Wood gasifier build.

Started by BAdams, June 25, 2013, 10:46:45 AM

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BAdams

I haven't been able to start on building a cabin yet but I have been working on a little project. I am in the end stages of building a wood gasifier. It needs cleaned up and a little paint, and I'm still working on trying different filter set ups but it works!! I ran a10hp wood chipper on it for the first time on Saturday.

https://m201.photobucket.com/albumview/albums/basails/IMG_20130423_151457.jpg.html?newest=1

BAdams

This is the video of the wood chipper running on it. I think it will be greator a generator also.

https://www.youtube.com/watch?v=PxWbm1Vtuhg&feature=youtube_gdata_player

This was the first and only time I have tried running an engine on it so far. I was very excited!


rick91351

Holy Cow  [cool] stuff!  SO exciting to see this kind of stuff working!! 
Proverbs 24:3-5 Through wisdom is an house builded; an by understanding it is established.  4 And by knowledge shall the chambers be filled with all precious and pleasant riches.  5 A wise man is strong; yea, a man of knowledge increaseth strength.

BAdams

I plan to use this unit to run a generator during power outages at the house. I can use the wood chipper to make my own fuel which I can get for free (tree limbs and such). I think it will be perfect for off grid when I build a cabin. I plan to have a small solar set up but to run power tools, water pumps and such I think this will work good. I should be able to run a 6-8000w generator with it.

BAdams

Thank you for the kind words Rick :) my wife thinks I'm a little crazy but most of my friends think it's pretty cool. There are a few guys that want to come over next time I run it and see how it works [cool]



rick91351

Is there a good on line site that explains the whole process?

Could you use 'saw dust' from a saw mill, like Jarhead's or Glenn's?

My neighbors sawmill produces a lot of saw dust with a big ol' circle saw.  It is carried out of the mill with a drag chain into a pile.    Then he also has a band saw mill like OJ or Glenn's it is mounted permanent.  He captures that saw dust with a five gallon bucket and dumps it into tubs.  It is a lot finer than the saw dust from the circle saw mill. 
Proverbs 24:3-5 Through wisdom is an house builded; an by understanding it is established.  4 And by knowledge shall the chambers be filled with all precious and pleasant riches.  5 A wise man is strong; yea, a man of knowledge increaseth strength.

BAdams

I use a sawdust filter as one of my filters with chainsaw dust as the filter media and I'm sure you could use the sawdust for that. You may also be able to mix it with larger chips or chunks to burn in the reactor. I think it would not work well as fuel by itself because a good charcoal bed is needed to have a complete chemical reaction and if the fuel is too small I think it would fall through the grate at the bottom too quickly.I still have more testing to do with mine. I have used only wood pellets so far but will be trying different sized chips to see how it performs.

I built my gasifier based loosely on FEMA plans which when I find the PDF link I will post here. I also found a series of YouTube videos by joshusburks that explains very well how he built his. To find his videos just search for  "fema 1.6" on YouTube. He also just started a website called buildagasifier.com and it has some good info. I think his site might have a link to the PDF for the FEMA plans.

BAdams

Maybe the fine sawdust could be pressed into pellets with a pellet mill?.


rick91351

Quote from: BAdams on June 26, 2013, 08:51:08 AM
Maybe the fine sawdust could be pressed into pellets with a pellet mill?.

A person could do something like that.  But then there is the moisture problem with the media.  I did not understand where the gas was coming from....  DHHHH!!!  ???   So if you were to burn wood chips or from a chipper you would have to dry them down to a low moisture reading.  Wood chips like paper chips, those used for paper in a pile will have a very high moisture content for years sitting in the pile.  Just one of the reasons they work well in the garden below the seed bed.   

Burning wood pellets for this seems some what counter productive cost wise.  BUT certainly not being a nay-sayer....  Great opportunity to power a stationary motor like a generator, or a mill of some type.  Just need to find a way so that the first line fuel production does not figure into the final cost of power produced.  Like a 100% or 90% byproduct.  Something that is going to just go to waste.  Here in the west we have huge acres of sage brush the is primary wildfire fuel.  Some mountain states have whole forests dead do to insect infestation.  Part of the Colorado fire situation now. 

c*  Rick   

   

         
Proverbs 24:3-5 Through wisdom is an house builded; an by understanding it is established.  4 And by knowledge shall the chambers be filled with all precious and pleasant riches.  5 A wise man is strong; yea, a man of knowledge increaseth strength.

BAdams

That's right, you do need dry fuel. The reason I use wood pellets as a fuel is because I wanted a dry fuel that would hopefully be consumed at a fairly consistent rate while I was testing the unit. I'm now at the point where I'm going to start making my own fuel by chipping tree branches/limbs. The wood chips would then be my fuel, not pellets. My chipper puts out about 3/4"x1" chips, and I think that should work fine but I'll be testing that out. I can get all of the free waste wood that I think I would need for free.
   As far as pellets go, no I wouldn't want to have to buy them but, if you can get free saw dust and press your own pellets it may be worth it. I think (stress added to think) the process of compression creates enough heat to dry the pellets. ???

I'm not an expert on this by any means, I just thought it would be a fun and useful project to work on. The process that is happening as I understand it starts with a charcoal bed suspended at the bottom of the burn tube or reactor on a grate. Your fuel( chips or pellets) sit on top of the charcoal and is burning where it contacts the charcoal. This is a downdraft system. The fuel is burning in an oxygen starved state at a very high temperature. As the fuel is consumed it is being turned into charcoal so as this happens you have to shake the grate once in a while to keep the fuel and charcoal from climbing up the tube. A chemical reaction takes place as air passes down through and creates flammable gases. Ash, tar and water vapor are also produced which are filtered out with a cyclone filter and a media filter.

If I can find a drawing of how the reactor works, I will post it c*

BAdams

http://buildagasifier.com/wp-content/uploads/2013/02/fema_wood_gas_generator.pdf

This is a link to download the FEMA wood gas generator plans.

This is a stratified downdraft design like I built, not the more efficient Imbert design. There is some good information in there with pictures and drawings. I recommend using better material and welding it together. Most of what is needed can be found at a salvage yard for cheep. I also recommend better filters, including a cyclone filter.

Don_P

One of the interesting things about these is that the flammable "gas" being produced is mostly carbon monoxide, which is thirsty for another O. You can burn it in an engine as a fuel. You should be able to run the reactor very efficiently on straight charcoal.

BAdams

I think your right about charcoal. The problem with it is the process of making it is time consuming.


rick91351

Charcoal at least does not technically use resources to produce.  Other than perhaps chain saw fuel and some bar oil.  Unless you want to break out the old crosscut and bow saws.   ;)  There were charcoal kilns all over the west from great domes or very simple block buildings.  (There was one at a large sawmill I was in and out of all the time.)  True it would be best to use hard wood but charcoal can be make from soft woods.       

I found several good easy ideas for making lump charcoal on the net.  Down to using a 30 gallon drum and a 55 gallon drum.  A person should be able augment the charcoal with dry branches, twigs and pine needles or pine straw if around conifers like we are.  Sort of using all the tree.  Or like some of the butchers claimed the Oink was the only thing we could not use.   

 


       
Proverbs 24:3-5 Through wisdom is an house builded; an by understanding it is established.  4 And by knowledge shall the chambers be filled with all precious and pleasant riches.  5 A wise man is strong; yea, a man of knowledge increaseth strength.

MountainDon

very cool! Thanks.

We could really make a lot of wood gas considering the quantities of slash and dead that we have been cleaning up this summer adjacent to our property in the mtns.
Just because something has been done and has not failed, doesn't mean it is good design.

BAdams

Thanks MountainDon! I think this will be great for the cabin as I will be off grid. There is always waste wood around to be used. I'm thinking to have a small solar system with a battery bank. I can run the generator off the wood gas for a couple of hours to charge batteries as needed or run power tools/water pump. No need for $3.50 gasoline [cool]