Dry washing with eco2pure or alternatives

[simonallen]

Hi Guys,
Bearing in mind I am running a 300tdi discovery and an alh engined golf tdi on my biodiesel, how effective are these dry wash medias? I am thinking it might be a bit less labour intensive to try and use these instead of spending the weekend in the garage to make the fuel if I can get the feed rate right?

also is the 350-700l treatment per kg of media accurate? even for 350l i think its worth it for 1kg of the stuff (seems about a fiver per kg on ebay). Fabricating a wash tower is no problem for me.

On the face of it, it seems to make the process quite idiot proof with a two stage no titration, then dry wash. Presumeably the only time I would need to dry the bio would be when initially drying the oil pre process?

Any insight would be greatly appreciated... again 
Cheers

[dgs]

Hi Simon,
Drywash media's can be very effective but the biodiesel needs to be a certain specification to get the best out of them. By this I mean that there should be no methanol or glycerol in the biodiesel. The media is only supposed to absorb soap.
I'm sure when it is new it will hold on to some methanol but imagine passing non de-methed bio through it all the time, you would end up with bio + methanol + glycerol exiting your column.

Ion exchange media's are not meant to handle soap levels of more than 500ppm, otherwise their life is grossly reduced and I'm sure the same goes for cellulose medias.

I'm sure the specs that eco2pure give are correct but this will pre-suppose the soap level doesn't exceed a certain level to start with.

The 'myth' that non washed biodiesel doesn't need drying is incorrect. De-methed biodiesel contains around 600ppm water from tests I have done, so it still should be dried. Again, when cellulose media is new it will probably dry bio to an extent but this effect will be short lived.

I used to use dry wash media, I must have used most, bio-pure, bio-lite, puralite, woodchip, sepiolite etc etc. Nowadays I water wash.

I've still got 3x s/steel + 1x plastic column, lots of media, will have to go on ebay sometime.

[simonallen]

Thanks for your advise. Do you think to stay away from it then? I am planning this as part of a new processor build, so will be looking to base it around a gl system, so I will be able to demeth quite easily inside the processor hopefully. I am just looking for something a bit less labour intensive as at present I am having to both introduce and dispose of the water used in my process via a watering can. This is taking quite a bit of my time, and although I will be present throughout the whole process, I would like to be a bit less "hands on" and cut down on the potential of mess.

[dgs]

If you de-meth and settle for at least 1 to 2 days there is no reason why you shouldn't use it. All I was really trying to say was some think it is the easy answer to good quality bio with minimum effort and it doesn't work quite like that.

I used to back wash a friends puralite with methanol and was amazed just how much glycerol came out of the stuff! After speaking nicely to him for several weeks I pursuaded him to water wash.

[simonallen]

So it should be reliable enough for running both my veg oil munching cars on the bio produced in this way? A time scale isn't really an issue, just the manual labour involved on my part carrying water around. I guess for the cost, i'll give it a go. Would be nice to reclaim some meth anyway, keeps the costs down :-)

Thanks

[dgs]

It should be fine, you seem to be the careful type. A soap titration on the end product would be a good indication.

[Jamesrl]

I've never washed bio, apart from one experimental attempt and that was enough to put me off for life.

I've been down the ecocrap/hard wood shavings route in all sorts of ways and forms, don't even bother with that now.

I use a very efficient demeth system to remove the excess methanol after an ASM based conversion with VERY dry wvo that's had a dam good glyc wash.

The bio is transfered to a settling tank and left for a minimum of 8 days to settle (don't even bubble now) and run through a J cloth filter just before its decanted into the fuel tank.

I've never had a filter blocker in 9 years

[THE-DOLPHIN]

Hi Simon I dry wash all the time do use good rapeseed oil all the time . I do gravity feed it through a three foot tower with filters each side of the unit soap test have been from 32ppm to 120ppm as for volume 6to8 hundred litres can be sent through I guess it all depends on how well you drain and settle the glycerol out I don't demeth just settle out in storage tank before filtering