I suppose many friends wants to save time in glycerine settling and washing Biodiesel.
Certainly, centrifuge can save time in glycerine settling, particularly in very cold weather, it is a trouble that glycerine becomes solid and disperse in the biodiesel during settling, hence, I suppose centrifuge is a good method and device to handle and ensure good glycerine settlement.
Also, bubble washing is a good method in purifying biodiesel; however, it really takes too much time for this process. I really wonder how the commercial biodiesel manufacturers solve this problem. I have some information from an Austria biodiesel manufacturer that they can manufacuture biodiesel in a continuous process whereas the biodiesel meets DINV51606 or ASTM IP-121. Hence, I suppose all the commercial manufacturers have washing process to ensure biodiesel manufactured meets international standards. However, how can they save time or even can immediately getting biodiesel using continuous process?
Does anyone having any idea in expedite the washing process? It is time-consuming process that I suppose all commercial manufacturers having methods in saving time.... but how?

Thanks for information...

Herman

Large manufactureres would solve this problem by having large multiple tanks.. one for the main reaction andt hen seperate washing tanks.

That way they can turn our biodiesel that has been washed in the same time it takes to do the initial reaction.

Herman,
If you were to contact Energea of Austria (for example) they would email you a brochure (as they sent me) stating that their reactor features "phase separators" at every stage (centrifuges, essentially) instead of settling tanks, is Siemens S7 automated, and requires steam, compressed air, methanol, potassium hydroxide, sulphuric acid, electricity, and liquid nitrogen. This gives them a throughput of 5 metric tonnes of, you guessed it, DIN standard BD. It'll only cost you $EURO 3,000,000 (without the fatty acid optional extra module). I would suggest your problem would not be just its cost but where to find 5 tonnes an hour to feed it.
Simo,
I think it would be a safe assumption that they are not using more or bigger tanks (I believe the only ones used are for storage of input and outputs), but solutions that are a little more energy-, accuracy- and technology- dependent.

Wooly of the SBC (dreams down in flames div'n)

Dear Wooly,
Thanks for your information.
I suppose the centrifuge process is important and useful in the process of separation of biodiesel and glycerine after trans-esterification. It save time effectively for this process.
However, do you mean that even for the washing process, Energea can save time by making use of centrifuge? Anyway, If the continuous process mentioned is practical, they must solve the problem of time-consuming process of washing such that the biodiesel manufactured meets DIN V51606.
You seems having some information about Energea. Would you please inform me more about their washing process for ensuring the quality of biodiesel meets the standard but save time in the washing process. (My concern is mainly in washing process as I know many manufacturers using centrifuge to speed up the separation process of glycerine settling) but washing process really a trouble, it may cause white sludges in the clear biodiesel after adding water...it may cause clear biodiesel turn hazy and it takes long time in bubble washing and settling. Dave has suggested several days. It is really time-consuming...)

The wash is indeed slow, but tanks are cheap and we don't have to stand and watch the washes in progress. The air flow separation times and water changes can be automated with timers and valves.

Energea use distilled water and recirculate it. They also produce potassium sulphate fertiliser in paste form. I assume they have a reverse osmosis plant to extract the water for reuse. They are also very energy efficient using about 1.5% of their biodiesel to run a power generator which makes hot water and steam from it's "waste" heat.

It's all great stuff if you need to process 5 tonnes per hour with accurate quality control. Not because of the time factor (rpt - tanks are cheap), but because at these flow rates, used water disposal would cost £oads.

Hermann

I don't really have any more information than what I've relayed to you from their publicity. Simo and Dave are right - it may be slow, but anything worth doing is worth doing properly. You could ease the pain of the wash by doing more at once.
The big boys have their toys; they come at a price, but when you have customers to supply, the price is possibly more realistic.

Wooly