Experimental fuel source

I'm going experiment with these.
They are from broken down pallets. The pallet manufacturing facility has skids of them out front, free for the taking, plus skids of broken down pallets.
The owner wasn't there today, but I am going to go back and ask if they could put a few skids of this stuff or the pallet wood on my trailer.
If the blocks don't work well, the broken down pallets certainly will. I can use it to heat the DHW over the summer and save the good wood for winter heat.
Has any had any experience with these types of blocks?
They look like giant pellets.
They are shredded wood fibers, most likely held together by some type glue or polymer.

My favorite words, free, give away, etc. They gotta make heat, even if you need to mix in a few 2x4 scraps off the job. Your saw & splitter already love them.

It would be good to know what the glue is that binds them together. Generally it is not advised to burn particle board, these look a lotb like a particle board product??

www.epa.gov/burnwise/bestburn.html

I went for it any way and put about a dozen or so on top of the bed of coals and then loaded it up for the night.


I checked on it 10 minutes later and she was gasifing just fine.
I cant open the gasifing chamber door on a WoodGun all the way, so I just crack it open.

I came out this morning and this is what I found.

To my surprise there were still several blocks left.
The were red like coals and still had a solid state about them.
You can see the block with the half hole in the lower left corner in both pictures.
And there are some of them in the back right corner along with the coals of a split laid up on the right side wall.

The ones we get here are like a BIOBricks and that size. But i assume they have glue in them. I have burn them when short of wood. They burn really hot so don't fill whole stove. I wish my manufacture would have more of them or separate them like yours. I also burn pallet slats from manufacture which burn hot but do not last long and you can get to many coals in chamber and boiler does not like that. Have to load boiler often. They are full of nails though so between loads you have to get them out. I use a big magnet for that. Foamit UP

Chances are that the adhesive isn't polyvinyl acetate (Elmers white glue) because it doesn't burn that well. It's almost fireproof. That leaves several other adhesives that could be the bonding agent. Several adhesives used in that application contain formaldehyde which for some reason is a necessary ingredient in these adhesives. You should probably assume that if they do contain formaldehyde is it going into the air for you and your family to breath.

I had an occasion in the past where I needed an adhesive that people were going to come in contact with and found it nearly impossible to find one that didn't contain the stuff.

Since formaldehyde is a relatively simple hydrocarbon (containing only carbon, oxygen, and hydrogen), I expect it would be pretty thoroughly consumed during secondary (if not primary) combustion. I think wood gas itself has a not insignificant amount of formaldehyde along with other hydrocarbons and toxic chemicals such as carbon monoxide in it even when burning clean wood.

The magic of secondary combustion is that the combination of high temperature, adequate oxygen, and sufficient dwell time serves to break down and oxidize all of that stuff yielding almost nothing except water vapor and CO2.

Bottom line: don't inhale the wood gas from your primary chamber, but flue gas should not contain more than trace amounts of hydrocarbons if secondary combustion is doing its job.

If you burn a lot of non-wood hydrocarbons you might need to adjust your secondary air.

I get more concerned if there are nastier chemicals containing more than just carbon, oxygen, and hydrogen. Things with chlorine, sulfur, or metals could produce some bad stuff in the flue gas.

I dont think you can do that on a woodgun.

Nope, not adjustable.

Probably not an issue in this case, but if the ratio of carbon/hydrogen/oxygen in your fuel mix is way different than firewood then the ideal primary/secondary ratio might be different. Every carbon molecule needs two oxygens, while two hydrogen molecules are happy sharing a single oxygen.

Keep in mind that I'm a mechanical engineer, not a chemist. Take anything I say with a crystal of NaCl. Maybe on the rim of a margarita glass.

I've been doing a little research on formaldehyde and like nofossil has said most of it will be consumed in the burn and have levels no higher then what is released from burning cord wood.

However, I went back to the pallet place and went in the back production area. They have bins made of pallets filled with solid wood blocks used in building the pallets as well as these particle board ones and also the slats from dismantled skids.
The manager said come by and we will give you as much as you want and load it right on my trailer. (for free)

Most of the solid wood blocks are oak and some are yellow pine. It will be a great source to mix in with cord wood.

Now, when he says as much as you want...are we talking a REPLACEMENT for cord wood quantity?

ac

There's a good possibility. If not completely replacing it, then a good portion of it

EDIT: replacing cord wood with the broken up pallets and the solid wood blocks not the fiber blocks.

I don't think it would be a good idea to completely replace cord wood.
Pallets are extremely dry and I think there would be a puffing issue.

http://www.apawood.org/level_b.cfm?content=srv_env_form

http://toxtown.nlm.nih.gov/text_version/chemicals.php?id=14

Doesn't look to be much of a concern, unless I drink it in large quantities or sit at the top of my stack with a towel over the top and inhale like a vaporizer.

Yeah, true. I burned pallets for the 1st year I had my wood stove since I had no other wood that would burn in it well. It was just about as much work breaking them down to burn and dealing with the nails in the ashes as it was to process firewood.

ac

I used to burn hardwood scraps from a local pallet shop in a Tarm gassifier. I did not burn the particle board type of blocks. I would destroy the refractory material in one season. The wood burned so hot and fast if I put too much in it would start puffing. I did this for two years and figured the cost of the refractory was not worth it and went back to cordwood. I burn a variety of hardwood and softwood now. I replaced the tarm which started leaking with a Vigas which will controls the burn a lot better than the tarm did and also use less wood.

Instead of those particle board blocks I got a bin of cut up pallet material and a bin that is mostly solid wood blocks with a few of the particle board blocks.

Man, what a job to get them off the trailer and in position. I worked like an Egyptian slave building the pyramids. I used a big steel pinch bar and 2 nice round logs(had no pipe) to move it. Oh and my motorcycle jack.

Its basically a full cord. I gave the guy who loaded the trailer 10 bucks.

Most likely the binding agent in the wood bricks is the lignin itself, a polymer structure within the cells of the woody stem and acts as a bio glue in most plant cells. Lignin has no specfic empirical structure and when heated by pressure it will form an amorphous-like substance that can "flow". When cooled it "hardens" and will bind the other materials within the pressed, heated, and cooled wood product. This binding occurs in the manufacture of pellets and, i believe, in the wood bricks as well.

I doubt that a block held together by the lignin itself would survive the compressive forces and moisture that these blocks will be exposed to in their working life.