hi jc
the methonol is 99%
naoh is 98%
ill try a 20% methonol batch as soon as i get a titration test done (still carnt find isopopyl in small small quantitys see above posts)
one more thing is the base for naoh 6g or 7g per litter of wvo ??

Tatty,

I don't use NaOH, but KOH is reportedly 1.4 times the amount used for NaOH. I have no reason to doubt this, but don't have personal experience with NaOH.

You can use the KOH info I gave you and just divide by 1.4

That means the 4.9g/l KOH would be 3.5g NaOH. Remember, this should give incomplete conversion, along with the 20% methanol. You can even try down to 17% methanol if you like.

It should be incomplete conversion, but again, you are trying to avoid soaps and emulsion issues.

Then you can gradually increase these numbers (KOH up to 8.0g/l = 5.7g/l NaOH) and back up to 20% methanol to get complete conversion.

The isopropyl we use in the States is easily found as "dry gas" or gas line antifreeze. Just have to check the percentage, as in the past few years the makers have thinned it down to a lower concentration.

This stuff is designed to bond with water in your auto fuel system and carry the water through your fuel filter and allow it to burn in order to remove it from your vehicle's system.

Hope this helps.

- JC

For titrations I use 80% isopropal from wal-mart pharmacy. You can check drug-stores if hard finding some other places.

Trc

Tatty

do a search on 'chemical suppliers' in your area on yell.com, or try your local chemist. I managed to get some isopropyl from mine about 6 months ago. We don't get dry gas or gas line antifreeze over here, not that I am aware of anyway.

LW

got a sample of isop--- (500ml) from the guys i get my methonol from for free
so i got to do a titration today for the 1st time, i done 8 tests and 4 of them came up at 6.
i tryed 20% methonol + 11g naoh (5g base + 6g titaration)
heated oil to 55c mixed all up
shook every 10 mins over an hour .
im pleased to say everything looks good so far (about 9 hours) 2 good levels of separation
im expectin some soap in the wash but i can handle that
so thanks for all the help guys im pleased i didnt give up

Whoo-hoo!

Now that you're seeing what it's *supposed* to look like, you'll get more of a feel for it.

That should help you recognize right reactions and wrong ones.

Good luck.

- JC

Nice one Tatty

If you make a lot of soap this could be due to wet oil, you can test this by heating a small amount of oil to see if it 'spits' - if it does then it has water in it. If so then try heating the oil to 60deg C and leave to settle overnight. Then use only the top 95% as most of the water will settle to the bottom as it is denser than the oil - if you are only making small batches you may have to figure out a way of doing this.

Another method is to mix the glycerin from the previous batch of bio with the oil, heat to 55degC and leave to settle overnight. Remove the glycerin before you titrate and process, this will take most of the water out with it and you should see a lower titration, therefore less FFAs.

Do some reading on these before you give it a try (glycerin pretreatment), as always be as safe as possible .

Let us know how the washing went.

LW

LW's right about the soap. Especially with the lower amounts of chemicals we discussed. If you still get lots of soap, it's likely to be the water.

- JC

every thing looks fine !!
im washing 10 lts at a time and after washing & drying im left with 8.5 - 9 lts .
do you think thats about right ??
(finnished bio passes 27/3 test)

tatty.

Tatty
90% yield sounds good, since you are useing oil that titrates a bit high even the 85% yeild not to bad. With oil that titrates at about 3.5NaOH I usually have about 92% yield.

Trc

Congratulations Tatty!

It's not magic, but it takes a little abracadabra

If you're losing some during wash, I wouldn't worry about it. You can take more time with a wash and lose a *little* less, but it's a time vs yield issue.

Typically, more settling time = higher yields and vice versa.

Trc59- I think he means he is losing this much during the wash, not in the conversion, but the info you gave should help him, too.

- JC

yes thats right jc im loosing in the wash .
During the 1st few washes im getting a little gloop
between the oil and water this is where i think im loosing yield
ive already filled my tank (and running better than ever)
in the uk your only allowed to produce 50lts a week before you have to pay tax ..(not fair)
thanks again guys
tatty