In the process of moving over to dry wash now from water wash. Plumbing system together and waiting for a few orders to come in. Anyway, Im using KOH atm to ensure my glycerin is liquid and I like how the KOH mixes so well with methanol. Still got half a pail of NaOH..

For a dry wash system is NaOH the preferred catalyst due to it falling out of solution easier that the K+ soaps?

Are people using KOH as catalyst and still have success using dry wash?

Im using purolite PD 206. Ive read a few places on this forum how NaOH soaps settle a lot better. Just wondering to what extent.. and if its worth changing back to NaOH if dry washing..

Thanks all,

Reece

Yes . I believe the original idea of drop out soaps when demething was coined by Graham Lamming in his GL Eco System and that NaOH was the prefered catalyst, or IIRC it is the one he used. It is what I use and it does what you'd expect it to, that is once heated and evaporated the methanol is no longer prsent and teh suspended soaps drop out of solution to cover the bottom of the demething tank. Mine is equipped with a standpipe so I draw from teh SP outlet, after settling, to then purify the fuel through the resin beds.

HTH

Hmm thats what I figured.. just hoping someone would say.. 'yeh use KOH you will be fine..settling rate of NaOH is overrated'

My main concern with going back to NaOH would be the state of my glycerine after I de-meth it. Maybe mixing with 25% water straight after demething (while still hot) will ensure that it is nice and runny at room temp...

I use KOH and dry wash using sawdust/woodchips. I try to remove as much meth as possible, then circulate Bio through the woodchips with a small fan blowing over it. I circulate it like this for 6-8 hours. I take samples to shake with water every so often. Well over 1000 liters so far, I use a filter that can be removed and examined for soap traces. It sure is less work and less hassle than using water.
I still maintain we are creating soap in huge amounts by adding water, then ..it takes huge amounts of water to get rid of the soap. I think its easier to get rid of the soap in its 'natural' state, rather than try to wash it out. By washing, you've created a second and third problem, getting rid of water and drying your fuel.However, these are my observations and opinions, I washed, made emulsions, wasted alot of bio throwing it out with the wash water, wasted tons of water, wasted tons of electricity trying to dry bio, wasted alot time and still plugged filters with soap for the last 2 years.Now I have it simplified so much.. a caveman could do it!

haha if a cave man could do it Im sure its a good process..simpler always works better

Im moving over to drywash for the reasons you stated about.. and for the matter what the heck are you suppose to do with the waste water while being eco conscious.

Ive never thought of that, creating soaps while water washing. Makes sense.