Cooking oil as a replacement for Diesel fuel

NPR had a story yesterday about a Welsh movement to use cooking oil in Diesel-powered vehicles instead of the petroleum-based fuel. It started when there was a strike or a blockade of refineries, and people needed power. Diesel costs about $4.00/gallon over there, but you can go to the market and buy cooking oil for $2.00/gallon. The man behind the movement to use cooking oil in cars collects used cooking oil from chip shops and other restaurants and then makes it usable for fuel. (He also pays a motor-fuel tax, and this seems to be based on the fact that used cooking oil is “waste” so the tax is lower than it would be if he used new oil.)

  1. What do you need to do to be able to run a Diesel engine on cooking oil? i.e., What changes need to be made to the engine and/or oil?

  2. If new cooking oil is half the cost of Diesel fuel, why use petroleum in Diesels at all?

  1. Do a search for “biodiesel” or “bio-diesel” and you’ll get plenty of information.

  2. Currently, petrolium oil is far cheaper than vegetable oil. Biodiesel only makes economic sense because you can use waste oil from cooking. If there were enough biodiesel cars to use all the waste oil, you’ll have to start using fresh vegetable oil, and then it becomes more expensive than fossil fuel.

Biodiesel is cooking oil processed with methanol and lye. It’s more stable over a wider range of temperatures than plain vegetable oil and able to be stored for long periods of time (cooking oil spoils if you store it too long). Diesel engines will run on straight vegetable oil, though. Check out Greasecar for some info.

Another link:

When I bought my diesel, my boyfriend sent this to me. Yeah, 'cause I’m so good with cars, you know I’d just go out and monkey with my brand new car. Yeah, right!

From scout1222’s link:

Why not use an electric heater to get the vegetable oil up to the proper temperature?

What’s the break-even point (in price per gallon of petrodiesel)?

What percentage of petroleum used in the U.S. is used to run engines (as opposed to making plastic, and such)? What percentage of vehicles and power plants in the U.S. would have to run on non-petroleum based Diesel in order to eliminate our need for foreign oil? (I recognise that there is a strategic advantage to buying oil elsewhere and saving our own for ourselves. But “What if?”)

I’ve heard that it takes 10 barrels of oil to make 100 barrels of oil from turkey offal. How many barrels of oil does it take to turn vegetable matter into Diesel fuel? Can oil made with animal byproducts be freely mixed with oil made from vegetable sources? (i.e., will a mixture perform the same as a “pure” source?)

If the nation turns to biodiesel made from plants, how will that affect food prices? More demand creates higher prices, but would that be offset by lower fuel prices due to economy of scale? What percentage of farm produce would need to be “set aside” to make fuel? How much surplus food do we produce, anyway?

I’ve often heard that people can get used cooking oil free from restaurants. Is this because the restaurants can avoid paying waste disposal fees? Or is it more likely that the restaurant would see their used oil as a commodity and charge for it? Wouldn’t it be more efficient for a company to collect the oil from many restaurants and process it for sale? (It occurs to me that a single collector might get the oil free since they can say, “Look. I get Joe’s oil free. You can either dispose of it with me, or you can pay to dispose of it.”)

Why don’t we see (bio)diesel-electric hybrids? I’m not talking about trains, where a Diesel powers electric motors; but something more like the Prius.

You ask alot of questions. Basically cooking oil is a waste product. It’s free. So you can use it in cars instead of diesel. Great.

Now how about if you wanted to run the whole economy on it? Well the US uses 6.5 billion barrels per year, or about 250 gallons of oil per year. Do you think there’s that much cooking oil floating around? Probably not.

So we’ll have to raise food specifically to create cooking oil and then burn that.
One square meter of land produces something like .11 liters of burnable oil per year, now maybe other crops produce more but that’s the figure I’ve seen. One of the inputs into harvesting bio-diesel or vegetable oil, is of course the fuel for the tractors and oil in the fertilizer etc. But anyway how much land would you need? I’ve read for the US it’s be about a square about 1500 miles by 1500 miles. Something like that. That’s in addition to regular food.

How much would it cost? I don’t know…how much does cooking oil cost now that is in stores? $8 a gallon or so? Probably somewhere in the vicinity of that. Maybe more because the fuel inputs would go up in price too.

The rest of your questions I don’t really understand. Why not a bio-diesel hybrid? Why not? If you can have a diesel hybrid, then you could have a bio-diesel one too. It would be more fuel efficient, whether that fuel is diesel or corn oil.

Whoops should read 250 billion gallons of oil per year (that the US uses).

So that’s about 1000 gallons per person per year approx. Do you think restaurants use 1000 gallons of cooking oil per person in the US per year, that otherwise would just get thrown away? Sounds a little high.

Basically my point is that now used oil is free because it otherwise needs to be disposed of. Some people get cheap fuel this way and good for them. But the more people do it then the price will go up as there is a limited supply.

Yes, I do.

Obviously not.

I wrote “(bio)diesel” so that I wouldn’t have to write “bio-diesel or petro-diesel”. I guess it didn’t work. Anyway, we have gasoline hybrids now (e.g., the Prius). Why are gasoline hybrids available on the market but diesel hybrids aren’t?

I’m not sure. I would think one would be soon.

All the relevant questions have been asked here so I chime in with a tangent:

I am currently working on an Olds 5.7 nat. asp. diesel v8 I swapped into a Postal Jeep and am experimenting with using waste vegetable oil (WVO) and used automatic transmission fluid as alternate fuels…with a bonus:

I will circulate the oils through the engine first as a sump lubricant.

Both WVO and ATF are apparently known for their respective detergency…the ckean the engine of varnishes and carbon deposits…and the oil is preheated to the proper viscosity required to pass through the injector orifice.

This 300-350 deg. F. oil is then routed to the fuel pump.

This eliminates the need for oil changes.

Read “this cleans the engine of varnish and carbon deposits”

Try .


Hello all, I just registered so I could post to this thread.

I’ve been doing a lot of research lately into biofuels and thought I’d share what I’ve found.

If you can get your waste oil for free, the cost to make a gallon of biodiesel is US$0.60/gal. BD burns cleaner than petrodiesel (often called “dinodiesel”), has a higher cetane (equivalent of octane) ratings, and contains no sulfur. It adds no carbon to the atmosphere, since all the CO2 produced by burning it was absorbed by the plant it came from.

I’m going to try making some of my own very soon now. My investment is going to be around US$200, mostly in lab equipment. I’m getting major portions of the system for free from people who are also interested. I live in a somewhat rural area, so there’s lots of farmers with tractors, etc, that would like to not pay US$1.90/gal for their fuel.

Enola Straight : I’d heard of doing this, but I’m worried about emissions from the used ATF - how much of it are you going to be using in the mix? Also, I thought WVO had a breakdown temp much lower than 300degF.

kennybath : Look for BD/electric hybrids to hit the roads sometime in 2008 (2006 in Europe).

Also, to answer your assertions: Currently most restaurants pay for disposal of their waste oil. That’s right, they make negative money on it. If more people start using BD, there will be a greater demand for WVO and the price will rise. Restaurants will be paid for their waste oil, up to about US$0.50/gal. If demand for BD rises further, there will be more virgin oil produced specifically for the purpose of making BD, at a lower cost than current vegetable oil prices. BD can be produced effectively from oils that are not useful for cooking.

Also, where did you get the .11 liters per square meter figure from? That’s about 118 USgal/acre, whereas numbers I’ve seen go from 18 gal/acre for corn, to 635 gal/acre for oil palm. The most common oil crops, soy and rapeseed (canola), are 48 and 127 respectively.

It is not necessary to raise “food” specifically for oil production - in other words, large-scale production of oil crops will not displace food crops. This is because after the oil is removed from the pant, it is still useful, mainly as cattle feed. The “cake” left over from pressing out the oil from corn is used as a highly nutritious, high-protein supplement for dairy cows.

Johnny L.A. : The conversion kits use a recirculating system instead of an electric heater because it’s more efficient - the engine heat has already been produced, so it’s better to use than than generate electricity and turn it into heat. Some people who run engines on SVO use electric preheaters in cold climates.

I don’t have hard numbers, but the cost of diesel is going up even more rapidly than the price of gasoline - the break-even point probably lies somewhere around $2.50/gal for oil produced specifically for BD production.

Animal fats are also useful for making BD - the process differs somewhat due to higher levels of Free Fatty Acids that have to be converted, but it’s still well within the capabilities of a single person at home.
In general, biodiesel from WVO is absolutely awesome when the waste oil is free, and better even when it is more expensive than petroleum products. I feel that it’s the best near-term biofuel we could possibly make. Ethanol fuel from biomass still has some problems, related to tariffs mainly, but it also has some technical shortcomings. Ethanol is a less dense fuel, so a larger volume is needed to obtain the same output from an engine. Also, the modifications to run a gasoline engine on ethanol are much more substantial than those required to run a diesel engine on biodiesel. Exotic solutions, like pure hydrogen or direct methanation fuel cells, aren’t here yet and will require much development and investment before they can replace gasoline. Biodiesel leverages existing engines and production lines, but replaces a dirty fuel with a clean one.

Incidentally, the first diesel engines built by Rudolf Diesel were run on pure peanut oil. Diesel designed his engines to run on renewable fuels, rather than petrochemicals. Somewhat prophetically, he said:

More info is here

Fuel prices in Europe are artificially high. The goverments tax the living hell out of fuel. Something like 75% of the price of a liter of fuel goes to pay taxes here in Germany. If you figure things back around to the normal VAT, you wind up paying $1.16 per gallon - one dollar for the fuel and 16% VAT. Cooking oil doesn’t look very attractive then, does it? It’s only a good deal then if you can get your cooking oil used for a whole lot less.

Here’s a little hint:
Go to Belgium. They’ve got lots of cooking oil to go around. They passed a law back about 1987 to the effect that the french fry stands had to change their cooking oil at least once a year. The french fry guys all threw a screaming fit and claimed it was the old rancid oil that gave the fries their distinctive flavor. :slight_smile:

Don’t know…that’s why its going to be an experiment. Hopefully, the turnover rate is good enough that the heated ATF is consumed as fuel faster than the ATF can break down and gum up the works.

ATF…especially Type F…is a high detergent oil; its an old mechanic’s trick to pour a quantity of ATF in the engine do dissolve varnish and other deposits, both in the sump and the fuel lines.