Whole tree chipping

[madhatte]

A lot has to do with season and time on the ground, too.  A pile that goes into the tub grinder six weeks after harvest midwinter is going to produce way greener chips than a 2-year-old pile going into the grinder mid-August.  However, that detail is left to the end buyer, as we sell biomass mostly just to get rid of accumulated fuels.  Oh, and to keep piles out of sight.  Lots of worry over keeping forestry operations invisible. 

[Samuel]

I think we are talking about 2 different types of chip.  The "chips" we use in our pulping process is a lot different and higher quality than chips produced from a tub grinder for biomass consumption in a pellet plant or such.

[madhatte]

Ah.  I suppose they would be completely different markets, then, too?  If so, then I am uninvolved with a log as soon as it's loaded on the truck, and know very little about the sorting and selling after it leaves the stump. 

[Jamie_C]

Around here chips produced for the pulp mills are sold by the "Bone Dry Tonne/Ton", samples are taken to get chip quality and moisture content so the "green weight" can be converted to BDT weight.

Biomass on the other hand is usually sold by the green tonne/ton with no allowances made for moisture content.

[Samuel]

Same method  here.  I did not realize we were talking about two things when we started.

[Jamie_C]

How is a tractor trailer load of chips sold. I am told it weighs 16.5 tons and that is wet wood. If a logger paid for 100 tons of stumpage and took out 10 loads of chips { 165 tons} is that ok?  Is the wet wood tons converted to dry wood tons, so as not to pay for the water?

The proper answer to that is to look at the contract or stumpage agreement and see just what the agreed upon products and weight/volume factors are. On it's face value i would say no it's not ok to pay for 100 tons of stumpage and take 165 tons but without seeing the contract it would be awfully hard to tell.

On another note how could somebody move all the equipment necessary for a chipping operation and only get a product yield of 165 tons, with our payloads here in Nova Scotia that would be about 5 chip van loads which wouldn't even cover the cost of moving in the chipper let alone all the support equipment.

[Samuel]

We typically do not move our chippers around unless there is at least a days work  (24 hrs) or 2000 m3 per site.  160 BDT would be about 2-3 hours work.

[SwampDonkey]

Thanks Jamie_C, bone dry tonne is oven dry tonnage then? Has to be. Less variance in the tonnage that way and your estimate of actual wood volume is more accurate. There is a reason, because there is a recipe to this pulping business.

[Jamie_C]

Thanks Jamie_C, bone dry tonne is oven dry tonnage then? Has to be. Less variance in the tonnage that way and your estimate of actual wood volume is more accurate. There is a reason, because there is a recipe to this pulping business.

As far as i know they are the same thing SwampDonkey, back when i was more involved in fibre procurement / fibre trades etc, etc i believe that here in NS they used BDT and in NB it was ODT. I believe the old Repap Mill used Oven Dry Tonne and the old Scott Paper/Kimberly Clark Mill here in NS used BDT.

[SwampDonkey]

I'm quite confident they are one in the same, thanks.

[Holmes]

Thanks Jaime-C  For the site  I was referring to the forester wrote 23.4 mbf.  vol.cds.17   Vol.tons 78. They cut the site for 5 days with a feller buncher and
 took more than 20 trailer loads of chips.  The adjacent site is 10 times larger. Holmes

[Jamie_C]

Around here the conversions used for mbf to tonnes is 4.76 so 23.4 x 4.76=111 tonnes, 17 cds is about 34 tonnes and 78 tons is about 71 tonnes so in total the harvest would be about 216 tonnes or about 237 tons. The 78 tons represents what type of product, if that is total amount of chips then you got totally taken, if not then where in the contract is the chip material or was it considered waste and taken for free.

I really hope that it didn't take them 5 days with a feller buncher to cut that amount of wood, around here that is the bare minimum a feller buncher would cut in a single shift in wood running about 18-20cd/acre.

[SwampDonkey]

Holmes, was this oak species? Because green oak (64 lb/ft³) is a lot heavier than green hard maple (56 lb/ft³) or green aspen (43 lb/ft³), green red pine is 49 lb/ft³. MC 30%


5.85 GMT per mbfm for 8' hardwood and 3.1 for ODMT  (MT =metric tonne) hard maple, yellow birch, beech because those three hardwoods are about the same for weight and specific gravity.

[Holmes]

Mostly hemlock,and some low grade hardwood

[Samuel]

If you are interested in whole tree chipping, but have never had the opportunity to see it, or like watching it, I made a video for our Japanese stakeholders and our customers to figure out what it was that we were doing.  When you click onto this link a window will open and the specific video I am referring to is the second one of three that are stored in this location.  Feel free to review them all, but the second one is the chippers running.  Let me know whet you think of it.

http://www.dmi.ca/about_dmi/dmi_in_alberta/prpd/co_overview_video/