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I’ve read a lot about running Diesel vehicles on plant oil, but one thing that was never clear was why some people claim that you need special chemical additives.

The article about converting vehicles to vegetable oil on the VegieCars.com [1] site explains all this. It seems that if you want to produce fuel which can be used in unmodified vehicles then you need to add a mixture of methanol caustic soda. This is going to be difficult, dangerous, have some expense, and probably not be that good for the environment.

The other option (which they recommend) is to modify the vehicle to accept straight vegetable oil. This means pre-heating the oil before it enters the engine (to lower it’s viscosity and make it vaporise more easily) and to filter the oil to remove solid objects and water.

A possibility is to have two separate fuel tanks so that you can switch between plant oil and petroleum based Diesel fuel. This is an option if driving in a cold climate (probably not an issue in Australia apart from a few mountains) and if you are concerned about the quality of your plant oil (a bad batch could clog the filters and force you to use petroleum based fuel).

They also have an interesting cost-comparison page to show you how much money you might save by using plant oil [2].

Their site is very interesting and has some good technical information, even if you never plan to drive a Diesel vehicle it’s worth reading if you are interested in cars.

17 comments to Vegie Cars

  • Feel free to drive a vegiecar.

    They are pollutants in their own way.
    Nothing pisses off other drivers or your neighbourhood than a car that smells like a vat of fish and chips all that is 6 months old

  • You seem to discount some important facts that make using vegetable oil not a viable option as a car fuel.

    0. Clean burning of vegetable oil in an internal combustion Diesel engine is a myth. Carbon residues are a major problem. Even when you take “vegetable” out of the sentence, it’s still a myth.

    1. Because of the differences between the petroleum (not “petrolium”, unless it’s Aussie-speak) fuels and vegetable oil the exhaust gases are very different. Of course the basic compounds (carbon dioxide and water) are the same, the fuel burning is never 100% efficient. Overheated vegetable oil (ie. fuel that wasn’t cleanly burnt) produces very nasty compounds, come of which cause cancer. It’s like smoking, it just smells differently and has a much larger scale. Or using the same oil for frying 50 times over.

    2a. Modern Diesel engines cannot use even a high percentage vegetable oil mixture (let alone a pure vegetable oil) because of extremely high pressures in the fuel system.

    2b. Older Diesel engine that is not 100% clean (and none is) will have problems with the accumulating waste from burning vegetable oil, which will affect performance and inevitably lead to it’s much faster breakdown.

    3. Vegetable oil is the mainstay of diet in poor countries. Using it as fuel is already leading to the major price increase, which in turn makes the situation of these people even worse and our savings would decrease with time, as the situation progresses.

    The website you cite is also wrong in one point. The injection pump is after the fuel filter, which would clog no matter what kind of vegetable oil you use.

    If I were you I’d stick to the mainstream fuel saving techniques, like eco-driving and/or hybrid drive systems for the time being. If you really have to use a renewable fuel, I’d rather go for a methanol-based fuel for a petrol engine, which doesn’t have any of the above flaws.

  • Using vegetable oil is not a solution, because as farmlands are reallocated for bio-fuel production, food prices rise.

    The cost of rice has increased 80% in the last five years.

  • Martin

    Using “bio” material to drive cars is one of most cynical developments of this decade.

    In Brazil and East Asia the tropical jungle is under massive destruction for new mono-cultures to produce “biofuel”. In Mexico the price of maize corn already rose, because US companies buy a lot of it for their SUVs, so the poor people can no longer afford it. Riots were the result. As a consequence of climate change the areas for cultivation are shrinking and the competition between production of food for the poor versus fuel for the rich is on the rise.

    Stop the “biofuel” lunacy now, because it kills biodiversity and leads to poverty and starvation.

    Want to save the environment? Ride a bike! Use the train! Do not drive a car at all and try to minimise flights and bus rides.

    (I do not own a car and my driving license is proudly collecting dust since twenty years. However, I help to destroy the ozon layer because of a European-Southamerican love affair. Lo siento, pengüinos.)

  • etbe

    Matt: Fish and chips smell a lot better than your average car exhaust.

    Marcin: 0: do you have a reference?
    1: Can you burn anything other than hydrogen with 100% efficiency? All car exhaust with current engines is carcinogenic anyway.
    2A: Why do high pressures preclude the use of vegetable oil?
    2B: Do you have a reference for this? I’ve seen documentaries from the 90’s of people running Diesel cars on vegetable oil.
    3: Oil is not the mainstay of diet in any country. Vegetable oil that has been used for frying chips is currently buried in landfill, it’s better to use it to run cars.

    The use of alcohol based fuels causes the problem you cite in #3. The production of alcohol from corn in the Americas has significantly increased the food prices in South America.

    Simon: The web site I cited is advocating using oil that is currently going to waste, so no reallocation of land is being done. There are a number of techniques being developed for producing bio-fuels from land that is not suitable for growing food crops.

    Also note that if the government subsidies on meat production in first-world countries were lifted then the amount of meat consumption would decrease dramatically. Using land for growing vegetable crops instead of beef is much more efficient.

    Martin: As a first step they need to stop driving SUVs in the US. SUVs are not safe vehicles, the government needs to raise the bar for passenger vehicle safety and force the SUVs out of the suburbs. You are correct about public transport, however it’s not an option for everyone to use all the time in most first-world countries.

  • Hi Russell or etbe – those kittens sound cute – hope they find a good home.

    Anyway, about the veggie cars (we spell it with two “g”s in the US – at least I do!) – I think its a great idea in low volume and for many people who enjoy working on cars and treating the planet nicely. I’ve heard more people say that the cars smell like french fries (aka freedom fries for you hawks out there) than fish. I like the idea because 1) its not too hard to convert a diesel car to run on used veggie oil, and 2) small amounts of veggie oil is discarded for a fee all across the US by fast food restaurants.

    For massive energy consumption needs, however, the model doesn’t scale, and you’d need more supply, and when it comes to eating versus driving, I think most people would rather eat. Therefore I feel that electricity is the only way for future transportation!

  • etbe

    Albert: I’d probably spell it with two g’s if I wasn’t quoting a domain name. ;) But as it’s not a recognised word it doesn’t matter much.

    http://etbe.coker.com.au/2007/03/15/worse-than-fossil-fuel/

    I agree that it will only solve a small part of the problem. At the above URL I did some hand-waving calculations about how far vegie fuel could stretch if combined with other fuel saving measures.

    Electricity is part of the solution for driving, but current technology allows 100Kg of batteries to drive a Prius for 10 to 20 minutes. A plug-in hybrid with significantly more batteries than the current Prius type vehicles and a tank of Ethanol or vegetable oil is a good option. I think that plug-in hybrids have the potential to reduce fuel use by 95% or better.

    Having all car fuel be from vegetable oil and electricity seems quite possible.

  • etbe

    http://www.neocarz.com/blog/2008/04/11/veggie-cars/

    Albert blogged about my ideas at the above URL.

  • @etbe:
    > 0: do you have a reference?

    Ask any automotive engine engineer, if the word of one is not good enough for you.

    > 1: Can you burn anything other than hydrogen with
    > 100% efficiency? All car exhaust with current
    > engines is carcinogenic anyway.

    Yes you can’t do that. However the worse thing in an engine is burning motor oil (the lubricant), which you can’t avoid by using vegetable oil as a fuel. The petroleum based fuels burn far more cleanly than vegetable oil because their physical parameters are better. It burns better because the particles are much simpler, being almost exclusively single carbohydrate chains.

    > 2A: Why do high pressures preclude the use of vegetable oil?

    Because of the nature of the fuel (poligeneous mixture of triglicerydes) it is prone to fractioning at extreme pressures that are common in latest common rail injection systems. We’re talking about pressures as high as 200 MPa (which is 2000x more than average air pressure for those suffering from imperial system). It’s more than enough to turn vegetable oil into peanut butter. Two times over.

    > 2B: Do you have a reference for this? I’ve seen
    > documentaries from the 90’s of people running
    > Diesel cars on vegetable oil.

    A Diesel-powered engines are capable of covering hundreds of thousands of miles with proper maintenance. Any Diesel engine (apart from the high pressure designs) is capable of running on vegetable oil “as is”. It doesn’t mean however that their MTBF wouldn’t drop by an order of magnitude. And it will. If you’re planning carefully and you’re lucky to have an Diesel engine *without* direct injection (which is both old and inefficient) the reliability will also go down, but not that drastically.

    > 3: Oil is not the mainstay of diet in any country.
    > Vegetable oil that has been used for frying chips is
    > currently buried in landfill, it’s better to use it
    > to run cars.

    In poor countries, where people don’t have money too eat meat or means of its production (it’s inefficient as you note) the vegetable oil is the second most important food compound, just after grain (be it rice, bean, soya or whatever). It’s also the main source of fat in the diet. In Poland until the 18th century using vegetable oil by the poor peasantry that couldn’t afford meat was a symbol of relative wealth. That’s how it is in modern poor counties.

    Using used frying oil “as is” is simply impossible because of the amount of waste it contains. Have you seen the residue in restaurant appliances? Used oil also contains the dangerous substances from overheating. If it was not for the two reasons, the cooking oil wouldn’t have to be changed at all.

    > The use of alcohol based fuels causes the problem
    > you cite in #3. The production of alcohol from corn
    > in the Americas has significantly increased the
    > food prices in South America.

    Well, I’ve heard about the problem, but I wouldn’t let the Americans run my business. In Europe, we’re far more ingenious. Mind that you can only make oil from oil crops. Methanol can be made from anything that rots: spoiled food, trash, wood chops, some organic industrial waste…

    I’ll add one more point:

    4. There is not one standard test I heard about which can be used to ascertain the quality of the fuel. This is especially important for sulfur, which is no longer a problem with petroleum-based fuels, and a mayor show stopper for vegetable oil in fuel. Just like with fossil fuels, bad quality fuel leads to more frequent malfunctions and unknown (potentially dangerous) compound of exhaust gases. The main reasons for the lack of standards are that engineers have no previous experience with using vegetable oil as an engine fuel and the nature of oil production process is far more unpredictable then with petroleum.

  • There is an Australian biofuel users group here including a pretty well used forum: http://www.biofuel.org.au/

    Plenty of real world experience with both older and newer high performance diesel engines.

    Although there may not be standards for straight/waste vegetable oil there are for biodiesel. You can buy standards approved biodiesel (http://www.environment.gov.au/atmosphere/fuelquality/standards/biodiesel/index.html and EN 14214 for Europe) from the pump either in some mix with regular diesel or up to 100% (B100). Gull in Perth sell B20, other suppliers will provide B100 but not off the pump (in Perth). Strangely despite diesels in Europe running fine the Australian branches of the same car companies pretty much go all out to say it’s bad, will destroy your engine, and void your warranty. Sure.

    There are people on the forum above with hundreds of thousands of kms on older vehicles (SVO/Biodiesel) and others with tens of thousands of kms on newer (Biodiesel). If there are problems they are usually around 2 areas:

    1. older pipes and fittings that the bio-diesel will damage over time – easily replaced with stuff that’s not affected.

    2. existing diesel car that was converted. Since the biodiesel acts as a solvent it often removes sediment stuck in the fuel tank that then passes through the fuel system. With caution (extra filters, checking filters) this can be avoided. Or just start with straight biodiesel in the first place.

    The production of Biodiesel uses the methanol/ethanol in the reaction and NaOH/KOH as a catalyst and to also neutralize the free fatty acids (by-product of re-using cooking oil). The output is biodiesel, glycerol, methanol/ethanol, and some other misc things like soaps if the oil wasn’t fully de-hydrated. The NaOH/KOH should be used completely if the amount was calculated correctly via titration of the raw oil in the first place. Usually the biodiesel is washed to remove any remaining contaminants (soap/alcohol) and let to sit and separate. You’ll get a layer of biodiesel and then glycerin/alcohol mix. You can reclaim the alcohol or just let it evaporate off. The glycerin can be used to make soap, in the garden (positive and negative depending on dose), and in animal feed – or disposed of. Biodiesel isn’t really any more toxic than the original oil. You could drink a litre and probably feel sick – drink a litre of normal diesel and you’d probably die.

    Burning biodiesel results in reduced CO2 than diesel but higher NOx emissions. Ideally the car manufactures could adjust the exhaust catalytic converters to do a better job of catching these.

    In Australia as Russell mentioned, we have a big excess in oil use that ends up in landfill. IMO better to use this than waste it. Other countries have their own issues and obviously if biodiesel takes off then we’d outstrip the waste raw material.

    The funny thing is that ultra low sulfur diesel (ULSD) is either diesel with synthetic lubricants or diesel with about a 2% biodiesel mix (at about 2% you’re getting most of the lubricity improvements of straight biodiesel already).

    Asking an Australian automotive engineer or mechanic about biodiesel is often a waste of time because frankly they haven’t got any experience and just spurt out the same crap as the standard policy of their company (i.e. it kills engines).

  • etbe

    Marcin: I’ll trust you on the Polish history. But as for the other issues I would like to see references or explanations. Over the years I have debunked many claims made by people who have qualifications related to computer science, and a few days ago I had a world-renowned expert make some false insinuations related to my work. So I am not prepared to just accept any claims made by someone who has some qualifications unless there is a logical explanation and/or a reference to a reliable source of information.

    Waste oil would have to be filtered of course.

    As for point 4, surely the vegiecars.com.au people will help with that.

  • @Jason Nicholls:
    Well, it does kill engines after all. However it’s only partially true. Nothing is black or white.
    Biodiesel and VO are two different things. Biodiesel is made *partially* from VO cracked to simulate Diesel fuel. It’s an addition to Diesel fuel and it can be (and is) tested just like it. In Europe (most common in Germany) the so called biodiesel sold now is B5. AFAIK none of the major manufacturers allow more than B20 in an unmodified engine. Even with that it’s not exactly the same. Just as you write, it’s a complex, tedious and expensive to make.

    > There are people on the forum above with hundreds of thousands
    > of kms on older vehicles (SVO/Biodiesel) and others with tens of
    > thousands of kms on newer (Biodiesel).

    It’s still more then an order of magnitude of difference in comparison to a regular fuel.
    B5 biodiesel can be used for any Diesel engine on the planet, B20 for most of them. B100 requires some simple modifications (some engine parts need to be changed). SVO requires heavy modifications, but is a decent fuel for big indirect injection Diesel engines in buses or older trucks. WVO is a toxic industrial waste. I wouldn’t use it in an engine even if got a car and the oil for free for the sake of environment and pity for the engine. Of course recycling it for fuel is doable, but it’s neither simple nor cheap.

    The “drinking proof” is simply stupid. You can drink a litre of pure methanol (if you’re used to it) and live, while ethanol would surely kill you. Both are made in a similar process from same base materials and a stock petrol engine would burn either.

    > Burning biodiesel results in reduced CO2 than diesel but higher
    > NOx emissions. Ideally the car manufactures could adjust the
    > exhaust catalytic converters to do a better job of catching these.

    I’m not sure about the CO2. I guess it’s comparable, within a few percent of each other. The net emission is neutral (renewable fuel), so from that perspective it’s better. The catalytic conversion of NOx is very inefficient, that’s why newer engines are designed to avoid it’s creation altogether for the most commonly used fuel, regular Diesel fuel. It’s one of the reasons not to use excessive amounts of biocomponents in Diesel fuel.

    @etbe:
    I feel that I included enough commonly known facts to ground my points. The difference is that I neither question your knowledge as an IT person, nor see you referencing anything to counter my point. From an engineer’s point of view the websites you cited is green propaganda lacking insight and failing to see the broader aspect I tried to point out.

    > Waste oil would have to be filtered of course.

    You can’t “filter” particles. They would have to be removed by a chemical process. It’s a noble thing to reuse waste. Just don’t assume that it’s either cheap or simple to make it work on a massive scale just because it’s readily available.

    > As for point 4, surely the vegiecars.com.au people will help with that.

    (I mean VO of course.) There is no international or national norm (except for case studies in some smaller countries) on that. No EU country worked it out yet. It’s all pretty much experimental. I’m sure guys from VegieCars are the forefront of technology then…

  • […] Comments Marcin Trybus on Vegie Carsetbe on Vegie CarsJason Nicholls on Vegie CarsMarcin Trybus on Vegie Carsetbe on Vegie Carsetbe on […]

  • > The “drinking proof” is simply stupid. You can drink a litre of
    > pure methanol (if you’re used to it) and live, while ethanol would
    > surely kill you. Both are made in a similar process from same
    > base materials and a stock petrol engine would burn either.

    Sorry for the self-quote, but I messed up bad. Methanol is *deadly*, while ethanol is safe. Sorry. :-] I sure hope nobody tried…

  • Michael Gunter

    I’ve been running an old Mazda Capella 2.0D “grey import” on 100% biodiesel since 2001. I went into the workshop, camera in hand, when the injectors were inspected and cleaned. The diesel mechanic said that some gumming was possibly an oxidized oil residue, related to biodiesel, but that the pitting seen on the tips of the pintles was normal wear seen with all diesel fuel types, over time.

    I wrote up the story, got it published in Renew magazine. The reconditioned pintles are OK, but in a few years time I think I’ll invest in a new set of pintles, for better power, and a tad less smoke under heavy acceleration.

    Yes, following motorist do get a bit of a foody smell, but according to University of Hawaii tests several years ago, biodiesel has 90% less carcinogenicity than fossil diesel, as the emissions of PAHs (polycyclic aromatic hydrocarbons) are 90% less

    The CO2 emissions are very similar to burning fossil diesel, but since biodiesel is made from 85% “seasonal” plant carbon, vs. only 15% fossil carbon, biodiesel has about an 85% reduction of fossil carbon per km traveled, compared to normal diesel fuel.

    When every landowner in Melbourne chops down all their ornamental plants, grows their own food at a commercial rate of production per square metre on 100% grey water, and becomes a vegetarian, then they can come to me and complain about my WVO depriving the poor of food. If the rich grow their own food on any land that they own, then prices for everyone will fall. Global food prices are rising because the status quo needs huge energy inputs. Peak Oil will soon lead to massive global food shortages, at which point governments can start telling the food producers “how the world works”, instead of the other way around. “The status quo is inevitable” ?? Pigs arse!! (to quote John Elliott)

  • > The CO2 emissions are very similar to burning fossil
    > diesel, but since biodiesel is made from 85% “seasonal”
    > plant carbon, vs. only 15% fossil carbon, biodiesel has
    > about an 85% reduction of fossil carbon per km traveled,
    > compared to normal diesel fuel.

    Let me get one thing straight. Reducing “fossil CO2” does *no* good. Really, it’s just setting back the moment when fossil fuels are gone for good (by a few seconds in your case). This is a road to nowhere and since it cannot be applied en masse it is also pretty much useless. You would be much more eco-friendly if you’d buy a car with a modern turbocharged Diesel (or even better a turbocharched petrol engine) and run it exclusively on fossil fuel. Your overall CO2 footprint would be much lower.

    Wake up people. There’s no such thing as “good CO2”. Fossil or not, any CO2 contributes to global warming. Using foodstuff for fuel does bad in two ways. First, since we’re one the world’s fat end we forget it’s best spent otherwise. Second, when you grow this bio components for fuel what do you think the machinery used to make it runs on? The only way out is using non-carbon fuels, or electric power.