Some info & perspectives on "bio-diesel" conversion - i.e. using plant oil not diesel

Betsy Og

If you are interested in this and, in particular, if you could offer any insight, have a read of below.

Its my summary of whay I picked up from Eilishoils.ie, greatgas.ie, ecocar.ie which are all Irish sites that talk about converting a diesel car to run on Pure Plant Oil. They link to Elsbett a German site from the makers of conversion kits.

What I took from the info (mostly from the Elsbett site - the firm who make the conversion kits and the most "technical" analysis) was:

1. The sites seem to deal with Pure Plant Oil "PPO" (what Great Gas would sell you on the forecourt) - also seems to be described as "SVO" meaning straight vegetable oil. I gather this is different from "Bio-Diesel" or RME. Is "bio fuel" a word at all, & if it is what does it describe?? I wish they could standardise the names a bit.

2. A conversion kit is necessary for running on 100% Pure Plant Oil (I gather that most modern diesels - especially German manufactured - should be able to run unconverted on, say, a 5% biofuel mix.) Kit costs about €850 to €1,200 per the German site, before delivery. Irish sites say factor in about €1,650 + VAT for, I think, fitted conversion.

You can still run a converted car on 100% petro diesel all the time if you want - could be relevant re resale. - I wonder is there any hoping of taking the kit with you to your new model???

3. The problems seem to be a) fuel has higher viscosity - less "runny" - means that if not treated then could clog glow plugs etc, b) may not burn completely if engine not at full temperature or not at "full load" - I'm not quite sure what "full load" means but I expect it means where the car is only ticking over and only a small fuel charge is injected into the combustion chamber, c) fuel storage could be problematic in cold weather, d) various acids may be produced as a by-product - this is why German diesels may be more suitable since this acid issue already arises to some extent due to the fuel mix on sale in Germany, e) there can be possible contamination of the engine lubricant oil.

4. There are some solutions to the above problems but it isnt exactly clear how well they fix the problem. The solutions deal mainly with a) heating the biofuel and adjusting the injector timing - the conversion kits deal with the heating etc, b) operating a 2 tank system where you start on petro diesel, then switch over to PPO once you are heated up, and before you shut down for the night you swap over to petrodiesel to "clean out" the system again, c) add "winter diesel" to your storage tank (which you will almost certainly need) to stop the cold from affecting it, d) using vegetable based engine lubricant oil or just changing the oil more regularly.

5. It seems increased engine wear can be a problem (despite the engine running at lower temperature). The "paper" produced for Shanghai conference (also on Elsbett site) talks about increased engine wear after 10 hours. It isnt clear if recent modifications have overcome this - and unless you are an international trucker I guess you're never going to drive 10 hours straight - & I presume thats against trucker regulations as well.

6. Before going for a conversion it says your car must be in very good nick - & interestingly it says one of the ways in which you car mightnt be in suitable condition is where it has run on biodiesel before ..... (in fairness I presume the conversion kit should/does take away most or all of the negative wear implications).

7. Apart from the 2 tank system mentioned above, you can have a 1 tank system where, I gather, you are 100% PPO all the way. When I checked for my car it was recommending a 2 tank system.

8. The major drawback seems to me to be the requirement in many cases for a 2 tank system, & it recommends 20 miles before switch to biodiesel. So you would want to be doing fairly serious miles every day to make it worthwhile. Maybe this leads us back to the old wisdom that you needed to be doing serious miles anyway to make diesel worthwhile - but diesel now has a slightly more "environmentally friendly" tag and some people just like 'em (like myself).

9.The other drawback, and again its not clear how well this has been solved by the conversion kit is that the PPO car doesnt seem to do too well when not at "full load" - which I take to mean idling or at low rev. Doesnt this rule out a lot of our urbanites ??

10. As an interesting aside the Elsbett engine, which is specifically designed for PPO, doesnt require any coolant system because it runs at lower heat.

So in summary I'm a wee bit deflated that the news is either a bit mixed or just not clear, and that a recommended 2 tank system for my car doesnt seem to make sense for me as not doing the requisite miles. I'm hoping someone will convince me otherwise !!

I'd say its when the major manufacturers start making PPO engines that the revolution will really take off - you can expect most of the above problems to get sorted more satisfactorily. Other things to consider is what "age" of car to convert - presumably you wouldnt modify a new car as more than likely would negate the warrunty, and once modified would you feel you had to run the car into the ground due to your extra investment (though not much) and maybe, more worryingly, re-sale problems.

Also, was told by a VW dealer that VW Ireland particularly dont recommend conversion on diesels newer than '02, due to the complexity of the engine.

Borzoi

It seems to beunlikely that PPO will really take off, much more plausible would be a diesel/bio-diesel mix - possible to run in unmodified or slighlty modified car engines.

Interestingly Zimbabwe used to (may possibly still) use a mix of ethanol and petrol in the pumps for all cars - this was mainly done to reduce hard currency going overseas, but there would be no reason why it couldn't be done here.

Matt Simis

Very first thing in your rundown should be that Biodiesel and SVO Conversions (which your post is mainly about) are different things!

BioDiesel is an ester made from SVO/WVO, which will run in virtually any diesel without conversion.

If the sites you read didnt make that clear straight away, I suggest alternative research sources such as:

http://en.wikipedia.org/wiki/Biodiesel
http://www.biodieselcommunity.org/
http://biodiesel.infopop.cc/groupee/forums/a/cfrm/f/498605551



Matt

Green Driver

Vegetable oil as fuel in a car

Betsy Og says "Also, was told by a VW dealer that VW Ireland particularly dont recommend conversion on diesels newer than '02, due to the complexity of the engine.". That statement should be checked out. I am not sure that it is correct.

I have been using rapeseed oil in a 2004 diesel Skoda Octavia since April 2006 and I am pleased with the performance. I bought the Skoda second hand and I spent about €2,000 euro, including VAT, getting it adapted to run on pure vegetable oil.

I have the one tank system, so that means that I can use rapeseed oil, or diesel, or any mixture of the 2. If I cannot get rapeseed oil, I can put diesel into my car.

Some cars cannot use the one tank system and have to use the 2 tank system, which sounds awkward to me. Apparently, with the 2 tank system, you have to use diesel for the first 10 minutes, and the last 10 minutes, of each journey.

I got the car in February 2006 and used diesel in it for 2 months. After I switched to using rapeseed oil, there was no reduction in performance. The car does about 40 miles to the gallon.

It is recommended that in frosty weather, if you are using the 1 tank system, you should put some diesel into the car from time to time.

The car was adapted by Allen Holman (DAS Garage,Gorey, Co Wexford), http://www.ecocar.ie/, and Peter O'Neill (Kilpedder, Co Wicklow) http://www.ecomotion.ie/.

I buy rapeseed oil fuel for my car from Eilish Oils, http://www.eilishoils.com/
They sell the rapeseed oil in 1,000 litre plastic containers which you can put in your garden and get refilled by them as necessary. I call into a place in Dun Laoighaire owned by one of the directors of Eilish Oils and get my car filled there at 84 cent a litre.

The rapeseed oil sold by them is exempt from excise duty, but they pay VAT on it.

It is physically (but it may be illegal if you do not pay VAT) possible to use rapeseed oil of the right quality bought in a shop as fuel in a diesel car which is able to run on rapeseed oil. I do not know if other vegetable oils, such as sunflower, or olive, oil, could be used as fuel.

Apparently, vegetable oil sold as food is zero rated for VAT, so if you use it as fuel, which is subject to VAT, you might be breaking the law. I am going to make enquiries to see if it is possible to arrange to pay the VAT on oil bought as food and then use it as fuel.


It was estimated early this year that after 30,000 miles using rapeseed oil I would have covered the €2,000 cost of the adaptation of my car. It is not possible to guarantee that figure, but if you subtract the cost of rapeseed oil at 84 cent a litre from whatever you are now paying for diesel, you will find out how many cents per litre you could save and then if you know how many miles a year you do you will be able to calculate how long, assuming 40 miles to the gallon of rapeseed oil, it would take you to cover the €2,000 cost of adaptation.

If you are a good mechanic, you could buy the kit and install it yourself. There is a German company called Elsbett, http://www.elsbett.com/ which has been adapting diesel engines to run on vegetable oil for years. The kit in my car was supplied by them.

If Bush makes a really big mess of the Middle East and there is a war, which I hope does not happen, the cost of petrol and diesel could go up a lot and it might take less than 30,000 miles to cover the €2,000 cost of the adaptation.

But it is also about the planet and preventing global warming. The CO2 which is emitted when I burn rapeseed oil in my car is CO2 which was taken out of the atmosphere when the oilseed rape crop was being grown, ie. just a year or two before I burn the fuel.

Therefore, when I drive my car, I am not making a net addition to the CO2 in the atmosphere.

By contrast, when you burn fossil fuel in your car, the CO2 which is emitted is a net addition to the CO2 in the atmosphere because the fossil fuels have been under the surface of the earth for 100's of 1,000's of years.

p2214716

hi just read your post i am a expereienced diesel mechanic i have an intrest in biofuels i think that the low preasuse diesel engines are the best to convert as far as i can see the trick is to pre heat the fuel best way two tank system heater plugs not problem also they say you need injectors set to higher preasures but with two tank system would this affect when running on diesel? i have 1.9 diesel vw 96 low preasure i want to convert this i dont think i need a factory fit system as you point out it expensive i have a smart way to pre heat the fuel with the cooling system on car has anyone done this before would like to work on this with some one who has an interest in over comming these problems using non factory fit solutions this will make fuel conversion cheaper has any one done a 1.9 before 96 what did it run like any probs ?

wet-paint

Yeesh, experienced mechanic maybe, but not so hot on punctuation or grammar!

p2214716

Do you want to discuss a very interesting subject, or do you want to be a smart ass.Maybe you were the know it all who sat at the back of the class,with their one liners,who never had anything of interest to say.Do you know anything about biofuels,or are you just a waster.

junkyard

p2214716 wrote:

Do you want to discuss a very interesting subject, or do you want to be a smart ass.Maybe you were the know it all who sat at the back of the class,with their one liners,who never had anything of interest to say.Do you know anything about biofuels,or are you just a waster.

Sorry to say it but there are a few smart arses around here, I'm not so sure they're as smart as they would like to think they are in real life. Welcome to boards.ie by the way p2214716. A friend of mine got his Corolla diesel van converted to run on vegetable oil and he's having no luck with it. Its almost impossible to start and when it is going its way down on power. I think you'd need a turbo diesel for any decent amount of power as there seems to be a big fall off in power after conversion. A main dealer friend of mine has also commented on the poor returns on mpg in the bio-fuel Fords too.

p2214716

That is very interesting,a few questions,did he have the injectors changed for ones with a higher breaking preasure.? If the fuel does not atomise in the cylinders you will suffer low mpg.If you are not going to change the injectors you must heat the fuel to at least 90 c or more.This will help with fuel flow problems also.I think a two tank system best,this will help with starting problems.The turbo is a red herring,they say power output should be the same.The best engines to convert are the old vw /merc engines.I will do one,just want to pick someone else brains.Is your mates corrolla two tank,if so,what way does he switch fuels,any air bleed problems.

I unhooked the fuel line on my diesel and stuck it in a bottle of sunflower oil and ran the engine.

It ran fine, no problems no difference really except i noticed that the 1 litre bottle was being emptied very fast. Does this mean that I would get really poor miles per gallon if I used 100% sunflower oil instead of diesel.
Its 79cent per litre in lidl lol!!!

craichoe

Deleted User wrote:

I unhooked the fuel line on my diesel and stuck it in a bottle of sunflower oil and ran the engine.

It ran fine, no problems no difference really except i noticed that the 1 litre bottle was being emptied very fast. Does this mean that I would get really poor miles per gallon if I used 100% sunflower oil instead of diesel.
Its 79cent per litre in lidl lol!!!

You could run on sunflower oil, but you'd have issues starting in cold weather, the Diesel engine was originally designed to run on Peanut Oil. Also, if you do start running on SVO you need to change your fuel filter 2 - 3 times in 4 months as the SVO will wash out the diesel deposits in the engine.

unkel

Old thread alert!