[FlatOut]

Here in Britain road fuel costs £1.40 a litre. I think that equates to about 115Rp - and it more than anyone would choose to pay.

I was always aware of the possibility of running some diesel engines on vegetable oil with minimal alteration so a few years ago, out of curiosity, I put the theory into practice. A customer who ran a restaurant had offered me his waste cooking oil - I didn't know what to do with it but stored it and began to read up a little.

The German company Elsbett came up time and again, so did the fact that certain engines would run unaltered on good quality oil without causing damage, providing they had good compression, good injectors and the timing was not retarded.

To cut a long story short, I have now been running on virtually free fuel for some while. I thought at first it would be guaranteed to do some damage eventually - well, this has not happened. The rapeseed oil is completely dry and filtered to 0.5 microns. Since the British climate can hardly be described as warm, a fuel heater in the form of a flat plate heat exchanger (connected to the heater circuit) thins the cold fuel once underway.

My Mercedes W124 series cars with the OM60* engines are the most tolerant of fuel viscosity owing to their inline injector pumps which use small pistons to pump the fuel at pressure to the injectors. They are indirect injection and so ideal for running on veg, plus there is no cambelt to cause problems, the ip is lubricated by sump oil and the engines will easily pass the 500,000km mark if correctly serviced.

Direct injection diesels are usually common rail injection and so quite unsuited to vegetable oil due to the intolerance of different fuel viscosities. There is also the risk of the direct injection resulting in unburnt veg fuel trickling down the pistion sides and gumming up rings and contaminating sump oil - which eventually leads to the solidification of the lube, and the end of your engine.

However the VW/Audi/Skoda 4 cylinder diesel cars with the Bosch VP37-type injector pump are direct injection yet also veg tolerant because of their bowl-in-piston engine design - providing they are not allowed to idle for too long and never sat ticking over for more than a few seconds from cold. They are extremely fuel efficient - my father's Skoda Octavia estate (110hp 1.9TDi) manages more than 20km/l on a run and runs very well on veg oil. The VW Pump Duse injection system is not suitable for veg oil. In the UK, Skodas made up to 2005 used the robust and simple system which has powered VW-group cars from 1989. VW and Audi stopped using this on most models by 2000.

Peugeot-Citroen diesels with indirect injection and a Bosch pump are extremely refined, economical units and love veg oil - for many these are the best car diesel engines ever made and the fact they run on veg oil makes them even better. Being indirect injection they are happy sitting in traffic jams all day without risking sump-contamination with unburnt veg fuel.

I have run all these engines for many miles using 90-95% veg oil fuel, with fuel heated by the coolant to thin it. In sub-zero conditions a little petrol (up to 5%, depending on engine) is added to thin the fuel, otherwise just 5-10% diesel which improves efficiency. The indirect injection units are capable of running 100% veg if necessary. Kerosene/paraffin is the ideal blending fuel, but this is illegal as road fuel in Europe.

I have started and run from cold at -18C on 90% veg oil without issue, which is a most demanding test. Injectors must be operating correctly, compression must be normal and the timing must not be retarded - and it is wise to change the sump oil every 5,000 km. Performance is as good as on pump diesel, although different. Flexibility is improved with low-down pulling power much improved due to the slower burning properties of veg oil compared with modern diesel fuel. The exhaust smells of cooking, emissions are about half those on diesel.

To dry and clean the waste oil I have a few oil barrels, piping, a pump, some 10 inch filter units and an immersion heater in one barrel. There are no chemicals or waste involved (other than draining a few drops of water from the bottom of the barrels every now and then), unlike in the production of biodiesel and I use gravity as the main filter.

Rapeseed oil is very good, with a very low gel point, relatively low viscosity and high cetane level. GM soya oil is less good, although many use it. I tend to avoid anything GM if I can. I know Jatropha oil is in abundance in India and although it clouds/starts to solidify around 2C, it has a higher cetane level than most veg oils, in fact it is as high as UK pump diesel - so much better than US pump diesel, for example.

There is nothing new in running oil-burning engines on plant oil instead of mineral oil. Rudolf Diesel envisaged this when he designed the engine and exhibited it running at the Paris Show in 1900 on peanut oil. In fact, mineral oil diesel is quite dirty and needs many complex additives to make it burn reasonably well and prevent it from fouling up the combustion chambers. In contrast, plant oils are cleaning agents themselves, 100% pure and non-toxic. Try spilling a little veg oil on a dirty carpet - rub it in and you will soon see a clean patch.

Providing you don't have a worn or out-of-adjustment engine and use clean, dry oil, there should be little problem if the injector system is suitable. Lucas/CAV pumps need to start (and so stop) on diesel since they are intolerant of cold veg oil - a second fuel tank is needed with changeover valves. At first I was very apprehensive and could hardly believe it when the engine thrived on the alternative fuel, but several tens of thousands of miles down the road I am loathed to ever fill up with diesel. It is dirty stuff, very expensive and you are at the end of a long supply chain. I now have my own fuel supply and if you are ever unfortunate to run out of fuel when on a journey, there are few households which don't have a bottle of cooking oil on the kitchen shelf.

The biggest single obstacle, once you have a suitable car, is low ambient temperatures. But there are tens of thousands of people running on veg oil in Europe, many in Scandinavia and the North of Britain where temperatures remain below zero for weeks on end.

Please feel free to ask any questions - it is not a difficult thing to organise. Just be aware that most cars made after 2000 are not suitable - they have problems even running on diesel!

[eq24]

Great post flat out. I remember in my time in cardiff most of the Chippy owners used to give their used oil to people who would later use it as fuel. In fact a close friend of mine an Irani genius used to use cooking oil in his Passat.

You are right about this only working in old cars as I had never heard this working in cars after 2005. I wonder if this would work in India but as diesel fuel is cheaper than cooking fuel and most restaurants over here do sell of their waste fuel for other uses, finding a perpetual source would be difficult.

Still if you could some more technical information and pictures would help immensely. I dare say a lot in India will try this but for those few tinkerers and experimenters it should be a good starting point.

[GTO]

Great thread, very informative post. Here's two related discussions:

Amby on vegetable oil

Locomotives

[alpha1]

In India, the price of vegetable oil is considerably more than the price of diesel ...
But nonetheless this is an excellent topic ...

Didn't Rudolf Diesel keep vegetable oil in his mind while designing the diesel engine?

(woops, you've already mentioned about peanut oil used by Diesel to demo his engine)


What about the slow oxidation effects of vegetable oil (which causes rancidity), also the gumming up in the fuel pump lines?
I think these would be more prevalent in a warm climate like India.

[FlatOut]

Originally Posted by alpha1

In India, the price of vegetable oil is considerably more than the price of diesel ...
But nonetheless this is an excellent topic ...

Didn't Rudolf Diesel keep vegetable oil in his mind while designing the diesel engine?

(woops, you've already mentioned about peanut oil used by Diesel to demo his engine)


What about the slow oxidation effects of vegetable oil (which causes rancidity), also the gumming up in the fuel pump lines?
I think these would be more prevalent in a warm climate like India.

Are you talking about the price of new oil or used? New oil starts from £1 a litre in Britain. Waste oil used to be all free, now perhaps it is 10 or 20p a litre from the back of the restaurant.

It is important to use oils which are least likely to 'dry' or polymerise under oxidation - for example rapeseed is in the middle, linseed oil at the

Drying results from the double bonds (sometimes triple) in the unsaturated oil molecules being broken by oxygen and converted to peroxides. Linseed oil is at one end of this scale, coconut oil at the other, with rapeseed in the middle. Coconut oil is the least prone to drying, linseed the most.

Rapeseed suits me with our temperate maritime climate, in a warmer climate cocunut oil, if available cheaply as a waste oil, could make more sense.

If you minimise the oil's contact with air, then there isn't a problem. Once in the fuel lines, there is no air. The problems with 'gumming up' of lines and filters is usually down to the cleaning properties of veg oil - it can dislodge years of filthy mineral oil diesel deposits. That's why carrying a spare fuel filter with you is a good idea.

The only real danger is if the engine isn't burning the fuel completely, for example with a worn injector or low compression. Then unburnt fuel becomes a hazard for the piston rings. Use clean, dry oil which has a drop of diesel added and in an engine which is suitable and in good health, there will be no looking back!

Top tip - the better the quality of the food establishment, the better the waste oil quality. It needs to be clean looking and opaque ideally, and as free as possible from fats which are solid or semi-solid at ambient temperatures. An emulsion with water can be cleared, but it makes for more work. The top 80-90% of good waste oil should resemble new oil, just a little darker. The darker it is in comparison to new, the more it has been used and the less suitable for use in your car.

I will take one or two pictures and post them soon. There's nothing much to see under the bonnets, though - it's all standard other than a heat exchanger for the fuel. This simplicity of operation is the key!

[Viraat13]

Originally Posted by FlatOut

Top tip - the better the quality of the food establishment, the better the waste oil quality. It needs to be clean looking and opaque ideally, and as free as possible from fats which are solid or semi-solid at ambient temperatures. An emulsion with water can be cleared, but it makes for more work. The top 80-90% of good waste oil should resemble new oil, just a little darker. The darker it is in comparison to new, the more it has been used and the less suitable for use in your car.

Sorry, that will prove to be a major stumbling point here in India. First thing, I doubt if restaurants ever change their oil. They probably just top it up. And if they DO change their oil, it looks like tar by the end of it.

Stroll by any shop selling fried goods like samosas or bhaturas and make it a point to look at how black the oil is. It's revolting, most of the times.

Good effort though, FlatOut. It'll be useful the day diesel isn't subsidised in India.
You mentioned having a W124.. I hope to see you in those threads.

[S5157]

What is the impact on emissions if we use vegetable oil?

[FlatOut]

Admin, please delete my second para. A friend arrived half-way through an edit and I missed the 30min limit!

[msaudf]

Does Coconut oil also have the same properties as vegetable oil?
The reason to the question is that I was once told by a bosch pump mechanic that coconut oil had abrasive properties and was sometimes used in injectors to get them to settle faster.
cheers
Saud

[FlatOut]

Originally Posted by S5157

What is the impact on emissions if we use vegetable oil?

At the UK annual safety test which measures tailpipe emissions and they are always lower when running on veg oil, usually 30-50% less. Additionally there are no unpleasant chemical additive packages as there are with diesel.

One such additive is silicone, which improves flow and combustion but there are very sharp nano-particles as a result in the exhaust emissions. Asthma and other respiratory diseases have been closely linked to diesel exhaust fumes. There is a chemical cocktail of toxins coming from any diesel car exhaust using European and American diesel (and probably most other diesel fuels around the world) which is hugely reduced or eliminated when running on veg oil. Just because there isn't black smoke like there used to be with older diesels doesn't mean the exhaust gases are any safer.

Additionally, veg oil from the catering industry is a waste product and has already served its original purpose. Also it is a renewable energy, although a lot of fossil fuel may be used in growing and processing the oil.

http://en.wikipedia.org/wiki/List_of_gasoline_additives (no specific list for diesel additives but this mentions them)
http://chemeng-processing.blogspot.c...-packages.html
http://drmyhill.co.uk/wiki/Chemical_..._and_treatment

Originally Posted by msaudf

Does Coconut oil also have the same properties as vegetable oil?
The reason to the question is that I was once told by a bosch pump mechanic that coconut oil had abrasive properties and was sometimes used in injectors to get them to settle faster.
cheers
Saud

Since I have never investigated using coconut oil I don't know the answer, but if it was filtered to 0.5 microns as I filter my oil, I cannot see how it could be so abrasive. But the Bosch pump mechanic would know what he was talking about, I presume it was the raw product?

Originally Posted by Viraat13

Sorry, that will prove to be a major stumbling point here in India. First thing, I doubt if restaurants ever change their oil. They probably just top it up. And if they DO change their oil, it looks like tar by the end of it.

Stroll by any shop selling fried goods like samosas or bhaturas and make it a point to look at how black the oil is. It's revolting, most of the times.

Good effort though, FlatOut. It'll be useful the day diesel isn't subsidised in India.
You mentioned having a W124.. I hope to see you in those threads.

Are there any restaurants or hotel kitchens which replace their fryer oil, I wonder? It may be worth investigating.

[alpha1]

Originally Posted by msaudf

Does Coconut oil also have the same properties as vegetable oil?
The reason to the question is that I was once told by a bosch pump mechanic that coconut oil had abrasive properties and was sometimes used in injectors to get them to settle faster.
cheers
Saud

How can oil be an abrasive unless there are solid particles suspended in it?

Originally Posted by FlatOut

Are there any restaurants or hotel kitchens which replace their fryer oil, I wonder? It may be worth investigating.

Perhaps KFC and McD in India.

Originally Posted by FlatOut

Since I have never investigated using coconut oil I don't know the answer, but if it was filtered to 0.5 microns as I filter my oil, I cannot see how it could be so abrasive. But the Bosch pump mechanic would know what he was talking about, I presume it was the raw product?

In India it's not the passion/interest + abilities which determines the profession.
Hence, I would not assume the Bosch mechanic to be a real authority in his own subject.

[FlatOut]

Originally Posted by alpha1

Perhaps KFC and McD in India.

Oh no, you have these awful places as well do you? I steer well clear, I value my health!

Originally Posted by msaudf

Does Coconut oil also have the same properties as vegetable oil?
The reason to the question is that I was once told by a bosch pump mechanic that coconut oil had abrasive properties and was sometimes used in injectors to get them to settle faster.
cheers
Saud

Possibly he was using the higher viscosity of coconut to create a situation where there was less lubricity for the injector, hence it would bed in more quickly? It is important to make sure that the veg oil fuel (and yes, coconut oil is veg or plant oil, as opposed to mineral oil) has good flow properties a and isn't too 'gloopy'.

This is usually achieved by heating it to thin it, as well as adding a drop of petrol (when sub-zero), some kerosene (ideal, but illegal in many countries as road fuel) or diesel.

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[Viraat13]

Originally Posted by FlatOut

Are there any restaurants or hotel kitchens which replace their fryer oil, I wonder? It may be worth investigating.

Apart from international chains, and top class restaurants, I doubt many do. And on top of that there is the added issue of procuring the used oil from these places. In the future, when diesel is priced at par in India, maybe some folk might try and give it a shot. Heck, maybe a few of these firms might indulge in some very clever PR later (highly unlikely though).

Do any chip shops and the likes advertise their used oil to generate awareness of their environment friendliness or something?

Originally Posted by FlatOut

Oh no, you have these awful places as well do you? I steer well clear, I value my health!

Hehehe. Considering the many different kinds of deep fried things you can eat here in Delhi (and the rest of India), KFC and McD's could even be called the healthier option.

[hrman]

Interesting thread. I was just thinking about how the viscosity of vegetable oil and can it fuel a diesel vehicle and here was your thread.

I was watching a feature on Discovery/ NGC where they were taking about American battle Tanks.
It seems they have designed Tanks which can run on Petrol, Diesel or Vegetable oils, since in war conditions, one type of fuel may be in short supply.
And the mileage? 5 Litres/ KM. Yes, Litres per km as against KM per litre.

[sparsh]

I believe this was already experimented and proven successful by garage called ChopShop. they were able to achieve this by running a car on vegetable oil by tweaking the filters and the engine pistons. I dont know if we can run it using used veg oil which we dump in the garbage. If yes, we can reuse the oil and make it more economical. Using this in the current generation crdi engines could be tough.