BIODIESEL & SVO DISCUSSION FORUMS





Sponsors    Biodiesel and SVO Forums Home    Forums  Hop To Forum Categories  Biodiesel  Hop To Forums  Making Biodiesel    glycerine pretreat question?
Page 1 2 

Moderators: Shaun, The Trouts
Go
New
Find
Notify
Tools
Reply
  
glycerine pretreat question?
 Login/Join
 
Member
posted
My oil usally tritrates about 5.5 or 6. So I wanted to do a pretreat to see how much differance it will make. My questions are: How long do I mix the two? and How long do I wait before draining off the glycerine? Thanks in advance! Tom


Tell me again....Why do I have FOUR jobs??????
 
Registered: June 21, 2009Reply With QuoteReport This Post
Member
posted Hide Post
Tom

I start with 60 gal of oil heat it to 145F pour in about 15 gal glyc. mix it for an hour then settle for an hour, drain glyc. you have to pay attention to where the glyc ends and the oil starts. re titrate and proceed as usual. I am going to start heating closer to 155-160 before pretreat, because my glyc is about 50*f and it cools the oil about 15*


Home brewing to feed my '02 Ford F350 Superduty
 
Location: Central New York | Registered: December 08, 2007Reply With QuoteReport This Post
Member
posted Hide Post
mofarmer
-do you have a ph meter that reads conductivety as well? this type of unit is very usefull in determining (when draining) when the byproduct/oil interface has been reached, as the byproduct is conductive and the oil not. Tom


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post
Member
posted Hide Post
A ph meter that reads conductivity...... I have an ohm (spelling) meter I use to measure the resistance in electical coils and elements and so forth..... will it work?


Tell me again....Why do I have FOUR jobs??????
 
Registered: June 21, 2009Reply With QuoteReport This Post
Member
posted Hide Post
mofarmer he is talking about a pH sensing electrode. An ohmmeter wont work. Just pay attention to your glycerin/oil layer. Remember its okay to get a little bit of glycerin in your reaction but not alot as it will screw up your formula (since some of your volume is now glycerin).

Glycerin pretreat works well to drop the ffa% by as much as half if you use glycerin straight out of the previous reaction, just blend for an hour and let decant for an hour or two to be safe. I have had experience adding sodium methylate straight into the glycerin and pumping it at high temp with a pump to mix it and adding it directly to oil. Assuming there is low water content in your oil you won't create much extra soap and can drop the ffa% to as low as 0.5%, starting from around 4-5.5% FFA.

Remember what you are doing is caustic stripping using glycerin as the vehicle for the Na+ ions instead of water. You create soap out of the FFAs and Na+. The soap then falls out of the oil into the glycerin phase (for the most part) and voila lower ffa oil. You lose 5-10% of your feedstock this way but it is better to be creating soap in the caustic stripping part rather than the transesterification part which will create water which catalyzes more soap formation and so on like a chain reaction.

Even if you do a glycerin wash and it only drops a percent or two remember you are also pulling out excess water (glycerin is water soluble and falls out in the glycerin phase) out of the oil which will give you better yield in your transesterification reaction.
 
Registered: June 07, 2008Reply With QuoteReport This Post
Member
posted Hide Post
AZ
-the best explanation of byproduct preteatment I've read so far.
mofarmer,
- no as stated by AZ the ohm meter will not work. conductivety as it was explained to me is reverse ohms. actually you are measuring the current flow in the liquid, not the resistance to current flow, if that makes any sense.
I have had this meter for almost 5 years now, cost about 95 bucks it is a milwaukee SM802 ph/ec/tds meter. I only found out about this meters ability to determined the interface between byproduct and oil, and between wash water and oil after much discussion with a biodiesel chemist named JIM. there is akso some relationship between total disolved solids and the interface, but I need to do more testing on that. this meter does it all!! Tom


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post



Member
posted Hide Post
quote:
no as stated by AZ the ohm meter will not work. conductivety as it was explained to me is reverse ohms. actually you are measuring the current flow in the liquid, not the resistance to current flow, if that makes any sense.


Tom Tom Tom... Big Grin
That does not make any sense. Razz
Conductivity is in essence a measure of resistance, the less resistance the greater the conductivity and vise versa. An ohm meter is a great tool for this when trying to find the separation between the biodiesel and byproduct layer, you will get an ohm reading when the probes are in the glycerin and none (infinity) when they are in the biodiesel. You could make a simple fitting on your reactor drain using a plastic cuppling or any other way to isolate the 2 probes from each other and just use a 12 volt test light connected to them to tell when you have hit the biodiesel layer. When the light goes out your into the good stuff.
A conductivity meter(EC meter)is just an ohm meter that gives a value based on the resistance over the distance between its probes, the reading is typically given in μS/cm (micro siemens/distance). They are typically used to determine TDS (total dissolved solids) in a liquid solution, commonly used in the hydroponic and plating industries.

Tom if you find a good use for an EC meter in biodiesel production let me know as I have a good one!
Cheers,
Jon
 
Location: Wellington County, Ontario Canada | Registered: February 07, 2008Reply With QuoteReport This Post
Member
posted Hide Post
Jon
-that dosn't make any sense? Big Grin Big Grin Red Face It didn't make any sense to me,(but thats what I was told) I still don't understand it. But we did try using an ohm meter about 4 years back, and could not get it to work. I'll have to try it again. The ec meter on the other hand works very well.
-thanks for setting me staight! Tom


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post
Member
posted Hide Post
Hey no worries Tom!
I have not tried it yet but am going by GL's dipstick cct. seen HERE. If the EC meter works so will an ohm meter, keep in mind that the distance between the probes may have to be very small, GL uses a space of 5mm between his with a probe length of 8~10mm using a 9v battery.
What is the EC reading you are getting?
If you dont feel like building GL's cct. you could try using a 12v test light on some demethed glycerin and bio and see how it works out. Keep in mind there is a potential for a spark here if a standard 12v battery or supply is used, limiting the current to 4~20ma should mitigate this issue...
Jon
 
Location: Wellington County, Ontario Canada | Registered: February 07, 2008Reply With QuoteReport This Post
Member
posted Hide Post
I did the pretreat on a batch today and it worked! tritration went down from 6 to 4.5. The glyserine I used was several weeks old and pulled from the bottom of the storage barrel. So next time I'll pull it off the top to see if it works any better.

I also tried the ohm meter and could not get a reading in the gls.or bio. I knew I had put in 17.5 gallon so I took out 20.


Tell me again....Why do I have FOUR jobs??????
 
Registered: June 21, 2009Reply With QuoteReport This Post
Member
posted Hide Post
quote:
Originally posted by mofarmer: So next time I'll pull it off the top to see if it works any better.


As a suggestion, store your glycerol in sealed containers to prevent loseing the methanol. It works well for next prerinse. I have seen my titration drop from 6 to 1.5.
 
Location: Winnipeg, MB | Registered: July 31, 2008Reply With QuoteReport This Post
Member
posted Hide Post
Jon
-electrial conductivety is a measure of a materials ability to conduct an electical current.
-ohm is a unit of resistance between 2 points on a conductor when the potential differance of 1 volt between them
-I just checked, so I don't think you can say they are the same thing!
-I drained byproduct today in the normal way, and measured EC during the drain. the ec measurement was 1.60mSu/cm for the fisrt 24 ltr, then droped sharply to 0.05. I closed the ball valve, waited 5 minutes and opened the valve to allow a very small stream, ec jumped to 1.60 and stayed there until all the by product was removed then droped to zero. After 9 hrs, there is NO biodiesel floating on top of the the byproduct! On the sight gauge, I have 1.5 ltr of oil more than I started with,I need to do my repo yet, but that shouldn't reduce the volume by much. I knew, in the past, I was discarding biodiesel with the by product, this seems to eliminate that problem. I bet this yield will be about 98 - 99% Tom

-Edit: I just checked the byproduct with an ohm meter, and there is no reading in any range?


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post



Member
posted Hide Post
quote:
Jon
-electrial conductivety is a measure of a materials ability to conduct an electical current.
-ohm is a unit of resistance between 2 points on a conductor when the potential differance of 1 volt between them
-I just checked, so I don't think you can say they are the same thing!

Smile
They are inverse or reciprocal. My statements above are accurate. See HERE for all you need to know about how conductivity is measured. Resistance is the opposition to conductivity and a resistance measurement between the set probes on your EC meter is what is used to calculate the conductivity measurement you see on your display... Guaranteed! Cool

Thanks for doing the testing!
Your ohm meter may not be accurate enough to get a reading. Did you fix the probes about an 1/8" apart?
I have a good meter and will check it out this week if I get a chance. I know I read somewhere on here about someone who built GL's dipstick and it worked. I am going to build one of his circuits this winter only with a buzzer that will sound when when the resistance goes up instead of the led going out when the resistance goes up...
Jon
 
Location: Wellington County, Ontario Canada | Registered: February 07, 2008Reply With QuoteReport This Post
Member
posted Hide Post
Jon
-isn't that what I said in the previous post? (oh no, you said inverse, I said reverse ohms)
-that gl probe from what I can tell is sending an electrical current through the by product, and when it hits oil game over! So when you make one of those, make two! Big Grin
-If you have an ec meter, try that as well. It would be good to get another opinion. Tom


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post
Member
posted Hide Post
OHM- The resistance between two points of a conductor when a constant potential difference of 1 volt, applied to these points, produces in the conductor a current of 1 ampere, the conductor not being the seat of any electromotive force.
 
Registered: November 09, 2003Reply With QuoteReport This Post
Member
posted Hide Post
From my limited correspondence course education in electronics, I would have to agree with Jon. The unit of measurement for resistance to current flow is the OHM. MHO is the unit of measurement for conductance (the lack of resistance to current flow). OHM - MHO -- reciprocals.
 
Location: Chambodia | Registered: December 31, 2007Reply With QuoteReport This Post
Member
posted Hide Post
Tom and Jon...kings of hijacking posts........ Big Grin
Add me to the list I guess now. Good discussion though! Smile
 
Registered: May 13, 2008Reply With QuoteReport This Post
Member
posted Hide Post
Darn! does that mean I'm wrong again? Big Grin Big Grin Big Grin Ok, I get it I think! Tom

Hook
WHAT me hijack Frown Big Grin Big Grin OK I'm sorry but this is a carry over from the third entry on this thread! Seems I'm wrong Big Grin Big Grin


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post



Member
posted Hide Post
Big Grin Wink Razz
 
Registered: May 13, 2008Reply With QuoteReport This Post
Member
posted Hide Post
I just stick two large sewing type needles through clear vinyl tube, it's self sealing and the gap is easily adjusted.
 
Location: West Michigan | Registered: April 26, 2006Reply With QuoteReport This Post
  Powered by Social Strata Page 1 2  
 

Sponsors    Biodiesel and SVO Forums Home    Forums  Hop To Forum Categories  Biodiesel  Hop To Forums  Making Biodiesel    glycerine pretreat question?

© Maui Green Energy 2000 - 2014