Hi Graham et al,
this is my very first post on this forum, and I followed your threads with high interrest over the last weeks.
Im working for a company in the industrial automation who sells all that stuff for the process automation and we had some projects for BIOD in the past.

I stumbled over this forum several month ago a started to follow some threads.

So, the working day isnt long enough, I decided to engineer a small setup for a continous process
right in my backyard.
Because of the very restricted room here in my yard and because I live in the center of a city, I try to avoid any large settling and processing tanks for the whole process and look for new processes to rightsize my system for the place I have.
I think it should be possibel to do this for about 100 liter/day in a continous process with a setup which could be placed on not more than 4 - 6 square meters.
A big problem for this is, that the whole process of BIOD is an EX-application with all the restrictions of ATEX and intrinsical safety.
When I look at some setups, posted in this forum, I wonder how long these guys will surwiwe their next batch !!!

Safety is a must, dealing with this stuff.

If there are any questions, regarding safety and the design of ATEX conform equipment, I will share my knowledge with all of you here in the community.


I`m going to setup my plant this or next year here in germany and I`m very interrested in your process of electric purification, because this would help me avoiding all these "large" tanks.

If there are any news on your purification pls let met know.


vy 73

Dieter


PS: Excuse my bad english, I`m not a native speaker and the 10 years of school english are so long ago.

Hi Dieter,

Your English is fine - everything understood.

This sounds like an interesting project, I'm sure a LOT of people will be intersted to hear more about your work.

There have been some good threads about continuous process.

Look for a thread by Johno - his 'double pumper' is very simple and effective . You should be able to find the thread if you use the SEARCH on this site.

The electrostatic purification works very nicely for separating glycerol from biodiesel, but still I am not able to separate soap reliably.

Also good for separating water from wet biodiesel, and for clearing emulsions - nearly instant. (But this probably does not interest you)

So, good luck, and please let us hear about your progress.

--... ...-- -.. . --.. . .---- ..-. ... / --. ....- .--- -... -.. ( . -..- )

Hi Graham,
very nice to find a ham ! But why ex ?
Found your ZE callsign for 1977-1979.

But OK,
the double bumper ist based on the work of A.P. Harvey et al,Department of Chemical Engineering,University of Cambridge.
I know his work, and will use a similar design for my reactor.
Will post my design when its ready.

lets keep in touch

vy 73, de Dieter

-.-

Hi Dieter

I found the information on Johno's Double Pumper.

Please see http://www.biodieselpictures.com/viewtopic.php?t=136

Hope that helps.

http://www.natcogroup.com/Content.asp?t=ProductPage&ProductID=3


Graham ,
These units will remove the glycerol and the soaps from biodiesel , but are much too large for the application . Perhaps if you were to down size the design to fit your needs you could get a working single pass separator .

Hi Graham,
sorry, I should read your hints first,
the double pumper ist a little bit different from the OFR design.

Thanks for the link

73 Dieter

Hi Graham
I read the whole thread, and I don't seem to find a complete process and Hardware needed for EF purification.
Can you please make such a list, noting what it's for (Glycerol, water etc) ; what hardware is needed and how to use it.
Thanks
Yair

Hi Dieter, Are you considering an OFR design? I building one and would be very keen to compare notes if you go down the same pathway. Mine is not exactly tiny with 24mm of 2" tube and 250 baffels but im aiming for a true continous process, primaraly for thermal efficency reasons. This presents interesting chalenges if you wish to fully automate the process. I think its a design that scales both up and down very well. It should be possible to build something realy small

I have built several major components but not assembaled anything apart from the oscillator. Graham posted apic of this for me a while ago.

I wish I could work full time on the project, unfortunatly running my real buisness gets in the way. I have however thought out a lot of the detail and I already have 90% of the materials. I have spent the last 6 weeks scouring ebay for Flex I/O analogue modules to suit the PLC system I am using.


What I realy want to test is the coalescer I have 1/2 build based on Grahams work. however I need the reactor and Its controll systems pumps etc working before I can do that. Its getting there but not as fast as I would like.

Regards
Tim Marshman

Hi Tim,

Nice to hear from you again.

Yair, I have not published any final designs, because I am still experimenting with different prototypes, but I can post pictures and drawings of what I have made so far.

Give me a week or so to get this done.

[QUOTE]Originally posted by Tim AU:
Hi Dieter, Are you considering an OFR design? .............

Hi Tim thanks for your response.
I will definitely use the OFR scheme, because imo it will fit perfectly into a continuous process of every scale.
I will use a pneumatic membran pump to oscillate the reactor, so I can easily adjust the stage of agitation inside the reactor.
I`n still collecting all the pumps and materials for my system.....

But, I think we are highjacking this thread.
Opened a new one : OFR continuous processing

http://biodiesel.infopop.cc/eve/forums?a=tpc&s=44760975...371031381#4371031381

regards Dieter

There was a revevent thread going but its gone dead. Guess we should ask Graham if he minds his thread being hijacked. Efective coalessing and sub micron particle removal are critical to getting a continous process working in true continous rather than semi batch with continous reactor mode.

Regards
Tim

[QUOTE]Originally posted by Tim AU:
There was a revevent ....

OK Tim,
dont checked if you were here,
I opened a new one,
look at my last post with the link.

Dieter

Wow, long read but worth it, tho I skimmed and probably missed a bit. I see several were considering trying a fence energizer, tho they are hard to find in a constant voltage version. It occured to me a bug zapper may be another off the shelf option to test with. Certainly high voltage and current limited, tho I'm not sure what the continuous current would be, as it may use a capacitor to deliver the zap.

On the subject of capacitance has anyone determined if there is any capacitance to a drum of bio? (pardon if it's a dumb question, I'm a bit limited in the electronics area). Reason I ask is even if you limit the circuit to say 10ma, if the container you're charging has a capacitance value, it could add to the current you are hit with if shocked. Seems to me it woud be low, but I'm not sure...

So I finally had some time to play around with this today.
I did a VERY crude experiment just to see for myself.
I dug out an old neon sign transformer I had from my tesla coil days to play with.
The transformer is 15KVAC 60ma
It is current limited and center tap ground.
Using one HV leg and ground gives me 7500vac 60ma.

So here is what I did, and an animated gif (very poor quality..I should redo it) of it.

I took a 1 liter batch that I did several weeks ago that still had the glycerol in the bottom.
I shook it as hard as I could for a few minutes to simulate a recent reaction (I know, I know..just a simulation).
I then poured the mixture into two jars.
One to hit with HV, the other as a control.

WOW. in less than 1 minute the HV jar was very well separated, while the control should little if any drop out.

Not that anyone had any doubts, but just another trial to show it certainly has promise for quick glycerol separation.

electro1.gif (831 KB, 131 downloads)

[QUOTE]Originally posted by vegenergy:
So I finally had some time to play around with this today.......

Hi Vegenergy,
your test looks very nice, the gif is not the best but the separation is very good.

Did u measured the current during the separation phase ?

Looks like this would be our washing process for the future !

regards Dieter

Hi Graham, Whats proving the gratest chalenge in your soap removal experiments? Are you trying to fully remove the soap electrostaticly or just up the particle size in pretreatment for downstreem filtration? I know of one big expensive comercial plant thats finding soap filtration a major chalenge. I have picked up a winery filter press with dimatious earth dosing. Im hoping that electrostatic pretreatment in combination with the earth filter will be efective and reliable without the need for chemical adsorbants.

Regards
Tim

Hi Tim

The biggest challenge for me right now is understanding why soap separation is so variable.

Sometimes it works well, sometimes not so well, sometimes not at all.

I can't find the reason(s) for the failures - I've tried being consistent in my tests, but get inconsistent results.

Some things do seem common....

> Use high temperature - above 60C. Seems to allow clumps of soap to bond firmly to each other.
> Bone dry biodiesel seems reluctant to allow any separation. Particles just seem to sit there, charge or no charge.
> Unsaturated damp biodiesel seems to give best separation (0.075% water/biodiesel ?)
> Some gentle agitation seems to help. A stagnant tank seems to allow 'stranding' of soap to occur, and these strands bridge the charge. If you measure the plate current on an oscilloscope, you can see a staircase effect, current rises in steps, where new strands join up.

A very gentle circular stirring encourages strands to form in the medium, but they don't have the strength to remain attached to the plates against the fluid motion, so tend to allow clumps to form.

If you are using an insulated container, keep the electrodes away from the sides of the container. The sides seem to accumulate a conductive soap layer.

This may be a clue for good filtration. Perhaps have the electrodes within a pleated sock filter, with a gentle flow of BD into the sock.

A good microscope would probably be a big help in understanding what the soap is really doing at different stages of the process.

Hi Graham,
Does the rate that the methanol is removed have any possible bearing on the outcome? This probably has some effect on the particle size and perhaps below a critical sub micron particle size we have a "Black Oil" type very hard to break suspension.

I suspect, and this would further support my above theory the watter is providing a place for the soap particles to stick together and stay that way. Its almost the perfect highly polar solvent with only marginal solubilaty in the ester,

If this is the case one would hope that the soap has a dehydrating effect on the bio. It would follow from this that there could be a quite critical ideal water content window, to achieve clumping and leave dry bio.

My 2 cents....... perhaps you can design some experiments to verify.

Regards
Tim

Alternativly

Hi Graham,
let us do some series tests on this.
In the moment Im setting up my lab, an I found a very nice thermocontrolled stirring device with 15 places. So we could do 15 tests in parallel at the same time.
For I have no HV supply in the moment, what would you prefer to build out of the box ?
I found several hints in this thread for building one, dont know what in your opinion is the best.

73 Dieter

Hi Dieter,

Sounds good! Try modest voltage of say 750 to 1000V.

Can be made quite simply from 4 to 5 pcs. 6VA transformers, 230:15V connected in reverse.

Feed 15V into all secondaries, in parallel.
Wire all primaries in series, in phase.

Basic AC, or try fullwave rectified DC. No smoothing capacitors needed. Current limit to 1mA with 5 x 100 kilohm resistors in series with each output cable.