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Teak wood chip/shavings for biodiesel dry wash

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October 29, 2015, 06:17 AM
Teak wood chip/shavings for biodiesel dry wash
Hi Everyone,

I make bio diesel using the gl-eco processor design.I make it from chicken fat.I do demeth the bio diesel but i want to filter out the soap and remaining methanol using wood chips.

Can I use teak wood chips/shavings?.I need to use wood that is available in India.Kindly let me know how I can do this.I'm currently getting a 55 gallon drum ready for this.

Thanks in advance.
October 29, 2015, 11:37 AM
Hi Clayton.Mas92.

I believe that anything cellulosic is suitable, but hardwoods are preferred to softwoods due to the likelihood of containing less plant resin.

Can someone else help out here?

October 30, 2015, 07:25 AM
Hi Paulus,
Yes thats what I was also led to believe.

Reading past posts however I've always been confused ie do the hardwood chips remove soap by the action of the tannic acid (converting the soap to ffa's as ion exchange) or do they have zeolitic properties, thus trapping the soap molecules.

Also are the chippings able to trap small quantities of glycerol?
October 30, 2015, 01:35 PM
Stephen A. Boyd PhD told me it's to do with polarity - cellulose has lots of OH- groups all over the molecule that each exhibit a net negative charge, whilst the Na+ or K+ end of the soap molecules are net positive. Opposites attract and thus the soap and cellulose bind together. It's similar to hydrogen bonding, but I do not know in this case whether the effect could be described as hydrogen bonding. Probably not.

As the glycerol ends up having three OH- groups attached to it (full conversion) which are net negative, I suspect they will not be attracted to the cellulosic OH- groups. This is also likely to be the case, I think, for DG's and MG's.
November 02, 2015, 11:11 AM
Thank you everyone for your replies.Its really nice to see a very helpful community on this forum.From your replies I figure teak wood chips are ok. I will upload pics of my setup once its ready.I will be using a 1/4 hp pump to pump the bio diesel from my settling drums into this filtration drum.

Any advice on how to avoid the notorious spontaneous combustion which I've heard so much about?
And after how long should i change the chips/shavings?

Thanks again.

November 02, 2015, 07:26 PM
I think the spontaneous combustion thing only can happen if the column is empty and if the ambient temperature is very high.

I've never had it happen with woodchips in a column with no bio. But have had it happen this last July with wvo soaked blue roll at the top of a black plastic waste bin. It was mostly starved of oxygen with the lid closed and I had been smelling burning all day.
When I finally realised where it was coming from I dragged the thing into the field, opened the top and it burst into flames!

Get yourself a soap test kit, when the bio exiting the woodchip approaches the spec for soap, it's time to change them.