I'd like to hear people's experiences testing for conversion with ethyl esters.

Thanks,

I've got some ethyl biodiesel that I made from corn oil. Is the 3/27 test done with methanol good enough?

That's what I'm not sure about. We made some test batch ethyl esters with store-bought virgin soy oil, and the 27/3 test seemed to work perfectly with ethanol. I'll have our technician test it out with methanol. A previous batch made with used fryer oil failed a methanol-based 27/3. I'm still trying to understand what's a real pass and a real fail, seeing as there doesn't seem to be a lot of data on using these tests with ethyl esters.

I tried this using ethanol and even isopropanol. The only conversion test I did was a SAFTEST though and I honestly don't trust that machine at all. However, the biggest difference I found using ethanol was the problem with enhanced solubility. LOTS more free glycerin and soaps were in the biodiesel phase due to the higher solubility of the ethanol and the fact that you just use a larger volume of it.

Why don't you trust SafTest?

quote:

Originally posted by kumar:
Why don't you trust SafTest?

My biggest problem with the machine is that there is no feedback from a bad sample.

There are also a few places in our process that the machine will give erroneous readings... that combined with the lack of feedback meant we gave up on it altogether and just got a GC

Kumar; What's SafTest? I will do 3/27 using methanol on my ethyl biodiesel derived from corn oil, soon. BWilder; What does the sodium soap do to your Gas Chromatograph colum? Triglyceride fatty acids don't dissovle much in methanol, so a 3/27 conversion test might be good enough. I don't have a GC and they want a lot of money to test an ethyl biodiesl sample at a professional, commercial lab.

SafTest is made by MPBiomedicals, and is an alternative means of testing for total glycerin. We like it more than GC because it seems to be at least as repeatable, if not moreso, is apparently just as good for ethyl esters as methyl esters, and is much easier to train people on.

I did a 3/27 methanol conversion test for the ethyl biodiesel (derived from corn oil) that I made. There is a very little bit of insoluble material at the bottom of the test solvent. I expect this is a usable test for ethyl biodiesel conversion. I don't know what the specks of insoluble material is. Maybe my lab equipment was dirty when I made this approximately 100 grams of ethyl biodiesel. I would say this almost passes. The material at the bottom of the methanol solvent is not liquid droplets, which is what I would expect from new corn oil. I treated the crude ethyl biodiesel with magnesium silicate that should have removed glycerin and soap and excess ethanol and some water.