Biochar Questionnaire

[Khriss]

Cheers, Stere, so it's bollocks realy. Any appropriate soil condition assessment then using basic materials ( lime for clay soil to 'crumb' the texture )  will give you an improvement . I can rest easy now. K

[AJStrees]

I believe there is a difference with what is called "enriched biochar", this is the product I have heard has great effects. Have had a few companies in to tell me about it as regards improvement with supplementary use of other machines to decompact soil while also using the enriched biochar to improve compaction and nutrition of soil where years of above ground works such as mulch circles had not created the necessary effect towards the health of the tree. But that is also not to say that mulch circles do not help trees, as I have seen results myself. They have also recommended adding "enriched biochar" to the mulch circle and watering it in to make improve the tree health. (Not a new idea in the horticultural world but something that I have started doing with some of the trees where I work). 

 

So I think it means there are things that can be done to improve the health of trees whereas earlier the conservation of the tree may not have been seen as possible and would have been potentially differed in structure or removed due to root rot or other such issues.  

 

https://www.carbongold.com/250-trees-saved-using-enriched-biochar-and-deep-soil-decompaction/

[Conor Wright]

Really good thread, so.. where does it leave me with approx 60 tons of chip and three acres of highly compacted silty soil?! The soil in question is potentially very good but has been used for three decades to harvest turf for instant lawns and as a result has high iron, low organic matter and serious compaction..
Having access to plenty of woodchip it seems to make sense to utilise this for soil enrichment, the original idea was to compost it over time and add to the soil as it becomes available.. deeper incorporation of char sounds like a better long term idea. Any useful information on how best to process this chip into useable biochar would be greatly appreciated..

[Khriss]

Without seeing lie of land Connor, soil ripper, as silty soils can be quite hard to drain, then what ever yr cropping or using will determine yr use of that chip which 'must' be rotted or it will pull nitrogen from soil whilst it decays. K

[the village idiot]

49 minutes ago, Conor Wright said:

Really good thread, so.. where does it leave me with approx 60 tons of chip and three acres of highly compacted silty soil?! The soil in question is potentially very good but has been used for three decades to harvest turf for instant lawns and as a result has high iron, low organic matter and serious compaction..
Having access to plenty of woodchip it seems to make sense to utilise this for soil enrichment, the original idea was to compost it over time and add to the soil as it becomes available.. deeper incorporation of char sounds like a better long term idea. Any useful information on how best to process this chip into useable biochar would be greatly appreciated..

You could PM Alec Gunner (agg221). He is a genius and has experimented with different methods of home produced char. Beau (Woodworks) has also been doing some very interesting work.

 

Alec's company set up some instruments on my retort kiln, measuring the composition of the gasses released during pyrolysis. Apparently they can be used for running engines and stuff.

 

Way above my pay grade!

[openspaceman]

28 minutes ago, Conor Wright said:

The soil in question is potentially very good but has been used for three decades to harvest turf for instant lawns and as a result has high iron, low organic matter and serious compaction..

What's the reason for high iron? Some of the more successful trials of biochar have been on sites with heavy metal contamination, re-afforesting mine tailings, but I don't remember iron being mentioned, it was a FC report which may be worth searching for.

 

Low soil organic matter is best addressed with properly composted plant material. Compaction in the short term will  need some mechanical action and biochar could be incorporated at the same time. Beyond that worms are your friend and look at the extremes farmers are now going to to keep machinery off most of the  planted areas.

28 minutes ago, Conor Wright said:

 

 Any useful information on how best to process this chip into useable biochar would be greatly appreciated..

I cannot particularly advise as it depends on circumstance. Following the lead of Alex Kingston in Canada I  changed the running environment of  the woodchip stoker of a KOB 500kW(t) boiler which heated greenhouses, shop and offices at  Slough such that it produced char rather than ash. Obviously this meant more wood chip was used  than if the chip had been totally incinerated. It produced a very charry ash but we had no use for it. The nursery produced  ornamental plants which needed an acid side of neutral soil, already the irrigation water was acidulated to counter alkali because it came from an aquifer below chalk, and as woodash is alkali and more suited to food crops...

 

When I worked on a farm in my youth the government subsidised lime spreading and I have no reason to believe it is not needed now.

 

Most of the current promoted production methods are old science; retorts, kilns and flame cap, all of which were known to John Evelyn when he wrote Sylva. As such they are wasting 70% of the energy in the rawstock.

 

We demonstrated running a gas turbine on the offgas but even that added to the capital cost to make the process uneconomic when a simple heating system co producing  char  would not have cost a lot more than a simple biomass burning system.

 

I envisaged a system that would make use of those difficult wastes arising from  our work, like sweeping, mulchings, stump grindings  and the small leafy chip which was causing a problem in the  heap destined for power stations. My biggest problem was a wealthy trumplike boss who, despite having a degree in ocean science, believed that marine organisms were creating petroleum deposits faster than we were extracting them and that we needed more CO2 to increase photosynthetic activity (which isn't happening overall) so  the carbon sequestration was an anathema to him.

 

I reluctantly sold off the major items I had accrued to make char when I retired due to having nowhere to run the process.

[Conor Wright]

2 hours ago, openspaceman said:

What's the reason for high iron? Some of the more successful trials of biochar have been on sites with heavy metal contamination, re-afforesting mine tailings, but I don't remember iron being mentioned, it was a FC report which may be worth searching for.

 

Low soil organic matter is best addressed with properly composted plant material. Compaction in the short term will  need some mechanical action and biochar could be incorporated at the same time. Beyond that worms are your friend and look at the extremes farmers are now going to to keep machinery off most of the  planted areas.

I cannot particularly advise as it depends on circumstance. Following the lead of Alex Kingston in Canada I  changed the running environment of  the woodchip stoker of a KOB 500kW(t) boiler which heated greenhouses, shop and offices at  Slough such that it produced char rather than ash. Obviously this meant more wood chip was used  than if the chip had been totally incinerated. It produced a very charry ash but we had no use for it. The nursery produced  ornamental plants which needed an acid side of neutral soil, already the irrigation water was acidulated to counter alkali because it came from an aquifer below chalk, and as woodash is alkali and more suited to food crops...

 

When I worked on a farm in my youth the government subsidised lime spreading and I have no reason to believe it is not needed now.

 

Most of the current promoted production methods are old science; retorts, kilns and flame cap, all of which were known to John Evelyn when he wrote Sylva. As such they are wasting 70% of the energy in the rawstock.

 

We demonstrated running a gas turbine on the offgas but even that added to the capital cost to make the process uneconomic when a simple heating system co producing  char  would not have cost a lot more than a simple biomass burning system.

 

I envisaged a system that would make use of those difficult wastes arising from  our work, like sweeping, mulchings, stump grindings  and the small leafy chip which was causing a problem in the  heap destined for power stations. My biggest problem was a wealthy trumplike boss who, despite having a degree in ocean science, believed that marine organisms were creating petroleum deposits faster than we were extracting them and that we needed more CO2 to increase photosynthetic activity (which isn't happening overall) so  the carbon sequestration was an anathema to him.

 

I reluctantly sold off the major items I had accrued to make char when I retired due to having nowhere to run the process.

Some food for thought there, thank you. Your knowledge of biomass and wood energy in all its forms is impressive.. did you ever consider writing a guide to small scale or community scale "forest to fire .. and beyond" type book? 

As regards the high iron content, thirty years of regular sulphate of iron applications for moss control has taken its toll.

With regard to addressing organic matter we have applied over 70 ton of farmyard manure, straw based, in various stages of breakdown, to the surface and allowed the grass to grow above, then cut that to form a second "mulch" layer.. will be applying green waste compost, from annual hedge clippings mixed with rotted fym this coming year.. then I hope to incorporate that in the autumn and reapply a top dressing layer, followed by a green manure of vetch and clover. That should give us a quality base from which to start productive vegetable production.. nb. We are already growing for our own use, quality is patchy, micro nutrients are lacking.

The biochar idea has a place in the scheme, I just would to get it right first time around.. would it suffice to make charcoal in a standard retort then crush it up and spread it or am I missing something?

[Conor Wright]

2 hours ago, the village idiot said:

You could PM Alec Gunner (agg221). He is a genius and has experimented with different methods of home produced char. Beau (Woodworks) has also been doing some very interesting work.

 

Alec's company set up some instruments on my retort kiln, measuring the composition of the gasses released during pyrolysis. Apparently they can be used for running engines and stuff.

 

Way above my pay grade!

Sounds interesting, would like to have more basic knowledge to hand before contacting him, your level of knowledge is beyond my pay garde on this matter, so i need to get my basics before  I can understand the dynamics! Could it be as simple as crushing charcoal and spreading it or is that a shot in the dark?! The main sticking point I have is how to get a heap of damp chip to char in the first place! I would like to keep things as energy efficient as possible i.e. no major external power inputs.. don't like the idea of predrying using diesel or electric power etc.

[openspaceman]

1 hour ago, Conor Wright said:

Some food for thought there, thank you. Your knowledge of biomass and wood energy in all its forms is impressive.. did you ever consider writing a guide to small scale or community scale "forest to fire .. and beyond" type book? 

Nope, I'm not that well organised. Apart from anything else all my ventures have been commercial failures and it's commercial success that drives economies.

1 hour ago, Conor Wright said:

As regards the high iron content, thirty years of regular sulphate of iron applications for moss control has taken its toll.

 

That's fine, the alkali effects of a high temperature char can start addressing that but a bit of lime wouldn't be amiss. I wonder what crop would take off excess iron?

 

On heathland restoration they attempted to grow cereals when reverting marginal arable land back to heath, the idea being cereals take a lot of minerals off site when harvested.

1 hour ago, Conor Wright said:

With regard to addressing organic matter we have applied over 70 ton of farmyard manure, straw based, in various stages of breakdown, to the surface and allowed the grass to grow above, then cut that to form a second "mulch" layer.. will be applying green waste compost, from annual hedge clippings mixed with rotted fym this coming year.. then I hope to incorporate that in the autumn and reapply a top dressing layer, followed by a green manure of vetch and clover. That should give us a quality base from which to start productive vegetable production.. nb. We are already growing for our own use, quality is patchy, micro nutrients are lacking.

Sounds good, the legumes will put a bit of nitrogen back in but won't overcome the oxygen and nitrogen deficiency of poorly composted wood chip, again compost tends to tend to the lower pH so you need to address acidity/

1 hour ago, Conor Wright said:

The biochar idea has a place in the scheme, I just would to get it right first time around.. would it suffice to make charcoal in a standard retort then crush it up and spread it or am I missing something?

Retort char tends to be made at lower temperatures (<450C) and still contains  pyroligneous compounds which are themselves acidic.  Also Cation Exchange Capacity seems to develop as the amorphous char develops graphite like structures above this temperature, char directly exposed to fire reaches higher temperatures but of course the yield is less.

 

I'm not at all sure about what size is best but I would want to avoid dust lest it be carried off into the water course.

[openspaceman]

1 hour ago, Conor Wright said:

The main sticking point I have is how to get a heap of damp chip to char in the first place! I would like to keep things as energy efficient as possible i.e. no major external power inputs.. don't like the idea of predrying using diesel or electric power etc. 

I agree you should not use a support fuel for drying but there is also no point in trying to make  char directly from wet material. In principle there is easily enough  energy in wood to make char from freshly felled material  but it will require a  bit of kit as mentioned earlier. Coupled with a bit of summertime air drying I can see even things like hedge cuttings could be done but note these may be better as a source of organic carbon and nitrogen which is otherwise lost in the carbonisation process.