Anybody use their sawdust for pellets?

[Brad_bb]

Just saw an ad for pellet mills etc.  A recent post was just asking for used for sawdust.  Milling we make a lot of saw dust.  But it looks like the pellet mills are not a cheap investment.  I guess you'd have to look at how much pellets are sold for(and divide by 2 for wholesale cost), How much dust you make, and how long it would take to break even.... Looks like  you need the have the dust pretty dry too, another processing step...

I wonder if pellet producers seek out local mills to supply them with sawdust?  Hmmmm....

[Tom the Sawyer]

I have a client who purchased one of those presses, reportedly powered by a 22 hp diesel engine.  He picks up my sawdust periodically and uses it to keep his extended family in wood pellets.  He runs the sawdust and planer shavings through several screens before processing.  He said he can go out in the evening after work and press a thousand pounds of pellets in a couple of hours.

I don't think he sells any, but might if my sawdust production was higher (most of my milling is on the road).  He started out bringing those white, plastic, 55 gallon drums.  Now he brings one-ton agricultural seed bags.  They have straps which make them easier to load with a forklift.

[rjwoelk]

Picked up a semi load of hard wood one time, they tried to make pellets for sale, they were a large operation, 3 very large kilns, they quite as it cost too much to produce.

[WV Sawmiller]

   Somebody posted about them on a thread here a while back and I went to the link. They had some videos and showed them making pellets and the process looked interesting. I went to their contact section and I asked them about the moisture content and electric power phase requirements for their mill. I never heard from them since but did get several solicitations from China and other countries trying to sell me their machines. I decided it was a scam and quit looking into it.

[Jim_Rogers]

Many years ago, I did some research and found a pellet press for $2500. And I asked them if they could make pellets out of my sawdust. They suggested I send them a 5 gallon pail of my sawdust, for them to try and see if they would make pellets. I never did that.
They told me that green sawdust was going to be "most likely" too wet to press. However some say the pressing process produces heat, and would dry them out. But I don't believe that they will. So you're going to need to dry your sawdust.  A simple sawdust drying system was going to cost $10,000.
Also, they said the most likely we'd need a" binder" to hold the sawdust together.

After all this, I thought that I could get some barrels and take them to the local woodworking shops that I know of in my home town and offer them to them. So that they could put their "dry sawdust" into the barrels instead of putting it in their dumpsters. Thus reducing their dumpster fees.
But, my brother was talking to me at the time, and he said: "then you've got to go around and collect the barrels, give them empty ones. Come back and press the sawdust into pellets. Do you have the time to do that?"
My answer at the time was: "no"....... it is almost a whole business in itself, in order to make money to pay of your investment.

Jim Rogers

[Josef]

Ill jump in here with a few thoughts. We have made pellets in the past with a Buskirk Engineering mill, and the process isn't that difficult.

First caution, the commonly available Chinese made mills are typically designed for livestock feed processing. They do not hold up well with wood fibers. It takes longer than you would expect to press an appreciable amount of pellets, typically 300 to 500 lbs per hour for most smaller "home use" mills.

Moisture content, particle size and lignin for binding are the limiting factors. Moisture over 14%, particles larger than 1/4 inch and using wood fiber exclusively will limit the production. Most wood fiber, both hardwood and softwood, doesn't have sufficient lignin to bind the pellets and typically requires supplimental binder. Moisture content too high and the pellet "explodes" when it leaves the press plate due to the steam from the high heat generated in the pressing process, sometimes over 300 degrees. Particles too large will cause the roller to push the material ahead of itself instead of pressing it into the die.

If the pellet explodes we will sometimes just dump them back into the press, as the steam carries away some of the excess moisture and they sometimes will bind fine on a second pressing. To control the particle size we sometimes use a hammer mill to reduce the fiber particles. To add lignin we will process grass fibers with the sawdust and a 50/50 mix presses well.

In the past we have pressed horse manure into pellets. Load it into a manure spreader, back it onto a concrete pad, broadcast it onto the pad thinly to air dry it for a day and gather it up. Sawdust bedding, hay waste and preprocessed feed products ( horse manure) make great pellets. One caution using plant fibers, they burn hotter than wood fibers and will create clinkers, so a stove with shaker grates is prudent, like those used to burn corn. The pellet press we used was a pto machine and it took all an 80 horse tractor had to run it.

I think I grinned for a week when I found I could actually do something productive with horse manure. But don't try to sell them, the possibility of harmful pathogens from the manure is to great a risk to expose yourself to that liability. We heated house, shop and greenhouse with them.

Joe

[Kbeitz]

Looks like a lot of work...

http://www.makeyourownpellets.com/

https://www.youtube.com/watch?v=chxL9ias3Xc

[Brad_bb]

Do to the initial capital costs, I think you'd have to pool people together to get the capital.  It would take time to get to the break even point if you could.  An serious analysis would be needed to figure out how long it would take to break even, and whether or not it took more input than you get out.  That is, would the time and work needed to gather and prepare proper raw material, plus the amortized capital costs, be more than the net value of pellets you get out of the works?  I just have a hard time believing this is doable as an individual.  I'd think you'd need to scale it up to have a chance break even or get in the black.

[Magicman]

I toured a commercial pellet manufacturing plant.  They used paper-mill quality chips, a hammer-mill, huge pressing dies, and closely regulated moisture controls.  It was very obvious that without governmental subsidies they would not be in operation. 

[Josef]

Good points Brad_bb,  the pto pellet machine cost was just over 8k (6 years ago), the farm equipment we already owned and the infrastructure was here. At the time a ton of pellets could be bought for $230. Sawdust and manure were by products of the farm, mulch hay could be purchased for $5 a bale (1000lb round bale). The tractor running the pellet mill consumed about 1 1/2 gph, $6 per hour back then, less now.

The 12 inch mill could reliably produce 700 lbs per hour. We mixed about 400 lbs mulch hay in each ton of pellets, the rest was sawdust and manure. We figured our cost to be about $30 per ton, not counting our own labor and took about 3 hours to produce. We consumed about 30 tons of pellets annually, with the greenhouse being the largest heating load on the wood boiler. Throughout the summer we devoted about 12 days to pressing pellets, and put out about $1000 in cash to make $7000 worth of pellets. We figured the machine would pay for itself in less than 2 years and with family help our labor was shared and the extended family also got pellets to heat their houses with.

If I were just pressing pellets to heat my house the payback would be closer to 7 years to pay for the 12 inch machine so you'd probably have to press a bit more and sell them. Buskirk did several demonstrations at Penn State with a complete processing unit that took in hay and put out pellets, on a trailer, quite a machine. It was being marketed as an outlet for non feed grasses.

[Brad_bb]

It's really a shame that we have all this sawdust that we generate, and have to find a way to dispose of it.  I've seen people build Rocket stoves (sawdust wood stoves) that you pack a cylinder with dry dust with a central intake air hole formed with a piece of pvc or similar.  I wonder if it's possible to make a rocket insert that would work in a regular wood stove?  Dry your dust in the sun, maybe tumble the ducts in a small cement mixture and add a little left over bacon grease (another by product of my breakfast I need to do something with).  A little bit of grease will help it pack and keep the formed intake air hole in the center, and use up the grease.  Size the formed piece to fit in a barrel or conventional stove...  Anybody ever try that?  Definitely less costly and less stringent standards than pellet mfg.

[jimdad07]

It's really a shame that we have all this sawdust that we generate, and have to find a way to dispose of it.  I've seen people build Rocket stoves (sawdust wood stoves) that you pack a cylinder with dry dust with a central intake air hole formed with a piece of pvc or similar.  I wonder if it's possible to make a rocket insert that would work in a regular wood stove?  Dry your dust in the sun, maybe tumble the ducts in a small cement mixture and add a little left over bacon grease (another by product of my breakfast I need to do something with).  A little bit of grease will help it pack and keep the formed intake air hole in the center, and use up the grease.  Size the formed piece to fit in a barrel or conventional stove...  Anybody ever try that?  Definitely less costly and less stringent standards than pellet mfg.

I actually have all the parts and pieces to build one of these sawdust stoves including an inducer motor for a forced draft.  I have a piece of 16" cast iron pipe for the inner chamber and a 6' tall bladder tank with 3/16" wall that will be the outside of the stove.  I won't be building it though until the barn is done.