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Bio fuel briquettes, compress paper pulp and sawdust into fuel bricks.

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To find a use for the large amount of sawdust produced from wood turning sawing firewood etc, the 2 choices  had was to dunp / compost  it or burn it. 

loose sawdust can be burned in a wood burner but can easily kill the fire and cause a lot of smoke. decide to try and compress it back into bricks that would burn better.

I researched the options of either dry compacting and the forces need where just to beyond my capabilities.

My only other option is to compress a wet mixture and use a binder such as news pulp.

I researched on youtube and instructables to see what the other people where using.

I found all the info needed but found some of the method where a bit fiddly for me as i have a few old hand injury's that make fiddly not an option. other option made small briquettes or the process was just to slow for the amount of sawdust i had lying around about 12 fertilizer bags full to be exact.

Ive done nothing new here, just added my 2 cents worth to the mix and try to improve what others have done before to inspire my own effort.  Enjoy. :-)

Thanks for looking and I hope you like my idea
 
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Step 1: The plan.

Even a little bit of wood turning creates a large amount of sawdust..

I decided to build a mould  that would be easy to fill and compress but would would produce a larger brick than that I had seen, and have a press that would be faster to operate.

I was lucky that I had the chance to buy a Sealy No2 bench press a few months back and had yet to fin a job for it.  I decided that I could modify the pressto use for this job and more usefull for other jobs.

I decided to use only what I had at hand. this would be a no budget build.

Materials used:
3/4" plywood (I do like the 3/4" plywood)
6" sewer pipe.

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flavio.mery6 hours ago

Did you try the cement mixer? Did it work?

Did you try the cement mixer? Did it work?
shaddyx3 months ago

This kind of home making winter fuel is a cool stuff. I have also at home some simple press, similar to yours - but I use a car jack. Secondly, for faster dry you should implement a (again) simple "thing". Insert a pipe inside the mold and drill a hole on the top cover. The briquettes will get a hole in the center so can dry faster also can burn more efficiently. Second, if you wish to get more dense briquettes and get rid off the crumbling issue add some flour in the mix. Do not use a lot of it because the drilled holes in the mold will clog. I use half kilogram flour for 50 kg mix. The rate is similar to yours, - 3 units of pulp and 4 units of sawdust. Water as like to get the mix in proper "shape". The mix should be used up to 15 minutes after adding the flour. For me the 50 kg mix is briquetted in some 10 minutes. And yeah - the pressed out water goes again inside the tank for paper soaking. As calculated there can be used (recycled) around 70% of the water.

Again, nice job - keep up rollin'

As hubby has a wood and metal working shop there's always plenty enough saw dust to go around...too much. Seeing as how this burns practically smoke free, going to try this certain type of grass I saw at a model forest that was labeled as bio fuel quality, grow some and add it to the mix and see what happens. Thanks for the great idea!!! :)

SLEDHEDONE7 months ago

what about adding used coffee grounds to the mix?

should work quite well, I've been making coffee logs of late, but 1 log takes about 6 weeks of coffee to make... going to try a new mix soon, and this has given me many ideas :)

Hi, very interesting. I have a lot of tree trimmings so have designed a press to make several (9,16 or 25) briquettes at a time fairly quickly. The mix will be comprised of wood chip, shredded paper and cardboard, water and anything else (within reason of course!) that will burn. The pressing force will be applied from above by a ten tonne bottle jack within a strong steel frame (two jacks could be used next to each other) and after pressing the mould assembly will slide across to clear the pressing plate and allow the briquettes to be ejected downwards onto a chicken wire drying rack. I expect to make the press next spring after finishing my new secondary combustion stove and make the briquettes in the summer so they will be ready for next winter. I will post drawings and photos in due course. Good wishes, John
raviolikid1 year ago
Interesting project! Thanks for sharing it.

lukeyj153 years ago
I was thinking that instead of making bricks with the sawdust, would it work if I injected the sawdust into an air stream and burnt it that way. I have tried burning sawdust myself and it tends to form a smoldering pile on the bottom of my fireplace. I think it does that when it has insufficient air to burn with. Due to the nature of sawdust, it tends to smother itself. But I remember seeing an instructable where you can breathe fire by using cornflour or some other fine powder by making a cloud of the stuff and igniting it. Similar thing with canola oil. By itself, a puddle of oil won't ignite, but when it is sucked through a wick it burns.
Dr Qui (author)  lukeyj153 years ago
A high pressure air stream capable of moving sawdust , sawdust and fire would be the 3 key ingredients for a dust explosion.
lukeyj15 Dr Qui3 years ago
Yes, but so would gas coming out of a stove. The key is control. Only having a small amount of sawdust burning at a time. Same with a car. It has thousands of explosions a minute in the cylinders, but they are controlled.
However, the day it went wrong, much like a gas stove, might well be your last. Is it worth it when there is no gain?
My brother dropped a loose handful of sawdust on a lit match, and it flared up. If you could continuously drop loose sawdust onto a heat source it would burn more efficiently than piling it up. The stuff at the bottom tends to get smothered by the surrounding burnt ash.
Dr Qui (author)  lukeyj153 years ago
When you compress the sawdust into briquettes they burn much better than loose sawdust, they don't smother themselves. 

I burned a few dozen over the Christmas holidays and they burn very well, they light quickly and burn like charcoal.
jsy9820023 years ago
Hi,

I saw your post regarding the conversion of sawdust to solid blocks.

I would just like to ask how much is the difference of the compressed saw dust to
solid blocks of wood in term of Density and heat output.

I am planning to use this as firewood in my Boiler, do you think it would be advisable?

Thanks!

-Justin Sy
Dr Qui (author)  jsy9820023 years ago
I honestly don't know, I did this method because I had an excess of sawdust and waste paper, the wet compressed blocks are the easiest for me to male as dry compressed blocks or pellets require a serious amount of hydraulic pressure and the sawdust need to be ground to a uniform consistency.

There is a Who its made that shows how the compressed

Solid wood burns well on its own i tend to keep this briquets for use in the open fire in my house as it only takes a few minutes to get a fire going.

I burn scrap wood in the wood stove in my shed but it has no boiler.

I would suggest that you contact the boiler manufacturer as some woods like pine can cause a build up of resin in the flue that can build up and block the flue, my first flue made was 3" (also poorly made) and blocked up with resin, I have i replace with 5" now which draws much better and has less chance of getting blocked.
Hi sir,

Sorry for the extremely delayed response.

I have been busy with an upcoming conference and was not able to attend to your reply.

Thanks for the detailed response. There is actually no problem regarding the blockage of the flue as I am already using actual firewood of the same wood specie to run my boiler.

I am just trying to find some use for the sawdust (same wood specie) produced in our sawmill.


Just in terms of density, can you still remember if the wet compresses briquettes were comparable or even close to actual firewood?

Thank you and sorry for the trouble.

-Justin
Dr Qui (author)  jsy9820022 years ago
Hi,

I did this as a way to get sawdust to burn without dampening the fire out as it usually does if thrown on loose.  I never put any thought into the fuel value of the end product,

I'm happy that they burn but the general view is that they have the same fuel value as coal, but i cant vouch for this as i would not know how you would go about a comparison test.

A friend of mine uses the commercial compressed bricks and they seem to burn pound for pound at the same rate a scrap timber that i have given him

Depends on how you define comparable, the answer is that they burn well in mu opinion 4-6 of them placed in an open fireplace (all i have used them for) either started with a fire lighter or a spray of wd40 or other oil or anything flammable if im lazy or want heat now, they light quite quickly and look as if they are going to burn out very quickly.

They actually turn to red hot coals and sit in the hearth glowing red for quite some time, once the fire is light 2-3 are added every 30 mins or so as needed, i find that about 10-12 will burn for an evening, i have only used them for when we have visitors and want a bit of fire going just for sake of it.

If you have a commercial sawmill you should look into building a sawdust compressor, a couple of places in my area that ued to give sawdust to any farmers that would come take it away have now built or installed brick compressors to make a salable product out of their waste, they sell well and are a good earner if you have a constant supply.

http://www.youtube.com/watch?v=WZQK1vlhA2Y

this seems to be a piton based thing, a hopper with auger that feeds small amounts of dust into a chamber with a piston that reciprocates and compresses the dust into a tube, the tube seems to need to be about 20feet long or so < i think this is so the back pressure can build up to the amount needed to compress the bricks. heavy flywheels are needed to keep the momentum up on the piston.  this method seems to be the simplest method for the diy builder, if i had a constant supply of sawdust i would build something like this.

I saw an episode of how its made that showed the compressed brick method for those fancy logs that city folk burn in their trendy wood stoves. The dusts need to be very uniform and to use anything rather than saw dust Ie bark wood shavings and cuttings required a heavy duty shredder to grind the dust uniform.

You can also have a hydraulic machine check youtube for these as i cant seem to find what i found there. the hydraulic method is more complicated and slower.

In summary for small amounts ie 20kg or so of dust every once in a while i would go with the wet brick method. for a constant supply from a saw mill i would put the effort in and build a piston based machine as it would give you a additional income from the waste and in theory should pay for its self in next to no time. 

over here a 10kg bag of compressed logs are around £5  and seem to be sold in every garage or convenience store i walk into,

hope this helps.

Andy.




Have you ever thought about adding grass clippings to the mixture? Ive got a lotta sawdust, but really, i think that this could be very benificial to me, so I wouldnt be able to keep up the sawdust output with how much i would burn, so i would have a continuous supply of more than enough grass clippings every week... you think it would work?
Dr Qui (author)  nickmccullough3 years ago
Problem is trying to get the grass clipping 100% dried out as they tend to start composting if there is any moisture left in them.
hmmmm, ok, well i think sometime ill give it a try, with some 1" brickets since those should dry out faster so they wont have as much time to compost
lennyb4 years ago
good instructable. i wonder could you put them in a charcoal barrel and char them to make cooking briquets? ive seen briquets with that shape for sale at the dollar store for a buck each. i doubt very much if they used fine hardwood for that.
Dr Qui (author)  lennyb3 years ago
I have since burned a few of the bricks, as soon as the catch fire they almost instantly turn to a block of red hot smoldering ash that slowly burns away.

I recon that they would be perfect for use on a BBQ and i hope to try this out sometime.
djsc lennyb3 years ago
I think they will tend to insulate their own centres from the heat, nice thin pieces might be good for biochar, and some uncharred briquettes could provide at least half the heat source to do the charcoalling. worth a try.
Dr Qui (author)  lennyb4 years ago
Thanks,

From what I have see on youtube etc they are OK to use on a BBQ as is

I have not burned any yet in my stove as its to warm to need to light it.

I have burned one to see what it was like and it looked similar to that of a BBQ coal.

thepelton3 years ago
I wasn't thinking of burning them, but inoculating them with edible cellulose eating mushrooms, such as Pleurotis Ostreatus. I wonder how well that would work?
Dr Qui (author)  thepelton3 years ago
I dunno to be honest, i recon there would be to much bad bacteria in the sawdust that you may have difficulty in getting the mushrooms started.

A few years ago a friend was selling mushroom and truffle kits in his shop, they all used boiled rice as the food source and demanded almost sterile conditions.

From what I know re mushroom houses and how they work there is a web like nerve system that is about 2 - 3" under the surface of mushroom compost, it almost like like a buried spider web that is the thing that acutely gets the mushrooms to grow. To farm mushrooms you have to emulate and maintain perfect growing condition all the time.

Some mushrooms and truffles have a symbiotic relationship with certain genus of trees. Can't remember what show this was on , probably BBC's life on earth with David Attenbourough.

Being neither plant nor animal mushrooms are literally mindblowing if you start to investigate how they work.


Truffles live under Oaks and Pines in the US Pacific Northwest.
I understand the concept of symbiosis. There are species of mushrooms that only grow near aspens in Colorado, and black morels are always found near a species of orchid.
to get sterile conditions, take the final product and stick it in a pressure cooker for about 20 minutes, should be fine after that.
djsc4 years ago
I like the idea of a multipurpose press; I have a bottle jack that I am using to build a cider press, never though of using it to compress paper briquettes.
Dr Qui (author)  djsc4 years ago
I have seen some other videos of guy using bottle jacks and scissor jacks, these work fine but I just found them to be to slow to allow you to work at a decent production speed for large volumes of material.

The bottle jack will be prefect for your cider press because you want more pressure to get as much juice out as possible.

I would like to see you cider press design as I have a small orchard that produces more than we can eat or give away and i have often thought of making juice or cider.

Andy.
There should be a basic cider press on Instructables, or maybe on the web in general.
The thing about cider production is that you ideally want to shred the fruit as much as possible before pressing, that is what really releases the juices.

Check out Mattias Wendle's experience in this matter
http://www.sentex.net/~mwandel/press/apple_grinder.html

His apple Grinder is the bee's knees!
mjlush4 years ago
I wonder if you can spike the mix with coaldust... I always end up with a bucket of it at the bottom of the bunker. Its just puts out the fire and/or falls through the grate if I try and burn it.
the chinese have been compressing coal dust into brickettes for some time.
Yes, you can! This will also help the briquettes to burn better. This process has been used to recycle newspaper and charcoal waste in Kenya.
Dr Qui (author)  mjlush4 years ago
Thanks,

From what I have see on youtube etc they are OK to use on a BBQ as is

I have not burned any yet in my stove as its to warm to need to light it.

I have burned one to see what it was like and it looked similar to that of a BBQ coal.

quadracer3 years ago
I make something sort of like this, But just to start fires. I add 1 tablespoon of left over candle wax to aid in the starting. Keep up the good work good sir
tweakgeek4 years ago
Hi, I have nothing relevant to add to this fine instructable.

Except my wife woke up startled and gave me a hard time when I read this from step 3:

" this had lead to the ass falling out of the mould and causing a right mess and some strong language."

Thank you, unknown poet.

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