Blending gasoline with vegetable oil to make diesel fuel

[Jeffrey S. Brooks Banned Find all posts View Profile Close Jeffrey S. Brooks]

Video: Making vegetable oil blend diesel fuel (VOBDF) by blending gasoline with waste vegetable oil (WVO)
YouTube - Blending Gasoline with vegetable oil to make Diesel Fuel

[silver_fox_aus1 Donating Member Find all posts View Profile Close silver_fox_aus1]

Re: Blending gasoline with vegetable oil to make diesel fuel

Hi Brooks,

1. Do you just blend 20% petrol with your WVO and that is all.
2. Have you ever blended ethanol with WVO.

I am just looking for a good blend currently blending 30% diesel with my WVO does have a harder starting aspect and have read if I am not mistaken that you just blend the petrol with the WVO and it does a good job.

Thanks Gene

[Jeffrey S. Brooks Banned Find all posts View Profile Close Jeffrey S. Brooks]

Re: Blending gasoline with vegetable oil to make diesel fuel

Hello Gene, yes, I have found a blend of 20% petrol to 80% WVO works best for my engine. I find no loss of power, or fuel economy, and the fuel remains liquid and the engine starts just fine down to 0F (-18c), and runs fine up to 120F (49c).

In several research papers where vegetable oil was used to extend diesel fuel blend they found that any blend with diesel fuel that included more than 50% WVO caused engine failure. So, if you are going to stick with diesel fuel as your blending agent, then I would recommend no more than 50% WVO in your blend. You will also find that such a blend will be susceptible to gelling at temperatures below 32F (0c). However, if you heat your fuel line, or add petrol to your blend, then those problems are going to be mitigated.

[tbird650 Senior Member Find all posts View Profile Close tbird650]

Re: Blending gasoline with vegetable oil to make diesel fuel

Gene
I get power loss when the engine gets up to operating temps with ULP as the blend. Just why I do and Jeffrey doesn't isnt exactly clear though our vehicles and setups amongst other things differ considerably. Perhaps even the ULP is different as I understand some has an alcohol content in the States.
I've now gone to using the 30% diesel blend that you are with better results for power when hot. Starting is more difficult from cold though better when hot.
One theory is that the fuel ULP content vaporizes as it reaches the hot injector, causing bubbles and consequently it doesnt inject and spray nicely. Power loss can occur when there is no bubbles returning in the return line as well. Bubbles do appear when the ratio of ULP is high and/or the ambient temps are high.
Another key difference is my fuel tank is inboard and can't get the benefit of air cooling. Consequently the ULP blended fuel can be quite hot and appears to aggravate the situation especially on long trips. My logging of temperatures has shown that even my van standing in direct sunlight during summer can elevate the fuel tank temps.
I've put up with power loss over quite some time and in varying degrees but it certainly gets frustrating when you start holding up traffic!
If you decide to try ULP blends, I'd be most interested to hear the result and experience.
Both blend types has advantages but neither is perfect. For me ULP has good cold start but power loss when hot while diesel blends give good power though cold starts suffer.

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: Blending gasoline with vegetable oil to make diesel fuel

Tbird,
What proportions of ULP: WVO did you try?
Were any blend ratios better than others in relation to your power loss / cold starting?

A member of WARFA was using 10% petrol in WVO for several years until I bought the car for my Mrs, now it uses a 5% ULP, 20% biodiesel blend with WVO.

Neither he or I have had issues with power loss.

Regards,
Tony

[silver_fox_aus1 Donating Member Find all posts View Profile Close silver_fox_aus1]

Re: Blending gasoline with vegetable oil to make diesel fuel

Hi Tony, TBird,

I have in the past used 10% and today used 20% on a 200 k trip and didn't notice any appreciable difference. Not that the old girl (sd 2.5 Nissan Navara motor).

I get a couple of tons of sweet potato each week and was wondering if anyone has used ethanol for blending. I noticed that it has 30% less economy according to one report I read and would assume that there probably be a power drop as well but as I tend to only travel at 80k doesn't worry me much.

Gene

[cuppatea Senior Member Find all posts View Profile Close cuppatea]

Re: Blending gasoline with vegetable oil to make diesel fuel

I thought JSB covered Ethanol in some of his first few threads? Not recommended from memory or at least a possible source of his issues.

[Captaincademan Senior Member Find all posts View Profile Close Captaincademan]

Re: Blending gasoline with vegetable oil to make diesel fuel

[One theory is that the fuel ULP content vaporizes as it reaches the hot injector, causing bubbles and consequently it doesnt inject and spray nicely.]

Hi Tbird,

I have never run stright or blended WVO, but I do enjoy the read when it comes to these threads. On the subject of the vapourising ULP, I reckon you would be hard pressed to get the ULP to vapourise on the Pressure side of the pump. The high pressure environment should well and trully keep the gases dissolved in the fuel.

I think there is something else at play here - I wouldn't rule out an air leak. tolerances have been known to change with temperature.

[Nuddy Senior Member Find all posts View Profile Close Nuddy]

Re: Blending gasoline with vegetable oil to make diesel fuel

[One theory is that the fuel ULP content vaporizes as it reaches the hot injector, causing bubbles and consequently it doesnt inject and spray nicely.]

More likely perhaps is the ULP may vapourise before reaching the IP where it is under vacuum. Then the integral lift pump may have trouble drawing the vapour.
Just another thought.

[tbird650 Senior Member Find all posts View Profile Close tbird650]

Re: Blending gasoline with vegetable oil to make diesel fuel

Good point about the pressure side of the IP, Captaincademan. Food for thought. If I had air leak, I've always thought I'd see it in the return line, however I have had accasion to see very, very fine bubble streams before which could easily go un-noticed.

I have to wonder what the IP looks like on the inside now that it's done 5 years with a huge amount of fuel run through it. Will it look like the IP I saw recently that was reminiscent of a jelly mold of fats/glycerine on the inside? Is the shut-off valve strainer partly caked?? Sadly it's very very difficult to get to.

What I know is that 30%dino blend performs significantly better in my Hiace than the usual 10 -15% ULP does. I wondered whether a fuel cooler would make a difference, like some of the big trucks have.

Tony
I've experimented recently with up to 1/3 ULP in an effort to prove something/anything, one way or the other.
The highest % blend started and ran ok till hot. Then it lost power and I noticed lots of bubbles returning to the tank. I had trouble keeping up with traffic and was as though the van was running out of fuel.
Other blends seem to loose power relative to the amount of ULP in the mix, (mostly) without any sign of bubbles. Currently my 30%dino blend has good power when hot and is quite a bit more viscous than the ULP blends were.

I've got the ULP blend fuel temps logged too. This shows that injector line temps go close to engine temp after some time driving or with heat soak after stopping. Fuel tank temps were up to mid 30's. Good power is with injector line temps under 40'. Best power is under 30' (remember my tank has no air cooling being inside the vehicle, also the fuel lines were the same till recently)

Another thought: Is ULP the same identical mix in each country or are we trying to compare apples with oranges?

Thanks for good constructive comments, team.

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: Blending gasoline with vegetable oil to make diesel fuel

While the injectors do receive very high pressures when injecting, in the period between fuel injection, there is little or no pressure in the injectors and injector lines. In this case, fuel could be forced from the injector and lines into the return line by the boiling ULP in the blend.

I am only postulating here, but I believe that this is a possible cause of the power loss at higher temperatures. It could also be due to vaporisation of the ULP on the suction side of the IP. Addition of a low pressure (4 - 7 psi), fuel pump would eliminate the suction side vaporisation as a potential cause. The addition of a fuel pressure/vacuum gauge would verify if the pressure remained at the IP inlet during testing of the impact of adding a fuel pump, on the high temperature fuel starvation issue.

Regards,
Tony

[Jeffrey S. Brooks Banned Find all posts View Profile Close Jeffrey S. Brooks]

Re: Blending gasoline with vegetable oil to make diesel fuel

Hi Tony, TBird...wondering if anyone has used ethanol for blending. I noticed that it has 30% less economy according to one report I read and would assume that there probably be a power drop as well but as I tend to only travel at 80k doesn't worry me much.

Gene

Sorry, Gene, I forgot to respond to your earlier inquiry regarding blending with alcohols, such as ethanol. I have not been successful at creating a solution with vegetable oil and alcohols, so I cannot at this time recommend it. However, there is some research in cosolvent blending that has successfully done this, but it requires one or more intermediate stages to force this blend.

[Jeffrey S. Brooks Banned Find all posts View Profile Close Jeffrey S. Brooks]

Re: Blending gasoline with vegetable oil to make diesel fuel

On the subject of the vapourising ULP, I reckon you would be hard pressed to get the ULP to vapourise on the Pressure side of the pump. The high pressure environment should well and trully keep the gases dissolved in the fuel.

I am with Captaincademan here, it is not likely that ULP will vaporize on the positive pressure side of the the pump. However, we have certainly heard of tbird650's problems with loss of power. From what he tells us, it appears that his fuel tank is getting heated with returned fuel, might be causing the ULP to vaporize on the negative side of the lift pump and causing vapor-lock there. He might find adding smaller quantities of ULP might work. I would like to hear of his results. Maybe 5-10% will work.

[tbird650 Senior Member Find all posts View Profile Close tbird650]

Re: Blending gasoline with vegetable oil to make diesel fuel

Tony
Yeah, Ive pondered over this as well. Obviously it's the hottest point being around engine temp. It's a pity we can't see inside the injector and lines. If indeed it's vaporizing at the nozzle, I'd have thought that some bubbles would be coming back from the bleed off lines. On my Hiace they are banjo'd and feed back via the return line.

I was thinking of a fuel cooler, mounted out front on the grill. However with the dino blend I'm in 2 minds. Part of me says I should not so I can take advantage of a bit of heat thinning. The fuel is noticeably more viscous and heat thinning might make for an easier time on the IP.

It would be interesting to hear of any ones' fuel line, tank or injector line temps so as to compare.

[craigcurtin Senior Member Find all posts View Profile Close craigcurtin]

Re: Blending gasoline with vegetable oil to make diesel fuel

Tbird,

I have used a combined mixture in my Surf for a while now - 5% ULP, 20% Dino, and the rest WVO

I vary the ULP and DINO content by time of year to give me reasonable starting etc.

What i am basically looking for is a reasonably thin mixture - i think if you were to reduce the amount of ULP down to around 5% and then blend with DINO until you found a good starting mix you would be OK - as your climate got colder you could add more ULP

The other thing to look at it making BIO - although a pain to start with you could then add a heap more to the mixture to achieve the same result i.e. BIO costs around 40c/litre to make so you could either cut your blending costs or up the BIO amount to achieve more consistent operation.

I have only just started making bio but have found it is not as scary or time consuming as first imagined

Craig