Making my own Biodiesel (small scale)

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Making my own Biodiesel (small scale)

adruss85

Don't touch those!
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Thought i'd post a quick tutorial/guide/example of how i am trying to make biodiesel from veg oil.

I'm doing this purely as a proof of principle exercise. If i can produce a small quantity of a rough product using nothing more than some chemicals then i figure scaling it up with proper equipment shouldnt be too difficult, and then move to WVO.

I'm a professional research scientist who works with hazardous chemicals all day, and i still was very cautions about how i was doing this. Anyone else who trys it i would advise to wear at least nitirle/latex gloves and some sort of overcoat. (i'm making it sound more dangerous than it is but better safe than sorry!). ;)

The first stage was to gather the ingredients. They are:
  1. Veg Oil (any old cheap rubbish will do but i ended up using sainsburys at £1.20/l :bang:)
  2. Methanol (you need approx 1/5th by volume of veg oil, but up to 1/4 is fine)
  3. Sodium hydroxide (for pure veg oil you need ~3.5g/l of oil
All these figures came from various sites i've found so have a read around for the best bet!

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First step is to mix the NaOH with the Methanol, which will take a while (do this in a glass or metal container as the NaOH can eat away at plastic and it also gets quite warm). This forms a cloudy solution called methoxide, which is basically a nerve toxin. In high concentrations this kills living cells before they have time to feel pain - nasty stuff. This concentration is relatively safe but is still highly flammable and should be handled with the utmost care. If you get any on you or your clothes, rinse it off thoroughly, wash clothes and if it was a large amount, see your doc!

The methoxide is used to replace the fatty acids in the oil with methanol, a process called transestrification. This drops the viscosity ALOT and makes it much more flammable! The by-product of this is just glycerin (soap) which needs to be removed eventually. Although i've not looked into the exact chemistry is should be available online somewhere.

Once the methoxide is ready, heat your oil to 60C, then move to your reactor vessel, which should be glass again.

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Thumbs up didnt really work!

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1L of veg oil and 200ml of Methoxide (200ml Methanol + 3.5g NaOH) makes ~ 1L of bio, and some soap (glycerin)! :D

Now pour the methoxide into the oil and shake vigarously for 10-15 seconds to get it properly mixed. Your mixture should go a banana milkshake/custard colour as the methoxide and oil mix, then as the reaction begins it will go a dark yellowy/brown. Pics shows phase seperation after pouring, just after mixing then after 15mins.

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Phases Separate (Wee :()

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Banana Milk :yuck:

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15mins later (Bad Wee :()

The warmer you keep it (around 50C) the better as this speeds up the reaction, and keeps the viscosity of the oil down, allowing the two products to separate.

The last pic shows 1 hour after mixing, and a very visible, thick glycerin layer at the bottom.

DSCN0078.JPG


Next i need to leave the reaction to finish, and all the glycerin to separate out. Then i'll tip the bottle upside down and find some way to get all the by-product out, and take the biodiesel into work to run some viscosity measurement/water tests etc.

From here, i could prob just put it in with a load of normal diesel and it'd be fine. If i wanted to run higher concentrations i would need to wash/dry the product thoroughly, then filter it, but the kit for this costs wedge so would only go to that stage if/when i feel a larger scale run would be worth it!

I hope this helps anyone who was thinking about this, or just provides a good read for a few nerds like me!

Will continute to update over the W/E!

Thanks for listening (y)
 
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read the post :bang:

I'm doing this purely as a proof of principle exercise. If i can produce a small quantity of a rough product using nothing more than some chemicals then i figure scaling it up with proper equipment shouldnt be too difficult, and then move to WVO.

f i wanted to run higher concentrations i would need to wash/dry the product thoroughly, then filter it
 
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i found it very intresting (y)

but at 1.20 a ltr and all the effort, if it worked would it be worth it?!!
 
whats the point? clog you tank with crap, make the engine run like crap and have a cloud of stinking smoke follow you, knacker your diesel pump and injectors and eventually kill the engine all to save a whopping few pence per litre,

rather you than me
 
whats the point? clog you tank with crap, make the engine run like crap and have a cloud of stinking smoke follow you, knacker your diesel pump and injectors and eventually kill the engine all to save a whopping few pence per litre,

rather you than me

Depends on the fuel pump you've got TBH.
 
whats the point? clog you tank with crap, make the engine run like crap and have a cloud of stinking smoke follow you, knacker your diesel pump and injectors and eventually kill the engine all to save a whopping few pence per litre,

rather you than me


I'm doing this purely as a proof of principle exercise. If i can produce a small quantity of a rough product using nothing more than some chemicals then i figure scaling it up with proper equipment shouldnt be too difficult, and then move to WVO.

:rolleyes:
 
whats the point? clog you tank with crap, make the engine run like crap and have a cloud of stinking smoke follow you, knacker your diesel pump and injectors and eventually kill the engine all to save a whopping few pence per litre,

rather you than me

  1. Properly made biodiesel cleans your fuel system
  2. Produces less emissions and smoke then white diesel
  3. See point 1
  4. See point 1
  5. Producing bio from WVO would only cost you the electricity to make it (better on a large scale) and the cost of the methoxide (about 20p/l of bio)
I used the oil from sainsburys just as an exercise. Costco do it much cheaper but ultimately the plan would be to use old chip shop oil.

I hope people realise this is not like shoving veg oil in your tank, it's something much more complex and ultimately better than using standard diesel if WVO is used.

Thanks for the support Uno45! :)
 
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adruss...what sort of molar concentration of NaOH did you use?

Interesting to see a pictorial guide on how you did it and with some explanation of the chemical processes going on. Nice one (y)
 
adruss...what sort of molar concentration of NaOH did you use?

Interesting to see a pictorial guide on how you did it and with some explanation of the chemical processes going on. Nice one (y)

I see where you're coming from. The NaOH i used was in pelet form, and was disolved into the Methanol, rather than mixed in solution form

The acid-base reaction needs only to run until all the fatty acids have been removed, i.e. you need a specific amount of NaOH per litre of oil, but this would also vary depending on type of oil. WVO is more acidic so a titration has to be done in order to work out how much is needed (details on the net somewhere!)

It's concetration in the Methoxide isnt so dependant, as it is entirely down to how much Methanol you want to use. You can use more but this is less efficient and eventually methanol would stop going into the fuel and be taken up in the glycerin and therefore wasted. You can get condensers which can recover this, but again, that's for large scale operations!

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EDIT: I kept the bio in the airing cupboard since i made it to try and keep the temp up a little, pic isnt very good but the reaction is well finished and the bio is getting pretty clear. There is probably a little water and glycerin still left in there though.

The glycerin layer at the bottom is EXTREMELY thick, and seperates out very quick if i give it a shake. I'll try put a vid up to show.

Tomorrow i'll work on a way to separate the two (prob just pour it out!)
 
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adruss...what sort of molar concentration of NaOH did you use?..... (y)

He's using about:

0.08974 mols

1 mol dcm3 of NaOH you would need 39g in 1 dcm3 of water (or 1 litre of water: Since 1 dcm3 = 1L) !


Heres how I worked it out:

He used 3.5g of NaOH.

So mass of NaOH = 39g mol-1 (Na(22) + O(16) + H(1))

3.5g /39 g mol-1 = 0.08974 mols
 
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Wow, just ask you local couriers what they use - plain old veg oil no additives. I know of two unmodified cars that has done over 100k on veg oil and still run perfect, one has had no diesel mixed in either. Bosch pumps will take veg oil, lucas will not, some bosch pumps fail not because of the oil, but the fuel lines are not compatible with veg oil, they dis-intergrate and end up fouling the pump. As per the opening post - be carefull as the oil itself is dodgy, and will clean your fuel system and will restore your tarmac drive back to oggin if you spill it. If you are VAT registered diesel works out about the same at the moment.
 
Just a note on this. I have been making bio diesel since january, with a few problemsmostly through over enthisiasm, now been fine on neat bio for about 2 months. Be wary of running on neat cooking oil if you get dipped by the ministry you are liable for fuel tax and vat, bio is exempt for the first 2500 litres per year, you also have to register with the enviroment agency as a waste carrier to collect waste oil from resteraunts etc.
 
I have run a Peugeot 406 HDi, Laguna DCi & currently running my Passat TDi on my home made bio with no adverse effects, I do 3000+ miles per month both for business & personal journeys........

I will be running my 2003 Miltipla on the bio too....

If buying waste oil from my supplier @ £85 for 240 litres + 2 Kg of KOH as the catalyst at £1.80/Kg (£3.60) + 40 litres of Methanol @ 47p/litre (£18.80) quates to £107.40 for approximately 230/220 litres of bio.........or 47.75 p/litre on a yield of 225 litres or £217.74 a gallon............:yeahthat:
 
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