[Stoves] Leftover alcohol.......was Re: Char from coir Re: Biochar Inquiry

[Philip Lloyd]

Yes, there are a zillion alcohols - don't forget glycerol, which has 3 -OH's
in one molecule!  And yes, some are formed during fermentation, but there
tends to be less of each, the longer the carbon chain.  You will get a bit
of propanol ("rubbing alcohol") less butanol ("butyl alcohol"), less still
pentanol ("amyl alcohol") and so on.  These make up a large fraction of
"fusel oil" left over after you have redistilled the crude ethanol you first
get from the fermentate - and the fact that it is referred to as an oil
warns you that it is not too good a fuel. It is quite difficult to get it to
combust cleanly, and if you don't, you land up with a lot of aldehydes and
other nasties in the air which smell terrible (fusel oil itself is pretty
grungy smelling). Many of these higher alcohols metabolise with difficulty,
meaning they are a bit poisonous, as the body can't get rid of them easily -
which is why alcohol for drinking is usually distilled at least twice (to
minimize the residual fusel oil in the product) if you go for batch
distillation.

 

Hope that helps

 

Prof Philip Lloyd

Energy Institute

Cape Peninsula University of Technology

PO Box 652, Cape Town 8000

Tel:021 460 4216

Fax:021 460 3828

Cell: 083 441 5247

lloydp at cput.ac.za

 

 

 

From: Stoves [mailto:stoves-bounces at lists.bioenergylists.org] On Behalf Of
Crispin Pembert-Pigott
Sent: 16 April 2014 07:15
To: 'Discussion of biomass cooking stoves'
Subject: Re: [Stoves] Leftover alcohol.......was Re: Char from coir Re:
Biochar Inquiry

 

Dear Paul

 

I was contacted by Simunye looking for a way to turn these alcohols into
some form of a useful product. As I recall there were 112 types of '-ol'. I
did not realise there were so many different ways to connect an OH to a
carbon construct.

 

So methanol and ethanol are two of them, and there are a huge number of
others that are formed during fermentation. I think perhaps Prof Lloyd is
the right person to make a comment on what they are and (perhaps) how
dangerous they are as domestic fuels.

 

All it means from a practical point of view is they have difference boiling
points so they are separated from the main products.

 

Regards
Crispin

 

 

 

Crispin,

Please provide more info (or links) about the LEFTOVER alcohols from ethanol
refining.

Paul



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