon oil drum by bolting two floor flanges together with a thick rubber gasket under the outside flange. I drilled the holes undersized for a tight fit and used bolts with a non threaded shoulder so when squeezed, there was no leaks. I did this also with the 55 gallon cooling drum and no problem with leaks. http://picasaweb.google.com/rbodell/Projects/photo#5149384968622067474

Despite the 2 GPM flow, I let it run for a couple of hours for the usual 10 gallons I process at a time. I run it on the lister when it is running so there is no cost from the power company.

Lately I have been diluting the oil with diesel before I process it instead of after. I use 3 gallons of diesel to 7 gallons of oil. This thins it out as much or thinner than heating it. After processing it for a couple of hours as I normally do, I cleaned out the diesel craft centrifuge and then heated the oil and processed it again for a couple of hours as normal. So far I have done this with two batches and the second time with heat got no more impurities out. Diluting it with diesel got me the same results as heating it. The only difference was the water I used to add sodium hydroxide with was visible when I cleaned it out as a gray goo. When I heated it the water evaporated because I never saw the water.

The couple of hours I run it is far beyond what is necessary, Running it continuously would be a waste of time. Also you really should be there to watch it while it is processing to clean the diesel craft when it gets full and to keep adjusting the pressure. I have a relief valve, but it often gets gummed up and I do not consider it dependable. If it does not release properly you can damage the diesel craft. There is plenty to do with taking samples, mixing them with water, waiting for the water to settle out and then test the water for acidity with litmus paper and adding a little sodium hydroxide until the acidity is rite.

So far this has worked fine and reduced the power needed to process the wmo by not needing the heating element.


« Last Edit: January 30, 2008, 06:08:00 AM by rbodell »
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rbodell

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Re: Waste Motor Oil Refining
« Reply #47 on: January 30, 2008, 06:16:32 AM »

    Dieselcraft Centrifuge?  ???    Where can I get one and how much$$$$.  ::)  I live in Edmonton Alberta. ;D

http://www.dieselcraft.com/ I think it was something like 200 bucks. You can find distributors through the website. It requires 90 psi @ 2 gpm flow.
« Last Edit: January 30, 2008, 06:18:16 AM by rbodell »
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rbodell

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Re: Waste Motor Oil Refining
« Reply #48 on: January 30, 2008, 07:33:33 AM »

So far this has worked fine and reduced the power needed to process the wmo by not needing the heating element.


I try to add about 20% gasoline and that thins it out considerably. I hadn't thought about that aspect - good call.

Nice way of adding a port to a drum too !

I didn't realize that the centrifuge needed babying beyond the initial startup when it might get loaded with crap fairly quickly.
What kind of ph levels are you seeing ?  I purchased a garden PH meter and the two samples I tested showed no appreciable acidity so I was considering not to worry about acidity and washing the oil. I guess it also helps that I wouldn't run a final oil percentage lower than maybe 50% for the 'roid or 25% for my truck.

Jens

Are you testing the oil itself or mixing some oil and water together, then letting it settle then testing the water? If you just test the oil, the acidity won't register. I have not found any WMO that wasn't acid so far. That doesn't mean it doesn't exist, but I would be real surprised if it didn't register some acidity.

I just used some litmus paper to test the water.

I mix water and oil in equal portions and shake it real good in a liquid dish soap bottle then let it set upside down for 15 or 20 minutes. Then with as little movement as possible, I open the top on the bottle over a dish and then close ti quickly. It only takes a couple of drops to test. As for percentages of wmo and diesel, that is up to you.
« Last Edit: January 30, 2008, 07:35:24 AM by rbodell »
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rbodell

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Re: Waste Motor Oil Refining
« Reply #49 on: January 30, 2008, 03:50:50 PM »
Yes, I tested the water after mixing and settling. I would still be curious as to the average ph level (the actual number) that you see. My tests did show acidity but so little that it was likely to matter (6.5 - 6.8).

Jens

the litmus papers I have show a 6.4 to 7.4 as nutral. 2 to 6.3 as Acid and 7.5 to 13 as Base. The nutral range is coparatively small so you shouldn't have anything to worry about. make sure you keep the sensor cleaned of oil as it can affect the readings.
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dpollo

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Re: Waste Motor Oil Refining
« Reply #50 on: January 31, 2008, 12:46:16 AM »
Is it possible that Jens' concoction has all the ingredients of an emulsion so in practical terms, it will never settle out.

I have drained similar goop from  the oil pans of old cars. A mixture of antifreeze, water, cheap motor oil, unburned gasoline  and bearing material. Has the consistency and flavour of a well known restauranteur's chocolate shake.

biobill

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Re: Waste Motor Oil Refining
« Reply #51 on: January 31, 2008, 03:11:05 AM »
  Maybe a dumb question (not the first) but can dry oil have a ph? I presume you are concerned about corrosion, but as long as water isn't introduced, is it really an issue? My limited understanding is that to be acid/alkaline, you need to be in solution with water and I can certainly understand how mixing water with used motor oil could raise or lower the ph of the water due to contaminants in the oil. But...if the oil's dry and you don't add any water to it, it's not corrosive is it???
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rmchambers

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Re: Waste Motor Oil Refining
« Reply #52 on: January 31, 2008, 03:40:48 AM »
I think it would have the potential to be corrosive.  Probably not while it's in the equipment prior to the injector tip.  Once it's in the engine and combustion takes place, some moisture will be created as a byproduct of combustion.  If some of the acidic material and moisture gets past the rings you can have some corrosion. 

aqmxv

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Re: Waste Motor Oil Refining
« Reply #53 on: January 31, 2008, 08:06:14 PM »
  Maybe a dumb question (not the first) but can dry oil have a ph? I presume you are concerned about corrosion, but as long as water isn't introduced, is it really an issue? My limited understanding is that to be acid/alkaline, you need to be in solution with water and I can certainly understand how mixing water with used motor oil could raise or lower the ph of the water due to contaminants in the oil. But...if the oil's dry and you don't add any water to it, it's not corrosive is it???

Technically, no.  Oil with no polar (water-like) solvent in it can't have a pH, because there's no way to have excess hydronium in solution.  However, in the real world, you have to assume that there's something polar around that can cause you grief, like water in the bottom of the drum.  The chemistry way to check for acid/base in a nonpolar solvent (oil, in this case) is to shake up an oil sample/water mix in a seperatory funnel, let it sit and settle (like vinegar/oil salad dressing) , and then draw the water fraction off the bottom for pH testing.  The dishwashing detergent bottle left to settle upside down is a great way to do this on the cheap.

You'll want to test some new motor oil to develop a standard procedure.  New oil should test somewhat alkaline because of the buffers added during manufacture.  If the WMO was changed promptly, it should  be alkaline as well.  Oil that was not changed in a timely manner goes acidic (especially in a gasoline engine that ran cold).  Acidic oil combined with water vapor made during the combustion process in the engine results in an acid bath for internal engine parts...which is why we change the oil in the first place.

If I had some oil that tested alkaline and some other oil that tested acid, the first thing I'd do would be to mix the two, heat, and stir a while.  The remaining pH buffer in the alkaline oil might just solve the acidity problem...

Diluting before filtering (centrifugal or exclusion) will definitely help with throughput.  It'll also increase the extraction efficiency of a centrifugal filter.
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rbodell

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Re: Waste Motor Oil Refining
« Reply #54 on: January 31, 2008, 08:59:50 PM »


If I had some oil that tested alkaline and some other oil that tested acid, the first thing I'd do would be to mix the two, heat, and stir a while.  The remaining pH buffer in the alkaline oil might just solve the acidity problem...

Diluting before filtering (centrifugal or exclusion) will definitely help with throughput.  It'll also increase the extraction efficiency of a centrifugal filter.


Occasionally I add too much sodium hydroxide. To counter it, rather than add acid, I add a little more oil. Works every time.
The shear depth of my shallowness is perplexing yet morbidly interesting. Bob 2007

rbodell

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Re: Waste Motor Oil Refining
« Reply #55 on: January 31, 2008, 09:04:35 PM »
At the local auto parts stoe the guy mentioned a customer that works at the power plant told him they reuse the expensive oil ($1,000 a barrel) in the generators They process it with a system that uses a vaccume. Is anybody familiar with this?
The shear depth of my shallowness is perplexing yet morbidly interesting. Bob 2007

dieseldave

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Re: Waste Motor Oil Refining
« Reply #56 on: February 02, 2008, 06:12:51 AM »

    Question:  Has anybody done a PH test of New Motor Oil out of the bottle?  If so,what was the PH?

rmchambers

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Re: Waste Motor Oil Refining
« Reply #57 on: February 02, 2008, 03:56:13 PM »
pretty sure it's going to be basic.  They have TBN numbers assigned which is the True Base Number - indicative of their base ph.  This is supposed to counteract the acidic effects of combustion blowby.

RC

One thing I wondered is that do synthetic oils that hold up better in an engine burn as well as regular oil when diluted and sent through a diesel engine?  Anyone tried firing a listeroid or other compression ignition engine on synthetic?

draganof

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Re: Waste Motor Oil Refining
« Reply #58 on: February 02, 2008, 07:01:51 PM »
pretty sure it's going to be basic.  They have TBN numbers assigned which is the True Base Number - indicative of their base ph.  This is supposed to counteract the acidic effects of combustion blowby.

RC

One thing I wondered is that do synthetic oils that hold up better in an engine burn as well as regular oil when diluted and sent through a diesel engine?  Anyone tried firing a listeroid or other compression ignition engine on synthetic?

I tried some Mobile One in my Changfa 195 at 100% and got lots of smoke. The engine will burn 100% WMO with no smoke so the 195 doesn't like it. I never did try a blend with diesel.

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Doug

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Re: Waste Motor Oil Refining
« Reply #59 on: February 02, 2008, 10:34:53 PM »
Synthetics will burn at higher temperatures.

They don't ignite well.
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