Making pellets out of sawdust... why don't more lumber mill companies do this?

[forestfan]

I hear that many lumber mill companies have tons of sawdust being produced - so much that they consider it to be waste and have to pay to have it disposed. Does that sound right?

I thought that at a minimum, it would usually be economically advantageous to gather it up, burn it in a boiler, and either lower your electricity bill or get the local utility to pay you for sending them electricity. And I expected that if you're in an area where wood pellets are valuable, then it would be even more advantageous to choose that rather than electricity generation.

Thoughts? Is gathering sawdust for pelletization or for electricity generation more challenging than I'm assuming? 

[rusticretreater]

The market for pellets is not all that big and any sizeable number of pellets hitting the market would oversupply it in short order.

There are markets for sawdust, but you also have to supply the right sawdust.  Not all sawdust is suitable for pelletizing, compressing, pulping or what have you.  I have an uncle who would get the sawdust from the local Merrilat Cabinet factory to use in his cow sheds.  Then it would end up back in the fields.

[forestfan]

What are you mainly thinking of when you say "right sawdust"?

Right size, consistency, moisture, type of wood? Other things?

And when you say there's a market for sawdust, are you saying that there are people who will both pay you for it, and also pick it up?

I assume markets of this nature only exist in specific places, right? And that in many places, there is truly no market, and sawmills have to pay to have it disposed of?   

[beenthere]

forestfan
Welcome to the Forestry Forum.
You have some good thoughts, which are not new as sawdust disposal has been a problem since sawing wood has been around.

Use the search button here and you will have a number of hits for such discussion in this forum since its beginning. Pelletizers have been around and exist, as well their problems trying to make wood pellets have been a major hurdle to overcome, or outlast, or the reason to just throw in the towel.

But don't give up if you continue thinking about solving the sawdust problem. 

[WV Sawmiller]

   I'd read the thread below. We talk some about the pellet making issues some here.

    From what I see the only people making money with pellet mills are the pellet mill salesmen. Seems to cost more to make them that what you get from selling so need government or other subsidizing.

https://forestryforum.com/board/index.php?topic=121096.0

[barbender]

If you're close I'll haul you all you want for free😁

[SawyerTed]

The process for making pellets seems simple.

Use waste small wood fibers/cheap sawdust and press, right?

The devil is in the details.  Sawdust alone doesn't bind together very well, enter the hammer mill.  

Then most sawdust and small wood fiber contain some moisture - sawmills saw mostly green logs, and keeping a roof over sawdust can be costly or blowing waste into a walking floor/dry van is another expense.  So sawdust often contains too much moisture, enter a drier - more$$$$.  Then add binder.  

Small pellet mills alone are pretty cheap $2-5k.  You get what you pay for, small mill, small production.  Then, where's the market?  (That should be the first question).  Here bags of pellets are cheap enough in bulk that a small operation couldn't pay the utility bills to make them. 

The costs tied up in waste disposal need to be as close to break even as possible.  It's cheaper and less handling to sell sawdust to the chicken houses and horse barns or just compost it. 

[Magicman]

I toured a big commercial pellet mill and learned that successful pellets are made from paper mill quality wood chips, hammer milled, and dried to the proper moisture content, not sawdust.  The only way that the pellet mill was successful was government subsidy.  I was not impressed.

[Ianab]

With the amount of farming in our area the mills have no problem selling all their sawdust, most going for animal bedding.  For a small mill sawdust can be a problem, but if you are producing truckloads a day, it's a saleable product, and it's a lot simpler to simply load a truck and deliver it, vs making pellets with a more limited market. One large commercial operation supplies sawdust to poultry farmers, then removes the "used" material, and processes that into fertiliser, as it's got plenty of chicken poop in it now. In that case, the sawdust is actually being used twice (and the company gets paid both times)

Larger mills just feed all their waste into a boiler to run kilns, or ever a co-gen plant to generate electricity. So to them it has value as fuel already.

[Southside]

Compost it and you have a value added product.  I sell a little, basically to those customers who see the composted pile and ask nicely if they can buy some.  I want it for the organic component it adds to our soil.  Moisture retention, soil tilth, and weed suppression in the produce when top dressed.  As long as it's composted it does not tie up nitrogen and makes for a great soil amendment.  

[Brad_bb]

This was one of my first questions when I got a mill in 2014.  What to do with the sawdust.  We talked about pellet mills.  Seems such a waste not to use all the saw dust.  But....the problems were:
1.Pellet mills, even the small ones, are a large capitol cost.  
2.Making pellets requires careful control of moisture content.
3.How much time do you want to dedicate to making pellets.  When you have a sawmill, you want to spend your time milling lumber, not making pellets.  By the time you mill, clean up, do all the stuff you need to, to stack and air dry lumber, all your maintenance.... you don't want to add another time draw to the list.  Anything that takes much time away from milling, is not making you money or being productive.

In the end, If you have a place to put your sawdust to compost, great.  I don't cut as much as some other guys, but I saw enough to be able to keep up burning my sawdust in two Vortex burn barrels(Look that up on youtube).  Learning how to burn sawdust is a learning curve. You can burn green sawdust.  You need some hot coals from burning some wood first preferably. If not some fuel oil.  Once you get the sawdust started, it sill slow burn because it has to dry the dust adjacent to the burning dust via the radiant heat and when enough moisture has left, it will start to burn.  I've found that dumping dust in one side of the barrel so it creates a 45 degree angle from one side of the barrel to the other, it allow the dust to start at the base and slowly burn up the slope.  If you have more burn-ables on top to create more radiant heat and create more of the air draw form the vents in the barrels, it will burn faster.  Only fill the burn barrel 25% full at one time and after that burns, add another 25%.  You also have to learn how to pour onto the hot coals so flames don't climb up the saw dust stream and burn you.  With the coals in the bottom, I quickly dump and to some extent is smothers them except at the base of the slope.  Green dust won't want to flame up, but you will invariably have some dry dust in the top of the can, or some that has dried on the ground, so you have to be careful.  Dry dust can burn quick like gasoline being dumped on a fire.  You should never use gasoline when you burn.  If you have to, use diesel because it takes a hotter temp to burn.

[Ron Wenrich]

There is a  market for wood pellets by sending them to Europe so they can keep their carbon emissions in check.  Pellets are considered a renewable resource, so it offsets the fossil fuels.  But, to be a player, you need to make a large quantity or find a broker who does.

Composting is probably a good option.  If you have any chicken houses in the area, add manure to speed up the process.  After it composts, put it in bags and sell as lawn soil.  You can probably get a good local business.  But, sales are very seasonal. 

Most small mills in my area sell dust as animal bedding.  We have a pretty sizable farming base as well as hobby farmers.

[doc henderson]

one of my waste barrels in the shop is for stuff to burn in the fire barrel and includes when I sweep up the floor.  I keep the hair on my arms and eyebrows in check if I dump the barrel into an already blazing fire.  the dust flares 6 feet in the air.

[PoginyHill]

The biggest hurdle to making pellets or briquettes is moisture. Unless you already have dry waste of the appropriate size, you'd need a dryer. Much bigger expense and operating costs than a pelletizer or hammer mill. Some of our veneer and plywood operations use briquette makers as a way to deal with dry waste, but green waste (wood chips, sawdust) is either burned, sold, or used to make mulch. Briquettes are handy because they can be used wherever traditional firewood can be. And the machinery is cheaper than a pelletizer, I think.
Co-gen is an option (wood-fired boiler and a turbine generator) but, as has been alluded to, that doesn't have a great return without government subsidies.

[DanielW]

What IanB says is correct: Any mill large enough to have a sizable quantity of sawdust has a market for it. Us small-scale operators may leave slabs, dust, and chips in the bush, but in a full-scale commercial sawmill every byproduct has a value and is used or sold. IN the US for instance: Look at 'Scott's' fertilizer and lawn-care plants, and you'll find many of them are built across the road from commercial mills, because they use the chips and dust for their mulch. And lots of commercial mills have regen/cogen steam plants that allow them to burn their dust and chips in one form or another.

[Ron Wenrich]

I helped to site a cogen plant back in the 80s.  We needed to locate a steady supply of fiber and it burnt 80,000 tons/yr.  That's about 10 trailerloads per day.  We had a steam user, so the plant actually didn't need subsidies to turn a profit.  I believe its still in use, but was converted to natural gas a couple of decades ago. 

Larger mills use their wood waste to fuel their kilns.  It probably could be done on a smaller scale.

[Brad_bb]

I've found that my hardwood waste slabs area great for mulch.  When I have the tree guys out in spring and fall or summer, I have them chip the slabs I have.  NO WALNUT goes into the chipper though.  I don't want it killing anything or taking the chance.  Ash and cherry have been great making a ton of mulch for my beds.  Just make sure not to make your slabs too thick.

[Ianab]

I helped to site a cogen plant back in the 80s.  We needed to locate a steady supply of fiber and it burnt 80,000 tons/yr.

The co-gen plants locally are integrated into the mill, AND the National power grid. More like a home grid tied solar power system, but with a 50mw breaker panel. They don't have to buy fuel, because the mill produces tons per hour, and they convert it into steam to operate kilns and generate most of the power the mill needs. Any excess can be sold to the national grid, or extra power pulled from the grid if needed. So the problem of sourcing fuel is solved, they have a huge stack of it out back. If they sold those byproducts as pellets etc, they would then have to buy electricity or Nat Gas, which would cancel out any potential profit from wood pellets. 

The power generated only accounts for about 2% of the countries generation, and the mills use most of that themselves, so it's not really about the power they are selling, it's the energy they don't have to buy.

[KEC]

Regarding the "right" or wrong sawdust, some sawdust is bad news for animal bedding and maybe for people working around it. If I remember correctly, Eastern Hemlock and Black Cherry sawdust can be a problem.

[Ianab]

Local mills exclusively cut pine, which is "mostly harmless". Walnut isn't good in animal bedding as horses have a bad reaction to it. So there are certainly species that can cause problems. ANY sawdust can be a health hazard if you breath enough of it, just some species are more toxic than others. 

[SwampDonkey]

There is a local softwood mill here making pellets at their operation, have for a few years. There is a hardwood mill north of here that have made pellets for a few years now. 10 years ago, there weren't enough pellets to feed the domestic market. It mostly went to Europe. No trouble now getting pellets, but it's still exported. I see a lot of companies in Maine that sell pellets from the local mill. There are heating fuel outfits in Maine, like Daigle Oil, that sell them in bulk trucks for pellet furnaces. I can remember sawdust furnaces around here for years. If the sawdust is off the planer mill, it's nice and dry. Off the saw it's pretty wet sawdust. Mills traditionally sold clean sawdust to pulp mills, but after 2008 a lot of them went away so the pellet industry developed. Any sawdust with bark and such usually goes as hog fuel. We have a number of heating plants and mills themselves that use hog fuel. 34 years ago was the end of big cone shaped sawdust burners at sawmills. There's a market for all of it. One thing I will say is that pellets are getting pricey. Split firewood delivered or your own is still the cheapest heat source. I'd rather lug a 10-15 lb stick of wood than to handle 50 lb bags. :D

[Ianab]

Wood pellets are a "thing", and there is a market for them. They simply aren't a thing locally. Sawdust / wood shavings / firewood (from slab wood etc)  you can sell. along with a few stray MW of electricity. 

So the "waste" isn't wasted, it's used in some way.  

[SwampDonkey]

Around here pellet stoves are common. I know of 4 such stoves within a mile of here.

[moodnacreek]

There are endless products that come from wood but in business you need a market. 

[WV Sawmiller]

SD,

   What is hog fuel? Oink - Oink?

[Ron Wenrich]

When I first started sawing on a manual mill, we had a sawdust pile and a local farmer came and picked it up.  He was using it on dairy cattle.  Problems started up when farmers were getting problems with mastitis.  Penn State did a study on it and found that mastitis was coming from sawdust, and specifically the bark in the sawdust.  Not as much of a problem with debarked logs.

When we went to the automatic mill, we added a debarker.  Dust was sold to dairy farmers, but from debarked logs.  We also sold a lot to horse stables, as well as chicken farmers. 

[SwampDonkey]

boiler fuel = hog fuel

[PoginyHill]

Hog is a generic term for any piece of machinery that reduces raw wood waste into conveyable chips for a boiler. Hammer mill, hammer hog, chipper etc...

[moodnacreek]

SD,

  What is hog fuel? Oink - Oink?

Wood scraps run through a 'hog' so they can be conveyed into a boiler [burned]. If memory serves it would be chips.

[Brian_Rhoad]

A chipper and a hog are different animals. A chipper cuts with knives. A hog shreds with hammers.

[Evgenii.B]

Firstly, the ability to sell pellets depends on their quality. High-quality wood pellets should have a calorific value of no less than 17,000 BTU, ash content not exceeding 0.7%, and moisture content below 10%. Bulk density should fall within the range of 38 to 46 lb/ft3. With sufficient equipment, high-quality pellets can be produced from various wood sources. However, the more technological processes involved, the more expensive the pellet plant. In other words, the more complex the production process, the higher the productivity required, which means a larger quantity of raw materials. It may be profitable to produce pellets from dry sawdust in one location, while processing wet trimmings may not be cost-effective elsewhere.

Secondly, the ability to sell pellets depends on the proximity to the consumer. Sellers and distributors of pellets purchase them from different plants and organize logistics based on consumer demand. If there is no major plant nearby but there are consumers, they may buy pellets from you at a higher price and save on delivery. Just give the sellers a call and ask them how much they'd pay for your pellets in your city.

Thirdly, there are large aggregators that collect small batches of products into larger ones and ship them by sea to Europe. With sufficient pellet quality and acceptable delivery costs to the coast, this can be a good method for year-round sales.

[booman]

I have acreage so I drizzle it over the land from a front end loader bucket.  Pellet companies I am told want 18 wheel truck loads of saw dust.  It would take me a while to generate that much.

[SawyerTed]

There's warehouses full of pallets of bagged pellets not far from me.

Surplus pellets are selling for $4 per bag with a 20 bag minimum and $125/ton with a 24 ton minimum ($2.50 per bag).

Competing with that is like trying to compete with Weyerhaeuser or Georgia Pacific making 2x4 suds.  

[K-Guy]

We had $7-8/bag this winter depending on brand and vendor. I would've lined up at $4/bag.

[SwampDonkey]

You'll never see $4 a bag for pellets up here. It's close to $7. I'm guessing bulk delivery into a hopper is the cheapest, a lot less to handle. Only place I here them advertise bulk delivery is in northern Maine. Those are coming from NB, from the mill across the river.

[SawyerTed]

Warehouse with bags of pellets 50 miles from here.  

[PoginyHill]

With crude oil and natural gas prices rather reasonable for the last several years, it has kept pellet (and firewood) prices suppressed as well. With crude approaching $90/barrel, maybe that'll change.

[Southside]

Pellets have their niche, but they will never compete at scale with oil or gas unless there is a complete society shift.  We have gotten to a place where people don't get up off the couch to turn the lights on, they have a robot mow their lawn, and some are trying to make it so you don't even have to drive your own vehicle.  You really think folks are going to lug bags of pellets home, store them somewhere, drag them inside, put them into a hopper, etc en mass?  As far as bulk goes - that works with oil because of a hose and the ability to reach the tank rather easily.  That is a very limited opportunity with a solid fuel like pellets. The vast majority of folks will complain about higher oil and gas cost, but they will pay the bill before the lifted $100K mall crawler ever hauls home a pallet of pellets. 

[Hilltop366]

I burn some pellets in a pellet boiler in an apartment building to reduce the oil bill when the prices line up, I'll be at about 700 bags this heating season at 40 pounds per bag. Best I could come up with locally is $7 per bag this year, $4 would be nice.

[SwampDonkey]

Also the prices on fuel oil, propane and natural gas is a lot cheaper in the US than in Canada or elsewhere. I haven't heated with oil in 20 years. In fact in my local area, wood in some form, firewood or pellets, is the overwhelming majority of heat. Mom's cousin in the city of Toronto burns wood they get for cheap from the city parks department when they remove trees. The city has a staging area where people get the firewood from, from my understanding.

I don't see anyone in these parts buying into that tech stuff. Rural folks here want easy, reliable. If you're up in years, then you certainly like push button convenience. If you can afford it, go for it. The cities are full of conveniences because where you live is the deciding factor. If you're in an apartment, you're likely using push button heat.

I know someone who suggested if they were building a shop they would install a heat pump. I said, I like wood too much.

[SawyerTed]

Transportation of commodities like pellets is the big ticket item.  Sometimes transportation costs more than the wholesale price of the commodity.  

That $125 surplus ton of pellets in a Virginia warehouse becomes a $325 ton of pellets once it's trucked to a high demand area.  

[SwampDonkey]

They send boat loads of pellets to Europe for electrical generation and heating. When they first started there was not enough manufacturing for the domestic market, now that has caught up. There was a time when you could not feed the demand, people with pellet stoves were virtually stranded and quite rightly pithed off that pellets could be sent oversees but not look after their own.  You couldn't buy any, period, didn't matter what the price was.   The EU consumes as much as everyone else combined.

[Evgenii.B]

You'll never see $4 a bag for pellets up here. It's close to $7.

The cost per ton of wood pellet production includes $10 for consumables, 100 kWh of electricity, and the workers' wages. Considering the smallest pellet plant capable of producing high-quality fuel pellets, it can produce 0.5 tons per hour. Taking into account the wage, the cost of one ton of pellets sums up to $20 for electricity and consumables, and $60 for 2 hours of labor, totaling $80 per ton. This makes sense if the sawdust is automatically delivered from the warehouse and there is no additional cost for transportation. The automated packaging machine, which packs pellets into 50-pound bags, adds an additional $15 per ton in expenses. Therefore, the cost of one ton of pellets with bag packaging approaches $100 when the pellet plant is located directly near the waste source. This is $2.3 per bag. I have attached a photo of what such a pellet plant looks like. With increased productivity, the salary expenses are significantly reduced.

The delivery and refilling of pellet containers is similar to liquid fuel. Pellets are blown into the containers with compressed air, and organizing their storage is no more difficult than for regular grain.

[Southside]

I don't see anyone in these parts buying into that tech stuff. Rural folks here want easy,

SD - you need to realize we on this page are the odd balls, and we are becoming dinosaurs.  Look around at the average age.  It's no different than farming, the number of people involved in it becomes less and less each year and the age goes up. I am talking in terms of commodities, not systems used by folks who can saw their own firewood, lumber, or grow their own beef.  Skill sets we take for granted are lacking in the vast majority of the population along with the ability to have any self sufficiency.  I deal with a lot of urban and suburban folks as customers and see it all the time.  I am talking about adults who don't know how to put air into a tire....

[SwampDonkey]

I'm too far away from any major center to see it here. 1/2 of the population in NB is rural. Cities here are not very big. You can travel for miles and there is sparseness everywhere, then boom you're at the city gates. There's no hundreds of miles of built up housing in suburbs. You have little developments, now and again. Travel 5 miles from the center of any city here and you're in undeveloped wilderness or old farms. The further from the river banks, the fewer and almost nonexistent housing. Where I live will never be anything more than potato fields and woods. In time it will likely be less fields since we've lost half of the farmland now. It will be woods growing back up as it has the last 150 years. The little increase in population in recent years is mostly ingress from other provinces, mostly retired or nearly so. A lot buying old 100+ year old houses. Very few new homes.

My carpenter told me he is working on a timber frame starting in June. It's $600,000 kit coming from Alberta and some parts of it south of the border from Alberta. That's another transplant moving east. It reminds me of a lot of mansions of money people in the US, many abandoned and falling down after the folks pass on. People video it all the time. It's certainly happened here to. Peirre Burton's estate is pretty much abandoned. He was a famous Canadian author. I wouldn't say his place was huge, but some people think their legacy will be carried on when they die. It doesn't, it fizzles and fades and is forgotten.

[beenthere]

Evgenii.B

Where are you located? USA, Canada, UK ??

Interesting how using copy and paste, the color and font changes in the post. ??

The video shown reminds me of back in the 50's when we used coal delivered, then scooped it into the stoker bin to be auger-fed into the furnace upon heat demand. Those were the days. For the coal dust problem, seems they sprayed the coal with oil.

Pellets are a convenient wood heat that way too (auger-fed), and one of few prime reasons for their being a thing (reality) for heat.
Not for the manufacturing, transportation, delivery, dependence, storage (keeping dry), quality, etc. that come with using pellets for heat. (IMO)

[Ron Wenrich]

Is that $7 the Canadian price or US price.  If Canadian, that would translate to about $5.11 US.

Using a wood pellets vs fuel oil calculator, and considering an 83% for both boilers, you end up with 1 gal of fuel oil = 16.4 pounds of pellets.  One ton pellets = 123 gal fuel oil.  A 50 pound bag would be 3 gal of fuel oil.  It sure sounds cost efficient for pellets if you disregard the added labor and storage needed.

My grandfather had a boiler that used rice coal.  He had a long auger that feed it and once a week he went into the basement and shoveled coal into the auger.  It also heated his hot water for 3 housing units.  I imagine the same could be used for pellets.

[Hilltop366]

$7 per bag Canadian, our furnace oil is around $6 Canadian per US gal.

I plumbed the pellet boiler into the oil boiler return line to pre-heat the return water. 

The pellet boiler is not big enough to take all of the load all of the time so I still use some oil during peak usage of heat or hot water. It reduces the oil usage by at least 2/3 during the winter and more during the shoulder seasons.

The pellet boiler has a small 4 bag hopper and a second 35 bag hopper with automatic auger that feeds the smaller hopper. I check it and add a few bags every 2 or 3 days or any day I'm there. It is close by so I'm there often.

[moodnacreek]

I don't see anyone in these parts buying into that tech stuff. Rural folks here want easy,

SD - you need to realize we on this page are the odd balls, and we are becoming dinosaurs.  Look around at the average age.  It's no different than farming, the number of people involved in it becomes less and less each year and the age goes up. I am talking in terms of commodities, not systems used by folks who can saw their own firewood, lumber, or grow their own beef.  Skill sets we take for granted are lacking in the vast majority of the population along with the ability to have any self sufficiency.  I deal with a lot of urban and suburban folks as customers and see it all the time.  I am talking about adults who don't know how to put air into a tire....

You know they make run flat tires these days 

[Evgenii.B]

Where are you located? USA, Canada, UK ??

I'm worried mentioning the country will get me banned. I'm planning to live and work in Colorado. I've been studying American culture for over a year now, and I like one-story America more and more. I've been interacting with local Americans from different states, and I've long realized the falsehood of my country's propaganda. Soon, the US will gain a specialist in wood waste recycling and natural fertilizer production.

To use pellets in other furnaces, it's enough to integrate a burner into the stove door. Many people are converting wood and coal stoves here. It should be noted that a pellet burner requires significantly greater draft in the stove. Sometimes, installing a pellet burner requires extending the chimney above the roof or increasing its diameter. I suspect that in the US, laws are much stricter, and most likely, such modifications would need to be carried out by licensed professionals.

[SwampDonkey]

Standard chimney where I live is 3 feet above the peek of the roof. Too short and you loose draft and you get back draft and a smoky room. Pellet stove chimneys are smaller than firewood chimneys around here and none are above the peek of the roof that I've ever seen. One fellow had a down draft problem and his hopper of pellets in the stove burnt up, not in the burn chamber. Almost had a house fire. I suspect an improper install. I don't know of anyone else who has had the issue.

[Evgenii.B]

Pellet stove chimneys are smaller than firewood chimneys around here and none are above the peek of the roof that I've ever seen.

That's absolutely true for pellet stoves equipped with control panels and blowers. They're as convenient as gas boilers, programmable based on weather conditions or set schedules. They automatically increase pellet feed and blowing, so they don't require strong chimney draft. Typically, these stoves come with batteries that allow them to operate during power outages. If the battery malfunctions, the fans stop, the temperature drops, and the draft disappears, which can lead to a fire.
I mentioned the increased chimney draft in cases where a passive pellet burner is installed on wood or coal boilers. It doesn't have fans or a controller. Its hopper seals tightly, so there's no smoldering of pellets when it goes out. Here's an example of such a retrofit in the photo.