In this article we’ll be discussing how to test the purity of methanol. Because methanol is a key ingredient in making Biodiesel, it needs to be as pure as possible or else it can cause problems with the reactions and cause poor conversions.
Why Test Methanol?
If the methanol isn’t pure enough, it can lead to poor Biodiesel conversions and higher than normal soap levels when reacting your oil into Biodiesel. This is because the contaminant in the methanol is usually water. Water plus oil plus catalyst makes soap (and sometimes lots of it!) Unfortunately, methanol LOVES to suck up water (that’s one of the main reasons methanol is used in fuel drying additives–ie. HEET fuel dryer), so it’s important that you know just how pure your methanol really is.
In most cases, if you purchase methanol new in a sealed container, you usually won’t have to worry about its purity. However, if you’re using recovered methanol or you’re using an old drum of methanol that’s been around for a while, it’s possible for water to have crept into it. As there are many things that can cause contamination to methanol, it’s always a good idea to test it for purity.
To test methanol’s purity, you will need the following:
1- A methanol hydrometer
2- A glass cylinder
3- A thermometer accurate to 1 degree
4- A methanol purity chart
5- A calculator
6- Some scratch paper
7- And some methanol to test.
It’s also helpful to use a stand to support the thermometer with, but it isn’t 100% necessary.
Step 1 – Add methanol sample to glass cylinder and insert the hydrometer
Step 2 – Allow the hydrometer to stabilize in the methanol (at least 1-2 minutes) and then read where it interfaces with the methanol level and record the reading
Step 3 – Insert the thermometer into the methanol and let it stabilize (about 2-3 minutes) and take a reading and record it.
Step 4 – Compare your reading to the methanol purity chart.
At 75 deg. F, the methanol should have a specific gravity of 0.7875
We recorded 0.789
Step 5 – Calculate the purity of the methanol
Subtract the standard from your reading (0.789 – 0.7875 = 0.0015)
Divide the difference by 0.00285 (0.0015 / 0.00285 = 0.5263)
Subtract the result from 100 (100 – 0.5263 = 99.4737)
This result is the purity of the methanol (99.47% pure)
NOTE:
The 0.00285 is the amount the specific gravity of methanol increases for every percentage point the methanol decreases in it’s purity.
Example:
100% pure methanol at 75 deg. F has a specific gravity of 0.7875
99% pure methanol at 75 deg. F would have a specific gravity of 0.7847
Making Biodiesel & Methanol Purity
When making Biodiesel, you really want to use as pure of methanol as possible. However, it is possible to make Biodiesel from lower grade methanol; however, it may not fully convert and you may create quite a bit more soap. In general, we recommend using methanol that is at least 97% pure or better when making Biodiesel. Much lower than that and you’re asking for problems.
Be sure to check out our Methanol Test Kits!
Our kits come with complete instructions and everything you’ll need to perform accurate methanol purity tests! We also sell the individual parts as well.
Watch a methanol test demonstration!
Link to video
Graydon,
Very interested in your methanol. I’m a shop teacher, usually make my biodiesel in summer time when I can. Last several years I’ve picked up a summer job and I’ve been away from bio d for a couple years. Ready to start up again this summer and have about 45 gallons of methanol that I’m not sure I can use or not. Going to test it at school with the chem teacher. If I find it’s not very “pure” anymore, is it still usable? Can I do anything to improve it to make it usable?
Thanks
Nick in WI
Yes. You can still use it. People usually blend it with brand new methanol until they get the purity mixed to where it can be used for Biodiesel.
You want to hit 97% minimum. If you’re higher than that, awesome!
I am very interesting in making Biodiesel please tell me where can i buy Methanol.Does it have any alternative name or use.
Thanks
Methanol can usually be purchased through a petroleum supplier (think Racing fuel outlet). You can also try chemical suppliers. You may also try Brenntag Pacific or Univar or Ashland Chemical. If you still turn up emtpy, give us a call as we can also supply it but the shipping is usually really expensive to ship methanol.
Also, here’s a listing of methanol suppliers around the US:
http://murphysmachines.com/resources/suppliers_locator.html
I appreciate your quick reply and eager to make some biodiesel.Actually I am from Pakistan not US.I bought one Liter of Spirit which is extracted from Sugarcane.I do not know if it works or not.
Thanks
That’s actually Ethanol. Kind of a pain in the rear to make Biodiesel from. It’ll work, but it usually requires more than 20% and the water washing is a royal pain with it (it tends to emulsify the Biodiesel).
More on making Biodiesel with Ethanol here:
http://biodiesel.infopop.cc/eve/forums/a/frm/f/9601000031
I never Ever found someone so helpful like you.I wish I was in US to payback the favour you are doing.I finally found a Local supplier who is selling Methanol and Stats they are showing on there website are (Methanol 99.85 %(w/w) Water 1000 ppm Ethanol 100 ppm Acetone & Aldehydes 30 ppm Acidity 30 ppm Non volatile 10 ).I do not understand any of this but as you mentioned in your videos that minimum of 97% pure is required and this is 99% if i am not wrong.I think this can do the trick.once again thanks to you for being so helpful,and sorry for my bad English as it’s not may native language.
Thanks
Yep. That’s pure enough. They’re just listing the other impurities. 99.85 is plenty pure enough. (ie. 1000 ppm water is equal to 0.1%, 100 ppm is equal to 0.01%)
Thank you.I will write you after making a small batch.
Sounds great!
Everything was going fine Diesel at top and glycerine on bottom until i poured hot water in which converted oil in Cloudy water and i ended up with half a liter of liquid soap.Please guide me what is wrong.
Thanks
Sounds like an emulsion. Check out our emulsion busting article for details on breaking it apart.
http://www.utahbiodieselsupply.com/blog/biodiesel-emulsions-101-preventing-and-curing-them/
I found a shop he is providing methanol and the formula on it is C2H6O.Is this ok
That looks like Dimethyl Ether or Ethanol.
It’s technically not methanol though. Methanol is CH40
Thank you for all your help.I think its not possible to make biodiesel in My country because i can not find Methanol any where.sadly!
Hello Dear
I hope you are Alright.After struggle of 3months i finally found methanol and formula is CH3OH.Please tell me if this is right thing.
Thank You.
Yes. That’s correct.
Thank you dear.I will write you tomorrow about results.
Hello Dear
Today i read about use of algae oil for biodiesel.I have plenty of uncultivated land and waste waters to produce algae.Can you tell me is it worth to do so.
Thank you.
i think it still in labs am i right…
eagerly waiting for your answer.