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Rayonier Confidential and Proprietary Information
Biomass issues for wood transactions (green weight vs dry weight)FIA user group meeting and Biomass/Bioenergy workshop
John Paul McTague - NCASI BMG-Chairman & Rayonier Inc.
Rayonier Confidential and Proprietary Information
Problem with green weight
Green weight remains relatively constant as the increase in moisture content compensates for the decrease in specific gravity.
Moisture content and specific gravity vary greatly with age of tree, and position in the bole.
Rayonier Confidential and Proprietary Information
Green weight is a poor and inaccurate way of determining biomass
Rayonier Confidential and Proprietary Information
Forest products industry has had an interest in estimating dry weight yields since 1965
Rayonier Confidential and Proprietary Information
Dry Weight
Dry weight is a function of specific gravity Highly correlated to pulp yield and strength
characteristics Rapid measurement and computation of dry weight
is problematic
Rayonier Confidential and Proprietary Information
Moisture content is a function of physiographic region, site quality, species, size, and age
Rayonier Confidential and Proprietary Information
Effect of age on dry weight density
Rayonier Confidential and Proprietary Information
Effect of tree size on dry weight density
Rayonier Confidential and Proprietary Information
CHST will provide eligible material owners (EMOs) matchingpayments at the rate of $1 for each $1 per dry ton paid, up toa maximum of $45 per dry ton
Rayonier Confidential and Proprietary Information
Washington Post, January 10, 2010 – ‘program has gone awry’
Rayonier Confidential and Proprietary Information
Three Three options under consideration, seeking comment: > Option 1: $/$ match up to $16/dry ton for heat, power or biobased
products. Match up to $45/dry ton for cellulosic ethanol or advanced biofuels. Inconsistent on whether or not this includes pellets
> Option 2: Match up to $45/dry ton. No payments made for conversion of biomass unless material is converted to heat or power above facility’s historical baseline as established by the Deputy administrator
> Option 3: >> Match up to $45 per dry ton for facilities that
» >>> Convert from fossil fuel consumption to biomass
» >>> For eligible material showing exceptional promise for producing innovative advanced biofuels
» >>> For every ton of remewable biomass above a facility’s historical baseline
>> Match of $16/dry ton for sale of eligible material to BCFs that do not increase renewable biomass consumption above historical baseline
Rayonier Confidential and Proprietary Information
Eligible material for BCAP payment• Eligible material: thinned trees, tops and branches,
salvage, chips and bark• Ineligible material: mulch, pulp, black liquor, finished
lumber
New proposed rulesFebruary, 2010
Rayonier Confidential and Proprietary Information
Solid wood
Chips and bark
Rayonier Confidential and Proprietary Information
Problem: moisture meters can not be used if the moisture content exceeds the fiber saturation point (fsp)
Below 30% moisture
content (dry weight
basis)
The traditional kiln drying technique must be used if themoisture content > 30% (dry weight basis)
Rayonier Confidential and Proprietary Information
Near infrared prediction of moisture content works well with consistent chip material, controlled light, and consistent height to material
Alternatives to kiln drying of samples
Rayonier Confidential and Proprietary Information
In Sweden, the STFI extracts large cores from load at scale house
If the process is speeded up, the core could heat up,dry, and give an incorrect estimate of moisture content
Rayonier Confidential and Proprietary Information
STFI schema
Rayonier Confidential and Proprietary Information
Investigate the applicability of NIR spectroscopy for estimating the moisture content and specific gravity of wet-stored logs
NIR widely used to rapidly estimate many wood properties, mainly lab-based measurement
Studies indicate that NIR can be used on green logs
Alternatives: a NCASI funded project at the University of Georgia
Rayonier Confidential and Proprietary Information
NIR testing
I
III II
IVSED
LED
~ 16’ (4.9 m)×
×
×
×
×
×
××
SED: Small-end diameterLED: Large-end diameter
Rayonier Confidential and Proprietary Information
Collecting NIR spectra on green discs
custom-made holder
Rayonier Confidential and Proprietary Information
Probes are coaxial cables soldered to stainless steel rods. The soldered assembly is potted in hard plastic resin
Alternatives: a NCASI funded project at the University of Georgia
Estimating moisture content of wet deck storage logs with TDR
Rayonier Confidential and Proprietary Information
Wood sample with TDR probe
Rayonier Confidential and Proprietary Information
Initial Analysis
Points with seemingly consistent distances were second inflection and second dropoff point
Rayonier Confidential and Proprietary Information
Initial Analysis
Rayonier Confidential and Proprietary Information
In the West, it’s common to estimate board foot volume for the truckload as a function of green weight and piece count
Rayonier Confidential and Proprietary Information
Hypothesis: It is easier to construct a green weight-dry weight prediction equation than build a green weight – Scribner MBF Dec. C volume relationship
Why not estimate dry weight as a function of green weight and other auxiliary variables such as: number of logs, average diameter, and stacking factor?
Vol (mbf) = 1.836 + 64.79 Weight (lbs) R2 = 0.29
Vol (mbf) = 2.466 + 79.35 Weight (lbs) – 0.085 (number of logs on truckload) R2 = 0.58
Rayonier Confidential and Proprietary Information
Lasers can mounted at the scale house to instantaneously scan the load and estimate number of stems and diameter
Rayonier Confidential and Proprietary Information
Estimate of piece count and diameters