Process for winter conditioning?

[Tony]

I steadfastly avoid winterisers for my bio and have thus far survived many winters without any problems with starting in the morning or blocked filters.  But, sometimes it's very touch-and-go and I don't much like that.

So here is my process, and I'm curious to hear other people's process, as I'm sure it can be improved!

When I'm satisifed the bio is settled and soap-free I pump it through a 1u filter into 25l drums.

I leave these outside to day/night cycle for at least a few days.  My reasoning here is that while the storage drum has plenty of thermal inertia, 25l drums don't, so will get colder (and conversely, in daylight get hotter).

When I'm in need of fuel I check the drums.  Here, one of three things has happened:

- the fuel is clear all the way through and it goes into the car without worry
- the fuel is clear on top and a layer of cream has formed at the bottom - the top layer goes into the car and the cream back into storage
- there are wax flakes and fluff all through the bio - I dare not put it in the car

The last case is always a disaster for me and I end up 1u filtering the flakes out and standing a few more days to see what happens, or just chancing it if it's not too dense - so far OK.

How does everyone else do it?

[Jamesrl]

The same as you Tony, decant into 25ltr cubies and out into the coldest place in the garden, dehind me shed.

I have been known to fuge the odd cubie or two whilst it REALLY cold, you'd be amazed at what comes out of apprently crystal clear bio.

[K.H]

Seems an awful lot of time and hassle to me, i much prefer to just stick a winteriser in, all the bio is then usable
I can see your reasons but not for me

[Dickjotec]

I run it off the storage tank, 400L max, into a jerry can and add 1L missfuel. It does sit in the settling tank for a couple of weeks before going into the storage via a J cloth rapped 10u filter so it has has a long time to settle befor use. As it goes into the tank if it is not crystal clear it goes back into storage.  I only use fully liquid oil at ambient  to make the bio. Had the Delica starting at -18 on the temp gauge, did struggle though.

[therecklessengineer]

I rely in the injection system putting enough heat into the fuel to keep it liquid.

I've found that with more modern vehicles (mid 90's onwards), the return to the tank is normally arranged to keep a small pocket of fuel in the tank recirculating. I believe that it is exactly to counter this problem with mineral diesel.

Certainly, my old Volvo (may it RIP) was very good in this respect. I could put it fuel that was solid waxy goop and it'd be just fine. I did have a few issues when it was really cold - the first start in a few days would require a heater under the car to liquify the fuel lines. Once running, it was fine.

The only troublesome vehicle  has been my old Landy. This returns to the tank in a different position to the feed. Anything that was in danger of solidifying or going waxy would result in a dead stop. Problem solved by wrapping the fuel line around a heater line a few times.

[Manfred]

Last year was my first and very mild so got away with just settling then using. Two batches ago while leaving in the garden to settle a week or so I've had waxy fallout, filtered ok before use the last batch nice and clear, but the temperature has lifted. Not being sure about winter I've got 5L of Coldflow 590. Cheap enough but with a cetaine booster. So with a mix and settle hopefully will make it through to spring.

[Tony]

I rely in the injection system putting enough heat into the fuel to keep it liquid.

I've found that with more modern vehicles (mid 90's onwards), the return to the tank is normally arranged to keep a small pocket of fuel in the tank recirculating. I believe that it is exactly to counter this problem with mineral diesel.

Certainly, my old Volvo (may it RIP) was very good in this respect. I could put it fuel that was solid waxy goop and it'd be just fine. I did have a few issues when it was really cold - the first start in a few days would require a heater under the car to liquify the fuel lines. Once running, it was fine.

The only troublesome vehicle  has been my old Landy. This returns to the tank in a different position to the feed. Anything that was in danger of solidifying or going waxy would result in a dead stop. Problem solved by wrapping the fuel line around a heater line a few times.

On the vehicles I've had the return does go to a pot the pickup is from, but only would heat the fuel effectively when the fuel level is low in the tank.  So I'm not sure that helps for suspended flakes.  (See photo of my Largo pickup below).

If the fuel system is adequately sealed I imagine the pump can handle sucking the wax through the fuel filter to an extent.

But that all sounds a bit dicey when out and about!

It does make me wonder about a small heat exchanger for biodiesel in the winter.

[Julian]

Heated filter as shown on the wiki, is probably the most effective counter measure I have.

The last couple of years my storage tank has been outside where wind funnels between two houses, so it should see coldest ambient.  That's fitted with a 1µ filter and in winter I only put small amounts in the tank at a time.

Only use selected oil for winter use and try to keep processing and finishing I  temperatures down ... I still advocate that from observation, high process temperatures can promote the stuff we've labeled HMPEs.

[Manfred]

Hi Julian. When you keep the processing temperature low what about demething and drying temperature or do you think that after processing it's ok to take up to about 85 to reclaim some meth before washing and drying.

[Julian]

This is quite a controversial point.   Some are adamant that "HMPEs" are wholly feed stock related, but from experience I'm fairly sure there's a link to process temperatures.  We really need to know conclusively what these "HMPEs" are.

I don't think initial drying of the oil has any effect, after all it's been used at very high temperatures before we get it, but I process at around 70°C and demeth at a maximum of 70 - 75°C.

[Tony]

I think this again feeds into the thought that any reverse reaction causes creamy dropouts when the temperate plummets.  I demeth up to 90C, if you're only going up to 75C that must leave more Methanol in the mix so less chance of reverse reaction and therefor less monoglycerides?

Last few winters I've done WBD so it'll be interesting to see how this winter goes with the two stage methanol starvation process.

[Julian]

I water acid/wash, so there should be very little or no methanol left in the final product.

[1958steveflying]

Two stage reaction demeth and settle, centrifuge and pump thru 2 3u polish pots into 400ltr storage, pump thru another 3u polish pot into the car. not needed winteriser since centrifuging.