Case Study Quality

wood chip biodiesel

By Luc Blais

More in the Fall 2009 issue

RolfQuo Biodiesel is a mid-sized commercial biodiesel producer situated at 18900 Clark Graham in Baie D'Urfe Quebec, Canada.
Recently, I had the opportunity to sit down with owner Andy Quosdorf and his plant manager, Kai Maddock, to discuss their operation and some of the innovative methods they use in producing quality biodiesel.

Your background is in chemical blending. So why biodiesel?

Andy Quosdorf: It's something we got interested in about three-and-a-half years ago. We were looking for another product to make in this location and because our tradition business, textile chemicals, was going down the drain.
Myself plus Kai, my plant manager, are motor heads, we like motors, engines, tinkering with things, and I came across biodiesel from one of my competitors actually, he mentioned it to me, so I googled it and that is how the whole journey started.

Your biodiesel production has gone through upgrades since you first started, not the least of which is the method used to purify the settled fuel. Can you elaborate on the history of what brought you to where you are now with this new method and the medias you looked at?

Okay, we started getting interested in "dry wash" media probably two years ago, simply because water washing takes forever and isn't that kind on the environment. In our operation here it takes on average two-and-a-half to three days to water wash a batch, and that is just too long.
In the lab we looked at several of the medias: the Purolite and the Thermax, and found them to be excellent, but I was a little nervous about the price, the cost of these resins.     

But you found that the resins lived up to their reputations?

Oh, absolutely! They live up to their reputations.

But price-wise they are a bit prohibitive?

Exactly. You know, we are a small operation here, we built everything out of used equipment ourselves and can't afford to buy a lot of fancy equipment and the resin itself.

So now you are using hardwood chips as a purifier.

Yup.

And that has eliminated water washing altogether. You use no resins or any other method?

Nothing at all.

Can you describe the process briefly?

After the glycerine has settled we run the test for glycerin content. Once the batch is deemed good, which is ASTM quality for glycerin, the test we use here, ...we flash off the residual methanol from the biodiesel, and quite frankly, there is very little left. And then at that point it is passed through the wood chips.
    
And what have you found with the wood chips as far as residual soaps are concerned?

Typically we start with soap values anywhere from 300 to 800 ppm before it goes through the wood chips and at the end it is from zero to 50 ppm.

So, well within ASTM regs?

Well within those boundaries, yes.
One thing I would like to mention is that we will be looking at different systems, physically. It is based on drums right now, steel drums, but I want to build two proper towers. Mostly because I can't get the flow rate I want from the drums; right now we can run about 2,000-3,000 litres a shift through there and I need to be higher than that.

So about 2000 to 3000 litres per eight hour shift?

That's right, but I want to be at least 10,000 litres, maybe 20.

So, wood chips are definitely the way to go?

Yup, yup, yup, definitely, we're convinced. Can't beat the price, and they work very, very well.
The most important thing is to properly prepare them, though. Very important. We put them through three bed-volumes of methanol, and then three bed-volumes of clean biodiesel, before we use them.


You started using wood chips for purification of the biodiesel instead of water, and as Andy said earlier, you've looked at resins and all kinds of other methods. Can you describe how you prepare and use the chips?

Kai Maddock, Plant Manager: So far we are having the chips given to us, so no need to buy at this point. They come from lumber mills and are all hard wood.
We would run methanol through there first to remove any resins from the wood or whatnot and the procedure is pretty easy; you fill up the drum and run methanol through basically until it runs clear.
At first it runs yellow, and sometimes even a little red. Once it runs clear you put maybe another 200 liters through just to be sure you got all the resins out. And then you force that out with at least 200 to 600 liters of finished biodiesel through it.

Is this per drum of chips?

Yes, per drum, but everything is reclaimed. You can use the methanol in a new batch and the biodiesel is reprocessed. So nothing is wasted.
The biodiesel flushes any methanol that may still be in the chips, and when we start we are sure all the methanol is out and the drums are already full of finished bio. Then we start a production run. We use little air pumps, so we can go pretty much at full speed, which will give us a tote, say 1,000 liters in, best guess, couple of hours.

That's not bad, 500 liters an hour flow rate?

That's right. What we have here looks like one, but is actually two columns, and you are dumping them into the same tote.

Okay, so you have a two-tier set up, and basically your right top drums dump into the bottom right drums and the same for the left side, and for that you use a small air pump?

Yes, and surprisingly it requires almost no pressure. Just enough to get it moving, and then it flows.
If you put a little pressure you can get really going but too fast isn't good, you're not getting suficient residence time to get all the soaps out.
It is fascinating, but it has its limits obviously. If you are starting with 3,000ppm soap or something, it won't take that out in one shot.

So, you'll have to run it through a couple times?

It is even set up that we can circulate it if we had to. We can just run it over and over if we had to. But if you are starting with 800ppm soap or less it does a really good job, it gets down pretty much to zero.

In one pass and you're good to go?

Yes. Even if if you start with a thousand, worst case scenario, you're starting with a thousand, you have to slow it down to get your zero.

But that is definitely a much more environmentally friendly method of purification than say, water.

We must have passed at least 50,000 liters; I don't have the exact numbers but it is at least that.

Through one set of four 200 liter drums (800 liters of wood chips)?

Yes, one set. The rates vary with what you start with. If the soap content is high you have to go slow. If we get a reading of 200ppm starting out we can then crank it up to the max and the biodiesel comes out at zero ppm for soap.

What do you do with the spent chips, or have you had to deal with that yet ?

So far we've not had to deal with that. But we have discussed it; we can pretty much press all the bio out of there, and then what is left isn't dangerous, it's wood chips and non toxic residual biodiesel. 

RolfQuo Biodiesel can be reached 8AM-4PM weekdays at (514) 457-4222.
Mr. Bill "Jehu" Guyan of Scotland is credited with inspiring RolfQuo's decision to use hardwood chips. His tireless research into this subject and others can be found at biodiesel.infopop.cc 

Luc Blais is a small-scale biodiesel producer and creator of the Black Crown Biodiesel Glycerine Soap Guide (find it at http://www.blackcrownsoap.com). He posts in online biodiesel forums as “Legal Eagle.”