Central Boiler Maxim and burning sludge pellets

[Deerdell]

Aren’t these bio solid type products loaded with PFAS and heavy metals ?

Toxic 'forever chemicals' found in Michigan farm's beef - Great Lakes Now

The Michigan Department of Health and Human Services “determined that prolonged consumption of the beef from this farm could increase PFOS levels in the human body,” a news release said.

www.greatlakesnow.org

Heavy metals in the sludge depends mostly on the town. Metal plating, fabrication shops, tanneries, put out a lot of heavy metals. Our town has almost no “industry”, And our sludge has very little metals in it.

PFAS is something new. I haven’t read much about it. To my knowledge, as of now it isn’t required to test for PFAS. I’m sure that will change in the near future.

 

[EbS-P]

Heavy metals in the sludge depends mostly on the town. Metal plating, fabrication shops, tanneries, put out a lot of heavy metals. Our town has almost no “industry”, And our sludge has very little metals in it.

PFAS is something new. I haven’t read much about it. To my knowledge, as of now it isn’t required to test for PFAS. I’m sure that will change in the near future.

My quick Google says 1000F should decompose some PFAS. Really it needs almost twice that to get 99%. You just don’t have much time at high temps in a pellet stove. PFAS concentration would be interesting. It does bio accumulate.

I’d go the coffee ground pellet route if I had an extruder.

 

[Highbeam]

My quick Google says 1000F should decompose some PFAS. Really it needs almost twice that to get 99%. You just don’t have much time at high temps in a pellet stove. PFAS concentration would be interesting. It does bio accumulate.

I’d go the coffee ground pellet route if I had an extruder.

I wish the multifuel pellet world would embrace all of the possible fuel sources. Whether sludge, coffee, grass, ag waste, etc. if it’s cheap and burns then why not? These modern pellet stoves can adjust to optimize the combustion.

Wood sawdust must be super cheap and plentiful in comparison.

 

[Deerdell]

I wish the multifuel pellet world would embrace all of the possible fuel sources. Whether sludge, coffee, grass, ag waste, etc. if it’s cheap and burns then why not? These modern pellet stoves can adjust to optimize the combustion.

Wood sawdust must be super cheap and plentiful in comparison.

I’d love to get a little pellet mill to play with. I know the decent pile of sawdust from my little hobby wood shop might make one or two bags of pellets. I’ve got about 3 acres of lawn in the farm that I rake the grass off all summer. It would be a losing investment, but it would be fun to play with.

 

[Jerichan]

Hello all,

First time posting on this forum, I’ve been on heating help for a little while and have been lurking on here. I’ve been watching for a good used outdoor wood boiler for a while, but have changed my tune towards a pellet boiler to heat my old Wisconsin farm house.

I work at the local waste water plant where we dry the sludge, and are looking into getting a pellet mill to pelletize the final product. We give away all the sludge, so I could have an unlimited supply of pellets. I also farm, so corn is always an easy option when the price is right.

Now I see for sale locally is a pair of central boiler maxim 255pe corn/pellet boilers for $4500 a piece. Not sure how old they are at this point, but they both look very clean, have the WiFi controller, and the listing mentions it might have an ash auger system that isn’t installed.

So I guess I’m looking for opinions on these boilers, anything to watch out for or problem spots I should look close at? Buying two used boilers for less than the price of one new boiler doesn’t seem like a terrible idea. Also, does anyone have any opinions or experience burning something like municipal sludge? From the searches I’ve done, it seems to get brought up once in a while but not sure anyone ever follows through with it. If I don’t buy these boilers, I’d like to find a good used indoor pellet stove to experiment with the sludge pellets in the shop.

I have a very early Maxim 250 that is still running OK, but it requires constant attention. I am perhaps the only person in Vermont to be burning corn instead of pellets. I do it for two reasons: 1) safety. It won't burn back into the hopper because corn won't burn without forced air. and 2) freezing. When the power went out and I was burning pellets, the furnace thought there was a back burn and sprayed water into the internal augers. The water turned the pellets into sludge, which then froze solid. Even after I redesigned the thing - with a hacksaw - it took me several hours to chip the sludge out with a screwdriver.
After finally finding a mechanic (only an hour away) who knows the furnace, I have gotten it reasonably well tuned. My main problem now is air: burning corn, the Maxim tends to produce a lot of ash and solid chunks. I poke it at least every day and have to shut it down, remove the main auger and redrill the air holes EVERY OTHER day. It runs pretty well when air is going through the auger mechanism and coming out in the corn, but when it clogs up, which it does quickly, it fills the ash-collecting lower part in two days. You'd need a camshaft inside it to clean it out constantly!