Hello everyone,

You all seem to know dry wash systems pretty well so I've got a question for you. I'm working to set up a small (few hundred gallon/week) biodiesel processor at Washington State University. We are trying to pick a dry wash chemical, but there are so many I don't know which one we should go with. I read through the forum postings on dry washing but can't come up with a solid answer except that Amberlite and PUROLITE are just finishing resins and not an actual dry wash. Can anyone help me out?

Visit here:
http://www.make-biodiesel.org/drywash/

for a writeup comparing the different drywash resins.

They are all primarily polishers. They don't work well with high soap content biodiesel made from WVO. The ecopure filter system is not posted yet as it's too new to know much about it.

quote:

read through the forum postings on dry washing but can't come up with a solid answer except that Amberlite and PUROLITE are just finishing resins and not an actual dry wash.

Don't know where you got that "solid answer" but it is not correct. I've used Purolite PD206 in a lead/lag configuration since the beginning of my 2008 processing season. You can read material directly from Purolite linked from my webpage on "dry Wash" here if interested.

Just like any other system, the "best" will be the one you are comfortable with and one that meets your needs.

Graham Laming designed a system that uses neither water nor resin in his GL Eco System by using simple chemistry to achieve results seen with complete water washing or resin purification.

Resin purification is not for everyone; it is not cheap to set up nor is it foolproof and requires you to do your homework as resin has it's limitations, but IMO, the inconveniences are far outweighed by the advantages for my situation.

I have to agree with Legal we have been using purolite for some time now and I couldn't be happier, the stuff works great and our finished Bio is awesome. A local friend who makes Bio, water washes and when he saw how affective the purolite is he was drooling. The thing that is holding him back is he doesn't have the resources to make his towers.If we had to start all over again I woudn't hesitate for a second.(no I don't sell the product and I don't get compensation for bragging about it) it just works great!!


Hope this helps!

David 610,

At Arbor Biofuels Company we sell both the Purolite's Gel resin (PD-206) and Thermax's Macroporous resin (T45 BD Macro).

Rick's link above does a very nice job of educating potential users.

We also sell the Eco2Pure for a gross filtering media for batches that have higher soap content or for producers that want to go directly from gross glycerol separation to ion exchange.

The terms "Polishing"/ "dry washing" or my favorite "purification"; are all a matter of context or view point. I think what is important is fuel quality and the total process efficiency (including your time - which to me is the most important).

As we discuss in our FAQ page, using Ion Exchange Resin columns are not a one for one replacement for traditional water washing of crude biodiesel - it is instead a different way to achieve similar or in some peoples cases, better results

We also sell the Ion Exchange resin towers along with a complete users guide/manual which largely determines whether or not purifying biodiesel with Ion Exchange Resin lives up to its promises...

GCG

To answer the question posed by the thread's title - we believe Thermax's T45 BD Macro offers several advantages over other products including Lewatit's Macroporous resin GF202:

1) First and foremost the macroporous nature of the bead allows the biodiesel molecule itself to penetrate the resin rather than relying totally on methanol to transport impurities to the inner portion of the individual beads.

2) Because of this more methanol can be removed prior to processing with the resin column with out sacrificing acceptable performance (economically and functionally).

3) The macroporous beads don't swell as much as the gel-type resins and therefore don't exhibit a few of the mechanical problems that come along with this bead swelling (due to rapid methanol adsorbtion)

a) significantly small pressure drops across the resin bed.
b) reduction in a fouling due to decreased gelly build up on top of resin beds.
c) less issues with pressure build up in resin columns due to compressed head space of columns
d) support screen plugging due to bead compaction

GCG

Thank you all for your expert input. Just so you know we have a basic B100 Appleseed set up built.

RickDaTech - Thanks for the comparison website, I'm going to read through it and learn what I can from it. You said- "They are all primarily polishers. They don't work well with high soap content biodiesel made from WVO."- That is not good because we are trying to take WVO from campus dining halls and produce biodiesel from it. So we might have to deal with high soap content.

Legal Eagle-I searched for it again but cant find it. Anyway thank you for setting me straight. Based on the first link in your reply Purolite sounds really good. You said- "it is not cheap to set up nor is it foolproof" the thing is that we are trying to set this up on a small budget and none of us are experienced like you forum guys. In regards to Graham Laming's GL Eco System, his results look very good, but we already have an appleseed built and are trying to make it work with as little modification as possible. I read through your page and your lead/lag configuration looks promising for us. Thanks for the help Legal, I'm going do do some more research on Purolite.

Thanks 51fitter. That's one more positive mark for Purolite use.

GCG- you really know your resin. I just did some reading on Eco2Pure and watched some of your vids. It sounds good, but let me run it by you to see if I understand: can we take raw biodiesel (that has had the glycerol removed) and run it straight from glycerol removal through the Eco2Pure and get good product? And one more question. For novice users what is best: Eco2Pure or an Ion Exchange Resin?

Thanks again for all your help everyone.

David

Another tip.

Look into the wood shavings thread as a way to reduce your soap content in the BD. It is undoubtedly cheaper than using resin.

I use shavings first and then macroporous resin as the final "polisher".

Thanks very much Eurocab

It looks that from what people are saying good results can be had from running BD through simple wood chips. And some are saying just let the BD sit in wood chips! That's just amazing ^____^ Excellent. I wonder if we can just have our raw BD sit in wood chips, filter it and call it good...?

We're trying to get the absolutely simplest system for cleaning BD, (like wood chips ) the fewer steps the better. Like I said before, my team and I are pretty much novices.

quote:

RickDaTech - Thanks for the comparison website, I'm going to read through it and learn what I can from it. You said- "They are all primarily polishers. They don't work well with high soap content biodiesel made from WVO."- That is not good because we are trying to take WVO from campus dining halls and produce biodiesel from it. So we might have to deal with high soap content.

To use one of the resins/beads effectively you will need to insert a step between draining the glycerin and using the resins that reduces soap content below 500ppm.

When it comes to cleaning biodiesel quickly, with minimal effort and cost, there are NO proven systems. The systems in use all have multiple process steps, that increase complexity or time like removing the methanol then settle then filter then pass through resin tower. There are proven systems, It's just I don't see any that are less complicated and less expensive than water washing.

You can try the wood chips or ecopure, but I'm not aware of any testing looking for contaminates leaching out of the wood chips into the biodiesel. I've also not seen anyone posting full ASTM testing results using wood chips or ecopure.

Water washing is a proven technology with water conserving techniques available. Someone ran a poll here recently (Don?) and it turns out like 90% of the people responding water wash.

There is also an experimental technique discussed on an Australian forum where they crush drywall into a powder and sprinkle that into their unwashed biodiesel. For quick and easy, that method can not be beat, but it can't make ASTM spec fuel.

Of course, you could join the unwashed. If your going to use the fuel in a vehicle that can take unwashed fuel, there would be no reason to wash it. Just let it sit for a week or so to clear up.

Ok, I didn't realize there was a soap limit on resin use. Thanks RickDaTech.

Wow, 90% that's a lot of you guys. Unfortuantely I think for us it's not an option. From what I have read (and I could be wrong) water washing is time consuming, and one of the stipulations for operating under a university bureaucracy is that a student must be present whenever anything is running. All of us have classes to attend and can't stay for long blocks of time. Also we are trying to pay students for their work on the project so such long hours might bust our budget as well.

Our goal is to supply the fuel to the campus motor pool for use in its garbage trucks, so I think we will need to meet ASTM. I'll have to ask but I'm pretty sure.

I'm doing a lot of forum and net reading on the eco2pure, hopefully I can come up with someone who can provide full ASTM? With water washing out, resin and eco2pure look like the only options.

David

David610
there is a lot of talent here, it can really help you from stepping in a hole. Monitoring your equipment is important many of the disasters that people have posted could have been avoided. I guess we are all learning just at different levels. Good luck with your project!

Thanks 51fitter

Yes, you guys know so much about biodiesel it's crazy. This forum has been a huge help. Thanks for the tip. We'll monitor our equipment like the government monitors our calls: constantly

David

David;
You can use water in a fairly quick and efficient manner, when done right.

Even though I've moved on to resin purification I used to water wash, but like many things I never did it the conventional way, that is with bubblers and or misters. My method uses a 120 degree full cone stainless steel industrial spray head. The page describes the conditions that must be present for this to be trouble free.

I've included my water washing experience on my webpage next to the link for "Dry Washing" so as to offer both methods and let people decide for themselves which best suits their needs.
My Water Wash page shows (with photos) the methodology I used; this one was the last set up I had after experimenting with many methods and found it to be the most efficient and least time consuming.

For someone who can dedicate several hours in a day and has things all set up and ready to go you can water wash and be ready to move to drying the same evening. The next day you are fueling your engine. I've done it just to prove that it can be done, but I do not have that kind of time in consecutive hours anymore so resin was a life saver, not to mention giving me more free time than before. I cannot guarentee that it would do the same for you as your situation is different from mine, but for me it is the only way to go, whichever is used; Purolite, Amberlite, Thermax, Eco2Pure, a combination. They all work when used properly. I've hit a GC ASTM passing grade for free and total glycerine using both water and resin from a reaction in a water heater, so it can be done.

In a school evironment water washing will teach more about residual chemicals as students will be able to see the water turn white and then eventually go clear to near clear, however water will also give you a water waste stream to deal with. You can't just dump methanol and caustic laden water just anywhere, so this is something to also consider.

Sorry, I am feeling verbose tonight.

quote:

From what I have read (and I could be wrong) water washing is time consuming

It does not have to be time consuming. Most homebrewers will have some segment operating unattended to cut down on the time spent with the processor.

If you wash hot, with hard water, have high conversion fuel, and give it time to settle out the glycerin completely before starting to wash, then it you should be able to do it in short segments between classes.

See one thing you may not have picked up is that at all stages, leaving it alone to "age" makes the process go easier. Some here like Legal have broken the process into steps that can run at the same time. It means you may have three or four batches in progress at any one time with each batch in a different process stage. That lets you operate on a short schedule with unattended gaps of whatever time periods in between.

Verbose is good Legal, the more you say the more I learn so by all means be verbose. I'm thankful for it.

I read both your water washing page and your drywash page. Comparing the two systems you use I have to again say the dry wash sounds more appealing and more suited to work with the set up we already have built.

I think we'll be in the same situation as you Legal, unable to dedicate several hours in a day so resin keeps presenting itself as the solution. Excellent, we are using a water heater too, so if we can get over the learning curve hopefully we can produce quality fuel too.

You are right, the water wash method will teach the most, but also like you said we'd have to deal with a contaminated water waste stream. The added cost of having the waste taken care of won't help us stay in the black on our operating costs.


RickDaTech-Yes, you are right. what I have read (and been told) since I posted last goes right along with what you say: it doesn't have to be a super long process. Unfortunately we couldn't leave anything unattended to save time (thanks to the rules).

A while back you said:

"To use one of the resins/beads effectively you will need to insert a step between draining the glycerin and using the resins that reduces soap content below 500ppm." What would you suggest to accomplish this step?

That aging idea is great. I missed that part, good call. Having a few batches moving at once could smooth out or production schedule a lot. We could slowly release the fuel that way instead of having a stop and go release. I'll have to look into how much BD we can store in the lab. Thanks Rick.

Now that I'm about to replace my exhausted resin I'm at last on the point of switching over to wood (oak) shavings. All my trial batches with this have been encouraging. I'll post results with pics of my first full scale (100L) batch sometime this coming week.

That would be great Jehu, I'm very interested in seeing how well the wood chips work in place of resin. Thanks.

quote:

RickDaTech-Yes, you are right. what I have read (and been told) since I posted last goes right along with what you say: it doesn't have to be a super long process. Unfortunately we couldn't leave anything unattended to save time (thanks to the rules).

Do you mean unattended with the power running or unattended with oils/biodiesel present? For instance can you leave the glycerin and biodiesel mix to settle without any power for a few days unattended?

quote:

"To use one of the resins/beads effectively you will need to insert a step between draining the glycerin and using the resins that reduces soap content below 500ppm." What would you suggest to accomplish this step?

There are two ways, GL and water wash.