Ambient processing

[countrypaul]

I've just put a batch of rough oil/fat in a barrel with some ASM and methanol, normally I would give it an hour to process at 60C, but this is between 5 and 10C. Can anyone based on their past experience give an idea on how long this should be left to react? Based on normal princples 1 hr at 60C would require about 3 days, but since there is no agitation will it need longer? My past batches like this with good clear oil got left for a couple of months in summer, can't remember why, but did achieve an easy 27/3 pass.

[Chug]

I've never done it without some sort of mixing Paul, even if only a short shuggle of the cube, so I wouldn't like to say how long with no agitation, maybe Dave has tried it and can enlighten us?

[Dickjotec]

How much oil is there?

[countrypaul]

How much oil is there?

4 barrels (ex mango chutney) each with about 25L of oil and 3.5L of methanol/asm

[dgs]

I've just put a batch of rough oil/fat in a barrel with some ASM and methanol, normally I would give it an hour to process at 60C, but this is between 5 and 10C. Can anyone based on their past experience give an idea on how long this should be left to react? Based on normal princples 1 hr at 60C would require about 3 days, but since there is no agitation will it need longer? My past batches like this with good clear oil got left for a couple of months in summer, can't remember why, but did achieve an easy 27/3 pass.

I've never done it without any agitation. In a 20 litre container with a few shakes it works fine, even outside in Winter.

When you say 'normal principles' you mean the rule of thumb of 10degs lower= double the process time. For whatever reason it seems not to apply to our process. Biggest drawback is the time the glycerol takes to drop but as regards the actual process you won't notice any difference (mixing aside)

I've been processing at ambient for a long time and must have saved a lot on electricity, especially at todays prices and more so what they will be in the New Year.

[DavidA]

All this would seem very confusing, particularly to someone coming to the game from scratch.

While the ambient processing must work (dgs uses it and gets results) it does seem to fly in the face of everything that is put out on the web.
Reactions generally require heat. I think that is accepted knowledge.

But is the downside of the ambient processing simply the length of time it takes (possibly weeks instead of hours), or is there something else going on ?

Maybe we could have a group-trial. Everyone makes a, say, 10 Litre batch in a cubie following the same Meth/ NaOH mix. Then report back the results ?

[countrypaul]

I gave the barrels a good stir but within a couple of minutes a thick layer of methanol/methylate had appeared on the top. I may get a chance to check them (and stir them) late in the week when they have had 4 days to react. I wil try and report results as and when I can check them.
The oil was fairly poor in appearance (did not titrate it) with a lot of fat present, so not easy to compare with decent clear oil as far as results go.

[dgs]

If you give them a good stir a few times during the first 24 hrs or so I'm sure it will work ok.

As you are doing a reaction on poor, non glyc washed oil surely you are wasting your precious ASM. Just use a bit of cheaper sodium.

[dgs]

All this would seem very confusing, particularly to someone coming to the game from scratch.

While the ambient processing must work (dgs uses it and gets results) it does seem to fly in the face of everything that is put out on the web.
Reactions generally require heat. I think that is accepted knowledge.

But is the downside of the ambient processing simply the length of time it takes (possibly weeks instead of hours), or is there something else going on ?

Maybe we could have a group-trial. Everyone makes a, say, 10 Litre batch in a cubie following the same Meth/ NaOH mix. Then report back the results ?

There is so much mis-information on the web about all aspects of biodiesel. When I started making bio I had lots of questions that no one seemed to be able to answer. Most of what I say comes from lots of testing and experiments over the years.

The 10deg/double time thing is just a rule of thumb and doesn't apply to everything. It doesn't seem to apply at all to our process. I've processed 500 lts in an outside IBC in mid Winter at no more than 5degs and it doesn't seem to take any longer.

I don't think there is any need to do more trials on this. Many on here now process at ambient.

Just to confuse you further there is also Julians intermittant pumping method. I use my pump for 8 mins per stage and I think Julian has now reduced his mixing even further.

[countrypaul]

If you give them a good stir a few times during the first 24 hrs or so I'm sure it will work ok.

As you are doing a reaction on poor, non glyc washed oil surely you are wasting your precious ASM. Just use a bit of cheaper sodium.

I am trying to tidy up alot of stuff at my father's that I should have done some time ago but various little things have been getting in the way!
The barrels are 60 miles away so not easy to give them a good stir a few times in the first 24hrs, they got one good stir and have them been left. You are right about using ASM, but I had nothing else around so decided to use what I had at that point. Not actually sure how poor the oil is, it doesn't look good, but has been settled, filtered and had no free water. Not sure if the gel present was just due to the temperature, or fat. I cannot remember where it came from, but do know it has been stored for over 2 years - and could be much longer! No mould in the containers it came out of which was a bonus. As I said earlier, I may get a chance to check them on this coming thursday and give them another good stir - might even try a 27/3 if all the methanol has been dissolved.

[WesleyB]

Can anyone say how long to react ?  I made methoxide solution with potassium hydroxide + methanol + some calcium oxide .  Using new corn oil with stirring I added the methoxide solution at about 21 degrees celcius .  I don't have my notes in front of me on that experiment  I left the reaction overnight .  After about 8 hours I treated the reaction liquid as if it was done .  If I remember correctly I got a 3/27 test pass .    If you  are processing at 5 degrees with stirring/mixing  it should take about 3 times longer or 24 hours , if water , and soap making isn't a factor .  Without mixing I don't know how long it might take . 

[dgs]

I've never known it to take any longer at ambient Wesley. However one extra spanner in the works is the fact that when I have done a reaction in my outside conical IBC I nowadays mix with air via a compressor. It works so well and being outside, the fumes aren't an issue.

If it were no for the fumes I would use air to mix my normal process inside, it seems so efficient and the compressor is about 350watts compared to 1500 for the tam120.

[DavidA]

So you would be pushing air at ambient temperature through the oil mix and thus reducing the oil temp quite quickly to that of the outside air, say 3C on a day like today ?

[dgs]

So you would be pushing air at ambient temperature through the oil mix and thus reducing the oil temp quite quickly to that of the outside air, say 3C on a day like today ?

I don't know how much the air temperature affects the oil/bio mix, probably not a lot. When the compressor gets warm the exiting air is also slightly warm. I have a spare tam120 and used to plumb it up to the ibc but it is 1500w so as an expt I used the compressor (which is what I use to glyc wash with) and found it works really well, it probably mixes better than the tam120.

[Dickjotec]

What sort of compressor and particularly pressure are you using, I might give it a go.