process

Biodiesel

Converting the oil to biodiesel is probably the best all-round solution of the three options (or we think so anyway).

You could simply buy your biodiesel. Most major European vehicle manufacturers now provide vehicle warranties covering the use of pure biodiesel -- though that might not be just any biodiesel. Some insist on "RME", rapeseed methyl esters, and won't cover use of soy biodiesel (which isn't covered by the Euro biodiesel standard). Germany has thousands of filling stations supplying biodiesel, and it's cheaper there than ordinary diesel fuel. All fossil diesel fuel sold in France contains between 2% and 5% biodiesel. New EU laws will soon require this Europe-wide. Some states in the US are legislating similar requirements. There's a growing number of US suppliers and sales are rising fast, though biodiesel is more expensive than ordinary diesel in the US. In the UK biodiesel is taxed less than petrodiesel and it's available commercially.

But there's a lot to be said for the GREAT feeling of independence you'll get from making your own fuel!

If you want to make it yourself, there are several good recipes available for making high-quality biodiesel, and they say what we also say: some of these chemicals are dangerous, take full safety precautions, and if you burn/maim/blind/kill yourself or anyone else, that will make us very sad, but not liable -- we don't recommend anything, it's nobody's responsibility but your own.

On the other hand, nobody has yet burned/maimed/blinded/killed themselves or anyone else making homebrewed biodiesel. Large numbers of ordinary people all over the world are making their own biodiesel, it's been going on for years, and so far there have been NO serious accidents. It's safe if you're careful and sensible.

"Sensible" also means not over-reacting, as some people do: "I'd like to make biodiesel but I'm frightened of all those terrible poisons." In fact they're common enough household chemicals. Lye is sold in supermarkets and hardware stores as a drain-cleaner, there's probably a can of it under the sink in most households. Methanol is the main or only ingredient in barbecue fuel or fondue fuel, often sold in supermarkets and chain stores as "stove fuel" and used at the dinner table; it's also the main ingredient in the fuel kids use in their model aero engines. So get it in perspective, there's no need to be frightened. See Safety and More about methanol for further information.

Learn as much as you can first -- lots of information is available. Make small test batches before you try large batches (see also Test-batch mini-processor). Make it with fresh oil before you try waste oil -- see next.

Where do I start?

Start with the process, NOT with the processor. The processor comes later.

Start with fresh unused oil, NOT with waste vegetable oil (WVO), that also comes later.

Start by making a small, 1-litre test batch of biodiesel using fresh new oil. You can use a spare blender, or, better, make a simple Test-batch mini-processor.

Keep going, step by step. Study everything on this page and the next page and at the links in the text. There are checks and tests along the way so you won't go wrong.

Go on, do it! Thousands and thousands of others have done it, so can you. Get some methanol, some lye and some new oil at the supermarket and go ahead -- it's a real thrill!

Here's the recipe. Or just keep reading, you'll get to the recipe in a minute anyway.

What's next?

Learn, one step at a time. It's all quite simple really, very few biodiesel homebrewers are chemists or technicians, there's nothing a layman can't understand, and do, and do it well. But there is a lot to learn. You'll find everything you need to know right here. We've tried to make it easy for you. You start off with the simplest process that has the best chance of success and move on step by step in a logical progression, adding more advanced features as you go.

• "I am a pipe welder who knew nothing about chemistry but I have learned a lot from this website. It's set up for someone who has never had a chemistry class (me). If I can understand this anyone can." -- Marty, Biofuel mailing list, 23 Oct 2005
  
  
• "For anyone starting out or still in the R&D phase of scaling up and tweaking the process to improve quality, disregard anything other than the tried and tested directions at JtF. Print them out. Read them and then re-read them. Follow the instructions, don't add or subtract anything and you will be making quality biodiesel." -- Tom, Biofuel mailing list, 5 Nov 2005
  
  
• "My best advice is to follow explicitly the instructions on the J2F website starting from the begining and you will do just fine. In my own journey of discovery I learned this. You cannot afford to cut corners. Don't be tempted to use less than accurate measures and think that it will be alright. There is no cheating." -- Joe, Biofuel mailing list, 4 Jan 2006

This is how it works -- comment from a Biofuel list member:

"Your website is very well done. I appreciate the layers of technical complexity. You have progressively more technical information layered in an escalating and logical fashion. I like the links as each new item is introduced, the user can click for more specific information on a topic and it opens in a new window. This eliminates the tediousness of having to constantly backtrack to where the new concept was introduced."

The process

Vegetable and animal fats and oils are triglycerides, containing glycerine. The biodiesel process turns the oils and fats into esters, separating out the glycerine. The glycerine sinks to the bottom and the biodiesel floats on top and can be syphoned off.

The process is called transesterification, which substitutes alcohol for the glycerine in a chemical reaction, using lye as a catalyst. See How the process works

Chemicals needed

The alcohol used can be either methanol, which makes methyl esters, or ethanol (ethyl esters). Most methanol comes from fossil fuels (though it can also be made from biomass, such as wood), while most ethanol is plant-based (though it is also made from petroleum) and you can distill it yourself. There is as yet no "backyard" method of producing methanol. But the biodiesel process using ethanol is more difficult than with methanol, it's not for beginners. (See Ethyl esters.)

Ethanol (or ethyl alcohol, grain alcohol -- EtOH, C2H5OH) also goes by various other well-known names, such as whisky, vodka, gin, and so on, but methanol is a poison. Actually they're both poisons, it's just a matter of degree, methanol is more poisonous. But don't be put off -- methanol is not dangerous if you're careful, it's easy to do this safely. Safety is built-in to everything you'll read here. See Safety. See More about methanol.

Methanol is also called methyl alcohol, wood alcohol, wood naphtha, wood spirits, methyl hydrate (or "stove fuel"), carbinol, colonial spirits, Columbian spirits, Manhattan spirits, methylol, methyl hydroxide, hydroxymethane, monohydroxymethane, pyroxylic spirit, or MeOH (CH3OH or CH4O) -- all the same thing. (But, confusingly, "methylcarbinol" or "methyl carbinol" is used for both methanol and ethanol.)

You can usually get methanol from bulk liquid fuels distributors; in the US try getting it at race tracks. With a bit of patience, most people in most countries manage to track down a source of methanol for about US$2-3 per US gallon.

For small amounts, you can use "DriGas" fuel antifreeze, one type is methanol (eg "HEET" in the yellow container), another is isopropyl alcohol (isopropanol, rubbing alcohol), make sure to get the methanol one.

Methanol is also sold in supermarkets and chain stores as "stove fuel" for barbecues and fondues, but check the contents -- not all "stove fuel" is methanol, it could also be "white gas", basically gasoline. It must be pure methanol or it won't work for making biodiesel. See Methanol suppliers

Methylated spirits (denatured ethanol) doesn't work; isopropanol also doesn't work.

The lye catalyst can be either potassium hydroxide (KOH) or sodium hydroxide (caustic soda, NaOH).

NaOH is often easier to get and it's cheaper to use.

KOH is easier to use, and it does a better job. Experienced biodieselers making top-quality fuel usually use KOH, and so do the commercial producers. (KOH can also provide potash fertiliser as a by-product of the biodiesel process.)

With KOH, the process is the same, but you need to use 1.4 times as much (1.4025). (See More about lye.)

You can get both KOH and NaOH from soapmakers' suppliers and from chemicals suppliers.

NaOH is used as drain-cleaner and you can get it from hardware stores. It has to be pure NaOH. Shake the container to check it hasn't absorbed moisture and coagulated into a useless mass, and make sure to keep it airtight.

The Red Devil-brand NaOH lye drain-cleaner previously sold in the US is no longer made. Don't use Drano or ZEP drain-cleaners or equivalents with blue or purple granules or any-coloured granules, it's only about half NaOH and it contains aluminium -- it won't work for biodiesel.

CAUTION:
Lye (both NaOH and KOH) is dangerous -- don't get it on your skin or in your eyes, don't breathe any fumes, keep the whole process away from food, and right away from children. Lye reacts with aluminium, tin and zinc. Use HDPE (High-Density Polyethylene), glass, enamel or stainless steel containers for methoxide. (See Identifying plastics.) See Safety

See also Making lye from wood ash.

Chemicals for WVO

Isopropanol for titration is available from chemicals suppliers. Some people have used the other kind of Dri-Gas, which is isopropanol, but they found that it's unreliable. Best get 99% pure isopropanol from a chemicals supplier. 70% pure isopropanol is also said to work, but we found it didn't give satisfactory results.

Contrary to rumour, "phenol red", sold by pool supply stores and used for checking water, won't work for titrating WVO, its pH range isn't broad enough. Use phenolphthalein indicator, specifically 1% phenolphthalein solution (1.0w/v%) with 95% ethanol. Phenolphthalein lasts about a year. It's sensitive to light, store it in a cool, dark place. You can get it from chemicals suppliers. See: Phenolphthalein