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Dry wash with wood chips

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June 16, 2010, 11:57 AM
Pierre
Dry wash with wood chips
ok thanks
sounds like cooling the bio prior to running through the saw dust is a step best not avoided
June 17, 2010, 04:45 AM
Jehu
quote:
Originally posted by Pierre:
Hi Jehu,
Do you send hot or cooled bio through your sawdust drum?
Thanks,
Pierre

I let my biodiesel sit overnight to let the last of the glycerol to settle, but its still well over 30C when I send it thru the sawdust at this time of year. I havent detected any detrimental effect on soap removal by the sawdust. If there is a problem with warm biodiesel maybe using a large volume of sawdust as I do avoids it.
June 17, 2010, 05:47 PM
Jeff G
Our co-op has been making bio using KOH exclusively for about 6 months. We started using wood chips to filter with great success until recently. We have started seeing extremely high soap content after settling over night and before filtering. Conversely, we have been using up our chips at a fast rate. Any ideas as to why soap content has increased? The only thing we have changed is we have been cutting back on methanol in the process while still achieving a passing 3/27 in final stage. Could the amount of methanol effect the soap content in the final stage?
Thanks in advance,
Jeff
June 17, 2010, 06:17 PM
Doug Weiner
My gut instinct is always hidden water, but if that was the case, then you definitely would not pass 27/3. Double check the temperature you are doing 27/3. Make sure the bio is around 70F when doing that test. Much higher and you will get false passes. Also make sure you are using PURE Methanol for that test and not recovered methanol.

If you are passing 27/3 then the problem is probably too much catalyst. Time to make a new base titration solution and double check how much KOH you really need. Also double check the KOH purity, the math and whomever is doing the measuring.

Are you using recycled Methanol as well? If so, this is most likely where you are introducing excess water. At best, in recovery you can get 94% pure methanol. Others claim differently but physically its not possible. So for 6 liters of recovered meth, you got about 240 ml of water - that's 2/3 rd's of a 16 oz (355ml) beer. If you adding the recovered meth back into your pure meth, over time you simply are going to have a purity problem. Keep the pure and recovered meth separate. But again, if this is the case, then you WILL NOT pass 27/3. The moment there is too much water in the ingredients, it kills the reaction causing too much soap and to much left over oil/di-glycerides.
June 18, 2010, 04:12 PM
Jeff G
Temperature has been at the back of my mind for some time but no one had said anything. We are in central Florida and it is hot as blue blazes. Even at room temp the fuel won't be anywhere near 70 degrees. I am afraid to put a sample in the fridge for a cooldown for it may pick up some condensation(water). I guess we could take a sample into the house or an air conditioned room and let it cool but that will take time. Any suggestions?
Thansk for your reply!
Jeff
June 18, 2010, 04:14 PM
Jeff G
We are using virgin methanol straight from the drum with the bung immediately replaced so I don't think moisture is an issue. I think it might be teh temp.
Thanks!
Jeff
June 18, 2010, 06:04 PM
Doug Weiner
Jeff, if you letting the bio cool for some time so it get down to ambient temps, its probably not more than 85, unless you are simply not waiting long enough, its not a deal breaker. Hot bio is. Refrigeration will help. Put a lid on the jar and when you take a sample, and then later put the syringe deep enough in to only sample oil. So it sound like you are more less passing 27/3 even if it is a little off, so water is probably not the issue here. (But always keep an eye for that issue) So that leaves excess Catalyst.

Something dawned on me that might be the culprit and it can happen 1 of 2 ways but they are same issue: solubility of NaOH (or KOH) in methanol. Basically, you can only dissolve so much catalyst in methanol. If your titration numbers are over 5(?) then basically, after you do all your catalyst calculations, you end up needing an amount of catalyst that exceeds the solubility of it in methanol. Thus, you end up with too much catalyst with a whole lot of FFA in the mixture and thus excess soap. What are your titration numbers?

The funny part is that you might have caused this issue yourself. By keeping your catalyst numbers the same, but lessening the amount of methanol, you might have put the reaction out of wack and now the undissolved (less then optimally dissolved?) catalyst is reacting with the FFA, thus more soap.

Lastly, an idea just struck me. How are you determining you have 'too much soap'? Just by the amount you remove now versus before? Unless its seriously impacting yield, you might have hit a good balance of methanol reduction and that when you are done making a batch, you have only a little methanol left and then when you take it out in the manner that you always have, you actually are getting most of out, so you are simply are seeing more soap drop out quicker. (This is the glass is half full approach. Sadly I believe its probably the glass is really half empty.)

1) Re-make titration solution. Double check FFA.
2) Double Check your math and how much catalyst you added. (Did you double add somewhere.)
3) Do another 27/3 test now with the oil at 70F. If it passes, you don't have a water problem.
4) Use more methanol in the next batch, I bet your soap problem might go away.

Doug
June 18, 2010, 06:44 PM
Legal Eagle
quote:
I guess we could take a sample into the house or an air conditioned room and let it cool but that will take time. Any suggestions?

Ice packs.



** Biodiesel Glycerine Soap - The Guide
- on 5 continents helping people make & sell soap from the Biodiesel Glycerine.


June 21, 2010, 01:00 AM
Pierre
sounds like incomplete conversion to me. Soaps? mono and di glycerides? excess meth drives the reaction to completion. why skimp?
June 21, 2010, 09:16 AM
Jeff G
I think you guys are on to something with the methanol. The last batch started to foam when we started to de-meth(aerate) the bio. We will bump the methanol up and see what happens.
AFA cooling we let it set over night so it is basically room temperature.
Thanks all. I will let you know how it turns out.
Jeff
June 25, 2010, 06:36 PM
Dom
Hi guys
In your experience how much KOH is too much for a given volume of methanol e.g. grams per litre
thanks
Dom


Dom

You can not change the winds, but you can reset your sails.
June 25, 2010, 06:59 PM
Doug Weiner
REMOVED:

If you saw my math, it was useless, sorry. That number was for my 26 liters of methanol for a 130 liter batch. Don't work backwards, I will get a real number and post it.

Doug


XXXXXXXXXXXXXXXXXXXXXX
IGNORE, left here for reference.
I was at seminar with the guys from Arbor Bio (Bio Pro guys) its like XXXXX for NaOh and like XXXXX for KoH.
XXXXXXXXXXXXXXXXXXXXXX
June 28, 2010, 01:27 PM
Doug Weiner
Ok heard back from Daniel at Springboard Bio and makers of the BioPro 190EX. (Yes I am promoting them as by far the best machine out there and if I had know how much time and money I was going to spend 2 and 1/2 years ago, I would have just financed a damn 190EX. Oh well.

Daniel is a real chemist with a masters degree, unlike me who thinks he is good at chemistry because 25 years ago I got a score of 4 out of 5 on a college Advance Placement Chemistry Exam. - which does help but makes me no chemist.

He reports the solubility is 133 grams of KOH in a liter of Methanol. This is a LOT LOWER than what info is on wikipedia. So for a 34 gallon WVO batch is (34*3.78 (L/gal) = 134L) 134 * .2 = 26 liters of methanol. 26 Liters of Meth * 133grams = 3478 gram of KOH as the MAX for 26 liters methanol.

Mmm... does not really fit my current theory of too much KOH. But still good to know, because if you are cutting your methanol and have high titration numbers, you could conceivably exceed the solubility point.

Well anyway, the only way to getting more soap is that the KOH is bonding with the FFA and the oil, but how this mechanism is occurring I can not yet explain. Perhaps there is more going on - like the higher concentrations of KOH requires the meth-oxide to be added slower or requires better mixing.

Doug
June 29, 2010, 09:39 AM
Jeff G
Gentlemen,
I think that our problem was excess KOH as we were pre-treating our oil with glycerin from a previous batch. We have been steadily cutting back on KOH with good results.
Question for today:
We have 150 gallons of bio that is just full of soaps. The soap test won't even work. How do we get this soap out? We have tried a "third stage" with just methanol with no luck. If it sets long enough will the soap eventually fall out? How long would be long enough if that is the case?
Thanks everyone!
Jeff
June 29, 2010, 12:15 PM
Doug Weiner
Demeth by circulating in an open air drum. For at least a day. Use some kind of spray nozzle or shoot the output against the side of the drum. Since its humid, heat the bio as you circulate if you can. (heat will always help) This should get the meth out. Cover and let sit for at least 2 weeks. Soap & Glyc should settle out. The remaining bio should be about 2000ppm down to 1500ppm. KOH soap just doesn't settle like NaOH soap.

Good luck.
June 29, 2010, 03:05 PM
Hamlin205
quote:
Originally posted by Jehu:
quote:
Originally posted by Pierre:
Hi Jehu,
Do you send hot or cooled bio through your sawdust drum?
Thanks,
Pierre

I let my biodiesel sit overnight to let the last of the glycerol to settle, but its still well over 30C when I send it thru the sawdust at this time of year. I havent detected any detrimental effect on soap removal by the sawdust. If there is a problem with warm biodiesel maybe using a large volume of sawdust as I do avoids it.

Jehu:
I pulled the trigger on a Rolfquo copy and wondering how full you pack your 200L /55Gallon Drum
with Sawdust ?? Do you use fine or a mixture of fine and shavings? I have seen some say pack it full some say 2/3 full .Like youself I will settle Bio for at least a day. Needing to size my system to handle 110Gallon batches. I have the materials for a four drum system ( 2 ea in parallel )with the capability to cycle it through again. Will 4 55 Gal drums packed full of a sawdust shavings mix hold 110 Gallons of Bio ?? What size/ mesh do you use to keep the sawdust out and are you happy with it ?? Rolfquo uses 70 mesh.
Thanks
Tom


1999 K3500 Dually with a new AMG 6.5TD turned up a bit by John Kennedy
Chevy DMax Totaled thanks to a 20 year old in a Mustang
Mercedes 300CDT
John Deere
On B99.?
June 29, 2010, 05:52 PM
Jehu
Hi Hamlin,

I pack my 200L drum 2/3 - 3/4 with fairly fine sawdust. This holds a 100L batch comfortably, but it doesnt hold my 150L batches (I have two proccesors).
The sawdust traps a lot of air which needs to be released. I do that with a long metal probe after I've added the biodiesel and the gurgling has stopped. After a few batches the sawdust becomes compacted two and the trapped air gets harder to release. I use only one drum which is open and gravity fed. In closed systems the compaction and trapped air may affect the effectiveness of systems in series, unless the biodiesel is pumped thru.

My internal mesh is a stainless steel sports car air filter, which is fairly fine. When I renew the sawdust I send the first batch thru again so that most of the really fine stuff gets trapped by the coarser stuff. I use a final 5 mic reverse osmosis filter in any case.
June 29, 2010, 07:11 PM
Hamlin205
quote:
Originally posted by Jehu:
Hi Hamlin,

I pack my 200L drum 2/3 - 3/4 with fairly fine sawdust. This holds a 100L batch comfortably, but it doesnt hold my 150L batches (I have two proccesors).
The sawdust traps a lot of air which needs to be released. I do that with a long metal probe after I've added the biodiesel and the gurgling has stopped. After a few batches the sawdust becomes compacted two and the trapped air gets harder to release. I use only one drum which is open and gravity fed. In closed systems the compaction and trapped air may affect the effectiveness of systems in series, unless the biodiesel is pumped thru.

My internal mesh is a stainless steel sports car air filter, which is fairly fine. When I renew the sawdust I send the first batch thru again so that most of the really fine stuff gets trapped by the coarser stuff. I use a final 5 mic reverse osmosis filter in any case.

Jehu:
Thanks for the reply !!
The interview with Rolfquo didn't address loading the system or mention problems with this design not being able to handle continuous flow.
I was hoping to push the fuel in the system out with the next batch, hopefully this would enable us to avoid air becoming trapped in the system??
Will have a half pipe over the filter to keep the weight off and compaction to a minimum. I cant help but think though that a half pipe allowing fuel access @ the ends only will tend to promote chanelling ??
Thanks again for the help.
I'll get some pictures together and an update soon.
Thanks again.
Tom


1999 K3500 Dually with a new AMG 6.5TD turned up a bit by John Kennedy
Chevy DMax Totaled thanks to a 20 year old in a Mustang
Mercedes 300CDT
John Deere
On B99.?
July 03, 2010, 10:43 AM
Hamlin205
quote:
Originally posted by Hamlin205:
quote:
Originally posted by Jehu:
Hi Hamlin,

I pack my 200L drum 2/3 - 3/4 with fairly fine sawdust. This holds a 100L batch comfortably, but it doesnt hold my 150L batches (I have two proccesors).
The sawdust traps a lot of air which needs to be released. I do that with a long metal probe after I've added the biodiesel and the gurgling has stopped. After a few batches the sawdust becomes compacted two and the trapped air gets harder to release. I use only one drum which is open and gravity fed. In closed systems the compaction and trapped air may affect the effectiveness of systems in series, unless the biodiesel is pumped thru.

My internal mesh is a stainless steel sports car air filter, which is fairly fine. When I renew the sawdust I send the first batch thru again so that most of the really fine stuff gets trapped by the coarser stuff. I use a final 5 mic reverse osmosis filter in any case.

Jehu:
Thanks for the reply !!
The interview with Rolfquo didn't address loading the system or mention problems with this design not being able to handle continuous flow.
I was hoping to push the fuel in the system out with the next batch, hopefully this would enable us to avoid air becoming trapped in the system??
Will have a half pipe over the filter to keep the weight off and compaction to a minimum. I cant help but think though that a half pipe allowing fuel access @ the ends only will tend to promote chanelling ??
Thanks again for the help.
I'll get some pictures together and an update soon.
Thanks again.
Tom


I picked up shavings/sawdust from my source and there is a mixture of both planar and sawdust
which I believe to be a good thing. My question though is there is a little really really fine powder in the mix. Is it possible this material will be washed to the bottom of the drum
and try to clog the screen over the exit?( copy of Rolfquo except a finer mesh on the pipe)
Should I try and filter some of the super fine out ?

Once the drums are full,I have designed in the ability to either cycle through again or divert to amberlite.
Should the fuel be pushed out with another batch to keep air out of the system ? If pushed out with another batch of fuel some co-mingling will occur.
Have also read that some believe that wood chips can add acidity to the fuel ?? is this possible with a rinsed hardwood only system ?
I am thinking of drilling many small holes in or near the bottom of the halfpipe over the outlet pipe to help with flow. Does anybody see a potential problem with doing this ?
Thanks again
Tom


1999 K3500 Dually with a new AMG 6.5TD turned up a bit by John Kennedy
Chevy DMax Totaled thanks to a 20 year old in a Mustang
Mercedes 300CDT
John Deere
On B99.?
July 03, 2010, 12:46 PM
Jehu
You shouldnt need any other dry wash medium with sawdust - the whole point is to save money. There will be a lot of fine dust coming thru the sawdust initially, but if you send it back thru it will soon be caught higher up the column. Theres no harm in leaving a batch in and pusihng it thru with the next batch to keep air out, but this might be time consuming as you will need to keep topping it up. Maybe if you let half a batch out then top up with another half batch, then repeat.