Wood ash

[Robbo90]

Last winter I had an amount of Willow that was well seasoned and being as it was free burnt very well. This year I have another batch of well seasoned Willow which is burning equally as well but I am sure this batch is leaving me with twice as much ash for the same volume of Willow as I burnt per fire last winter. I am using the same fire ( B & G infire 800) and each burn is for roughly the same time and a fire is fuelled from the same log basket so volume of wood per burn is similar.

Any idea's as to why I have extra ash?

Yours confused :confused1:

[Woodworks]

Are you using more smaller branch material? Had this come up when I was selling a lot of small diameter logs from our hedrow trees, customers said it burnt well but left a lot of ash.

[cornish wood burner]

Could you be burning smaller diameter logs so more bark for the same volume of wood.

More bark = more ash

[openspaceman]

Are you using more smaller branch material? Had this come up when I was selling a lot of small diameter logs from our hedrow trees, customers said it burnt well but left a lot of ash.

 

That's because the bark %age goes up and bark has a higher mineral content.

[openspaceman]

Could you be burning smaller diameter logs so more bark for the same volume of wood.

More bark = more ash

 

You beat me to it Ian.

 

If you look at machines harvesting eucalyptus for pulp in warmer climes you may notice they set the knifes to strip most of the bark, which is left to decompose, removing the white wood only means less fertility is exported with the crop.

[cornish wood burner]

You beat me to it Ian.

 

If you look at machines harvesting eucalyptus for pulp in warmer climes you may notice they set the knifes to strip most of the bark, which is left to decompose, removing the white wood only means less fertility is exported with the crop.

We notice the difference when burning slab wood compared to round wood. I'm farly sure that bark has a bit less energy as well

[openspaceman]

We notice the difference when burning slab wood compared to round wood. I'm fairly sure that bark has a bit less energy as well

 

Most biomass has about the same calorific value on a dry ash free basis but conifer beats hardwood on weight for weight by about 10% because of the higher lignin content, so given a high ash content and low lignin you are probably right.

 

What we found with willow asrc was the ash has a low fusion temperature and clinker became a problem the short period we tried it.

[cornish wood burner]

Most biomass has about the same calorific value on a dry ash free basis but conifer beats hardwood on weight for weight by about 10% because of the higher lignin content, so given a high ash content and low lignin you are probably right.

 

What we found with willow asrc was the ash has a low fusion temperature and clinker became a problem the short period we tried it.

 

Bark is a couple of % down on energy and high in minerals so not top class fuel, according to Joseph Binder ( Binder Boilers ) who I met about 10 years ago. Looking back now he gave us some very good info, pity our installers didn't spend more time with him.

Never knowingly burnt willow in the boilers but we have had ash melting at one stage in the early days when the Austrians changed the settings remotely. Looked bit like Portland cement and water with no sand.

I sometimes burn willow in my Rayburn but funnily enough it doesn't seem to get quite that hot.

[Stereo]

I've been burning coppiced hazel for the last while in the form of small logs and can confirm much more ash. Still burns very well though and in many ways is cleaner to handle than split wood. Don't mind the ash as it's good for chicken dust baths!

[Robbo90]

I was struggling to understand why I had extra ash as the log size is similar to last years supply but looking in the wood store today some of the lumps of willow seem to have bark thats nearly 1 inch thick. At least I have learnt something new and useful today.

Cheers !!!