How about wood heating without the flame or flue gases?

[gadget]

Biomass heat!

I have been thinking again of building a wood composter/heater. For those of you that haven't read much about this, the BTU's from composting wood is suppose to be very similar to burning wood - pound for pound.

Its come up before in discussion. Biggest challenge is space and initial high cost since its basically a radiant heat setup(warm water) and an insulated building. I'm switching my house to radiant heating anyway so that will cover allot of the cost. It would be easy to add other sources of heat to the system with a common water storage tank. I am low on space though.

Here is my thoughts....

Large shed, figure at least double the size of the wood storage you would normally burn in a year, maybe even much bigger. Shed would be very well insulated with heat collection tubing placed in the roof above the biomass.

Have a top load door for dumping in biomass, probably lots of wood chips from the tree trimmers. A side or bottom door for emptying out the shed once a year when solar heating can covering your hot water needs, maybe end of summer. Maybe have a long shaped shed and put a conveyer belt at the bottom so the compost could be rolled out. Similar to those truck bed unloaders. You could also place the hot water storage tank in the same shed.  

Once its going, your suppose the get a nice slow heat output. The faster/higher the heat output, less time for heat duration and vise versa. You can alter the heat output by changing variables like oxygen/nitrogen, etc.....Its basically like a bank account in some ways, once the BTUs are used, you will have some nice soil for the garden.

It can also heat or preheat your domestic hot water.

I'll working on some drawings. Any input or ideas?

[giovanotti]

Biomeiler, is what you are looking for.

You need a lot of carbon (wood chips..) based material, some add manure (nitrogen).
In the structure, spiral pipes are built in, which serve as exchanger to collect and transport heat (you want to harvest as much heat possible)..
Assemble, soak well with water to become anaerobic composter.
Process is not endlessly lasting.

Input pound minus gasses (that you do not see) = less pounds of very good mulch (or even compost, if biology is let to recolonize).

[gadget]

Nov 11, 2020 2:34:13 GMT -8 giovanotti said:

Biomeiler, is what you are looking for.

You need a lot of carbon (wood chips..) based material, some add manure (nitrogen).
In the structure, spiral pipes are built in, which serve as exchanger to collect and transport heat (you want to harvest as much heat possible)..
Assemble, soak well with water to become anaerobic composter.
Process is not endlessly lasting.

Input pound minus gasses (that you do not see) = less pounds of very good mulch (or even compost, if biology is let to recolonize).

I was wondering if it worked in an anaerobic condition with similar performance. It would be more complex if oxygen was required. Thats good to know. I did a test 55 gallon plastic barrel with a lid, full of wood chips last winter in my greenhouse but it never got going. I don't know what I did wrong but I think it was just to small of a mass to store enough heat in the core to get going. It was already in the 35F temp range when I started. I added plenty of "man" nitrogen but it never warmed up or broke down all winter. I'm wondering if it needs heat to get the correct bacteria growing before you remove the heat. Kinda like starting a bacterial "fire", conditions need to be there first and maintained.

Not sure if there is a need for fire/methane safety if it over heats or gets a high methane/air concentration.

I'm thinking a dual system. Start one up and get it full and running. Have a second one that starts up a month or two later? That way you don't run out of heat in the middle of winter.

I found a really good article that mentioned using large pieces of wood and getting a years worth of continues heat output. It was a very large pile and insulation was the pile itself. Imagine being able to through some large logs in along with all the small pieces. No more chopping fire wood. I'm guessing a larger unit would be needed and it might take longer to get started. Mix wood chips / grass clippings in between the logs

I really like the idea of slow steady heat. It goes very well with radiant heating.

I get a drop of wood chips every year on my drive way that I put in my grow beds and walk paths in the garden. I'm always amazed at how hot it gets in the middle of the pile. 

[josephcrawley]

In an ancient mother earth news I recall an article about John Payne heating water with a coil in large piles of wood chips.

Maybe it would be of use

[JLMtech2]

Hi, Gadget, "Composting" another great idea. I typed "composting" into the YOUTUBE search line and up came ways that could be adapted to heating a green house by composting carbon based waste. Described are fast and slower ways to generate heat using piles, bins and tumblers.