Filtering feedstock

[nathanrobo]

I've been telling people that AFAIK feedstock only needs straining down to around 600mu before reacting.  And I still suspect that this is true.

I've known of the odd person that has intended fine filtering of feedstock prior to the reaction, which I've thought unnecessary, but in the light of this new era of open mindedness and experimentation, plus the fact that I have feedstock building up, waiting for a new processor, I've decided to give it a go.  I've also been googling to see whether the question had come up before and found one source (a bit old though and from France), suggesting that it'd be useful to remove phospolipides & gummy substances.  Does anyone have any observations?

My proposed evaluation is not too scientific, but may give an indication on whether this is a waste of time or not:

Do 1/2 dozen batches and record amount of chemicals used, difficulty washing, amount of glyc and any problems in the process.  Then do 1/2 dozen batches without filtering to see if there is any difference.  Are there any tests which could be... well a bit more objective??

 

 

[julianf]

Julian (brtp), i think, filters his feedstock, on (i think) the grounds that the BCBs probably hold a fair bit of moisture.

Ive been considering doing so recently, as id like to add a FPHE for heating the reactor, and i fear it getting blocked.

Would be interested to know if you find additional benefits

[Tony]

Mine is course filtered then settled in such a way that very little if any BCBs get reacted.  Keeps the Glyc clean too in case it ever gets used for a Babington or similar burner.

[julianf]

I actually find that the grime comes out with the glyc wash, and what is left is pretty smooth.  But thats still not much good for my own plans.

Nathan - that's something you may want to factor in somewhere -

Id say that the feedstock that's been glyc washed is somewhat different to the raw stuff that goes in.  That may be a consideration for your tests?

[Julian]

Julian (brtp), i think, filters his feedstock, on (i think) the grounds that the BCBs probably hold a fair bit of moisture.

Ive been considering doing so recently, as id like to add a FPHE for heating the reactor, and i fear it getting blocked.

Would be interested to know if you find additional benefits

Yup, always filtered my oil very carefully.  I have no proof, but as JF says above, I've always suspected that even microscopic food particles harbour moisture.  It's also far kinder on the pumps.  in nearly five years of making bio the worst that's happened to my one Leo was a mechanical seal and a slightly bent impeller blade ... and I only found that because the seal went!

Main filtering is done through a couple of home made socks ... http://www.biopowered.co.uk/wiki/Tips_and_wrinkles_1#Homemade_sock_filters

[julianf]

im guessing you pre-heat somewhere, to get all those HMPEs through that you are so fond of?

; )

[Julian]

im guessing you pre-heat somewhere, to get all those HMPEs through that you are so fond of?

; )

Me? Not normally depends on the source of the oil.  If it's contaminated with water or of unknown origin then it goes through a Frymax tub with the bottom replaced by gauze which sits in the top of this ... http://www.biopowered.co.uk/wiki/Simple_fat_melting_and_de-watering_tank  where it gets a rough dewatering at 65 - 70°C.  Water is drained off and it's cooled.  Any liquid oil is pumped through the socks and settled.  The solid is saved for grotty batches during the summer.

[nathanrobo]

I actually find that the grime comes out with the glyc wash, and what is left is pretty smooth.  But thats still not much good for my own plans.

Nathan - that's something you may want to factor in somewhere -

Id say that the feedstock that's been glyc washed is somewhat different to the raw stuff that goes in.  That may be a consideration for your tests?

I've found that feedstock goes fairly clear after glycerin washing. But I was thinking collecting my oil into a flat drum clip top 205 litre with an immersion heater in it, then sucking it up via a foot valve and strainer and pumping it into a storage drum via a 200 micron stainer, then fuging it in the drum.

Then when I get my processor up and running, I'd just heat, dewater (which should be easier?), then glyc wash and process all in the processor. 

What du think?  Where are the holes in the process?

Btw I though this might be another 'nathan going over the top' scheme, but pleased that others are filtering feedstock, so might be worth well!

[nigelb]

To give this experiment any sort of credence may I suggest that any batches are made with the same feedstock. You'll have to blend "all" the oil together so that each batch has the same level of contamination, FFA's, water and anything else that might be in it. I suspect that different oil blends will effect any results.

Just my thoughts.

Me...I just filter through a sieve. It's worked well for me over the last six years. The glyc wash tends to remove most of the crap.

[Tony]

I settle my oil in an 1100 litre steel tank, a lot of water seperates on its own without heating.

[nathanrobo]

To give this experiment any sort of credence may I suggest that any batches are made with the same feedstock. You'll have to blend "all" the oil together so that each batch has the same level of contamination, FFA's, water and anything else that might be in it. I suspect that different oil blends will effect any results.

Just my thoughts.

Me...I just filter through a sieve. It's worked well for me over the last six years. The glyc wash tends to remove most of the crap.

I've been doing the same (via a 400 mu sieve), then glyc washed.  Even told people not to do it, but for the reasons cited by some of those already filtering (as apposed to straining), I'd like to give it a go.  Any advice I give will then be based on more than just a view.

In other words I can't diss it unless I've given it a go!

Ref the diving of the batches, that's going to be difficult, so need to give it some thought.  Maybe I could course filter half a drum at a time then fine filter the other half and go that way until I use it. Like I say, I'll give it some thought. 

Besides experimentation, as first mentioned the other reason for doing this is not to be storing manky feedstock for a few weeks.  It's be nice to have really clean oil in a number of drums.  Having a really clinical little process seems quite appealing.

[Head Womble]

Another benefit I can see from filtering the oil is reducing the amount of BCB's that sick to the heater element.

I only strain my oil down to about 1.5mm and do have to clean my element regularly.

I'd love to filter it properly, but a lot of my oil is semi solid so it would have to be done when hot.

[nathanrobo]

Well... I'll get on with and begin posting again when I process the first batch.  I've put most of the kit aside to do it

:-)

[Julian]

Another benefit I can see from filtering the oil is reducing the amount of BCB's that sick to the heater element.

I only strain my oil down to about 1.5mm and do have to clean my element regularly.

I'd love to filter it properly, but a lot of my oil is semi solid so it would have to be done when hot.

Good point, I'm still using the same heating element as when I started.

[nathanrobo]

Another benefit I can see from filtering the oil is reducing the amount of BCB's that sick to the heater element.

I only strain my oil down to about 1.5mm and do have to clean my element regularly.

I'd love to filter it properly, but a lot of my oil is semi solid so it would have to be done when hot.

Good point, I'm still using the same heating element as when I started.

Suppose that wouldn't b a prob if I opt 4 dual cone, water heated SS jobbie? But i'd go with the idea that BCB's if high in distribution may trap in a fair bit of water. 

The question of Phospholipids /gummy stuff mentioned originally may be relevant for more reasons that I had originally expected.  Firstly they seem to have a detrimental effect on emissions, but also are very similar to mono's and di's in nature and gellify to cause filter plugging etc.  Could this be the waxy stuff that is melting at 50deg and going solid at between 40 - 45 deg?

These links are well worth some consideration and discussion:

http://b100research.com/company-news/effect-of-phospholipids-on-the-average-biodiesel-producer

http://www.biofuels-news.com/content_item_details.php?item_id=400

http://www.biodieseldiscussion.com/forums/showthread.php?t=15749

"Well after an afternoon of research, I think I found the answer. And this may bear on the mysterious filter clogging problems of near-spec biodiesel.

Molecules like phospholipids and diglycerides, which have both polar and nonpolar components, can form worm like micelles in the presence of small amounts of water. These long micelles can become long enough to act like polymers, become entangled and form gels. I haven't found any reference that talks, in particular, about mono or diglycerides and these tubular micelles, but I don't see why these molecules would not be subject to the same behavior."