A new processor in the making :-)

[Bueff]

Re: A new processor in the making :-)

Thanks Matt,

all the electrical work will be done by a sparky friend of mine, with all bells and safety whistles. I am planning to use 2 temp switches one for the oil heating and one for demeth. Once the reaction is complete, I start the demeth process with the glycerine still in the processor, that way I hope to recover as much as possible. Hopefully we get it going within the next few weeks, its about time

[WesleyB]

Re: A new processor in the making :-)

I'm not sure if this would be sensible to most biodiesel persons. Once I set up a vacuum still and pulled commercially anhydrous methanol gas through hot biodiesel in an effort to remove water from the still pot. I put about a 300 millimeter above zero atmospheric pressure vacuum over the still pot, then vented a warm/hot methanol flask slowly through the hot biodiesel. The vacuum pressure caused the methanol to boil, which was then bubbled through the hot biodiesel I intended to dry. I bubbled anhydrous methanol gas through hot biodiesel I thought I was pulling water out of with the dry methanol vapor going in and wet methanol vapor coming out. Well a sensible person might ask, what does that have to do with this subject? It seems to me that by pulling dried air through your biodiesel you will obtain a methanol rich vapor that by a cold condenser you might obtain methanol condensate. The condenser might need to be especially cold, I'm not sure. Thanks

[Bueff]

Re: A new processor in the making :-)

Does anyone recover methanol while the bio and glycerin are still in the processor, just read here http://www.answers-to-your-biodiesel...-recovery.html not to do it as it would reverse a reaction.

Any thoughts? I was hoping to finish the reaction and then heat the batch to 75 degrees and recover the methanol, would be great to get away without having to build yet another vessel :-)

[WesleyB]

Re: A new processor in the making :-)

I've not done whole batch demething myself but I read a while back that someone in Ireland had done it and from experience had found that the reverse reaction does not occur much if at all.

[WesleyB]

Re: A new processor in the making :-)

A bit more information Bueff that might be pragmatically helpful in building a processor, large or small. I have not done whole batch demething but I have demethed by vacuum distillation, after removing the glycerine layer. At about 300 millimeter pressure above a perfect vacuum pressure (760 mm is atmospheric pressure) I demethed crude biodiesel after removing the glycerine layer, The methanol first started boiling off at 36 degrees centigrade and I shut the still down when the still head temperature had risen to 40 degrees centigrade. So in a heavier walled still you can pull some amount of vacuum and cause you methanol to boil off at a lower temperature. The still pot might inwardly collapse or inplode if the walls of the vessel or hoses can't stand up to the vacuum pressure. There is an energy efficiency balance that could be obtained by using a vacuum still to do whole batch demething AND if there is a reverse reaction during whole batch demething the reverse reaction is slower at a lower temperature. Generally for organic chemistry reactions with every 10 degree celcius increase in temperature the reaction goes at least twice as fast. I need to mention that at lower pressure during distillation the condenser temperature has to be lower or the methanol won't condense in the condenser and will go into and out through the vacuum pump.

[Prickle]

Re: A new processor in the making :-)

Does anyone recover methanol while the bio and glycerin are still in the processor, just read here http://www.answers-to-your-biodiesel...-recovery.html not to do it as it would reverse a reaction.

Any thoughts? I was hoping to finish the reaction and then heat the batch to 75 degrees and recover the methanol, would be great to get away without having to build yet another vessel :-)

Hi Bueff
I tried this on the weekend. .. My usual practice is to take my 95 ltrs of WVO to 64 degrees c .. add 18 ltrs Methanol / 800gms potassium hydroxide mix .. pump stir for 1.5 hrs add 5 ltrs water ... pump stir for 15mins .. let sit for 2 hrs .. drop glycerin out .. take up to around 80 degs c under vacuum / condenser .. by doing this I reclaim around 800 to 1000 ml of methanol .. covers the cost of the power

On the weekend I did the same except after 1.5 pump mix I took the mixture up to 80 degrees c for around 1 hr and recovered 1.7 ltrs of methanol back ( probably could of gone harder but I also had heard of being able to reverse the reaction) .. anyway I then added 5 ltrs of water and pumped stirred for the usual 15 mins .. Let it sit for an hour and then went to drop it out .. If came out as thick mayo .. but I let it sit in a bin for about an hour with a ltr or so of vinegar stirred in and it split the mayo and I ended up with some of the best Bio I have ever made. Clear like lemon juice .

So I will be trying something like this next time.

[Bueff]

Re: A new processor in the making :-)

Thanks Prickle thats real good info, I have used the 5% prewash method previously and found it very helpful in regards to washing the fuel. It was a lot easier to do and avoids emulsions that the "normal" way of doing it could cause. I actually increased it to 10% using hot water, no issues there. Maybe adding water before you demeth would prevent emulsions, I would guess that the methanol you would recover might not be as pure as if not pre washed but I have read on the english forum and a number of people are doing it this way. They experienced no issues at all by reusing methanol even after a 5-10% prewash.

I would be interesting to see what the shake up test would say!

[Bueff]

Re: A new processor in the making :-)

Alright boys, here are some more up to date pics, this is the condenser for the meth recovery and the processor in the container.
Hoping to connect the rest over the next few weeks. :-) As we all do :-)

[SUZUDDIS]

Re: A new processor in the making :-)

Hi Jens

Goodness , it's been a while. Hope the new processor is coming along well. long time since we pulled it off the trailer....
hope the pics upload soon.
Michael

[Bueff]

Re: A new processor in the making :-)

Alright guys, the first 1000l batch was put on this weekend, everything was working okay but since it is the first batch in the new processor there are a few things that need fine tuning.

First of all I don't know how accurate the PID was at the time of processing, it seemed to fluctuate a fair bit while the generator was running, since then I have connected it to the solar inverter and it is a lot more stable in reading the temperature.

The oil I used was apparently quite old, so I tried a few titrations and the average was about 7 KOH. As I used 8 as a base I put 200ltr of methanol and 15kg of KOH in the mixer and it took about 30 min for the pump to pull it all through the venturi and mix it all up, meanwhile a paddle mixer is spinning at app. 30rpm in the tank.

I turned everything off after 1 1/2hrs and we had dinner with friends.

When I started draining the next morning, I put all the glycerin in open 200l plastic drums as I was curious on how much glycerin there would be. So far I have filled 2 drums and it keeps coming.

Any chance that I have created a massive amount of glycerin with only 200l Methoxide?
When filling it in my test bottles ist dark, non see through and does not settle out.
It smells like glycerine too. As it is still at app. 55 degrees it is quite liquid.

Is there any way to test the product wether it is glycerine? I will have to reprocess the batch most likely once I have the methanol out.

Anyway to sume it up, I would like to know whether a quite hight amount of glycerin can be expected with older oil, and is there a way to test for bio conversion while the glycerin is still present?

Apart from that I loved the fact of no more drums lifting and just pressing buttons to operate the whole thing

Thanks for your thoughts!

have a good evening!