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Biodiesel or SVO?

12 January 2005

Although biodiesel is drawing increasing attention from automakers, policymakers and farmers, there is another biofuel that can be used in diesel engines: straight vegetable oil, or SVO.

The two approaches, although apparently similar, are operationally and philosophically quite different. Broadly stated, you can either modify (refine) plant oil to create biodiesel to run in an unmodified diesel engine, or you can modify an engine system to allow it to use unaltered vegetable oil.

Journey to Forever, a terrific resource on multiple aspects of sustainability, puts it this way:

Does the SVO option work? Yes—IF you go about it the right way. It’s not quite that simple a choice. For one thing, if you want to use waste vegetable oil, which is often free, you’re going to have to process it anyway, though less so than to make biodiesel. And it still might not be a very good fuel.

The main problem is that vegetable oil is much more viscous (thicker) than conventional diesel fuel. It must be heated (thinned) so that it can be properly atomised by the fuel injectors. If it’s not properly atomised, it won’t burn properly, forming deposits on the injectors and in the cylinder head, leading to poor performance, higher emissions, and reduced engine life.

Nonetheless, experience is showing that SVO systems are a practical proposition with a lot of advantages to offer, not least of all that using SVO can be cheaper than turning it into biodiesel and uses less energy than making biodiesel does.

But you have to be willing to take on the modifications. For those inclined to a D-I-Y project, there are a number of resources and kits available.

I will start including SVO on the site, including product news and lifecycle and emissions studies.

A few SVO links and online resources

January 12, 2005 in Biodiesel, D-I-Y, SVO | Permalink | Comments (29) | TrackBack (2)


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Green Car Congress is on top of it again: Green Car Congress: Biodiesel or SVO? Good analysis comparing BioDiesel to Straight Vegitable Oil. I still like Biodiesel. Less potential problems with clogging and no heating required, use it straight in... [Read More]

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To see a WVO conversion being installed, and to learn how to do one yourself, see

WVO = Waste Vegetable Oil

SVO = Straight Vegetable Oil

Just FYI, SVO/WVO have different implications as far as emissions when compared to biodiesel. For example, the combustion in a vehicle running SVO/WVO releases acrolein, a known carcinogen, but this is absent from biodiesel as a result of the chemical differences.

This is just one example, but people thinking about WVO/SVO instead of biodiesel should do their research if the motivation is environmentalism...

We are the leading promoter of jatropha in India for biodiesel production.
Can we use jatropha oil directly without going for transesterification process?
Sir, since we are promoting farming for the biofuel , if SVO OF JATROPHA CAN BE DIRECTLY USED FOR RURAL MACHINARIES it would be a great help in success of our project as economic viability would be enhanced.
kindly explain the process of utilisation of SVO or modification in vehicles required
centre for jatropha promotion

we r doing our project on biodiesel(direct blending)can u help to our project.
Thanking you.


can you point me to some more info on this acrolein thing. I'm looking at what levels are produced and at what levels is it really toxic. Their are many things that in high levels can cause cancer but in small amounts do not, so knowing these points is fairly important.

i am engg. student , trying to use jatropha as a fuel in automotive cars directly without Transesterification process . I am having difficulties in doing this. Can you help me.

Can one safely blend used vegetable oil with commercially available diesel fuel with no negative effects and up to what proportions. I have in mind 30% veg oil to 70% commercial diesel. This in a normally aspirated diesel engine? This vehicle runs in subtropical areas where no temperatures below zero are encountered.

The acrolein issue was a red herring. It was discovered burning wvo on a bunsen burner in a lab by folks who have never touched a diesel engine. WVO emissions are very similar to biodiesel emissions. No, you cannot mix vegetable oil with diesel without heat in most engines and environments. Damage to the injector pump and injectors usually follows. If you want to run wvo, do it right with two tanks and heated oil.


can u tell me what is transesterification? can u tell hou to convert jatropa oil to bio diesel in detail.

thanking you sir,


i am an engineering student want to do a project on the perfrmance of jatropa bio diesel. could u please explain about esterification of jatropa oil

thanking u sir


You can find all the information about biodiesel and WVO in the journeytoforever link up there. Dig thru that site and read it carefully. Dont be lazy to do research study is not always the case of copy n paste :)

Can anyone one give me a link and/or info comparing emissions outputs of a properly implemented SVO system compared to that of a modern diesel engine?

i am engg. student,working on Jatropa as a Bio-Diesel to find out the performance of I.C.Engine. How should i carry the test & on which point i should be
thanking u

What are the modifications required in an IC engine if we use jatropha bio-diesel as the fuel.Incase if optimum modifications be made will that be efficient?
kindly clarify me at the earliest.

sir i am intersting to make biodiesel. i want some help to making biodiesel. how can use SVO to make biodiesel. thankyou.

Recently I was turned onto the idea of WVO/SVO over BD... And this ELSBETT single tank seems the least complicated and most assured of the fuel heating options. However, since it is assured for SVO only, the question becomes, where can i get SVO? Do i need to go to a public-access 'warehouse' store to find cheap SVO? [costco, smart'n'final, walmart =( ]

i am mba student.i would like to start up business in biodiesel.kindly guide me to proceed further.i am in kerala.
expecting favourable reply.


Kay, I don't think anyone who has converted diesel engines here in North America or in the U.K. knows what jatropha is. Nor how one would go about making biodiesel from it, or convert an engine to run on SJO (straight jatropha oil) . All I can think of is to follow the links at the top of the page. These will lead you to the conversions necessary for biodiesel from vegetable oil and for running SVO. Try the same processes using this jatropha stuff instead of vegetable oil and see how it works!

I have the same question as Alex about the SVO conversions. I just got my Mercedes & am leaning toward making biodiesel of WVO since you're not supposed to put WVO in the converted cars. And then I wouldn't have to worry about all that heating & injector angles & filters & stuff. Diesels are strange to me as it is. I just learned what glow plugs are! So, am I understanding correctly that if you want to use WVO, making biodiesel would be a better choice?

am an engg student intrested in doing projet on jatropa oil as a fuel on the performance of ic please provide information on this.

i m doing project on bio diesel using jatropha as fuel, so it would be very kind of you if you tell us whether we can use it directly or not.

I am building a web site that will advertise who is selling biodiesel, I will not be associated with I repeat not associating this website with biodiesel org.

If you want free advertising call me 954 458 5220

Space is limited

I intend to make this the #1 website for biodiesel info and retailers in the US.


I am not a manufacturer or producer, I am an advertiser!!!

PASS THE WORD!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I am building a web site that will advertise who is selling biodiesel, I will not be associated with I repeat not associating this website with biodiesel org.

If you want free advertising call me 954 458 5220

Space is limited

I intend to make this the #1 website for biodiesel info and retailers in the US.


I am not a manufacturer or producer, I am an advertiser!!!

PASS THE WORD!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


I am doing project on producing SVO from jatropha. I get difficulity while trying to modify our SVO product. how can we produce SVO directly low viscous then before? we have modified our diesel machine to be compatible of using SVO with convertion kit. It takes the heat of radiator to get contact with SVO to make SVO become less viscous. but it will be great if the product output from reactor have low viscosity. could anyone suggest me what should I do?

Thanks Lot...


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