Author Topic: Experiments with blends  (Read 1978 times)

Jhanananda

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Experiments with blends
« on: July 21, 2015, 06:21:48 AM »
As most of you know I started blending WVO-based fuels with gasoline on a 6.2L N/A diesel engine around February 1st 2007.  The blends I tried are:
1) 95%WVO plus 5% gasoline.  I found the engine would only start if I had the block heater on for 2 hours before cranking the engine, and it would run rough, and never smooth out, and it smoked.
2) 90%WVO plus 10% gasoline.  I found the engine would just barely start cold on a hot day, and run rough, but better than the above, but never smooth out, and it smoked.
3) 85%WVO plus 15% gasoline.  I found the engine would start cold on a hot day, and run rough, but better than the above, but never smooth out, and it smoked.
4) 80%WVO plus 20% gasoline.  I found the engine would start cold with a normal glow plug cycle on a cold day, and run and idle fine, and it did not smoked any more than diesel fuel.  In fact the blend behaved in that engine just like diesel fuel.  So, I stuck with that blend for about 6 years.  However, disregarding other failed experiments, that blend ran fine, but the injectors would coke annually, and the injector pumps would fail annually.
5) 70%WVO plus 30% gasoline.  About 3 years ago I started experimenting with higher levels of gasoline.  At that time I found if I increased the gasoline content over 30% that the engine would run better for a short period of time until seal failure in the injector pump, so I settled on 30% gasoline in the blend.  It resulted in the IP lasting twice as long (2 years), and the injectors coking, but serviceable for at least 2 years.
6) 60%WVO plus 20% diesel fuel, plus 20% gasoline.  My current experiments are to reduce high melting point triglycerides, and reduce the overall WVO component to see if I can make a fuel that will run on an indirect injected naturally aspirated diesel engine for an indefinite period of time.

Results so far:
About a week ago I blended fresh WVO with diesel fuel at 20%, and left it to settle for a week.  Yesterday I poured off the clear component (90%) separating it from thick and dark sediments at the bottom, which were about 10% of the blend.  At that time I checked the specific gravity of the blend and found it .888sg, which was surprisingly light.  I then added 20% of a blend of various waste solvents on top of the diesel-WVO blend, and left it to settle for another week.  I will report back next week sometime.

Additional findings:
I made fuel 2 days ago from the last remaining blend of 70%WVO plus 30% gasoline.  Before filtering I checked the sg of the blend and found it high at .877sg.  About an hour before filtering I added 1L of acetone to the blend, then after allowing an hour to go by I extracted another sample from the bottom to examine the blend's specific gravity.  At that time I found it to be .857sg, which was remarkable to me that 1L in 80L would reduce the specific gravity of the blend so much.  It suggests that acetone alone at as little as 1-2% might be all that is needed to produce a serviceable WVO-based fuel.  This also suggests that Excalibur might find acetone blending might solve his observed problems with his engine running gasoline blends as high as 20%.
« Last Edit: August 09, 2015, 05:18:49 AM by Jhanananda »
I have run various blends of waste oils and unleaded gasoline since Feb, 2007 in a 1983 Chevy G-20 van with a 6.2L diesel V-8 engine, with a Stanadyne Rotary DB2 IP. I have started the engine with no difficulty on an 80/20 (WVO/gas) blend down to 3F (-16c).  I now run 60/20/20 (WVO/diesel/gas)

Jhanananda

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Re: Experiments with blends
« Reply #1 on: August 08, 2015, 07:49:12 AM »
I repeated my above experiment with my last batch of fuel, which turned out to be very odd.  I started with a blend of WVO at 80% to diesel fuel at 20%.  I found the specific gravity of the blend was quite high at .885.

From an earlier experiment I found adding acetone at 1% would lower the specific gravity by one whole point; however, this time it only dropped the specific gravity to .880.  So, I added gasoline at 20%.

I then measured the specific gravity and found the top specific gravity was .812sg, which is that of the collection of solvents without WVO; whereas, the bottom was .905sg, which was that of unblended WVO. So, for some reason the gasoline grabbed the other solvents in the blend away from the WVO.  I am going to guess that it was the work of the acetone that I had just added.

Other problems observed in my new blending style is diesel fuel does not seem to produce as much sediment as gasoline blending.

Conclusion:
It looks like there is going to have to be an order to the solvents added to a blend.  I am going to guess it should be gasoline first, then diesel fuel, then acetone to bring the specific gravity down to .845sg.
« Last Edit: August 09, 2015, 05:19:36 AM by Jhanananda »
I have run various blends of waste oils and unleaded gasoline since Feb, 2007 in a 1983 Chevy G-20 van with a 6.2L diesel V-8 engine, with a Stanadyne Rotary DB2 IP. I have started the engine with no difficulty on an 80/20 (WVO/gas) blend down to 3F (-16c).  I now run 60/20/20 (WVO/diesel/gas)

Excalibur

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Re: Experiments with blends
« Reply #2 on: August 08, 2015, 01:49:52 PM »
It could be gasoline blending that has an alcohol content is an aid to settling. The thought is it relaxes the oil. Surfactant might be the right term here.

Jhanananda

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Re: Experiments with blends
« Reply #3 on: August 09, 2015, 05:17:48 AM »
It could be gasoline blending that has an alcohol content is an aid to settling. The thought is it relaxes the oil. Surfactant might be the right term here.

Yes, Excalibur, I am willing to consider that alcohol in gasoline might be a factor; and exacerbating that issue, is a polar solvent has to be added to gasoline to make alcohol blend with it.  However, I am reminded that an Australian biodiesel forum, where we met years ago, claimed that alcohol just floated on top of WVO.  At that time I was unwilling to believe it, because my experience showed gasoline blended readily into WVO.  Now, I have one experience with gasoline floating on top of WVO, and I am trying to understand it, so that it does not happen again.

The variable is, in the past many years I had always blended gasoline with WVO after the initial settling phase, where most of the food particles and high melting point triglycerides are removed.  So, I am going to return to that method, then add acetone at 1%, then diesel fuel at 20%.

Another variable that is worth considering is most of my blending experience has been with canola (rape seed) oil.  Whereas, this last experiment was with soy oil.
« Last Edit: August 09, 2015, 05:21:21 AM by Jhanananda »
I have run various blends of waste oils and unleaded gasoline since Feb, 2007 in a 1983 Chevy G-20 van with a 6.2L diesel V-8 engine, with a Stanadyne Rotary DB2 IP. I have started the engine with no difficulty on an 80/20 (WVO/gas) blend down to 3F (-16c).  I now run 60/20/20 (WVO/diesel/gas)