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

Project:

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

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.

Comments

[jsy982002]

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]

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.

[jsy982002]

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]

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.

[lukeyj15]

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]

A high pressure air stream capable of moving sawdust , sawdust and fire would be the 3 key ingredients for a dust explosion.

[lukeyj15]

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.

[thepelton]

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]

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.

[alibabbarudolph]

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]

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.

[alibabbarudolph]

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

[lennyb]

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]

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]

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]

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.

[thepelton]

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?

[kretzlord]

to get sterile conditions, take the final product and stick it in a pressure cooker for about 20 minutes, should be fine after that.

[Dr Qui]

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.

[capt.tagon]

Truffles live under Oaks and Pines in the US Pacific Northwest.

[thepelton]

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.

[djsc]

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]

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.

[thepelton]

There should be a basic cider press on Instructables, or maybe on the web in general.

[Angstridden.Hipster]

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!

[mjlush]

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.

[thepelton]

the chinese have been compressing coal dust into brickettes for some time.

[origamifox]

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]

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.

[quadracer]

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

[tweakgeek]

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.

[melmcc]

Hi Dr Qui, in my part of the world old newspaper is made into mulsh and put into a brick making press, water squeezed out and the brick put out to dry. With the saw dust even better. Maven: in a part of Natal there is no fuel to burn and the local people collect all the cow patts pack them in the sun to dry and that is the fuel for the fire to see them through the winter. Due to the fact the dung has dried it has no smell when burning.

[drewSaysGoVeg]

I have a gasoline log splitter that I'm thinking of rigging up to make some of these with. Question: When you press your pulp, how long do you leave it to drip? Minutes or hours? Do you press enough of the liquid out immediately that you can move to the next one? To give me a rough idea, how many bricks can you make in a day?

[Dr Qui]

If you have a gas powered hydraulic system you may be able to dry compress sawdust, check out youtube as there are loads of ideas thee.

Pressing the pulp forms a solid brick that can be handled with out fall to bits if the mix is right.  they are still quite wet at this stage, depending on the weather and your climate it can take between 3 days to maybe 2 weeks for them to dry, I air dry mine for a few days until they firm up a bit and then move them to a shed with a good air flow going though it until they are bone dry and hard.

I have only ever done 3  trugs at a time that would make on average 45 bricks, that is the my limit before my bones start to creak and I am best to stop.

If you had an electric cement mixer to prepare the pulp you could make hundreds in a day, I can fill and press 3 trugs full in under an hour, about 1 brick every 30-40 seconds if I am set up right.

[explosivemaker]

dang...we need a pic showing how high they could be stacked TOWER OF FIRE!!!!!!!

[ourmoneypit]

Thanks for this instructable. My spouse is a woodworker and we have both turned wood, also. I find her planer produces the most sawdust, by far, though. I was wondering what I was going to do with all the wood shavings once I was done levelling the various dips on our property. This is an excellent idea.

[Dr Qui]

Cheers,

You should make compressed bricks and burn them to heat your home and then use the wood ash to level out your property.  you get the most out of your waste that way, wood ash is also a good fertilizer.

Good luck

[Captain John]

Hi . I have two cows, and they poop a lot. Can i use dried cow dung in the same manner? It might smell, but it would also burn and some tree did not have to die.

[faileas]

dried cowdung is a pretty traditional fuel. It also dosen't smell too bad... go for it!

[maven]

Dr JD Hooker used soft fresh cow dung stomped (with a rubber boot clad foot) into a wooden brick mold. The resulting dried logs were burned in his workshop heater and the ash spread on his veggie garden with great results. The article was in BackWoods Home magazine. Yay! I found the article! http://www.backwoodshome.com/articles2/hooker87.html