I have begun recovering my methanol out of my unwashed fuel. I have read where others doing this filter out the soaps that precipitate out. My question is this.... How long do you have to let the hot BD cool before you can filter? Or perhaps more specifically, at what temp does the soap precipitate out, and can be filtered out?

After I filter out the soaps, I'll be using Purolite as a polisher. I believe Legal Eagle is now doing this as well. Maybe he'll jump in.

All the best.

What I am now doing is somewhat of a variation on the GL method, or is at least somewhat built on the same premise, that when methanol is no longer a factor or it's concentration has been sufficiently reduced soaps and residuals will drop out.

I am heating the BD to where the methanol begins to evaporate. I do this drawing from the floor drain of my drum and once evaporation has begun I then switch it over to the standpipe outlet. I am using the 120 degree full cone spray head I had installed with my water wash system (see my website for the section on water washing)to aid in atomisation which in turn helps the evaporation process.

I continue to circulate like this until the BD has cooled down, which can take a couple hours.

It will then settle out over night, sometimes a couple days, after which I will meter it via the standpipe outlet through the resin beds using ball valves to control the flow rate.

For my configration I am halving the maximum flow rate and final filtering through a CAT canister type 2 micron fuel filter.

There are three indicators that I am getting drop out using this method; first is when I transfer a new bacth from settling tank 1 to settling tank 2 and I flip open the floor drain on tank 2 and I can visually see the residual soaps join the flow from tank 1. Secondly I use my 2 micron can as a check and balance. When I was water washing with very softened city water I was getting quite a bit of soap formation and although I tried to scoop out most of it the CAT's were plugging at a very consistent rate, and I went through 4-5 sets of two per set in a season (8-10 cans, and these are the BIG ones); I am still on the first one this year with thousands of litres put through it and no sign of clogging so far.

Thirdly is the GC results I got for free and total glycerine from samples of BD BEFORE resin and AFTER resin from the same flow. I hit an ASTM pass (just barely) of .240 with just the settled BD and once it went through the resin beds that dropped to .161, a definitive ASTM pass for free and total glycerine.

I am about to toss a sample into the freezer as soon as I can get another digital thermometer (the other one crapped on me) to see what I get as a gel point. My oil has been consistent over the past three years, all the same contacts giving me all liquid canola that titrates at a combined consistent 2.3 NaOH, and I already know what I was getting with water washed BD, so now I am curious to see what happens when there is potential methanol residuals in the BD. The engines I supply are not showing any signs of having any adverse effects from it, so this should be interesting.

HTH 'cause it's all I got for now.

Hi Legal, thanks for the response.

I'm doing almost the same thing you're doing. Except that I'm filtering out the soaps, or at least that's the plan. My Purolite tanks are filled, but not yet plumbed into the stream. I've only got one 45 gallon batch up to the point where I've distilled off the methanol, and I've filtered down to 1 micron, but I see no evidence of soap in the bag filters. That's the reason for my question about the temp at which the soaps should be solid enough to filter out. I heated the 45 gal of unwashed BD to 195*F; turned off the heat, and continued to circulate until it cooled to 170. Then I let it sit overnight. This morning, it was still about 110*F when I began filtering. I was thinking that was too high, but I'm not sure. I'm filtering in the same barrel I heat to recover the methanol in. It's pretty well insulated so the temp doesn't drop as fast as maybe I need it to so the soaps drop out.

Here's my setup:


The far right barrel wrapped in the silver foil insulation is the reactor; to the right of it (barely visible in the pic) is my settling tank for glycerin seperation. It's got Joe_M's 2 ported adaptor in the bottom so it has a standpipe in the conical bottom. It's sweet. From there the unwashed fuel goes to the left drum wrapped in silver foil insulation. This has the filter housing mounted on the from left leg. The methanol collection drum is sitting on the floor to it's left. The tube hanging up in the copper coil is the vent that goes out the window with an exhaust fan blowing out.

Here's the other angle:


You can see the Purolite tanks sitting on the far left. Once the soaps are filtered out, the fuel will take a trip thru the Purolite for polishing.

I just don't see any evidence of soap drop out yet. I know I got methanol into the collection drum. I don't know..... I'll try again tomorrow. I'm helping a buddy move in the morning, but I'll be plumbing the resin tanks and pushing fuel thru tomorrow evening.

All the best.

are you using NaOH or KOH? The NaOH soaps will definately be "chunkier". You should be able to have solid soaps in the 120F range.

quote:

Originally posted by Dogma721:
are you using NaOH or KOH? The NaOH soaps will definately be "chunkier". You should be able to have solid soaps in the 120F range.

Good point.

Conspirator:
I do hope you've done the mods to those tanks. They're great and work well, but require a rework or will see the resin want to migrate between tanks, or worse, willl migrate out of the second one into your collection cotainer. PITA.

My DryWash page has information and pics on what mods ned to be done. Once these mods are done though it is trouble-free and works great.
The tanks you have look like the 6ft variety, which means that your flow rate is 1USgal/min. This will make thing much simpler than how I have to do it, if you want to put out the $$ (of course. Flow meters. They only go down to .5gal so that leaves me out so I use a couple ball valves for flow control, but with a higher flow rate this would definetly be an option on my shopping list.

It is important to get proper residence time in the resin beds, so even if your flow rate is below the maximum that is not a bad thing. I've reduced mine to 1/2 the max and am getting good results, or good enough for my satisfaction.

I just love being able to react a batch on Friday morning and have it ready for use Sunday evening. In speed of process it is only slightly quicker than the way I was water washing, but it considerably less labour intensive and leaves behind NO waste water stream, which means a system with this type of set up can be efciently used in arid areas or places where water use is closely monitored and/or costs a bundle for overuse. You can set up a mobile trailer unit where all you need is electricity to get an end product.

It opens up many avenues hertofore closed due to the need to use water, and plenty of it.

I use NaOH.

Yes, I've done the mods to the tanks, with one difference. I did not put a 'T' at the bottom of the down tube. I just put the SS mesh over the end of the 1/2" black iron pipe, and clamped it on.

Well, it's been sitting for another day. I'm about to go filter and see if I get out any soap.

All the best.

conspirator,,,

are you recovering straight into your methanol barrel? does your system work well? I like simple!

Mike,

I'm recovering into 'a' methanol barrel, but not the one I draw off of for each batch. This one was an empty one, and it will stay mostly empty because I will make sure I keep it that way.

Yes, so far it works great.

Dogma721, thanks. That's the info I was looking for. Do you know this from personal experience? Or is it in another thread somewhere that I couldn't find?


Legal,
My Purolite tanks are 56" high. Each tank has 75# of resin with room for over 100% expansion. Since I am removing methanol and soaps prior to the resin, I would expect the resin life expectancy to be 4-5 times normal.
I plumbed the resin tanks and pushed my first 45 gal batch thru. I'd love to get some GC testing done like you did to see what the resin is actually doing for me. Maybe in a couple months. After all these upgrades, I'm a little poor right now. Hey, at least I'm not buying diesel!!!

I'd also be curious about your freezer tests to see if the cloud/gel points are any different. Please keep me informed.

One last question..... towards the end of the batch, I noticed that the overflow/return line was causing some air bubbles in the lines as the overflow splashed down into the remaining fuel in the drum. As you know, these tanks aren't set up well for purging air. How do you handle this?

All the best.

In the pics above you see a 20 ft copper condensing coil leading to a 55 gal drum sitting on the cement floor. I thought this would provide enough cooling to prevent the loss of too much methanol vapors out the vent.

I was wrong.

I have modified the setup to include another 20 ft of copper, for a total coil length of 40 ft. The top end is still connected to the tank where I heat the fuel. However the 55 gal drum on the floor is history.

Using my old wash tank, the coil connects to the top of the 6" standpipe inside the tank. The drum is then filled with water. 38 Ft of the copper is submerged in the water and is completely airtight. The 50 or so gallons of water cools the flow of vapors through the copper and I'm getting a much better flow out the bottom (now collected in a 5 gal carboy). The top few inches of water eventually gets hot, but vertically, 90% of the water is still cool and has sufficient surface contact with the copper to cool the vapors. In between batches, the entire drum of water cools to 70-75*F, so there's no need for additional water.

All the best,