Posted on 10/24/2016 9:32:24 AM PDT by nickcarraway
I understand your cynicism — but, you’re wrong. Burning wood releases far more energy than is required to collect and prepare it. There’s a huge supply available, without having to clear-cut forests. One source not mentioned in the article — firebreaks around communities.
“16 carloads per hour or almost 4 car loads per minute? Something ain’t right.”
It would appear that your math is the something that ain’t right!
I have eight acres in South Carolina and Matthew brought down enough Hickory, Oak and Cherry on my place to heat a hotel in this climate.
It’s always the inverse that gets me!
Correct. Many coal-fired plants are constructed at the mine site and the coal is belt conveyed to the plant as it is mined by shovels. The power is transmitted to the grid and its ultimate user. It's much cheaper to transport the power via lines, than it is the coal.
Additionally, coal has about 12.5K btu/lb, where dry wood has about 8K btu/lb. So transportation costs per btu are 1.5 X that of coal. Coal can easily be pulverized into dust which is the most efficient way to burn it. Wood is a bit more difficult to "size" for efficient burning.
It's a different proposition if you are already in the wood processing business - paper, sawmill, plywood, etc. Wood waste - bark, sawdust, trimmings - has to be disposed of anyway, so burning to produce steam has a benefit. The steam heat can be used in the production of electricity, or to dry green lumber. Before pollution laws were strengthened in the 60s and 70s, most sawmills burned their wood waste in "TeePee" burners, rather than trying to generate steam.
Many modern sawmills not incorporated with a paper mill also produce wood pellets. It pays much more than chips/ton to the paper plants. However, to sell pellets in the residential market you need to bag/palletize/shrink wrap and load on flatbed trucks or in a boxcar.
The problem with regular wood pellets(like I burn in my Harman pellet stove insert) is that if they get wet, they are trash. Hence the bagging and shrink wrapping. If you get a regular wood pellet wet, it expands to about double in size and turns back into sawdust. I have some bags that got wet last year. I made a pellet sifter based on other peoples design on the internet.
Torrafied pellets do not absorb moisture like regular pellets. Therefore, you can load them in hopper railcars or bulk load on a ship and transport for much less per cubic ton. This is why most of the manufacturing plants are being located where they can load ocean going vessels or river barges.
Cogeneration of electricity has come back in vogue. Seneca Sawmills in Eugene, OR spent millions($30m) putting in new cogeneration plants that burn their own wood waste. They make steam to power their kilns and produce electricity that they sell back to the grid. This was mandated by Oregon State law. There were also major tax incentives both state and federal to help their return on investment.
Major tax incentives. So the question of whether the fuel is actually economic is now likely distorted by government fiat. Just like the home rooftop solar panels wouldn’t pay if not for the tax credits. And the windmills that kill birds by the bushel basket. They’d never pay, save for the PC cachet and the tax breaks.
I spend 35 years working in the wood products biz. Burning wood efficiently in a steam generating boiler is an involved process, and the boilers are high maintenance systems.
Seneca had taken their cogen plant out. The tax incentive helped them put it back in. The ROI was just a lot quicker with the tax incentive.
There is a biomass electric generation plant here in NH that is not associated with any sawmill. It buys van loads of chips/woodlot waste. I am told they pay a little more than what it costs to truck the chips to them, but not a lot more.
FYI, I am a lumber broker. Just curious, what did you do in the wood/lumber business for 35 years?
Willamette Industries, Boise Cascade, then a couple of independent design/construction companies that specialized in wood plants - sawmill, particleboard, OSB, plywood, engineered wood.
I did design work for the two majors, and then in later years, sales and estimating for projects. Mostly in the Southeast - East Texas to Georgia. Not too many mills in that territory that I’ve not visited, or done some work in.
Pellets for residential are simply compressed fine sawdust. Thats all they are.
Here are the leaders in bio mass plants for schools and colleges, etc. They used to make pellet plants but found that pellets are to expensive in costs and then engineered their boilers to use RAW wood chips.
Actually, the process is a bit more involved. First, the sawdust, chips, etc, are refined (sized) into a uniform consistency. Then the raw material is dried (often using fossil fuel) and then pressed into pellets through dies.
http://www.woodpellets.com/heating-fuels/pellet-processing.aspx
The company I retired from built and installed parts of a couple of plants here in Louisiana a couple of years after I retired. The pellets were for export. Back when oil was $100/bbl, and natural gas was $6-$8/MCF, it made economic sense. Not to much now.
I don’t even know if the plants are running now.
The key to burning wood is consistency. You can burn dust, or you can burn chips, or you can burn pellets. But you can’t burn a combination of the three efficiently.
The problem is the air/fuel mix. To properly burn, you want just enough air to support combustion. Too much air, and it goes up the stack as waste heat. Not enough, you get incomplete combustion (smoke).
With consistently sized fuel, you can control that much better. Hence the efficiency of coal dust, a very consistent fuel. So too with gas or atomized oil. The air molecules contact the fuel efficiently and is completely utilized. Very little waste heat.
And don’t get me started about dirt in the bark and chips. It will eat a boiler up. The dust and sand act just like sandblasting on the boiler tubes. They will erode and begin to leak.
How do you get dirty fuel? First you drag the logs out of the woods with a skidder and collect dirt. Then pile it on the ground at the mill prior to burning. The sand and dirt that doesn’t go up into the hot gas stream turns to glass on the boiler grates and cause a mess. Grates have to be constantly raked.
Its also amazing to see a year-old induced draft fan with blades made of hard surface weld overly that have been completely destroyed by the dirt and sand.
We have a power plant in Ashland Wis. that has been burning wood chips for decades and seem to be doing well with it.
We have many tree that are good for nothing but fuel plus there is s lot of bark and scrap wood from several manufacturing plants around that sell there by products as fuel.
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