A proposed method to improve the speed and efficiency of BioDiesel production.

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Target time: 1 day, from raw oil to finished, clean dry BioDiesel.

First proposed on this discussion forum thread. Moved here on 18 June 2006.

Resulting fuel meets ASTM D6751 Standards.
Thanks to SpeedRacer for posting the Magellan Labs results here.


Direct Link to latest procedure..click here

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IMPORTANT: BioDiesel production involves hazardous chemicals and processes, which can be lethal or seriously damaging to health, property and the environment if proper care is not taken.

It is your responsibility to protect yourself, those around you and the environment from harm.

Failure to take the proper precautions could result in death, serious injury, loss of property, prosecution.

Do not attempt any of these procedures if you are not familiar with Hazardous Material handling procedures and regulations, electrical installation regulations and proper procedures, local environmental protection bylaws etc.

This process is intended for people who are experienced in the safe and responsible handling of the materials and equipment used in BioDiesel production.

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Introduction

The most common methods of making BioDiesel usually include a water-based washing process, to remove soap, glycerol, catalyst, debris and methanol from the BioDiesel reaction product.

These materials must be removed, to protect the engine and its components from damage and poor performance.

However, water-based washing has disadvantages, which can include:-

Time consuming, usually needing a few days to complete

Prone to causing emulsions, which can result in loss of fuel and time wastage.

Uses water, which may be a precious commodity

Water then needs to be removed from BioDiesel - time consuming and energy intensive

Another method of cleaning the BioDiesel uses Magnesol, a waterless process, but one which introduces a fine powder to the fuel, which must be completely removed before use.
This can be a disadvantage and offputting to some, who feel uneasy about adding a potentially abrasive powder to their fuel.

Another Approach

The new proposed method does not use water or magnesol.
Instead, it uses a simple principal - the fact that soap and glycerol and catalyst and debris can not exist in solution in BioDiesel.

Why then, does freshly processed BioDiesel contain soap and catalyst and glycerol?

The reason is that the freshly reacted BioDiesel contains methanol. Methanol readily mixes with BioDiesel, and is an effective solvent of soap and glycerol.

If we can get rid of the methanol, the BioDiesel will be unable to hold any soap or glycerol or catalyst, and we will be able to extract pure BioDiesel easily.



The Method


Step 1 - react the oil as usual
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Treat your oil feedstock as usual, filter & dewater if necessary, titrate, and react.

Immediately after reacting, I suggest you add 5% water by volume, mix thoroughly in the reactor for 15 minutes, and leave to settle for an hour or more, to allow the unwanted byproducts to settle. This improves BioDiesel yield and removes some soap and methanol and catalyst.

Drain off the byproduct and store safely for later use or disposal.

Your raw BioDiesel is now ready to be cleaned of any remaining unwanted materials, which will include methanol, soap, glycerol, catalyst, water, and particulates.

Step 2 - liberating the soap, glycerol & catalyst
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We now need to remove all the remaining methanol from the BioDiesel.

There are a number of ways you can do this. The most energy efficient will be to leave the BioDiesel in an open topped container in the sun, but this can take many weeks to complete, and can introduce rainwater, dust etc, to the BioDiesel. It also releases methanol to the atmosphere, which is environmentally undesirable.[ Edit added 19 June 06 GL ]

Instead of washing the methanol away in water, we want to evaporate the methanol, and ideally recover the evaporated methanol for re-use and to limit its release into the air.

[ Section edited 19 June 06 to propose an improved means of limiting release of methanol to the environment - GL ]

To do this, I propose the methanol be heated in a sealed container, with a fractionating column and condenser to recover methanol and separate it from any remaining water in the process.

This is where I want to concentrate development of the process, as it is critical for its future broad acceptance to limit its environmental impact.

I'd welcome all suggestions for helping to ensure the distillation process remains repeatable and reliable for all.

When no more methanol remains in the BioDiesel, you should stop the process and remove any floating soap/methanol scum from the surface.

Step3 - Test for remaining methanol.
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Heat a small sample, say 100ml, up to 80C in a heat resistant glass flask. During the heating process, you should see no signs of any bubbles or gassing in the liquid. If any bubbles appear, you need to continue with the methanol removal process.


Step 4 - Filtering the BioDiesel
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Move the BioDiesel into a clean dry tank, through a 100 micron bag filter.
Recirculate the BioDiesel through the 100 micron filter, changing as necessary, until the filter shows no signs of capturing any more soap.

Change to a 10 micron filter and recirculate, changing the filter as necessary, until the filter shows no signs of capturing any more soap.

Cheap, washable 14" bag filters are ideal...




Step 5 - Test for soap
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Your BioDiesel should now be clean and dry and ready for use, but to be sure, test it first...
Fill a glass jar 1/4 full of clean water. Add your filtered BioDiesel so the jar is 3/4 full.

Gently shake the jar for a few seconds and leave the jar to sit for 1/2 an hour.

Don't shake it to death, you don't want to make mayonnaise out of it, or you'll get microdroplets of oil suspended in the water, which will make it look milky and you'll think it's soapy and waste your time trying to remove something which doesn't exist. A few gentle tumbles will soon tell you if you've got soap.

The water at the bottom of the jar should be perfectly clear, the BioDiesel will be cloudy, as it will have water droplets in it. But the water should be clear.



You may feel uneasy about using a filter as large as 10 microns. There's nothing to stop you using a finer filter before use, but I believe it may not be necessary.

Using a microscope, I cannot see any particulate matter at all in the BioDiesel, whereas I could detect particles of less than 10 microns in the raw oil before processing.

I believe these particles end up binding to the soap and glycerol, and are effectively removed when the residue is separated. This process continues when filtering, any small particles (sub filter pore size) seem to bind with larger entrapped soap matter in the filter.

Conclusion
I believe that this new proposed method should speed up the complete process from raw oil to finished product to only 24 hours. This has been my experience on 2 x 80 litre batches and several small test batches, although in my trials I evaporated the methanol. A heated still should speed the process further.

Developing a reliable and easily achievable distillation process for recovering the methanol from the biodiesel and the glycerol byproduct should be the prime focus now, based on a suggestion given by GM [ Edit 19 June 06 GL ]

Good luck , I hope it works as well for you as it does for me.

[ Edited 27 Aug 06 to add ASTM D6751 report link at top of the post - GL]

This message has been edited. Last edited by: GrahamLaming,

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