Biopowered - vegetable oil and biodiesel forum

Biodiesel => Chemistry and process => Topic started by: Julian on March 15, 2013, 04:16:52 PM

Title: Remember that dark brown gunk me and several people were getting?
Post by: Julian on March 15, 2013, 04:16:52 PM

Had a bit of a result today.  Left a card with the owner of an Italian restaurant when out to dinner, about a month ago. 

He called yesterday and I collected this afternoon.  220 ltrs of dark but all liquid KTC oil, with hopefully and ongoing collection of around 100 ltrs a month ... fingers crossed.

Anyway while chatting to my new best friend, Enzo the owner, I mentioned the colour of the oil and said that was strange because he obviously changed the oil quite regularly and I would expect that colour from oil that had been used to death.  He recons that, as they fry a lot of floured calamari (and very nice it is too, it's the little, whole baby squid I've only previously found in Italy), it's the flour that turns it a dark colour.

Coupling this comment with my thoughts that what I was seeing previously was fine BCBs set me wondering.  I'll do a titration on his oil to see if it's over used, but could flour remain throughout the process and manifest its self at the wash stage?

Title: Re: Remember that dark brown gunk me and several people were getting?
Post by: nathanrobo on March 15, 2013, 06:46:53 PM

Not sure that this directly answers the question, but a few of us were talking earlier about BCB's each holding a bit of moisture and possibly depending on what the foods were, being acidic.  A high but fine distribution through the oil could have some effect on the lye and the reaction?

Title: Re: Remember that dark brown gunk me and several people were getting?
Post by: Julian on March 15, 2013, 06:57:24 PM

I've always believed that food particles harbour water and go to great lengths to get rid of them.  But I was wondering if flour, being so fine, manages to escape my filtration and glycerine settling.

Title: Re: Remember that dark brown gunk me and several people were getting?
Post by: greasemonkey on March 15, 2013, 07:17:30 PM

Maybe do a Dr pepper on a sample, then find some way of testing it. Boil the diesel off and see what's left, maybe?

I don't know, but I would tend to think that flour could be quite hardy, won't dissolve in much, and could carry through.

Title: Re: Remember that dark brown gunk me and several people were getting?
Post by: Jamesrl on March 15, 2013, 07:58:06 PM

Mmmmm! flour, I have a supply from a Fried Chicken place (not KFC) who change their oil very regularly but is as black as y'rat.

They use Flour with spices etc to coat the meat.

Title: Re: Remember that dark brown gunk me and several people were getting?
Post by: Head Womble on March 15, 2013, 11:12:11 PM

I can back that up,
one of my collections started doing fried chicken, but stopped about 6 months later (KFC opened up over the road),
their oil was very dark during this time.

Title: Re: Remember that dark brown gunk me and several people were getting?
Post by: Julian on March 15, 2013, 11:29:51 PM

Interesting, so it looks like it's true.  I'll try and do a titration on it tomorrow.

Would a page on the wiki describing various feedstock contaminants along with photos be of any merit?  Could probably amass quite a library over a period of time.

Title: Re: Remember that dark brown gunk me and several people were getting?
Post by: Julian on March 16, 2013, 12:43:41 PM

Just tested two of the eleven cubies, one titrated at 4 and the other at 5.  So not lightly used as stated.

All the same I'll try and make a batch exclusively from this oil and see if the gunk is evident.