Make Biodiesel!




About: Ask me questions. I know the answers.

Instructable #2 in my series on biodiesel.

This is my tutorial for using my appleseed processor to make biodiesel. This tutorial will get you through the process of making biodiesel, but not the necessary washing process. I will do my next instructable on dry-washing biodiesel.

Biodiesel is a great way to go green, and cut your carbon footprint quite substantially, not to mention it's cheaper than diesel. Biodiesel will run in a diesel engine, I don't recommend trying it in a gas engine.
The process for making biodiesel uses an oil, a catalyst, and an alcohol. In this case: Waste vegi oil (WVO), NaOH (lye), and methanol.

Please read up on this before you start, and please understand the chemical dangers involved in this process.

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Step 1: Safety

First off, some disclaimers and safety info.

NaOH (or KOH, depending on your catalyst of choice) is extremely caustic and will cause extreme irritation if it comes into contact with your skin, eyes, or any other part of you. Methanol is a harmful alcohol. It will cause blindness or death if ingested; one way it's absorbed into your body is through your skin, so simply handling the stuff with bare hand is bad for you. Lastly, Methoxide, the substance produced when you mix your catalyst with the methanol, is an extremely toxic nerve agent. It can do some serious bodily damage.


I use a chemical resistant p100 respirator when I do this process, as well as eye protection. I use some heavy-duty chemical-proof gloves from Northern Tool. Long sleeves are recommended.

Step 2: Necessary Supplies

Before you make the fuel you need to filter your oil. I filter mine down to 50 microns. I know people who don't filter at all and some people who filter as fine as 10 microns. One person I know simply lets it settle for a few days and disposes of the sludge that settles on the bottom.
To filter it I just hung a bag filter above a clean 5 gal. bucket. I used an old sock to get out the large particles before it went through the filter.

For the actual making of the fuel you will need:

- an appleseed processor

-WVO (you'll get as much fuel as the amount of WVO you use)
You can get this from restaurants, but you need their OK before you take it. You will get arrested and get in a pile of trouble if you just take the oil. Avoid burnt oil, as this will not react to make biodiesel. Most fast food places burn their oil.

-A catalyst: NaOH (sodium hydroxide) or KOH (potassium hydroxide)
The difference? well, KOH dissolves better in the methanol and NaOH tends to make the final byproduct (glycerin) more congealed. Also, you use different amounts depending on which you go with. NaOH is cheaper, and that's why I went with it.

Methanol is used for race car fuel, and can be purchases at many chemical supply places. This is the most expensive part of the process. Methanol is at about $5 a gallon. This still ends up being cheaper than regular diesel, since you add 20% methanol for the amount of WVO you use.

Safety equipment you'll need:

-chemical resistant p100 respirators
Got 2 at Lowes for $25-$30 each

-lab goggles

-chemical resistant gloves

What you'll need for the titration:

-Isopropyl alcohol
get this at an auto parts store

-distilled water

-a very tiny bit of your catalyst (NaOH or KOH)

-a sample of your WVO

-3 oral syringes
Get these at the drug store

-Phenol Red indicator (like for testing your pool water)

Step 3: Filter the WVO

I'm going to leave the collection part up to you, I'm just going to tell you what to do with the oil once you have it.

You should get it in Carboys, it's easiest to use this way.

my basic setup is very low tech, just a bag filter hung from a broom stick over a clean bucket. I used a sock this time around to try and get a longer life out of my filters. I have on clean carboy I put some oil in, and put the rest in another bucket.

Some people like to heat their oil before they filter it. Probably not a bad idea, and I may do this in the future.

Do not use any crappy oil that looks like a cloudy mess at the bottom of the oil. You can see it in one of my pictures. It has water in it, and will ruin your reaction, avoid using this at all costs.

Step 4: Titrate Your Oil

This is where we test the acidity of the oil, by measuring the free fatty acids, to see how much NaOH is needed for the reaction.

Start by measuring out 1 gram of NaOH and mixing that with one liter of the distilled water. This gives you a 1/1000 solution. Keep this, you won't use it all on one titration.

Next measure out 10 milliliters of the isopropyl and 1 milliliter of your WVO sample. Mix these in the same jar. Now add about 5 drops of Phenol Red indicator to this solution; swirl to get it mixed. Fill the last syringe with your lye/water solution and add 1/4 milliliter at a time while swirling the jar. Once it turns bright pink and stays that way you need to count exactly how many milliliters of lye/water solution you used to neutralize the acidity of the oil.

Now we can use this information to tell us how much NaOH to use in the reaction.
The formula is this:

For NaOH- # of liters of oil x 4 grams + titration

For example, say I titrated at 2 milliliters and was using 50 liters of oil. I would do 50 x 6=300. 300 grams of NaOH for that batch.

Step 5: Prep the Oil

Take a carboy filled with oil and connect a section of hose from the carboy to the intake valve on your processor.
Use hose clamps to secure the hose to the carboy lid with the ball valve on it. Be sure to have primed the pump.
Now open the valve on the carboy and the intake valve. Turn on the pump and make sure the glycerin drain and out-take valve are both closed, so oil doesn't come shooting out.
At this point it is very important to have the pressure vent on the processor open, this way you can leave the valve nearest the processor tank closed and let as much oil as you can be sucked though the intake point and get pumped into the tank. Also, be sure to have the vent on the back of the carboy open, or you'll create a vacuum and the carboy will implode.

Once all the oil is in the tank you can turn on the element. If you're using more than 5 gallons of oil you obviously will need to disconnect the hose and repeat more than once.

Heat the oil to 130 degrees F. (you can open the drain valve, get a quick sample, and use a quick-read thermometer to check. )

Step 6: Methoxide Mixing and Introduction to the WVO

This is the most dangerous part of making the fuel.
Measure out 20% of the total volume of oil worth of methanol into a carboy with a vent. (1 gallon of methanol per 5 gallons of oil and so on.)

Be wearing eye protection, chemical resistant gloves, and a respirator at this point.

Measure out the calculated amount of catalyst and put it in/on a coffee filter or something that you can dump quickly. Dump the catalyst into the carboy and immediately screw on the same lid or same kind of lid as shown in the previous step, the one with a ball valve on it.
Shake vigorously and crack the valve open away from you and other people. It will hiss. Shake it up some more, to be sure you get things dissolved all the way. You may need to vent it once or twice more to release the pressure.

Hook this up the same way you did the carboy with the oil. Make sure it's all very tight and secure, you don't want this stuff leaking. leave the intake valve closed for now. Open the valve on the carboy and remove the vent cap so there is a slight bit of air coming into the carboy as some of the liquid trickles down the hose.
Open all the valves in the circuit on the processor and start the pump again so the oil is circulating. Leave the element on.
Now very very slowly crack the intake valve so the methoxide is introduced very very slowly. If you introduce it too quickly it will make soap. Not what we're shooting for here. Tilt the carboy to make sure all the methoxide drains out. Close the intake valve.
Double check the pressure vent on the processor. chemical reactions are happening and the pressure needs somewhere to go.

Let this go for about an hour before you consolidate it all in the tank. Let it sit with the element on for the next 12-14 hours.

Step 7: Draining the Glycerin

The main byproduct of biodiesel is glycerin. You put in 20% methanol, and get out 20% glycerin. Glycerin is useful, and can be used to make soap and things. You can also compost it. Just be sure to boil off any leftover methanol before you use it. There may be some unreacted catalyst, too.

After 12-14 hours it should be separated out. Open the valve nearest the tank and make sure the valve on the other side of the drain is closed, then slowly open the drain valve. Drain into a bucket until what's coming out changes color. At this point you've drained the glycerin and have reached the fuel. Drain the fuel into a separate bucket/container.

Step 8: What's Next?

Now all you need to do is wash your fuel before you can put it in a car. There are several methods to wash fuel, and if you use water you need to be sure to dry it. I'm dry-washing my fuel. Dry-washing uses Magnesol, and it uses no water.

My next instructable will deal with the washing process.

Please don't run unwashed fuel in your car, and please don't forget to dry/filter after you wash.

Now I know some of you are wondering about this, and yes, I am going to add a methanol recovery system. As soon as I add the larger tank I'm adding that and some other upgrade type things.



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115 Discussions


hi name is ashok kumar mohapatra.i read your is very helpful for me to make my biodiesel project...if u will help me regarding this within low budget...then i can start my project...thank u.


Question 1 year ago

How do you get solid fryer Oil to be a liquid


11 years ago on Introduction

If you're making biofuel from waste products good on you, but if you think that biofuel is the 'green' solution to everyones transport needs I have to rain on the parade a bit. Biofuel sounds like a good idea until you start thinking about the consequences of it a little.

Like the way it's pushing up the price of foodaround the world, and the fact that producing food crops uses about 2.3 times more fossil fuelenergy to grow than the energy they provide.

Looks like I can swap destroying the climate with my car for causing global famine with my car. Makes you wonder what would it take to get people to ride bikes instead.

15 replies

Reply 11 years ago on Introduction

One word: Algae. Biofuels from food crops- bad idea, biofuels from non-food sources- the way of the future.


Reply 3 years ago

Please can I get your contact(facebook account, mail or whatsapp)


Reply 11 years ago on Introduction

Well, biofuels from non food crops sounds good, until farmers who were growing food crops realise there's more money in growing fuel crops and give up growing food. It's not rocket surgery, it's market economics 101. If everyone switches to biofuels we can kiss the last of the world's rainforests goodbye. Biofuels from algae does sound promising, but then there will be impacts on marine environments. It just takes a lot of area to power the private car fleet with plant based sources. But you know I use biofuel for most of my transport needs: I eat food and ride a bike.


Reply 11 years ago on Introduction

Yes, but algae can be grown in the middle of nowhere. The fact that soil conditions matter a lot less with algae means it doesn't have to take up food crop land, or rainforest areas. There's still plenty of ground to cover, but algae is very promising.


actually, soil conditions don't matter at all to algae, because it grows in the WATER, thats right, not the middle of nowhere, the middle of the OCEAN, its actually a promising idea, I've heard of it before. About the farmers switching to it, most like there land, not the ocean, I'm sure that a new job niche will only do good things for the economy (now, I've tried to make this neutral enough so that I don't spark a huge debate, but, in advance, sorry if i offend anyone)


Well, the most promising way to grow it right now is in tanks, above ground. No harvesting required. This could be done in the middle of nowhere, somewhere where the soil is no good for growing food-crops.

remember we can always go down or up so we could have tanks stacked on top of eachother 10 stories down and 10 stories up, that would reduse the surface area of the tanks on land by 95%


I like the one where they use overgrown plastic baggies hung row after row, with the algae solution pumped into the top and it slowly winds its way to the bottom. Still has big tanks to drain it into, but it does allow for circulation and central harvesting / maintenance / feeding. Some bloke in El Paso TX seems to have come up with it, but they are still working on which is the most profitable strain of algae for them. personally I have seen plenty of swimming pools and ponds that could use to have some cleaning done ... at least there the algae could be used rather than just thrown / flushed away if algae harvesting was easy to do.


Reply 4 years ago on Introduction

Overpopulation is going to destroy man-kind far before climate change. Thank the good folks who are against contraception and work so hard for disease control for that.


Reply 11 years ago on Introduction

yep, but riding bikes on a 50 mile one way commute in Houston TX or LA kind of sucks. ... such is life for those outside the sweet spot areas where walking, bicycling, or even train commuting is an option.

The Dark Lordstib

Reply 6 years ago on Introduction

If he's making it from WASTE oil, than tell me again how that will drive up food prices? It was going to be thrown away anyways; hence the term "waste".


Reply 8 years ago on Introduction

dident you read the comment above? bio fuel is being grown with alge that feeds on sewage waste and has 50% its weight in useable oil, that dose nothing to food prices and it cleans waste water naturaly, oh and after they extract the oil from the alge the left over "green powder" is considered a "super food" that is sold in health food stores so its making food also.