I used to be a millwright in a pellet mill and we used water and vegetable oil with a LOT of heat and a rotary press mill the mills were really pricey but if you used a hydraulic ram and an extruder you can do it that way just break the pieces into chunks

We use any old small cardboard boxes eg fag packets, toilet rolls basically any box that's log size.
Pour in some dust and shavings, ram it down with a piece of wood keep going till the box is full.
We burn these along with logs.
I know it's not practical if you intend to burn large quantities of dust but the outlay is zero which is always a favourite with me.

To get rid of both used motor oil and sawdust I take an empty waxed half gallon (2 litre) milk or juice container and fill with about 3 inches of sawdust followed with about 3-4 oz. of oil contuinuing the process until about half filled when I tamp the layer of sawdust down well with a piece of 2x4 and continue until completely filled up and packed reasonably well. After folding the top closed and left standing vertically for about 10 minutes to soak in, it's ready to light with crumpled paper in a woodstove. Just one will provide close to 2 hours of medium heat depending on the stove size. I have never noticed any oil smell from the chimney outside yet.

Frankly I think used motor oil should be properly recycled - soon enough we´ll have too little, and burning it is obscenely polluting. Saw dust , shavings etc will burn without further effort in the right type burner and stove, with a whiff of blown air, and fed into the fire slowly. Last 10 years I saved natural gas worth 4-6000$ a year for heating a large workshop and house. Even if you don´t care about pollution , Oil peak , carbon emissions etc , the savings should be enough.

I have a small woodburning stove (4kw) I make sawdust logs & also add any debri I have from log cutting, bark, ivy, twigs etc.

. Take 2 sheets of a tabloid newpaper, wrap round a template log of your desired size & seal base & length with tape (I use free tape from my work but any will do)

. Fill with mixture of sawdust & burnable debri (I usually fill the first third with sawdust, then the rest with a mixture of both.

. Thoroughly tamp down as you fill & then seal other end with tape.

I find these will burn anywhere up to 2 hours & are ideal to add at the end of the night as they will burn slowly overnight keeping the stove going until the early hours.

I'm very seriously thinking about purchasing a wood gasifier. If you haven't heard of this, you should look into it or google search it. How about powering everthing you have with wood..? Search Google for "Wood Gasifier" .. you will be impressed! I was, and I almost got into steam... what a mess. I 've been off the grid with solar and wind for years and now discover that wood gasification would have been better and cheaper...

Gasification is an old process. In WWII many cities in Europe used this process as wood was the only fuel around. The gas is low BTUs compared to natural gas...about half. In Milwaukee, they used coal gas from gasification of coal.

When gasifying, it is my understanding that not all the wood is converted to gas, but there is a lot of pure carbon left. One concern is how to get this residue out of the burner when the burner is cool. Without a fluidized bed, the fuel size and initial MC must be fairly uniform. Also, the gas cannot be allowed to cool much as it will condense, forming what we typically call creosote. Sometimes we use a two stage gasifier in order to get a cleaner gas. I saw one unit where the gas for the initial gasification was passed across the cool, incoming fuel to clean it a bit. Because of the dirty gas, the transportation of wood gas for very many feet is not possible. Similarly, storage is not easy. Also, if wet fuel is used, there will water vapor gas produced too that must be handled. Also, when the unit is shut down, there can be residue issues as things condense to very hard solids, plug lines, grates, etc. All these items can be handled in a gasifier, but do require a bit of special care. Gasification works best with a constant load.

I built a saw dust burner 4 yeasr ago. I burn green dust with up to 60% moisture.
This burner heats my shop that is 2100 sq feet and my house. I was a second class boiler engineer in Ohio. after several changes I came up with the exact design that will work without no burnback.
I am going to shrink the design down to a home unit within the next year. When I get everything in order it will make up prints for this.
Best regards

Mike

i think a bucket of water mixed with a small amount of flower would make a harmless glue to mix with shavings and dust to form a block.i am in process of trying out.

What kind of flowers do you recommend?

the best wood flour comes from aspen, but other species are easily used.

The most common adhesive for charcoal briquets is corn starch. For wood dust, often heat and a little moisture and then pressure will be adequate to bind together pellets.

Awesome thread guys, thanks so much for the info!

Why not make the sawdust to pellets or briquettes. The high pressure of the press causes the temperature of the sawdust to increase greatly, and the lignin contains in the sawdust plastifies slightly forming a natural "glue" that holds the pellet together when it cools. You even can add some shredded cardboard or newspapers, those material will all help to make wood pellets easier.

Small size pellet mill is not expensive, 15hp residential pellet mill only costs USD940.00, but you will get 100kgs wood pellets each hour. Briquette machine are not recommended, even we have screw briquette extruder for hollow briquettes, hydraulic wood bricks press, because they are more fit for commercial production scale. Their price are high.

But it is important to control the moisture content of sawdust before pelleting. 13% to 17% moisture content will be better to get good quality wood pellets.

I have seen folks on YouTube and in some old WW1/2 era plans of taking a barrel (or paint can) and put a pipe (temporarially) down the center. Cut a hole in the top and bottom of the can/barrel the size of the pipe (think 4-6" dia in a barrel/drum or 2-4" in a gallon paint can. Dampen sawdust and put it in the can/drum. Tamp it down every few inches around the OUTSIDE of the center pipe. Once full (no space at the top) pull out the pipe and put on the top. Now you have a metal cylinder filled with saw dust. Set it aside to dry out till you need heat or until dried out. ... When ready to use, put on a non-combustible surface with air space underneath (a couple of bricks or so, it needs some height for air flow). Put a flue on top to get the gasses out if inside a building. Crumple some paper and put it in the bottom of the sawdust area, and light the paper. When the sawdust catches, it will burn inside the can, and will burn for quite a while, and surprisingly (to me) completely. They said a barrel should burn for about 8 hours (in what I read).

I have found ,if you have 18+moisture a mold an a press you have what it takes to make sawdust an small shaveings, stick together. you will need a heated drying chamber to reduce the moisture.

http://www.youtube.com/watch?v=jMdRRhVJorY

Is a link to someone doing a stove Iike I was alluding to earlier.

Yesterday I cobbled together my first attempt at a rocket-wood-dust-stove for purposes of mass heating & dry steam generation:
50g steel outer exhaust down flow drum,
30 g steel dust charge drum ot (wood dust compressed in place),
vertical burn hole formed with a 4.5"OD plastic pipe set in a
steel air supply & fire starting tube 7" ID, with rough fit sealed with earth false floor.
Assembly set on water leveled & stabilized ground (puddled foundation earth)

Test fired last night. Burned well initially without the lid on.
With the lid on the lid did not get hot enough to support secondary combustion of the flue gas and so power the pump of flue gasses downward.
I somewhat expected that since there is a 3" gap between the top of the 50g barrel and the open top of the 30g drum.
That space is needed for pipes to superheat and dry the steam (open flow system arising from a pressure cooker on top of the 50g drum lid) .
A bit of hot steel to facilitate the secondary burn appears necessary.
Just to test that I dropped a bit of screen over the top of the saw dust's burn hole - now the dust burnt clean and hot.
But the burn was not given its secondary burn by the lid so that the down flow of flue gas would be pumped ram-jet style.
Draw was not nearly enough to produce the burn rate my intended use required - even with the lid off.

A right-gapped lid on on the inner 30g drum may do the job of starting and concentrating the burn so that the outer rim of the lid and upper edge of the 50g drum will get hot enough to complete the secondary burn powering the down draft pump. Sound a bit like wishful thinking. I might test that tonight.

My compressed-to-form dust charge collapsed at about 2/3 burnt. That may have been prompted by weight of the screen I used.
I suspect that my saw dust also needs to be drier and more uniform in moisture.

I would sure like to get it right for this evening test burn. Any insights or guesses will be greatly appreciated. TIA.

Since the burn face and its tube diameter grows as the dust charge is consumed it seems like it should continually work better until its form remains collapse.

Does anyone know if this is true?

I think their must be a limit to that 'better', perhaps some height to diameter ratio because while burn face doubles as tube diameter doubles - tube circumstanced area quadruples.

I saw a link somewhere on a DIY rig made from a electric fire place log splitter. It had a cylinder with part of the side missing with a hopper for dampened sawdust to go into the cylinder. The right compressed it into a long 1" dia or so pellet and just pushed it out the end into a pipe. The pipe guided the continuous 'pellet' through a pipe to the top of a barrel, where a metal 'finger' at the end of the pipe pushed 'down' on the pellet so it would break off into 2 to 3" long pellets (I am sure smaller length if smaller diameter would work). After being compressed, the moisture would heat and evaporate in the process getting the wood saw dust to combine. If being burned in doors, I suggest NOT burning MDF dust (to much plastic in it) or possibly even treated, but other stuff should be able to be burned nicely for domestic heat. ... wish I could find the link. He had an 'automatic shutoff' when the hopper went close to empty or the barrel was close to full.

Found the posting. This is a build blog of an automated DIY briquette press that compresses sawdust. It is not a how-to but most folk should be able to replicate it. He said it takes about 13KW to make a barrel of briquettes. That would be about $1 to $3 in electricity depending on your rates, and his machine runs automatically without supervision. It is left to the interested reader to change it to produce pellets instead of briquettes ;-)

Alois's Brickette Press