Hi got passed by customs&excise to make my own biodiesel.reading on the forum about glycerin pretreatment,can anyone explain please.
vino

Congrats Vino. Did they make it difficult to register? It seems to vary according to what officer is dealing with it.
Glycerine pretreatment is simple enough. When you have finished a batch you draw off your glycerine and while it is still warm add it to your next batch of wvo. Mix it up and leave it overnight. The residual methanol, catalyst and heat goes to work and partially converts the oil.
After you draw off the glycerine the wvo thats left will have a lower titration level than before. This method is very useful if your iol supply is poor quality, say titration number 3 to 6.
Im doing a batch on Saturday morning, thats tomerrow, all welcome for a chat and a cup of coffee.

Hi,imakebiodiesel
I seem to have posted this topic in the wrong place.The customs officer was very helpful and had done his homework on biodiesel.After 3 months I have to send him an account of biodiesel used and ingredients used,and a bank draft.I thought they would have given me a letter to produce in case I was stopped at a check point.I also had to apply for a waiver of env.impact&health and safety report.
vino

If you keep photocopies of your statements and cheques in your car you will be covered in the event of being dipped. I was dipped outside Rosslare earlier this year. They immediately noticed the colour difference. I explained and produced the statements. After a phone call to verify that I was genuine they waved me on. That felt good. The average fine here is 2500 euro and they keep your vehicle until you have paid.
The waiver on the environmental impact and health safety assessments is a really important issue. If a tax inspector is having a bad day he, or she, can use it to close down a small operation like ours. Being able to show that others have been granted the waiver might help in that situation.
Do you know that if you use part of your output for heating oil you only need to pay 4.7c per litre and if you use it for electricity generation 0c per litre. Naturally a fair bit of my output during the winter goes into the boiler and my Lister Petter generator consumes a suprising amount each month.

I was wondering what the case was in northern ireland with regards to customs & excise.
I've looked at thier website and believe we are exempt from duty and dont even have to register but I think we are supposed to keep a records of how much we produce,can anyone clear this up?

Im no expert on the tax situation in Northern Ireland but my understanding is you are allowed to produce 2500 litres without any tax liability. You must carry records of your production and methanol and catalyst purchases in your car in case you are stopped. Im sure this has been discussed in depth on the UK biodiesel connections. Perhaps someone from the North would like to research the topic and post their findings. Ive asked the Moderator to rename this thread Fuel Tax in Ireland because Im sure many people would view this if it was properly identified.
Copper, I wasnt able to get any KOH this week so it will be 2 weeks before Im up north again. If you just need enough for a batch or two, I can let you have some from my stock.

Biodiesel Demonstration on Saturday 18th Oct at 9.30. Location Railway Station Lismore Co Waterford. Ring 086 3169230 for directions. All welcome.

Copper, Ive got your KOH. It was 35GBP incl vat for 25k. Give me a ring when you want to pick it up.

just back from the sun
I will call down next Saturday the 15th

Talking to homebrewers as I do, I realize that very few recover methanol from their glycerol byproduct. There are several good reasons why you should do this not the least of which is that it saves you a lot of money. Your glycerol will contain 20-25% methanol. Methanol vapour is a pollutant and a greenhouse gas so should not be allowed to evaporate into the atmosphere.
The recovery still that I use is very simple and could be constructed in a day.
The boiler is a 20 litre veg oil drum. Cut the handle off to reveal the flat area in the centre of the top. Drill a hole with a hole saw and fit a 1" tank fitting. Make a tapered wooden bung to close the pouring hole. If you dont have a lathe I can make you one. Thats the boiler done.
The reflux column is a 21" length of copper pipe with a T fitting at the top. The top of the column has K type temperature probe glued into place and the pipe is filled with stainless steel potscrubs. A length of garden hose is attached to the tee to to carry away the methanol vapour to the condenser.
With the column attached to the boiler you are ready to go. As a source of heat a gas ring or an electric hotplate will work although I place mine on top of my workshop stove.
It produces methanol of about 85% purity and once it is running it can be left unattended for hours.
In my next post I will show how I built a condenser and how I raise the purity fron 85 to 100%.

vino

if you carry over your glycerin from your last batch and use it to pre wash the new one...and continue to carry over each batch of glycerin you wont need to recover.

here's the trick

prewash with glycerin /methanol mix from previous batch[make sure no water prewash]
let it mix 1hr or so
let it settle ..but not overnight..otherwise the gycerin will be too thick[with naoh]
drain this gylcerin and use for soap or throwing away...whatever

this glycerin will have little or no meth in it;;;;;;;somehow it gets transfered to new wvo mix

now titrate....it will be lower
process as normal....drain gylcerin
drain this gylcerin/soap/meth mix and keep for next batch prewash

you can recover some meth from biodiesel now if you wish[i use gl method]

but recovering from gylcerin not needed as you will be using it in next batch

you'll find you will need less meth ...maybe 18% ...depending on what method you use

so far so good for me


keep it simple

edwardob,

quote:

if you carry over your glycerin from your last batch and use it to pre wash the new one...and continue to carry over each batch of glycerin you wont need to recover.

Have you been able to establish what percent of the methanol remaining in the glycerine/byproduct is transfered to the oil being treated?

quote:

you'll find you will need less meth ...maybe 18% ...depending on what method you use

Have you been able to establish how much the pretreat allows you to cut methanol and keep conversion constant?

There are many reports praising this method. I have not yet seen controlled tests.

quote:

Originally posted by Andrew M:
edwardob,

quote:

if you carry over your glycerin from your last batch and use it to pre wash the new one...and continue to carry over each batch of glycerin you wont need to recover.

Have you been able to establish what percent of the methanol remaining in the glycerine/byproduct is transfered to the oil being treated?

i ain't the scientific type....but the gylcerin is as thick as you can get when cold..whereas with meth in it it is very liquid
indicating to me there not much there....
not very scientific

quote:

you'll find you will need less meth ...maybe 18% ...depending on what method you use

Have you been able to establish how much the pretreat allows you to cut methanol and keep conversion constant?

There are many reports praising this method. I have not yet seen controlled tests.

i personally have reduced by 2% and will try to push it a little further....
not exactly the info what you're looking for
all i say is try it !

edwardob,

quote:

not exactly the info what you're looking for all i say is try it !

My point is that lots of people have made claims on this subject which are, up to now, unsupported with data.

I don't doubt that using pre-treat improves the reaction. I do question some of the claims people have made about the mechanism.

quote:

i personally have reduced by 2% and will try to push it a little further....

Have you tested to see that your are reaching (at least) the same degree of conversion? Do all the other variables remain constant?

the end result is all the data i need..3/27 test is passed
and i'm using less methanol....not adding extra labour demething gylcerin.....

that's my experience and claim which is all i'm passing on to vino..and whoever wants to read/test it

on forums like these people make all kinds of ideas...
some water..wash and swear by it
i never use water.....

some need acurate scientific evidence

i don't have nor will i ever probably get into it...bio science that is.


all i say is enjoy it whatever way you do it.

i hope vino has some idea what the process is now regading pre wash with gylcerin.

but don't quote me

The glycerine pretreatment edwardob describes is very effective. I have used it many times when using poor quality oil. If you do it quickly while there is some heat in the glycerol it works much better. You can use glycerol where the 5 % water wash has been used but it is less effective. I still recover methanol from glycerol used this way and would expect to get about half the quantity I would get from normal glycerol so it is still worth doing but obviously a bit less cost effective.

Just a couple more comments on methanol recovery/ glycerol pretreatment.
It is much more effective using KOH because you can continue to pretreat as long as there is any heat left, 24 hours , no problem.

I make biodiesel in a 150 litre batch and I use 33 litres of methanol. I add a 5% water wash and I get 40 litres of glycerol at the end. I recover 9-10 litres of methanol from the glycerol.
So my total use of methanol per 100 litres is 16 litres. I have no fuel cost involved in distilling as my still is powered by yellow grease which I need to get rid of anyway.

Andrew M

imakebiodiesel is another experience..one of many.i'm sure

what you do next is try it.....
if your expeience is good ..that's all the data you need.


accurate data is usually the result of controlled experiment

the reason people have different results is because
everyone's shed is different....setup is different.....oil quality is different...equipment is differnt

try it ..i'm confident you see results

To finish up my descripton of how I recover methanol, the hose from the reflux colunm is connected to a condenser called a "plumbers delight".
I wont describe it here because full instructions to make one are elswhere on this forum. Search under Plumbers Delight.The condenser for this still only needs to be about a foot long but it makes sense to make it bigger in case you ever construct a bigger still,

If the temperature at the top of the column is restricted to a max of 74degrees C you will get a purity of around 85%. To remove the remaining water I use Molecular Sieve. This is pellets of a mineral called 3A Zeolite. It has a unique ability to absorb small molecules like water but not big ones like methanol. It will absorb 20% of its own weight in water so its a simple calculation of how much you need to remove all of the water.

I mix the 85% methanol and the molecular sieve and let it stand for an hour. I strain the methanol through a kitchen sieve to recover the molecular sieve. I let it air dry for a few days and then recharge it by heating it up to 250 degrees for a few hours in my workshop stove. It can be reused thousands of times. I test the finished methanol with a hydrometer to make sure it is 100% pure and reuse it.
I have found recovered methanol to be just as good as "virgin" methanol provided it is properly dried.

Vino, I promised a long time ago to send you a copy of my mineral oil tax statement. My apologies for not doing it sooner. Here at at last is a copy. As you can see its not very complicated, I state how much biodiesel I have made in the three months and I break down my usage into road use , heating and electricity generation. I enclose a cheque for the total tax due.