I'm finally getting back to working on my bio some here. I was having some issues with my lag tank that contains Purolite. For now, I'm just bypassing it and working on how the fuel looks before and after the lead tank containing Thermax.
The vial on the left is raw unwashed biodiesel. The vial on the right was run through the Thermax tank. The first picture was taken late this morning after settling over night. Notice how clear the water is in the unwashed vial. There is some stuff stuck to the walls in the water layer. The water in the Thermax vial is cloudy. Also, the bio in the Thermax vial appears like an emulsion. The Thermax vial also took much longer to settle.
The 2nd pic is from just a couple of minutes ago. The Thermax vial still looks more cloudy, and whatever was causing it to look like an emulsion seems to have settled out into a thin layer between the bio and the water.
I'm a little confused with these results. I would have expected them to be the other way around.
Oh and BTW, ignore the humidity reading in the background...its busted. I don't live in a rain forest
It appears the dry wash is not doing much to remove soap.
assuming temp, water hardness, and amount of shaking was all equal this whould not have happened. You should get a soap titration kit and run some tests. You can do it really cheap just go get some muratic acid at 32% and add 1.16 ml into a liter of water, this will be your titration solution and you can look up the rest of the test on the net.
Could there be something wrong with the resin? Why would the water be more cloudy after going through a wash tank?
Also, the raw bio is VERY clear to begin with. I'll post a pic of that soon.
All I can say is your results are strange. How long did the raw biodiesel settle prior to the shake test?
I made this batch a while ago...I'm thinking September. Here are a couple of pics of the raw unwashed bio. This is the first batch I'm putting through the Thermax and Purolite. While that shouldn't matter...it doesn't mean it isn't part of the issue.
Were the shake tests done at the same time? Is this the first time you have used the Thermax and was it new when purchased?
I have actually taken clean biodiesel and run it through my Thermax columns and picked up soap from the columns. That is a sign that it is time to flush the resin with methanol.
Yes, first batch through. Yes, new when purchased.
I know with some dry wash media they require a few litres of bio being run through them before they work at their best and the first few litres through can be cloudy so folks just send the cloudy stuff through it again.
scum/emulsion at the interface of water/bio could be unconverted oil in the form of MG's/DG's, did this batch have an instant bright and clear 3/27 pass?
I've probably run 20+ gallons though there so far, and the sample for the shake test are from the bio most recently passing through (after the 20+ gallons).
27/3 test sure seemed good to me. I could run another 27/3 and post a picture of the result.
If the layer at the interface was unconverted oil why would it be larger after its sent through a wash tank? Again, this all seems backwards.
It could possibly be caused by the reaction of the resin with the soap still in the fuel. The sulfonic acid might be converting the soap back to FFA's. I know it is doesn't seem like it should happen that way; but maybe if you didn't prime the resin with clean biodiesel first, it is causing unexpected results. Have you done a soap test on it yet?
I would run it back through the column and see if it clears up some.
I would also let enough pass through -- maybe 10 gallons -- before conducting another shake test.
Haven't done the soap test yet. I have a friend looking to see if he has some Bromophenol Blue on hand so I don't have to track some down.
I don't mind running more through there except for the thought that if its messing the fuel up in some way, I don't want to have a bunch of crappy fuel sitting around.
If you think there may be a conversion back to FFA, would a 27/3 re-test be worthwhile?
I would think that another 27/3 would tell you something. If you have more fallout than before then you could assume (right or wrong) that there was soap in the mix that has been converted back to FFA's. I wouldn't worry too much about making a bunch of crap at this point. The resin should only make it better.
Bromophenol blue is cheap and you should learn the soap titration. I don't think it is necessary to use all the time, but it helps to achieve a reference point as to how and when your process works. Once you see it working right then you can just use it every now and then to check your results. This is how I do it and it works for me.
I have never found the answer... What do you do with the soapy methanol? I am hesitant to dry wash because I dont know what to do with the waste methanol after cleaning.
I am not sure I understand the question, but you should not have soapy methanol. If you distill the methanol, the methanol vapors are condensed back to liquid and collected in your methanol container. If you gas the methanol off, you release it to the atmosphere. The soap will fall out of solution with the demethed biodiesel and settle to the bottom of your settling tank. The soap can be acidified and used in an AE batch.
If you water wash, you wash the methanol and soap out of the biodiesel and I guess dump it in the septic tank or sewer. Not sure about that as I have never water washed.
In either case there isn't any "soapy methanol" to deal with.
Thanks for responding. I'm sorry you didnt understand. The methanol that is recovered from cleaning the dry wash towers is going to be soapy. I was asking what to do with the soapy methanol. In my area (Northern California) it's illegal to gas off methanol into the atmosphere. I built a condenser but I am too nervous to use it. I'm afraid of an explosion. Wouldn't it be more dangerous to cook off 95% methanol/5% soap than 85% biodiesel/15% methanol?
My set up is in my shop. It takes about 5 hours to get the biodiesel up to 145F and then I collect about 1/2 gallon before its time to go home. I cant leave it unattended so I shut it off and start over the next day. How long does it take you to demeth?
I am sorry, my brain must still be frozen. I have only cleaned my Thermax resin once. I took the soapy methanol, added a small amount of acid to it to crack the soap back to FFA's and used it in an AE batch. It was actually my first AE batch and I wasn't too sure how it was working out. It did work, but it was a long arduous task to complete, because I really didn't know exactly what I was doing.
I know that some of the guys on the forum distill methanol to reduce impurites (water). I am like you -- a little bit uneasy about it. It would be safer in my mind to use it in AE.
My drywash uses amberlite. What I do is get a good even slow flow going and let it filter over and over for a period of three hours. Slow is the key IMO as I think too much pressure would cause the bio to pass through the resin too fast and not give it a chance to work.
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