How do you air dry your wood down to 20% ??

[openspaceman]

2 hours ago, Rough Hewn said:

Nope.
Syn gas is not given off during drying.
Has to reach temperatures of several hundred centrigrade to gasify.
How hot is your drier?

Syngas doesn't form at less than 800C and then it will be too contaminated with other products to be syngas with wood as a rawstock. The portmanteau word  comes from synthesis gas which was fairly pure H2 and CO used to form other more useful organic chemicals, like petrol, from coal.

 

Below about 330C the whole thing is endothermic and the early products are highly oxygenated so no good as a fuel, You have to be up in the 300-440 range for pyrolysis to be self sustaining and give an offgas which will support combustion, in the absence of a support fuel.

 

You can use the exhaust from a spark ignition engine to pyrolyse wood but then it is difficult to keep a flare (necessary for controlling smoke and pollution)

 

We heated wood in the output of a vegetable oil gasifier and fed the offgas to a small gas turbine but only ran it briefly, long enough to produce nice logwood charcoal though. Ideally we would have liked to heat the wood with the turbine exhaust and then dry the wood downstream from that.

[renewablejohn]

53 minutes ago, Rough Hewn said:

Are you personally involved in this?
Sounds fascinating.

Yes its been my development over the years.

[renewablejohn]

42 minutes ago, openspaceman said:

Syngas doesn't form at less than 800C and then it will be too contaminated with other products to be syngas with wood as a rawstock. The portmanteau word  comes from synthesis gas which was fairly pure H2 and CO used to form other more useful organic chemicals, like petrol, from coal.

 

Below about 330C the whole thing is endothermic and the early products are highly oxygenated so no good as a fuel, You have to be up in the 300-440 range for pyrolysis to be self sustaining and give an offgas which will support combustion, in the absence of a support fuel.

 

You can use the exhaust from a spark ignition engine to pyrolyse wood but then it is difficult to keep a flare (necessary for controlling smoke and pollution)

 

We heated wood in the output of a vegetable oil gasifier and fed the offgas to a small gas turbine but only ran it briefly, long enough to produce nice logwood charcoal though. Ideally we would have liked to heat the wood with the turbine exhaust and then dry the wood downstream from that.

Think you need to look at the by-products on torrefication of wood then you will find a suitable fuel to run a gas engine.

[Stere]

How much for one of theese systems approx?

 

Alvan Blanch - Processing The Worlds Crops Since 1952

WWW.ALVANBLANCHGROUP.COM

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Welcome to Alvan Blanch - A British manufacturing and project engineering company that specialises in...

 

 

 

 

 

[renewablejohn]

1 hour ago, Stere said:

How much for one of theese systems approx?

 

Alvan Blanch - Processing The Worlds Crops Since 1952

WWW.ALVANBLANCHGROUP.COM

---

Welcome to Alvan Blanch - A British manufacturing and project engineering company that specialises in...

 

 

 

 

 

Far cheaper than the thermal plate dryer I use.

[arboriculturist]

I know plenty who air dry their firewood in barns, but does anyone successfully air dry outdoors in stillages / potato boxes etc.  and still manage to keep them dry outside during the winter months?

[difflock]

I would contend that one of the key benefits of the "billet bundle" system, despite a little more handling, is their outstanding suitability for air drying.

With the bottom row set on rails, very little ground contact and good airflow even at the ground, plus stacked 4 or 5 high(I dont imagine more than 5 high would be stable or safe) even better exposure to airflow, and easy to both cover and secure a cover over, and even if left uncovered, simply "write off" the top row, if they happen to be surface wet,  restacking them 4 /5 high again, and the 3/4 rows beneath will be dry regardless.

As in, even with the exposure to wind driven rain, the wind soon removes any moisture due to the rain.

And if they are lifted after a few good days of blowy sunshine, despite any previous rainfall they will be shockingly dry.

Marcus

Edited February 25, 2020 by difflock

[arboriculturist]

5 minutes ago, difflock said:

I would contend that one of the key benefits of the "billet bundle" system, despite a little more handling, is their outstanding suitability for air drying.

With the bottom row set on rails, very little ground contact and good airflow even at the ground, plus stacked 4 or 5 high(I dont imagine more than 5 high would be stable or safe) even better exposure to airflow, and easy to both cover and secure a cover over, and even if left uncovered, simply "write off" the top row, if they happen to be surface wet,  restacking them 4 /5 high again, and the 3/4 rows beneath will be dry regardless.

As in, even with the exposure to wind driven rain, the wind soon removes any moisture due to the rain.

And if they are lifted after a few good days of blowy sunshine, despite any previous rainfall they will be shockingly dry.

Marcus

That's really informative thanks.

 

Like it or loath it - It's going to be all about the 20% MC - coming soon !!!

[nepia]

1 hour ago, arboriculturist said:

I know plenty who air dry their firewood in barns, but does anyone successfully air dry outdoors in stillages / potato boxes etc.  and still manage to keep them dry outside during the winter months?

I store and dry in IBC cages.  In answer to your question - I have no idea but my customers love the logs, one commenting in an e-mail last week 'so much better than the wet sycamore we were given'!

 

I actually couldn't give a hoot whether my logs are 19.9% or 20.1% as long as my customers are happy, which they are.  I've had several tell me they're the best logs they've ever had (God knows what shite they'd been buying before!)

[arboriculturist]

31 minutes ago, nepia said:

I store and dry in IBC cages.  In answer to your question - I have no idea but my customers love the logs, one commenting in an e-mail last week 'so much better than the wet sycamore we were given'!

 

I actually couldn't give a hoot whether my logs are 19.9% or 20.1% as long as my customers are happy, which they are.  I've had several tell me they're the best logs they've ever had (God knows what shite they'd been buying before!)

I think most are agreed that anywhere below 25% is perfect Firewood, however when the 'Log Police' descend things may take a turn for the worst.

 

The general public are regularly easily swayed IMO by what they are told in the media, good or bad, fact or fiction, which will be a shame in part, as there are thousands of small producers who supply good quality dry firewood. 

 

The powers that be are on a mission to re-educate the public regarding 'ready to burn' firewood and a lot of resources will be expended in the media.

 

The vast majority of suppliers large and small, unless they buy in or are able to produce forced dried firewood, will without question find themselves affected by the incoming and planned future legislation.

It's harsh, but this is something that few of us will be able to ignore however much we would like to, as it's now not going to go away.

Edited February 25, 2020 by arboriculturist