Reprocessing with HMPEs

[Tony]

This is a wild stab in the dark type experiment.

I've dried 80l of WVO, and added my accumulation of HMPEs this winter (45l) for a grand total of 125l (sucked in via Nige's very sucky venturi - though it took a little while!).

The whole lot has been heated to 100C and a sample taken shows nice clear liquid (all HMPEs melted).  I'll keep this sample to cool and sit for a few days.

I also took a sample to do a 10/90 on using one of Nathanrobos fabulous centrifuge tubes, and it couldn't confirm things better if it tried - 6.4ml of dropout from a 10ml sample.  Which is exactly the ratio of HMPEs to WVO.  Interestingly, and I don't know if this is significant, the liquid above the dropout was quite cloudy. Monoglycerides?

So I'm going to react it with 16l Meth (20% of 80l) and 550g NaOH (based on how the WVO titrated plus a little for luck - it is all nice and dry)!

So anyone want to take a bet on the volume of HMPEs I'll get at the end of this?

[Rotary-Motion]

cloudy - only see thisn when  clear oil is mixed with rough stuff via a pump, like emulisified, could get the same with pure fat and clear oil, not sure...

[Tony]

The layer above the dropout is mostly Methanol with a little bit of in it rather than fatty/high melt oil suspended in clearer oil so could be anything.

[1958steveflying]

cloudy - only see thisn when  clear oil is mixed with rough stuff via a pump, like emulisified, could get the same with pure fat and clear oil, not sure...

This is cloudy meth in the 10/90 test above the dropout, are you referring to this or to cloudy oil ?

[1958steveflying]

This is a wild stab in the dark type experiment.

I've dried 80l of WVO, and added my accumulation of HMPEs this winter (45l) for a grand total of 125l (sucked in via Nige's very sucky venturi - though it took a little while!).

The whole lot has been heated to 100C and a sample taken shows nice clear liquid (all HMPEs melted).  I'll keep this sample to cool and sit for a few days.

I also took a sample to do a 10/90 on using one of Nathanrobos fabulous centrifuge tubes, and it couldn't confirm things better if it tried - 6.4ml of dropout from a 10ml sample.  Which is exactly the ratio of HMPEs to WVO.  Interestingly, and I don't know if this is significant, the liquid above the dropout was quite cloudy. Monoglycerides?

So I'm going to react it with 16l Meth (20% of 80l) and 550g NaOH (based on how the WVO titrated plus a little for luck - it is all nice and dry)!

So anyone want to take a bet on the volume of HMPEs I'll get at the end of this?

I'm making a guess at 45l but it would be good if it turned out to be much less. We have been meaning to do a 10/90 on Hmpe's but your results have given the answer.

[Rotary-Motion]

cloudy - only see thisn when  clear oil is mixed with rough stuff via a pump, like emulisified, could get the same with pure fat and clear oil, not sure...

This is cloudy meth in the 10/90 test above the dropout, are you referring to this or to cloudy oil ?

oil

[nathanrobo]

I melted a little less than 10ml of HMPEs and tried to dissolve in Meth (about 90ml)  a while ago and most or all of it dropped out.  Now I have some meth again, I'll try to repeat and post photos.

I'm not sure that what we are calling HMPEs are High Melting Point Esters.  I'm not even convinced that what we are all referring to as HMPE's are all the same substance.

I've settle fuel for some weeks outside in steel drums and then pulled into my polishing tank and centrifuged.  I seem to get a consistent sized cake each time:



I've put these in a glass jar and melted on top of the wood burner, then left it to settle by the side of the burner and it's gone solid again (quite firm).  I find this really strange!  I know that what's pulled out is concentrated, but there's nothing in my process that is this solid, the glyc is fluid, the oil is fluid, full reaction, water washed , dried bla bla bla.

[Tony]

That's what I thought,  liquids in, solids out? Umm?

[julianf]

This is just a quick idea -

Blends can alter melting points - eg when people blend palm etsers with rape esters to get better cold temp performance.


So -

Might that be the case with the triglycerides also?  That the feedstock, although liquid, may actually be a blend, with the higher melting point fats being kept in suspension by the others?


If so, you could imagine a scenario where part of the feedstock 'blend' gets converted, whilst part of it remains as a triglyceride?

[julianf]

Nathan -

Do you have enough from your centrifuge to run a dr pepper reaction?

[nathanrobo]

Nathan -

Do you have enough from your centrifuge to run a dr pepper reaction?

Got maybe 200 grams. Can try a Dr. Pepper tomorrow.

[Tony]

5 days of settling so far, and a sample from this batch is showing only a very thin layer of HMPEs at the bottom.  Not done waiting yet though, got some nice cold weather coming to properly chill it (very obliging of it)!

[nathanrobo]

5 days of settling so far, and a sample from this batch is showing only a very thin layer of HMPEs at the bottom.  Not done waiting yet though, got some nice cold weather coming to properly chill it (very obliging of it)!

by observation, the fuel that produced the HMPEs in the picture had settled for some weeks, but didn't have detectable HMPE's.  When I pulled the fuel out of it's drum and into my new polish / dispense tank, it got sucked in through about 20 feet of clear reinforced 3/4" hose. The hose pulled from the bottom of the tank and if there were HMPE's that had settled out it would have gone white or at least cloudy in appearance and then clear.  This didn't happen, just clear (ish) fuel all the way through.

Seems to me that some of this stuff can form but then be suspended.

[julianf]

I keep meaning to buy a flea for my magnetic stirrer - Tony has found that agitation in his car causes more fall-out from bio, and im wondering if gentle agitation may help flocculate hmpes when its cold also.  Ie in keeping with your comment about this stuff forming, but remaining in suspension.

Ive wondered before if the water wash benefits im told of may also be due to the water giving somthing for the HMPEs to form on and then be removed.

Does anyone have any findings on how the titrated water wash possibly affects HMPEs yet?

[Tony]

Initial mix was 45l creamy HMPEs and 80l WVO (36% HMPEs).  Whole lot heated to 100C and melted to clear liquid.

I took a sample from this, which is currently showing about 20% HMPE formation (11 days on).

I made bio with this mix, and took a sample (after bubbling trace Methanol off).  This shows about 3-4% HMPE formation tops (11 days on).  The weather has been bitterly cold - plenty of thermal cycling!

I'm hoping this is representative of the 125l I've got standing - if so I'm definitely keeping all my HMPEs from this point forward for reprocessing.

I don't understand why, but it seems to work!