An intro to...WTT ExoT process control 0 50 100 150 200 250 0 10 20 30 40 50 60 70 80 90 100 110 120...
Transcript of An intro to...WTT ExoT process control 0 50 100 150 200 250 0 10 20 30 40 50 60 70 80 90 100 110 120...
An intro to
WTT ThermoTreat 2.0
Peter Klaas, Ph.D.
Managing Director
Wood Treatment Technology A/S
Agenda
• Introduction to Wood Treatment Technology A/S (WTT)
• Introduction to thermo modification technologies
• The new WTT ThermoTreat 2.0 process
• The new WTT ExoT process control
• The 2.0 technology
• Quality compliance and control
• Summary
WTT engineering & manufacturingFounded in 1978 Owned by Brothers Uhre & Peter KlaasPart of the Eurocon group
Bicocide impregnationVacuum dryingThermo treatmentRoyal Hot-OilAmmonia treatmentFully automated 24/7Special processes
Unique track recordExperienced team
Innovative engineeringInternational network
____________________
= Business case certainty
What is thermal modification?
• Wood consists of hemicelluloses, cellulose and lignin
• Hemicelluloses attract water and are available sugars to fungi and insects
• Hemicelluloses can be removed by two processes, Pyrolysis and Hydrolysis
• Pyrolysis is decomposition by means of high temperature without presence of oxygen
• Hydrolysis is decomposition by the addition of water
• New compounds are formed in the wood in a reaction catalyzed by acids – hence the brown color
What is the difference between the open and closed systems?
Open System Closed system
Pyrolysis Hydrolysis
Atmospheric Pressure, High Temperature
High Pressure, Low temperature
Wood must be dried – no free water Water needed for hydrolysis– no drying < 12%
Long cycle time Short cycle time
Higher energy consumption & process emissions
Lower energy consumption & processemissions
The new WTT ThermoTreat 2.0
Patent application no. PA 201670528
WTT ThermoTreat 2.0 process – whats new?1st Generation closed system ThermoTreat 2.0
Cycle time (hrs) 24 12/8
Energy consumption(kWh/m3)
205 120
Steam (kg/m3) 15 1.3
Pressure in modificationphase (bar)
8 14
Heat transfer coefficient(W/mK)
11 104
Nominal heating capacity(kWh/m3)
44 222
Nominal cooling capacity 35 444
Pressure dynamics Unstable – quality risks Stable – risks eliminated
Approximate modificationcost (EUR/m3)
70 40
Improved heat transfer capability
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He
at t
ran
sfe
r co
eff
ice
nt
(W/m
K)
Temperature (Celcius)
Watervapour, atmosphericpressure [W/mK]
Nitrogen, 10 Bar intialpressure [W/mK]
High heat transfer capability of
ThermoTreat 2.0
Low heat transfer capability of open systems and 1st
generation closed
Improved heat transfer capability
• Reduced cycle time due to faster heating and cooling
• Constant heating and cooling rates cause less stress on wood and technology
Elimination of steam in the reactor atmosphere
• Reduced energy consumption• Energy not needed for turning water into
steam atmosphere• Reduced heat loss from the system due to
shorter cycle times
• Quality problems from condensates staining the wood avoided
• >90 % reduction of condensates virtually eliminates waste water
• Improved pressure dynamics…
… improved pressure dynamics
With steam at elevatedtemperature, small changes in temperature.... causes large changes in pressure
Improved pressure dynamics
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Pre
ssu
re (
Bar
)
Temperature (Celcius)
Water vapour (85%rm)
Nitrogen
• During the exotherm, temperature quicklyincreases to over 200 °C at the wood core
• With steam, the atmosphere expandsexponentially creatingpressure shocks
• This is eliminated in 2.0
The new WTT ExoT process control programPatent application no. PA 2016 70531
Durability / Strength trade-off
Temperature
Du
rab
ility
Stre
ngt
h(M
OR
)
UndertreatmentOptimal treatment
Overtreatment
Problem:
• Hemicellulose content varies significantlybetween species and even between charges;
• It is practicallyimpossible to derive the correct treatment recipefrom test trials
Solution: Exploiting the differential wood component properties
Hemicellulose Cellulose Lignin
Hydrolysis/low
temp
Yes No No
Pyrolysis/high
temp
Yes Yes Yes
Exothermic peak
in Nitrogen
atmosphere (oC)
290 (xylan) 360 320
Hemicellulose Cellulose Lignin
Modification
effect on
durability
Very high low low
Modification
effect on
strength
Low High High
The ExoT process control strategy
• Goal: to remove as much hemicellulose, and as little cellulose and lignin, as possible to maximize durability increase and minimize strength loss
• Strategy: Use the hemicellulose exotherm as process control parameter. When the exotherm is complete, all available hemicelluloses are removed
WTT ExoT process control
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Tem
pe
ratu
re (
Ce
lciu
s)
Time (minutes)
Atmosphere temperature
Temperature, wood core, spruce,32 x 100 mm
Start cooling of atmosphere
HemicelluloseExotherm
The 2.0 Technology
From small to large volume with standard modules – Plug and Play installationSuitable both for small volumes with manual operation and large volumes with fully automated, 24/7 operation:
• Standard Ø 1800 x 11000 24 h cycle: 3,000 m3/year
• Standard Ø 1800 x 11000 12/8 h cycle: 6-9,000 m3/year
• Multiple standard modules tied together for volumes > 9,000 m3/year
Compliance & Quality Control
Compliance & Quality Control
• Comprehensive product tests for Scots pine, Norway spruce & Beech• EN 113 Durability, lab tests
• EN 330 Durability, field, with surface coating
• TS 12037 Durability, field
• Performed in Q3-Q4 2016
• Product Data Sheets; Scots pine, Norway spruce & beech
• Product tests and PDS for other species available on customer demand
• Quality Management System under NTR available on customer demand
• Tests and documentation of emissions Q3 2016
Summary overview: key figures & pointsOpen system Closed system
First generation 1.0 WTT 2.0
Cycle time (hrs) (use class 3.2) 42 24 12 (8)
Total energy consumption (kWh/m3 wood) 600 205 120
Steam (kg/m3 wood) unknown 15 1.3
Energy for steam production (kWh/m3 wood) unknown 11 1
Pressure in modification phase (bar) atmospheric 8 14
Modification temperature ( oC) 230 180 170
Heat transfer coefficient at 100 oC (W/mK) 11.4
(1 bar)
11.4
(1Bar)
101
(10 Bar)
Nominal heating capacity (kWh/m3 wood) 25 45 222
Initial cooling capacity (kWh/m3) N/A 35 444
Pressure dynamics N/A unstable stable
Process control system Standard recipies Standard recipies ExoT
Modification cost incl. depreciation and labour
(EUR/m3) (use class 3.2)
80 - 100 70 40
Thank You for your attention