Hi Steve, I agree with you both as far as the processes weighed against one an other by themselves. However are you factoring this for gasification and the waste that you are going to throw away. Depending on the chipper, you are going to end up only a percentage. The bigger the chipper the bigger the feed stock = more usable chips. My Step Dads chipper gobbles up 16" diameter trees. But this just is not going to be the norm for most and with a small chipper you will be lucky to get 25% - 50% usable chips. This is what Im getting at. Verses if you ground this same volume and pelletized you would get nearly 100% of that yield. Yes pelleting comes with additional energy in, but is it really an added process? If you are no longer sorting the fuel isnt this replacing that process? Part of the drying process also a big part of pelleting.
Just trying to bring some points I think are valid. I will build this processing system If I have to eat crow, I will eat it with a smile
Pelletmaking 1kWh-10 kg pellets
From wood to sawdust is the same 1kWh-10 dust. You start with a chipper, then a grinder and so on.
if you use green/fresh wood, you need energy for drying.
Energy in one kilo wood, either logs or dust is 4 kWh. So, if you don t use a waste material, you are throwing 50 % of the potential energy in wood away. And then you start gasifying…
How nice would it be if you can run on sawdust-waste?
Not meaning too interupt your conversation with MATT RIDER. The biggest problem would be for transportation, being sawdust is so light it would take the hole bed of the truck too go 50 miles if your auger wasent too big and could actually get too the sawdust too push it too the hopper, could work for stationary at best. only if it was free sawdust. saw dust too me is harder too work with than wood chunking exersize.
Ultimately, I will build all this process directly onto the machine. The user will just load cut split fire wood into the hopper. The machine will automate the full process. feed the logs into a grinder, the pellet press on demand. This will be a very slow process requiring very little energy input for this process. All it has to do is keep up with the machine and produce from 6 lbs up to 15 lbs pr hour max. This will have a hydraulic press.
Another version eliminates the grinder and you just dumps chips into it. The press will cut through them. Not sure if that will work or not but machines that do this exist.
That woodchunker topic of Jan is super. Look how clean and simple everything funtions, top.
And sorry, my calculations above are not correct, you don’t lose 50%. It is much less, but anyway. Imho you lose way to much energy, but most of all: it is just almost impossible to make pellets on a small scale. From the financial/time perspective. As Steve says, from an energy point of view it is undesired.
And yes, sawdust is light and maybe not for transportation. I won’t argue that.
First, I am reading. And that can stay for a while until everything is understood. Then maybe a stationary solution. Only if it can be succesfull, trouble free operation.
Joep, you are basically like my typical customer. They dont want to make fuel, they dont want to the run the machine, they want it to run 24 hours with out any intervention. All they want to do is put fuel in it and push a button and it works.
Even if those processes require more machine energy input, there is still user energy input. This is the part we want to eliminate
Yes, that is right. If you wouls sell a gasifier that runs on sawdust, we would have a deal. If I want it clean and easy, I will buy a generator and pour diesel in it.
Sorry Matt, only trying to protect you from the same mistake I made. But try and you know it is a dead end. From different points of view.
If you were living near my place you could pick it up and try for yourself. We were cleaning out everything and then I saw the installation again. Had a lot of fun with it, I know I can now, but there are better ways to spend energy, money and time.
You say pellots on demand is good i agree if your gasifier cans are smaller more effient units, what about sawdust on demand instead, would there be a gain from burning wood chunks.
Right, nobody wants to do ‘grunt work’. So the whole wood fuel thing doesn’t work.
But maybe a sawmill would buy a system that used sawdust, because then they will have to do less ‘grunt work’ handling sawdust. It’s all about reducing ‘grunt work’. If you can do that they will pay you.
Rindert
Its still easier than the other methods. You have to chip nearly four times the volume to produce that same equivalent in pellets. Nobody can seem to wrap their head around that. Your only chipping 25% of you would otherwise. Sorting chips is time consuming its a lot of work and so is drying the fuel. Unless your good with a small hopper that you are going to need to refill a lot than chunks would be a good solution. But bulk feeding is easier said than done.
Yup Im not ruling out going with straight up saw dust. But I still see an issue with energy density and run times. Trying to keep em compact and cost effective to produce it all adds up.
Grinding / burning sawdust on demand.Drying shavings on demand with heat exchanger available heat. Even IF had too grind dryish wood, this would eliminate chunking step, and open the auger feed posibilitys, and carry more wood being solid bigger logs before grinding.Pump heat down the length of the auger tube, insulated. Lots of heat sorce too build around too use.As steeve Uric is been saying about useing the recycle heat for the drying. Just need too get the logs too the grinder automated, could get miles more down the road with out refilling all the time. kill two and a half birds with that set up.Or i should say three and a half .
Hey Mr. Steve, hope n trust all is well in your world ;~) Appreciate the acknowledgement and even more your works.
My target fuel is brush pile “stompage”, since the day my 10 year old son stomped out a 5 gallon bucket of it in 2 minutes. He is now 21 and may be able to do a little better than that these days should the need arise ;~) Far less energy consumed than pellet processing from sawdust with all the hauling, forming, yada inputs. Plus stompage is a far superior fuel to pellets in moist environments.
To me it is a question of scale - the smaller the better. I don’t run a sawmill. I can clean out a fencerow, with a small chain saw or machete and pile up the brush. Rabbits and quail have safe haven for a year or two. Then we can stomp the dry stuff into a bucket and have a fuel density comparable to propane by volume.
Don’t see what I am missing in this scenario other than thoughts of grandeur. Works great for homestead scale energy, if anyone should ever want to live easier right they are. Lots of brush round here ;~)
