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What tree species gives the most BTUs per acre per year?

Started by wolfram, January 21, 2010, 03:50:11 PM

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stonebroke


SwampDonkey

I think that would be the extreme and probably rare.

Some tabulated MC of sapwood are listed in the Handbook, and heartwood are listed as well, based on averages I assume.

Western red cedar 249%
sugar pine 219 %
basswood 133 %
cottonwood 146%

MC% is based on weights when oven dry. Heartwood moisture content can be almost the same in some species or as much as 5 times less in others.

The data quoted by Jim above is all out of whack because one column is talking about wood at 12 % MC (look it up in the Wood Handbook if you want to see), the next is talking about green wood at 30 % MC, possibly higher, followed by BTU's based on a cord shorted of volume and at 20 % MC. And no clue of methodology until you Google around and find the same data being used by someone else willing to explain it. :D
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

SwampDonkey

Quote from: Ron Wenrich on January 22, 2010, 05:41:16 AM
"Switch grass is more like 6 tons/ac per year from what I have learned.  I guess that it depends on the quality of the site.
"

Auburn study.  http://bioenergy.ornl.gov/papers/misc/switgrs.html ; They even said they got 15 tons/acre the one year.

What about fertilizer input costs and would you eventually have to fertilize those poplar sites? With the grass it would be an annual harvest verses 5-10 years apart for the poplar. So you would need more acreage of the poplar to have a continuous stream of wood at different stages of growth.  Around here there is so much poplar through the country that you wouldn't have to worry about cutting the same ground for decades. Enough time to rebuild the soil between harvests? Never seen anything grow any faster than largetooth on a good site. 8" DBH in 13 years. :)
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

downeast

Whew Msr. Swamp, you mean to say that the moisture content can be > the weight of the wood ?  :o :o As a fellow "bright one" ( graduate degrees, pro experience in and out of academia and mil ) I have got a bridge to sell you.  ;D No offense SwampD, butt, some things are not the duck Groucho. As in: "if it looks like a duck, sounds like a duck, s&%$s like a duck,......."
Hey, we now cut the firewood this winter, split and stack for next. Period. It is the duck.

JMNSHO

SwampDonkey

"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))


WDH

If you take a block of wood and perfectly squeezed all the water out of it so that the wood had 0% moisture, and if you captured that water that you squeezed out, you could then weigh the dry block of wood and you could weigh the water.  In some species, the water removed from the wood weighs more than the dry block of wood it was removed from.  So, if you divide the weight of the water by the weight of the dry wood (that is how M% is calculated) then the moisture content will be greater than 100%.

If the wood and water weighed exactly the same, say 50 pounds of dry wood and 50 pounds of water, then the M% would be 100%, or 50 divided by 50 x 100.   
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

downeast

Quote from: WDH on February 15, 2010, 08:38:20 AM
If you take a block of wood and perfectly squeezed all the water out of it so that the wood had 0% moisture, and if you captured that water that you squeezed out, you could then weigh the dry block of wood and you could weigh the water.  In some species, the water removed from the wood weighs more than the dry block of wood it was removed from.  So, if you divide the weight of the water by the weight of the dry wood (that is how M% is calculated) then the moisture content will be greater than 100%.

If the wood and water weighed exactly the same, say 50 pounds of dry wood and 50 pounds of water, then the M% would be 100%, or 50 divided by 50 x 100.   

I still have a bridge to sell you.  ;D  50 / 50 x 100 = ____. We never learn't that far.  :D
You're talking theoretically about a closed system experiment. Now, truth telling time: have you done this with that block of wood in a closed system ? Real world, real time. Results ? M% = ??????
There are statistics, and there are ......................... :o

beenthere

south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

Ianab

Bit of confusion here  ???

% moisture content is measured by comparing the DRY weight of a piece of wood, with it's current weight. And thats done by drying it in an oven untill ALL the water is driven out.

So say you had a piece of wood weighing 1lb, you oven dry it untill it's totally dry and it weighs 1/2 lb.

That means it had 1/2 lb of water, and 1/2 lb of wood, the ratio is 100%.

It is not exactly the same as we measure percentages in other stuff, but it's how moisture in wood is measured. Don't ask me why, but I suspect it's to make the maths easier as it's measured from DRY, not from some random wet measurement.

Re the Wood regaining moisture, yes it does, real world. I've tested green blocks of wood by microwaving them untill they got no lighter. 0% moisture. Then you leave it out on the bench for a week, and it re-gained some of the weight, about 12% eventually.

You can test this youself if you want.  ;) :)

Ian
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

downeast

Quote from: Ianab on February 20, 2010, 03:36:32 PM
Bit of confusion here  ???
% moisture content is measured by comparing the DRY weight of a piece of wood, with it's current weight. And thats done by drying it in an oven untill ALL the water is driven out.
So say you had a piece of wood weighing 1lb, you oven dry it untill it's totally dry and it weighs 1/2 lb.
That means it had 1/2 lb of water, and 1/2 lb of wood, the ratio is 100%.
It is not exactly the same as we measure percentages in other stuff, but it's how moisture in wood is measured. Don't ask me why, but I suspect it's to make the maths easier as it's measured from DRY, not from some random wet measurement.
Re the Wood regaining moisture, yes it does, real world. I've tested green blocks of wood by microwaving them untill they got no lighter. 0% moisture. Then you leave it out on the bench for a week, and it re-gained some of the weight, about 12% eventually.
You can test this youself if you want.  ;) :)
Ian

Sorry Ian et. al, We're back to Groucho's duck. :(
If you measure a body's % of moisture it is the %. Period. That's what we Call Scientific Method. Ain't no other valid measurement.  ::)  That is what a Closed System will measure. It's controlled, repeatable, accepted. Now, if you want to make another kind of measure, fine, like 200% moisture content !!!??!? . But it's not science or real.
It's kind of like the arguments over what a cord is. Rick, face, banana cord, volume, mass, air space, round logs, tighly packed splits, lamb chops, Dodge Ram pickup bed cord. Everyone knows.  ;D :D ;D ::)

BTW Ian: why does NZ policy mandate plantation reforestation. Single species, in neat rows on the hills. It is strange to see this lack of diversity and 'order'  for a healthy regen.

beenthere

de  Care to elaborate more on what it is you are hinting at?

south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

WDH

Quote from: downeast on February 20, 2010, 10:33:37 AM
Now, truth telling time: have you done this with that block of wood in a closed system ? Real world, real time.

Yes.
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

Ianab

QuoteThat is what a Closed System will measure. It's controlled, repeatable, accepted. Now, if you want to make another kind of measure, fine, like 200% moisture content !!!??!? . But it's not science or real.

The science is the same, it's just what are you comparing? It's just a ratio, expressed as a percentage.
It's the amount of water compared with the amount of DRY wood. The amount of dry wood is a fixed value, the weight of green wood is a variable. Imagine trying to do the maths on drying rates if you were working from percentages of the current moisture content, which is a moving number.

It may be more correct mathematically, but in a practical sense it's a nightmare.

QuoteBTW Ian: why does NZ policy mandate plantation reforestation. Single species, in neat rows on the hills. It is strange to see this lack of diversity and 'order'  for a healthy regen.

Simple economics. 99% of the timber production in NZ is introduced plantation forest. Pine, Douglas fir or Euclayptus grown on a 20-50 year rotation. It's planted and harvested as a crop, just like corn or beans, just a little longer between planting and harvesting.  None of your timber speces are endemic to NZ, and the native species are very slow growing with a complex succession process through several stages of forest growth. Might be 50-100 years before the desireable crop trees are even established, and maybe 300+ years for them to mature. A forest giant might be 800+ year old.

So you have 2 types of forest, commercial plantation, mostly pine, which is intensly managed and harverested. And native forest, which is only a fraction of the original pre-human amount and is mostly preserved in parks and reserve land. Either untouched or slowly regenerating.

There is some limited harvesting of native timber from private land, but it's strictly controlled and the annual timber supply is very small.

Ian
Weekend warrior, Peterson JP test pilot, Dolmar 7900 and Stihl MS310 saws and  the usual collection of power tools :)

SwampDonkey

downeast, the methods for measuring wood MC is tried and true. Been done longer than you and me have been on this planet. :D There is also two kinds of water in wood, bound water and free water. Free water effects weight only and bound water affects, weight, specific gravity, volume and other physical properties of wood. The threshold where volume and physical properties of wood change is the fibre saturation point, which can't really be pinned to one exact MC%, but academically they use 30 % MC as a point of reference. Hard maple, beech, yellow birch and eastern spruce and fir are very close to that figure. You need to know these things when making paper because water doesn't make you money, only wood fibre. It's like trying to make bread and thinking the amount of water doesn't matter, there is a recipe.  ;)

Wood moisture is measured that way because physical properties continuously change from green condition until every bit of moisture is removed (oven dried). Don't confuse air dried seasoned wood for oven dried. Seasoned wood varies by climate and reaches equilibrium with the surrounding air, they call it the Equilibrium Moisture Content. Why you suppose they set your flooring lumber in your living room for a week or two? To get the wood to equalize with the climate in that room. ;)

If you can't grasp that then relative humidity is really going to jam those wheel cogs. ;)
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

2020 Polaris Ranger 570 to forward firewood, Husqvarna 555 XT Pro, Stihl FS560 clearing saw and continuously thinning my ground, on the side. Grow them trees. (((o)))

downeast

Quote from: SwampDonkey on February 22, 2010, 07:07:56 AM
downeast, the methods for measuring wood MC is tried and true. Been done longer than you and me have been on this planet. :D There is also two kinds of water in wood, bound water and free water. Free water effects weight only and bound water affects, weight, specific gravity, volume and other physical properties of wood. The threshold where volume and physical properties of wood change is the fibre saturation point, which can't really be pinned to one exact MC%, but academically they use 30 % MC as a point of reference. Hard maple, beech, yellow birch and eastern spruce and fir are very close to that figure. You need to know these things when making paper because water doesn't make you money, only wood fibre. It's like trying to make bread and thinking the amount of water doesn't matter, there is a recipe.  ;)

Wood moisture is measured that way because physical properties continuously change from green condition until every bit of moisture is removed (oven dried). Don't confuse air dried seasoned wood for oven dried. Seasoned wood varies by climate and reaches equilibrium with the surrounding air, they call it the Equilibrium Moisture Content. Why you suppose they set your flooring lumber in your living room for a week or two? To get the wood to equalize with the climate in that room. ;)

If you can't grasp that then relative humidity is really going to jam those wheel cogs. ;)

There are times when too much info is overload. The grey matter is jammed......How'd ya know ?

WDH

Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

Magicman

Danny, I'm gonna have to feed you real soon..... digin_2
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WDH

Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

ihookem

I got a bunch of Black locust today. If you can get it to grow fast it might be worth planting if you can get seedlings cheap. It was very heavy wood but also holds a lot of moisture. The Ash was much lighter but drier.

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