Biomass and wood chip grades

[QuattroKev]

The farm where my lock up is has a new biomass boiler, they buy in a large amount of G30 chip.

 

The farmer and owner is sound and we get on well know him for years, he was happy and keen to let me tip off my own chip into their stores. I'm only a start up outfit and will only be tipping the occasional tipper load of chip, I have a Forst TR6.

 

The engineer however got his knickers in a twist about taking my chip as it has some greenery in it and it was smaller than the chip they buy in.

 

Any one know what grade my chip is? And whether its really going to do any harm to the boiler mixing in the out tipper load of my stuff, into 50 odd ton of their bought in chip?

 

Firms I have worked for sell chip to stobarts with all kinds of leaf material in it.

[TimberCutterDartmoor]

Slight difference between green tree surgery chip and graded dried G# chip...

 

Lol.

[cornish wood burner]

The tree surgeon chip I have seen is normally small as you say. If the boiler uses G30 it will be quite small and chances are the size will be ok providing no out of spec long pieces. Greenery it not good as biomass boilers have several pressure, temperature and O2 sensors sensing pipes etc which could get a tar coating when burning wet or green material. That said we have burnt wet and green material but our boilers will be much bigger with a bigger mass so resistant to a slug of wet material. We would mix with dry material anyway. Your engineer is right to be concerned but it depends on quantity of yours and their material.

[Tom D]

Its stringy oversize pieces that cause the biggest problems, they can block the augers. If he hasn't got a drying floor to dry the chip forget it it will be way too wet, otherwise it should be fine... I have a TR6 and a Heizohack with a g30 screen, there isn't that much difference in the chip sizes. You can send your chip off and have it graded if you like......

[QuattroKev]

As I say the firm I used to work for sold all their chip to stobarts and it was but big pile fed by all kinds of different chippers from Hizohack down to various 6 inch TPs and everything in-between, and was stored uncovered. So must be a use for that kind of chip somewhere

[farmer rod]

The difference in value of chip as a fuel, comparing 30% moisture and 40% moisture is £18/ tonne, (this relates only to how much heat can be got from it)

 

So what you have to be wary of is adding your tonne of connie chips ( poss 60% moisture) to some valuable dry chip

 

If you can dry it out it would be fine, but even better if you get the leaves and needles out, as I gather they contain more chlorine which does for the insides of boiler.

[openspaceman]

 

If you can dry it out it would be fine, but even better if you get the leaves and needles out, as I gather they contain more chlorine which does for the insides of boiler.

 

Actually trees don't have discernible amounts of chlorine, people think the chlorophyll contains chlorine but it doesn't, the words share the same root for "green".

 

Leaves, bark and needles have far more ash and of course green needles and leaves are wetter.

 

The ash can be a problem, especially if contaminated with dirt as this can lowe the slagging temperature. grasses and cereals are bad for this.

 

Where you do get chlorine from is PVC coverings and things like neoprene coatings. These produce dioxins when incompletely burned but hydrogen chloride also, which quickly absorbs any steam present and condenses as hydrochloric acid on the firetubes and flue.

[openspaceman]

The difference in value of chip as a fuel, comparing 30% moisture and 40% moisture is £18/ tonne, (this relates only to how much heat can be got from it)

 

How did your trials with drying chip by turning it over with the telehandler in the summer month's go?

 

I meant to say earlier that the 6" forst with the feed turned to half speed produces lovely chips from small lengths of wood.

 

Leaves wouldn't be a problem for the feed but could cause ratholing problems in the firebox as well as the moisture being a big issue.

[farmer rod]

How did your trials with drying chip by turning it over with the telehandler in the summer month's go?

 

I meant to say earlier that the 6" forst with the feed turned to half speed produces lovely chips from small lengths of wood.

 

Leaves wouldn't be a problem for the feed but could cause ratholing problems in the firebox as well as the moisture being a big issue.

 

The pile of Arb chip in the empty cattle shed was spread out about a foot deep, then when I was passing with the bucket on, I would push it up and rake it out. I think I have convinced myself that it harder to get rid of that quantity of water than I thought. Wet or not, I am using it for bedding down the catlle, 6" deep as a base layer, then I alternate a bale of straw with a couple of buckets of chip spread around. Not sure whether thats the right formula, but its looking ok and keeping them clean. (Slight apprehension about the N consumption of the wood, and what happens when we spread the muck)

 

The chip quality of the various Arb type machines that I have seen would be fine to go through the feeder, I think the heizo on brash still lets stick like bits through even with the G30 screen, and thats what we are running on now, planned maintenance is to get rid of the birdsnest at the top of the auger before lobbing another load in the feed area. I do have a feeling that the air ravels through G50 chip better and thats why Arb chip is such a pain to dry.

 

The whole idea of using Arb chip is out the window , as my registration for the BSL means that I must chip it myself from "sustainable and legal wood", luckily I have plenty, indeed too much, and I think I ought to get rid of my stack of Ash poles, but the trouble is I put the stack in a field where it could dry well, far away from any hard road. (Rooky error!)

[cornish wood burner]

I too have tried spreading and drying G50 but only a thin layer seems to dry.

Might be worth trying a deeper heap to generate a bit of heat and steam off the moisture. That seems to work in our shed to some degree if it is pushed around enough.

Some years ago I did read of a trial (in Austria I believe )where they heaped and covered with a breathable membrane to lose the water