Hybrid populars for a renewable fuel

[pybyr]

Slowzuki wrote "no coals"

I am not sure if it is the case with all of the downdraft gasifiers (where the wood in the upper chamber collapses into coals above a "nozzle"), but with my Econoburn, I do find that being able to generate and maintain a bed of coals seems to make a major difference in both duration and efficiency of a burn. While I do not have instrumentation, when I look at BTU charts for heat content of different species of wood, and then note the "effective heat" that I get out of a full firebox full of different species, the disparities are even bigger than the chart would indicate. From all I've read (and it makes sense to me) BTU content in concept/ under lab conditions tracks the net dry weight of the wood, but using the combustion technology that I am using, it seems like woods that develop a substantial and sustained bed of coals (maple, yellow birch, hophornbeam) yield an output (both intensity and duration) that is almost 3:1 compared to woods (poplar, pine) that don't- even though the data suggest that it should be more around 2:1.

 

[Backwoods Savage]

It appears to me that many folks here do not understand there is a big difference between the hybrid poplar vs aspen. They are not the same! Repeat: They are not the same. Hybrid poplar is mostly trash wood. Someone asked about drying. They will lose probably 75% of their weight when dried. They will dry in the round but like other woods will dry faster when split.

The claims about these trees are very highly inflated to say the least. We did play around with some as an experiment and found they were more a pain in the rear than what they were worth. The wood is about the poorest I've seen for burning and if anything, the btu rating is as much over rated as the claims of those selling the things.

One of the worst things we ended up with are all the roots that are on top of the ground and they do grow lots of roots. Even more than the roots, they grow limb! Lots and lots of limbs. They are also not a hardy tree at all as they get weak spots and break. I have some pictures of some of the trees we left just to show you some of the mess you might get with these things. Also, the rate of growth my be right in perfect soil but we were told we had ideal soil for these trees and it took between 15-20 years before any got to any size that we would have considered for firewood. We have only a few left that are growing from some stumps but we cut the last of the big trees when we sold our pines last winter. Good riddance to bad rubbish.


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[woodsmaster]

I'll agree with backwoods that they are junk trees. They can however make a nice wind block or some shade for
someone who don't have time to wait for an oak tree or whatever to grow. My dad planted some auss trees ( hybrid poplar willow ) and they did grow very fast, like 5' in a year. He had soker hoses laid out to water them and watered them a lot. They served him great. Got to be about 50' in around 12 years. they were very messy trees and the fire wood from them was so light when dry that it would probably blow away in a storm.

 

[Backwoods Savage]

J.T., it sounds just like the hybrid poplars. It is amazing how light the wood gets and just by that you know there is not much heat in it.

btw, we also planted 2 hybrid elm and they grew much faster and not so many limbs and those did make good shade trees. They grew fast but I don't remember how many years we had them. They started showing signs of weakening so we dropped both of them. They too had the nasty root system with some of the roots coming completely out of the ground! Methinks the hybrid trees are not a good way to go.