I have a food manufacturing client who said he has to dispose of his oil due to excess oxidation. Before we pick up the 1st load I wanted to go over some questions with the more chemically gifted people in this community.

My concern is what exactly does excess oxidation mean to me, the biodiesel producer? I have a general understanding it's just a breaking down of the oil itself, being organic and all, but will this increase FFAs, or will it render the oil unusable?


Thanks guys,
Ryan

All oil starts oxidising as soon as it is heated in the fryers.Excess oxidation will make the oil darker in colour and push the acid value up,which is going to give you lower yields-can you get a sample to see how high it titrates?(it might not be any worse than normal)If it oxidises further you can run into polyimerisation

As oxygen attacks the oil, the molecules break up and free fatty acids are created.

Okay, so it's just very cooked oil. Okay what I'll do is ask for a sample of the product, and we'll see where it titrates. I wouldn't mind doing large scale esterefication to bring down the acid value. I'll let you know how the sample is, hopefully nothing above a 15 or something lol

As the double, triple, poly bonds get heated excessively they start to break down. As the comment before you start to get polymerization. You also start to develop Trans fats and other various configurations. Hence why it is unhealthy to cook oil at very high temperatures and for extended periods of time. Rather if you do cook with oil, try to keep the temperature down, and keep the cooking minimal.
The body can process unsaturated fats better than it can saturated. Unsaturated has double bonds which the body can break down. Saturated is all single bonded and is very difficult to break down. These therefore should be avoided. Too bad they taste so good..

Regardless of what happens to the fatty acid structure, as BD producers the main concern is over the amount of fatty acids which have been broken away from the triglyceride. Your titration answers these problems. Fatty acid structure of your biodiesel will determine its cold flow and oxidative stability properties

That's what I meant to say

You guys are absolutely fantastic. This community is such a brilliant success because of the overwhelming willingness to help each other.

I really appreciate all the help I receive from all of the people in various trades.



Ryan

quote:

I have a food manufacturing client who said he has to dispose of his oil due to excess oxidation...

Are you sure it 'has excess oxidation' (must have been their words) due to overcooking, or did it go rancid, or was there a mystery cause neither you nor they even considered... a mystery...

Probably one of the first 2. Just that you didn't specify. I could see a stock of blue plastic drums of oil going rancid due to declining orders. My uncle collects sunflower oil from a company that has to order more than it will need each month as a business necessity. Although if the containers are never opened or are resealed properly, they won't go stale for at least 5 years.

Just wanted to clarify, since you said it was a food manufacturer and not a restaurant.

Good post Reece123! This could explain why despite having a good fuel, I end up getting acidity and oxideation after a while in stored fuels. I crack very ugly waste oil (solid hydrogenated gunk that is rancid most of the time) See my last post in the thread <rancid oil> by dhillis

quote:

Originally posted by Frogmobile:
Good post Reece123! This could explain why despite having a good fuel, I end up getting acidity and oxideation after a while in stored fuels. I crack very ugly waste oil (solid hydrogenated gunk that is rancid most of the time) See my last post in the thread <rancid oil> by dhillis

Yep and the more FFA's you have floating around the more it will create too..

I notice you're from Queensland, I worked in the coal seam gas fields there for about 6 months Down near Roma, Wandoan, Emerald and Rocky..the amount of coal trains constantly going every 5 minutes is crazy! all going north to china by boat.. apparently they store the imported coal in the ocean too.. crazy stuff..

Yap, crazy alright, so much for the so called Green House Effect (whilst you try to save the planet with your biodiesel!)

ha all our biodiesel efforts combined per year would probably only off set only one of those huge coal trains that go by every 5 mins..